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Chlorpyrifos-based insecticides induced genotoxic and cytotoxic effects in the ten spotted live-bearer fish, Cnesterodon decemmaculatus (Jenyns, 1842)
ABSTRACT
Mortality, genotoxicity, and cytotoxicity of the 48% chlorpyrifos (CPF)-based formulations Lorsban* 48E® and CPF Zamba® were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronucleus (MN) and alterations in the erythrocyte/erythroblast frequencies were employed as end points for genotoxicity and cytotoxicity, respectively. For Lorsban* 48E® , mean values of 0.13 and 0.03 mg/L were determined for LC50 at 24 and 96 h, respectively, and these concentrations reached mean values of 0.40 and 0.21 mg/L for CPF Zamba® . Mortality values increased as a positive linear function of the CPF Zamba® concentrations, but not for Lorsban* 48E® concentrations. There was no significant relationship between mortality and exposure time within the 0–96 h period for both formulations. LC50 values indicated that the fish were seven fold more sensitive to Lorsban* 48E® than to CPF Zamba® . Lorsban* 48E® within the concentration range of 0.008–0.025 mg/L increased MN frequency at both 48 and 96 h of treatment. Similar results were also observed when fish were exposed to 0.052–0.155 mg/L of CPF Zamba® , regardless of the exposure time. Cellular cytotoxicity was found after Lorsban* 48E® and CPF Zamba® treatments for all concentrations and time exposures, estimated by a decrease in the frequency of mature erythrocytes and a concomitant enhanced frequency of erythroblasts in circulating blood. Furthermore, our results demonstrated that Lorsban* 48E® and CPF Zamba® should be considered as CPF-based commercial formulations with marked genotoxic and cytotoxic properties. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Different transcriptional responses of heat shock protein 20 in the marine diatom Ditylum brightwellii exposed to metals and endocrine-disrupting chemicals
ABSTRACT
Diatoms are sensitive indicators of water quality, and hence used for environmental hazard assessments; however, their toxicogenomic studies have been insufficiently attempted. In the present study, we determined the cDNA sequence of heat shock protein 20 (Hsp20 ) gene from the diatom Ditylum brightwellii , and examined the transcriptional responses of the gene after exposing it to environmental stressors such as thermal shock, metals, and endocrine-disrupting chemicals (EDCs). The open reading frame (ORF) of DbHsp20 was 531 bp long, encoding 177 amino acid residues (19.49 kDa) with a conserved C-terminal and α-crystallin domain. The genomic region of DbHsp20 did not contain introns. Phylogeny of eukaryotic Hsp20s showed D . brightwellii was closely related to other diatoms. With regard to the gene expressional profile, real-time PCR results showed that the gene was significantly upregulated (P  < 0.001) under thermal stress, with the highest change of 3.2-fold. Metals' (copper and nickel) treatments showed that it was induced after a certain point of treated concentration. On the contrary, EDCs did not display noticeable change on the expression of DbHsp20 . These results suggest that the diatom Hsp20 basically responds to thermal stress, but may differentially respond to toxic substances such as metals and organic compounds such as EDCs. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Toxicity and enantiospecific differences of two β-blockers, propranolol and metoprolol, in the embryos and larvae of zebrafish (Danio rerio)
ABSTRACT
The risk presented by β-blockers on aquatic organisms remains uncertain, particularly given the enantiospecific differences in toxicity of chiral β-blockers. In this study, the toxicity of two β-blockers, propranolol and metoprolol, was determined. The 96-h LC50 of propranolol in the zebrafish larvae was 2.48 mg/L, whereas 50 mg/L metoprolol did not result in death. Both β-blockers decreased the heart rate and hatching rate and increased the mortality of the zebrafish embryos. Among these indicators, the heart rate was the most sensitive. However, the acute larval and embryo toxicity results displayed no enantioselectivity. Additionally, the transcriptional response of the genes encoding the β-adrenergic receptors and those involved in other physiological processes, including the antioxidant response, detoxification, and apoptosis, in zebrafish larvae exposed to the β-blockers was examined. Although the changes in gene transcription were fairly minor, significant enantioselectivity was observed for β-blockers, suggesting that the transcriptional response was more sensitive for the evaluation of enantiospecific toxicity. Based on these results, the pharmaceutical drugs were not expected to pose a risk to fish; however, this conclusion should not be considered final. These results also demonstrated that the enantiospecific toxicity of chiral β-blockers should be investigated when performing an ecological risk assessment. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Ambient vapor samples activate the Nrf2-ARE pathway in human bronchial epithelial BEAS-2B cells
Ambient air pollutants have been reported to induce oxidative stress based inflammatory responses in humans and experimental animals. However, most of these reports describe the actions of the particulate phase of ambient and exhaust samples. We describe here results of studies investigating the actions of the vapor phase of ambient air samples collected in the midtown area of Los Angeles on human bronchial epithelial BEAS-2B cells using DNA microarray analysis. Among 26 genes whose expression increased fourfold or more, four genes were associated with detoxifying genes regulated by the transcription factor Nrf2. Consistent with these results, the vapor samples activate the Nrf2-ARE pathway, resulting in up-regulation of heme oxygenase-1 (HO-1), glutamate cysteine ligase modifier subunit, and cystine transporter (xCT) mRNA and proteins. No appreciable increases in pro-inflammatory genes were observed. These results suggest that ambient vapor samples activate the Nrf2-ARE pathway but not an inflammatory response. Also, treatment of the vapor samples with glutathione resulted in reduction in the Nrf2 activation and HO-1 induction, suggesting that electrophiles in vapor samples contribute to this Nrf2-dependent antioxidant or adaptive response.
Erythrocyte nitric oxide synthase as a surrogate marker for mercury-induced vascular damage: The modulatory effects of naringin
In this study, endothelial nitric oxide synthase activity and nitric oxide (NO) production by human erythrocytes in the presence and absence of mercuric chloride (HgCl2 ), L -arginine (L -ARG), N ω -nitro-L -arginine methyl ester (L -NAME), and naringin (NAR) were investigated. In addition, the levels of reduced glutathione (GSH) and related enzymes were estimated in erythrocytes hemolysate. The protein carbonyl content (PCC) and thiobarbituric acid-reactive substances (TBARS) levels were also determined. The results of this study revealed that the treatment of erythrocytes with either HgCl2 or L -NAME induced a significant decrease in NOS activity and nitrite levels compared with control cells. Furthermore, mercury exposure significantly increased the levels of PCC and TBARS but reduced the GSH level. The activities of glucose-6-phosphate dehydrogenase, glutathione reductase, glutathione peroxidase, and glutathione-S -transferase (GST) were inhibited. The exposure of erythrocytes to HgCl2 in combination with L -ARG, NAR, or both ameliorated the investigated parameters compared with erythrocytes incubated with HgCl2 alone. These results indicate that mercury exposure decreased both erythrocyte NOS activity and nitrite production, and that these parameters might be indicative of mercury exposure. The data also suggest that concomitant treatment with NAR can restore NO bioavailability through either its metal-chelating properties or its antioxidant activity.
Comparison of the effects of bisphenol A alone and in a combination with X-irradiation on sperm count and quality in male adult and pubescent mice
Bisphenol A (BPA) is employed in the manufacturing of epoxy, polyester-styrene, and polycarbonate resins, which are used for the production of baby and water bottles and reusable containers, food and beverage packing, dental fillings and sealants. The study was designed to examine the effects of 8-week exposure (a full cycle of spermatogenesis) to BPA alone and in a combination with X-irradiation on the reproductive organs and germ cells of adult and pubescent male mice. Pzh:Sfis male mice were exposed to BPA (5, 10, and 20 mg/kg) or X-rays (0.05 Gy) or to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The following parameters were examined: sperm count, sperm motility, sperm morphology, and DNA damage in male gametes. Both BPA and X-rays alone diminished sperm quality. BPA exposure significantly reduced sperm count in pubescent males compared to adult mice, with degenerative changes detected in seminiferous epithelium. This may suggest a higher susceptibility of germ cells of younger males to BPA action. Combined BPA with X-ray treatment enhanced the harmful effect induced by BPA alone in male germ cells of adult males, whereas low-dose irradiation showed sometimes protective or additive effects in pubescent mice.
Effects of Pb(II) exposure on chlorella protothecoides and chlorella vulgaris growth, malondialdehyde, and photosynthesis-related gene transcription
ABSTRACT
Greater exposure to Pb(II) increases the likelihood of harmful effects in the environment. In this study, the aquatic unicellular alga Chlorella protothecoides (C. protothecoides ) and Chlorella vulgaris (C. vulgaris ) were chosen to assess the acute and chronic toxicity of Pb(II) exposure. Results of the observations show dose-response relationships could be clearly observed between Pb(II) concentration and percentage inhibition (PI). Exposure to Pb(II) increased malondialdehyde (MDA) content by up to 4.22 times compared with the control, suggesting that there was some oxidative damage. ANOVA analysis shows that Pb(II) decreased chlorophyll (chl) content, indicating marked concentration-dependent relationships, and the lowest levels of chl a, chl b, and total-chl were 14.53, 18.80, and 17.95% of the controls, respectively. A real-time PCR assay suggests the changes in transcript abundances of three photosynthetic-related genes. After 120 h exposure Pb(II) reduced the transcript abundance of rbc L, psa B, and psb C, and the relative abundances of the three genes of C. protothecoides and C. vulgaris in response to Pb(II) were 54.66–98.59, 51.68–95.59, 37.89–95.48, 36.04–94.94, 41.19–91.20, and 58.75–96.80% of those of the controls, respectively. As for 28 d treatments, the three genes displayed similar inhibitory trend. This research provides a basic understanding of Pb(II) toxicity to aquatic organisms. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Phoxim-induced damages of Bombyx mori larval midgut and titanium dioxide nanoparticles protective role under phoxim-induced toxicity
ABSTRACT
Phoxim (O ,O -diethyl O -(alpha-cyanobenzylideneamino) phosphorothioate) is a powerful organophosphorus pesticide with high potential for Bombyx mori larvae of silkworm exposure. However, it is possible that during the phoxim metabolism, there is generation of reactive oxygen species (ROS) and phoxim may produce oxidative stress and neurotoxicity in an intoxicated silkworm. Titanium dioxide nanoparticles (TiO2 NPs) pretreatment has been demonstrated to increase antioxidant capacity and acetylcholinesterase (AChE) activity in organisms. This study was, therefore, undertaken to determine phoxim-induced oxidative stress and neurotoxicity to determine whether phoxim intoxication alters the antioxidant system and AChE activity in the B. mori larval midgut, and to determine whether TiO2 NPs pretreatment attenuates phoxim-induced toxicity. The findings suggested that phoxim exposure decreased survival of B. mori larvae, increased malondialdehyde (MDA), carbonyl and 8-OHdG levels, and ROS accumulation in the midgut. Furthermore, phoxim significantly decreased the activities of AChE, superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione-S -transferase (GST), and levels of ascorbic acid (AsA), reduced glutathione (GSH), and thiol in the midgut. TiO2 pretreatment, however, could increase AChE activity, and remove ROS via activating SOD, CAT, APX, GR, and GST, and accelerating AsA–GSH cycle, thus attenuated lipid, protein, and DNA peroxidation and improve B. mori larval survival under phoxim-induced toxicity. Moreover, this experimental system would help nanomaterials to be applied in the sericulture. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Allethrin induced toxicity in the male reproductive tract of rats contributes to disruption in the transcription of genes involved in germ cell production
ABSTRACT
Pyrethroids are known to be neurotoxic. However, their toxic effects including that of allethrin on the male reproductive tract are not elucidated. Adult male rats were treated orally with 25, 50, 100, and 150 mg/kg body weight allethrin every day for 60 days. Lipid peroxidation was increased (p  < 0.001) in the caput, cauda, and testes. Nitric oxide production was increased (p  < 0.001) in the caput, but unaltered in the cauda and testes. The activities of catalase, glutathione peroxidase, glutathione-S -transferase, and superoxide dismutase were decreased in the caput and cauda where as a decrease was observed in the testis obtained from allethrin treated rats. In the epididymides and testes, damage to tubular architecture, congestion, degeneration of epithelial cell lining, intestinal edema, and presence of dead or degenerating spermatids were observed in a dose dependent manner. The expression profile of genes involved in spermatogenesis (Tgf-beta1 ), sperm maturation (Spag11e ), and sperm function (Defb22 ) were reduced (p  < 0.001) in allethrin rats. The expression of p53 gene was decreased and increased phosphorylation of MAPK (p42/p44) expression was observed the male reproductive tract tissues of allethrin treated rats. Although earlier studies have reported the effects of allethrin inhalation because of the use of mosquito coils and vaporizers, our results for the first time prove that oral exposure to allethrin could affect fertility and may contribute to deregulation of cell cycle in the male reproductive tract. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Selenium modulates β-cyfluthrin-induced liver oxidative toxicity in rats
ABSTRACT
This study was designed to investigate the possibility of β-cyfluthrin to induce oxidative stress and biochemical perturbations in rat liver and the role of selenium in alleviating its toxic effects. Male Wister rats were randomly divided into four groups of seven each, group I served as control, group II treated with selenium (200 µg/kg BW), group III received β-cyfluthrin (15 mg/kg BW, 1/25 LD50 ), and group IV treated with β-cyfluthrin plus selenium. Rats were orally administered their respective doses daily for 30 days. The administration of β-cyfluthrin caused elevation in lipid peroxidation (LPO) and reduction in the activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S -transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). A decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases (AST and ALT) and alkaline phosphatase (ALP) were decreased, whereas lactate dehydrogenase (LDH) was increased. Selenium in β-cyfluthrin-induced liver oxidative injury of the rats modulated LPO, CAT, SOD, GSH, GST, GPx, and GR. Also, liver AST, ALT, ALP, and LDH were maintained near normal level due to selenium treatment. It is concluded that selenium scavenges reactive oxygen species and render a protective effect against β-cyfluthrin toxicity. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Ellagic acid induces apoptosis in tsgh8301 human bladder cancer cells through the endoplasmic reticulum stress- and mitochondria-dependent signaling pathways
To investigate the effects of ellagic acid on the growth inhibition of TSGH8301 human bladder cancer cells in vitro , cells were incubated with various doses of ellagic acid for different time periods. The phase-contrast microscope was used for examining and photographing the morphological changes in TSGH8301 cells. Flow cytometric assay was used to measure the percentage of viable cells, cell cycle distribution, apoptotic cells, ROS, mitochondrial membrane potential (ΔΨm ), Ca2+ , caspase-9 and -3 activities in TSGH8301 cells after exposure to ellagic acid. Western blotting was used to examine the changes of cell cycle and apoptosis associated proteins levels. Results indicated that ellagic acid induced morphological changes, decreased the percentage of viable cells through the induction of G0/G1 phase arrest and apoptosis, and also showed that ellagic acid promoted ROS and Ca2+ productions and decreased the level of ΔΨm and promoted activities of caspase-9 and -3. The induction of apoptosis also confirmed by annexin V staining, comet assay, DAPI staining and DNA gel electrophoresis showed that ellagic acid induced apoptosis and DNA damage in TSGH8301 cells. Western blotting assay showed that ellagic acid promoted p21, p53 and decreased CDC2 and WEE1 for leading to G0/G1 phase arrest and promoting BAD expression, AIF and Endo G, cytochrome c , caspase-9 and -3 for leading to apoptosis in TSGH8301 cells. On the basis of these observations, we suggest that ellagic acid induced cytotoxic effects for causing a decrease in the percentage of viable cells via G0/G1 phase arrest and induction of apoptosis in TSGH8301 cells. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Neurotoxic effects of lambda-cyhalothrin modulated by piperonyl butoxide in the brain of Oreochromis niloticus
Abstract
The objective of this research was to investigate the neurotoxic effects of pyrethroid pesticide lambda-cyhalothrin by the modulation of cytochrome P450 with piperonyl butoxide in the brain of juvenile Oreochromis niloticus . The fish were exposed to 0.48 μg L−1 (1/6 of the 96-h LC50 ) lambda-cyhalothrin and 10 μg L−1 piperonyl butoxide for 96 h and 15 days. tGSH, GSSG, TBARS contents, GPx, GR, GST, and AChE enzymes activities were determined by spectrophotometrical methods and Hsp70 content was analyzed by ELISA technique. Lambda-cyhalothrin had no significant effect on the components of GSH redox system, lipid peroxidation and Hsp70 levels but inhibited AChE activity. In the presence of piperonyl butoxide, lambda-cyhalothrin caused increases in tGSH, GSSG, TBARS and Hsp70 contents, GST activity, and decrease in AChE activity. Present results showed that in the presence of piperonyl butoxide, lambda-cyhalothrin caused neurotoxic effects by increasing oxidative stress. Adaptation to its oxidative stress effects may be supplied by GSH-related antioxidant system. Piperonyl butoxide revealed neurotoxic effect of lambda-cyhalothrin. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Markers of oxidative stress in hepatopancreas of crayfish (orconectes limosus, raf) experimentally exposed to nanosilver
Abstract
Silver nanoparticles, chemically neutral particles in the size range of 1–100 nm, express strong antimicrobial activity and therefore have a broad range of applications. The increased use of consumer products with nanosilver (nanoAg) may result in its release into the environment, and may particularly affect aquatic systems. The mechanisms of the harmful effects of nanoAg against aquatic organisms are unclear. Therefore, in the present study we investigate the pro-oxidative potential of these nanoparticles in experimentally exposed crayfish Orconectes limosus . Markers of oxidative stress and parameters of the antioxidant cell defense system such as total glutathione, glutathione reductase and the level of sulfhydryl groups were examined in the hepatopancreas of both sexes of O. limosus collected seasonally from Białe Lake (Poland) and subsequently exposed to nanoAg particles for 2 weeks. Exposure to nanoAg led to a high concentration-dependent increase in the rate of lipid peroxidation and a decrease of protein-bound SH groups which indicates protein oxidation. These markers of oxidative stress were accompanied by decreased levels of thiols and reduced activity of glutathione reductase. These results indicate a deficiency of reduced glutathione and suggest that the exposed organisms have less efficient antioxidative mechanisms available to counter ROS-mediated cellular stress. Furthermore, we find that confocal microscopy is of limited utility in monitoring the presence of silver nanoparticles in tissues of exposed crayfish. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Determination of heavy metal content and lipid profiles in mussel extracts from two sites on the moroccan atlantic coast and evaluation of their biological activities on MIN6 pancreatic cells
Abstract
Mussels may concentrate pollutants, with possibly significant side effects on human health. Therefore, mussels (Mytilus galloprovincialis ) from two sites of the Moroccan Atlantic coast (Jorf Lasfar [JL], an industrial site, and Oualidia [OL], a vegetable-growing area), were subjected to biochemical analyses to quantify the presence of heavy metals (Cd, Cr, and Pb) and to establish the lipid profile: fatty acid, cholesterol, oxysterol, phytosterol and phospholipid content. In addition, mussel lipid extracts known to accumulate numerous toxic components were tested on murine pancreatic β-cells (MIN6), and their biological activities were measured with various flow cytometric and biochemical methods to determine their impacts on cell death induction, organelle dysfunctions (mitochondria, lysosomes, and peroxisomes), oxidative stress and insulin secretion. The characteristics of JL and OL lipid extracts were compared with those of commercially available mussels from Spain (SP) used for human consumption. OL and JL contained heavy metals, high amounts of phospholipids, and high levels of oxysterols; the [(unsaturated fatty acids)/(saturated fatty acids)] ratio, which can be considered a sign of environmental stress leading to lipid peroxidation, was low. On MIN6 cells, JL and OL lipid extracts were able to trigger cell death. This event was associated with overproduction of H2 O2 , increased catalase activity, a decreased GSH level, lipid peroxidation and stimulation of insulin secretion. These effects were not observed with SP lipid extracts. These data suggest that some components from OL and JL lipid extracts might predispose to pancreatic dysfunctions. Epidemiological studies would be needed to assess the global risk on human health and the metabolic disease incidence in a context of regular seafood consumption from the OL and JL areas. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Assessing multiple endpoints of atrazine ingestion on gravid northern watersnakes (Nerodia sipedon) and their offspring
Abstract
Ecotoxicological studies that focus on a single endpoint might not accurately and completely represent the true ecological effects of a contaminant. Exposure to atrazine, a widely used herbicide, disrupts endocrine function and sexual development in amphibians, but studies involving live-bearing reptiles are lacking. This study tracks several effects of atrazine ingestion from female Northern Watersnakes (Nerodia sipedon ) to their offspring exposed in utero . Twenty-five gravid N. sipedon were fed fish dosed with one of the four levels of atrazine (0, 2, 20, or 200 ppb) twice weekly for the entirety of their gestation period. Endpoints for the mothers included blood estradiol levels measured weekly and survival more than 3 months. Endpoints for the offspring included morphometrics, clutch sex ratio, stillbirth, and asymmetry of dorsal scales and jaw length. Through these multiple endpoints, we show that atrazine ingestion can disrupt estradiol production in mothers, increase the likelihood of mortality from infection, alter clutch sex ratio, cause a higher proportion of stillborn offspring, and affect scale symmetry. We emphasize the need for additional research involving other reptile species using multiple endpoints to determine the full range of impacts of contaminant exposure. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Effect of nonpersistent pesticides on estrogen receptor, androgen receptor, and aryl hydrocarbon receptor
Abstract
Nonpersistent pesticides are considered less harmful for the environment, but their impact as endocrine disruptors has not been fully explored. The pesticide Switch was applied to grape vines, and the maximum residue concentration of its active ingredients was quantified. The transactivation potential of the pesticides Acorit, Frupica, Steward, Reldan, Switch, Cantus, Teldor, and Scala and their active compounds (hexythiazox, mepanipyrim, indoxacarb, chlorpyrifos-methyl, cyprodinil, fludioxonil, boscalid, fenhexamid, and pyrimethanil) were tested on human estrogen receptor α (ERα), androgen receptor (AR) and arylhydrocarbon receptor (AhR) in vitro . Relative binding affinities of the pure pesticide constituents for AR and their effect on human breast cancer and prostate cancer cell lines were evaluated. Residue concentrations of Switch's ingredients were below maximum residue limits. Fludioxonil and fenhexamid were ERα agonists (EC50 -values of 3.7 and 9.0 μM, respectively) and had time-dependent effects on endogenous ERα-target gene expression (cyclin D1, progesterone receptor, and nuclear respiratory factor 1) in MCF-7 human breast cancer cells. Fludioxonil, mepanipyrim, cyprodinil, pyrimethanil, and chlorpyrifos-methyl were AhR-agonists (EC50 s of 0.42, 0.77, 1.4, 4.6, and 5.1 μM, respectively). Weak AR binding was shown for chlorpyrifos-methyl, cyprodinil, fenhexamid, and fludioxonil. Assuming a total uptake which does not take metabolism and clearance rates into account, our in vitro evidence suggests that pesticides could activate pathways affecting hormonal balance, even within permitted limits, thus potentially acting as endocrine disruptors. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
The mancozeb-containing carbamate fungicide tattoo induces mild Oxidative Stress in goldfish brain, liver, and kidney
Abstract
Tattoo belongs to the group of carbamate fungicides and contains Mancozeb (ethylene(bis)dithiocarbamate) as its main constituent. The toxicity of Mancozeb to living organisms, particularly fish, is not resolved. This work investigated the effects of 96 h of exposure to 3, 5, or 10 mg L−1 of Tattoo (corresponding to 0.9, 1.5, or 3 mg L−1 of Mancozeb) on the levels of oxidative stress markers and the antioxidant enzyme system of brain, liver, and kidney of goldfish, Carassius auratus ). In liver, Tattoo exposure resulted in increased activities of superoxide dismutase (SOD) by 70%–79%, catalase by 23%–52% and glutathione peroxidase (GPx) by 49%. The content of protein carbonyls (CP) in liver was also enhanced by 92%–125% indicating extensive damage to proteins. Similar increases in CP levels (by 98%–111%) accompanied by reduced glucose-6-phosphate dehydrogenase activity (by 13%–15%) was observed in kidney of fish exposed to Tattoo; however, SOD activity increased by 37% in this tissue after treatment with 10 mg L−1 Tattoo. In brain, a rise in lipid peroxide level (by 29%) took place after exposure to 10 mg L−1 Tattoo and was accompanied by elevation of high-molecular mass thiols (by 14%). Tattoo exposure also resulted in a concentration-dependent decrease in glutathione reductase activity (by 26%–37%) in brain. The data collectively show that exposure of goldfish to 3–10 mg L−1 of the carbamate fungicide Tattoo resulted in the development of mild oxidative stress and activation of antioxidant defense systems in goldfish tissues. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Microcystin-LR induces protein phosphatase 2A alteration in a human liver cell line
Abstract
Microcystin-LR (MC-LR) is a potent inhibitor of protein phosphatases 1 and 2A, and has potent hepatotoxicity and tumor promotion activity. Numerous studies on MC-LR toxicity have been conducted in rat hepatocytes, but few studies of the effects of microcystins on human hepatocytes have been done. In this study, HL7702 cells (a human normal liver cell line) were incubated in MC-LR for 24 h. The existence of MC-LR in HL7702 cells was confirmed. Furthermore, PP2A activity and the alteration of PP2A subunits were assessed. The results show that PP2A activity decreased from the concentration of 1 μM MC-LR, showing a concentration-dependent decline, to about 34% at 10 μM MC-LR. This activity undergone opposite change with alternations of phosphorylated Y307-PP2A/C and PP2A/C subunit but showed same change with the alteration of the ratio of methylated L309-PP2A/C to PP2A/C. B55α, a regulatory subunit of PP2A, was slightly increases in cells treated with the highest concentration of MC-LR (10 μM), and colocalized increasedly with rearranged-microtubules after 1 μM MC-LR exposure. However, the proportion of early apoptotic cells did not show any change at various concentration of MC-LR for 24 h. To our knowledge, this is the first report showing MC-LR-induced alteration of PP2A phosphatase in human cultured hepatocytes, and the mechanism of action seems to be similar as described before in vitro . The alteration of PP2A and microtubule seems to be the early event induced by MC-LR exposure. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Association of sick building syndrome with neuropathy target esterase (NTE) activity in Japanese
Abstract
Sick building syndrome (SBS) is a set of several clinically recognizable symptoms reported by occupants of a building without a clear cause. Neuropathy target esterase (NTE) is a membrane bound serine esterase and its reaction with organophosphates (OPs) can lead to OP-induced delayed neuropathy (OPIDN) and nerve axon degeneration. The aim of our study was to determine whether there was a difference in NTE activity in the peripheral blood mononuclear cells (PBMCs) of Japanese patients with SBS and healthy controls and whether PNPLA6 (alias NTE) gene polymorphisms were associated with SBS. We found that the enzymatic activity of NTE was significantly higher (P < 0.0005) in SBS patients compared with controls. Moreover, population with an AA genotype of a single nucleotide polymorphism (SNP), rs480208, in intron 21 of the PNPLA6 gene strongly reduced the activity of NTE. Fifty-eight SNP markers within the PNPLA6 gene were tested for association in a case–control study of 188 affected individuals and 401 age-matched controls. Only one SNP, rs480208, was statistically different in genotype distribution (P = 0.005) and allele frequency (P = 0.006) between the cases and controls (uncorrected for testing multiple SNP sites), but these were not significant by multiple corrections. The findings of the association between the enzymatic activity of NTE and SBS in Japanese show for the first time that NTE activity might be involved with SBS. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Effects of subchronic exposure to low-dose volatile organic compounds on lung inflammation in mice
Abstract
Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance. Exposure to some kinds of volatile organic compounds (VOCs) leads to lung inflammation, oxidative stress, and immune modulation. However, it is suspected that sub-chronic exposure to low-dose VOCs mixture induces or aggravates lung inflammation. To clarify the effect of this exposure on lung inflammatory responses, 40 male Kunming mice were exposed in four similar static chambers, 0 (control) and three different doses of VOCs mixture (groups 1–3). The concentrations of VOCs mixture were as follows: formaldehyde, benzene, toluene, and xylene 0.10 + 0.11 + 0.20 + 0.20 mg/m3 , 0.50 + 0.55 + 1.00 + 1.00 mg/m3 , 1.00 + 1.10 + 2.00 + 2.00 mg/m3 , respectively, which corresponded to 1, 5, and 10 times of indoor air quality standard in China. After 90 consecutive days of exposure (2 h/day), oxidative stress markers in lung, cellular infiltration and cytokines, chemokine, neurotrophin in bronchoalveolar lavage fluid (BALF), and immunoglobulin (Ig) in serum were examined. VOCs exposure could increase significantly reactive oxygen species (ROS) in lung, the levels of interleukin-8 (IL-8), IL-4, eotaxin, nerve growth factor (NGF), and various types of leukocytes in BALF, IgE concentration in serum. In contrast, GSH to GSSG ratio and interferon-gamma were significantly decreased following the VOCs exposure. These results indicate that the VOCs mixture-induced inflammatory response is at least partly caused by release of the ROS and mediators from the activated eosinophils, neutrophils, alveolar macrophages and epithelial cells. © 2013 Wiley Periodicals, Inc. Environ Toxicol 2013.
Histological alterations in the structure of the testis in tench (Tinca tinca) after exposure to 17 alpha-ethynylestradiol
Abstract
Environmental pollution with synthetic estrogens may pose a serious threat to reproduction of aquatic wildlife species. The current study describes the effects of 17α-ethynylestradiol (EE2 ) on the structure of the testis in tench (Tinca tinca ). Adult male tench were exposed to sublethal doses of EE2 (50, 100, and 500 μg/Kg t.w.) under semistatic conditions for a period of 30 days. The condition factor (CF), testicular somatic index (TSI), and histology (including a morphometric analysis) of the testis were examined. No consistent differences were observed in the CF of EE2 -exposed tench when compared with nonexposed fish. A significant decrease in TSI could only be observed at a 50 μg/Kg t.w. EE2 dose (p < 0.05) when compared with the control group. The histopathology of the testis was associated with loss of normal tubular structure with increased doses of exposure, decrease of tubule number, degeneration in Sertoli and Leydig cells, increase in necrotic testicular cells including formation of syncytia structures and, finally, a high incidence of fish with early primary oocytes at 100 and 500 μg/Kg t.w. EE2 . These results indicate that long-term exposure to EE2 may produce clear negative effects on testicular structure in tench. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Subchronic neurotoxicity of chlorpyrifos, carbaryl, and their combination in rats
Abstract
Anticholinesterase pesticides have been widely used in agricultural and domestic settings and can be detected in the environment after long-term use. Although the acute toxic effects of chlorpyrifos and carbaryl have been well described, little is known about the chronic toxicity of the pesticides mixture. To investigate their chronic neurotoxicity, Wistar rats were exposed to chlorpyrifos, carbaryl, and their mixture (MIX) for 90 consecutive days. The activities of serum cholinesterase (ChE) as well as acetylcholinesterase (AChE) and neuropathy target esterase (NTE) in nerve tissues were determined. Furthermore, the histopathological examination was carried out. The results showed that ChE activity significantly decreased in all treated rats except the rats treated with low dose carbaryl. Treatment with middle- and high-dose chlorpyrifos and MIX in rats significantly inhibited AChE activity in the central nervous tissues, whereas treatment with carbaryl alone did not. In sciatic nerve, AChE activity was significantly inhibited by high-dose carbaryl and MIX, but not by chlorpyrifos alone. No significant NTE inhibition was observed in all treatment groups. Histopathological examination revealed that both chlorpyrifos and MIX treatment induced hippocampal damage. However, no obvious hippocampal damage was found in carbaryl-treated rats. Carbaryl and MIX, but not chlorpyrifos alone, induced pathological damage of sciatic nerve. Taken together, all of the results indicated that chlorpyrifos and carbaryl have different toxicological target tissues in nervous system and showed corresponding effects in the nervous tissues, which may reflect the different sensitivity of central and peripheral nervous tissues to different pesticides individually and in combination. © 2013 Wiley Periodicals, Inc. Environ Toxicol 2013.
Effects of chlorpyrifos on reproductive toxicology of male rats
Abstract
The aim of this study is to investigate the effects of subchronic exposure to chlorpyrifos on reproductive toxicology of male rats. Forty healthy male rats were divided into four groups: three exposure groups and a control group. Chlorpyrifos was administered orally to male rats at 0, 2.7, 5.4, and 12.8mg/kg for 90 days to evaluate the toxic alterations in testicular histology, testicular marker enzyme activities and related genes expression levels, sperm dynamics, and testosterone levels. The body weight and the testis weight of animals did not show any significant changes. Chlorpyrifos brought about marked reduction in testicular sperm counts, sperm motility, and significant growth of sperm malformation rate in exposed males. Histopathological examination of testes showed mild to severe degenerative changes in seminiferous tubules at various dose levels. The levels of testosterone (T) showed a decreasing tendency, and there was a statistical difference between the 5.4, 12.8 mg/kg groups, and the control group. The levels of follicle stimulating hormone (FSH) were significantly increased in 5.4 and 12.8 mg/kg groups, but there were no obvious effects on the levels of luteinizing hormone (LH) and estradiol (E2 ). A significant increase in the activities of LDH and LDH-x was observed in chlorpyrifos exposed rats in 5.4 and12.8 mg/kg groups, but the expression levels of related genes had no significant differences between chlorpyrifos exposure groups and the control group. These results suggest that chlorpyrifos has adverse effects on reproductive system of male rats. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Comparative toxicity of pyrethroid insecticides to two estuarine crustacean species, Americamysis bahia and Palaemonetes pugio
Abstract
Pyrethroid insecticides are widely used on agricultural crops, as well as for nurseries, golf courses, urban structural and landscaping sites, residential home and garden pest control, and mosquito abatement. Evaluation of sensitive marine and estuarine species is essential for the development of toxicity testing and risk-assessment protocols. Two estuarine crustacean species, Americamysis bahia (mysids) and Palaemonetes pugio (grass shrimp), were tested with the commonly used pyrethroid compounds, lambda-cyhalothrin, permethrin, cypermethrin, deltamethrin, and phenothrin. Sensitivities of adult and larval grass shrimp and 7-day-old mysids were compared using standard 96-h LC50 bioassay protocols. Adult and larval grass shrimp were more sensitive than the mysids to all the pyrethroids tested. Larval grass shrimp were approximately 18-fold more sensitive to lambda-cyhalothrin than the mysids. Larval grass shrimp were similar in sensitivity to adult grass shrimp for cypermethrin, deltamethrin, and phenothrin, but larvae were approximately twice as sensitive to lambda-cyhalothrin and permethrin as adult shrimp. Acute toxicity to estuarine crustaceans occurred at low nanogram per liter concentrations of some pyrethroids, illustrating the need for careful regulation of the use of pyrethroid compounds in the coastal zone. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Toxicity evaluation of β-diketone antibiotics on the development of embryo-larval zebrafish (danio rerio)
Abstract
This study evaluated the effects of β-diketone antibiotics (DKAs) on the development of embryo-larval zebrafish (Danio rerio ). When exposure to DKAs, developmental malformations, such as hatching delay, curved body axis, pericardial edema, uninflated swim bladder and yolk sac edema, were observed at 120 h postfertilization (hpf). The estimated 120 hpf nominal concentrations of no observed effect concentration and lowest observed effect concentration for DKAs were 18.75 and 37.50 mg/L, respectively, suggesting that DKAs have much lower toxicity than other persistent pollutants. Following DKA exposure, embryonic heart rates were significantly reduced as compared to the controls at 48 and 60 hpf. The peak bending motion frequency appeared 1 h earlier than in control embryos. The 2.34 and 9.38-mg/L treatment groups had a higher basal swim rate than control groups at 120 hpf in both light and light-to-dark photoperiod experiments. The occurrence of high speed swim rates was enhanced approximately threefold to sevenfold in the 2.34 and 9.38 mg/L treatments compared to the control. Glutathione (GSH) concentrations in the 2.34 and 9.38-mg/L treatments were significantly higher than the control at 72 hpf, suggesting that GSH production was induced at the end of the hatching period. When exposed to DKAs, zebrafish superoxide dismutase enzyme (SOD) activities were significantly inhibited in the early embryonic period, demonstrating that the clearing ability in zebrafish was lower than the generation rate of free radicals. In summary, the combined DKAs were developmentally toxic to zebrafish in their early life stages and had the ability to impair individual behaviors that are of great importance in the assessment of their ecological fitness. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Camellia sinensis (green tea) extract attenuate acrylamide induced testicular damage in albino rats
Abstract
Acrylamide is a proved toxin for testicular function, found in food when heated for long period of time. Green tea (Camellia sinensis) is a potent antioxidant; the aim of this study was to investigate the protective effect of green tea extract against the toxic effects of acrylamide in rat testes. Methods: acrylamide was administered orally to rats in different doses and also the extract of green tea was administered orally to different groups of animals in combination with the acrylamide. The weight of animals, testosterone hormone level and histopathological effect upon testicles were evaluated. Results: Testosterone hormone level in serum, and histopathological findings were significantly improved with the co-administration of green tea extract with the acrylamide. Green tea extract reversed all the toxic effects of acrylamide even in high dose for long period (90 days). Conclusion: Green tea extract is a potent antioxidant antidote for the acrylamide toxic effects upon testicular function. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Wogonin attenuates endotoxin-induced prostaglandin E2 and nitric oxide production via Src-ERK1/2-NFκB pathway in BV-2 microglial cells
Abstract
Microglia are the major component of intrinsic brain immune system in neuroinflammation. Although wogonin expresses anti-inflammatory function in microglia, little is known about the molecular mechanisms of the protective effect of wogonin against microglia activation. The aim of this study was to evaluate how wogonin exerts its anti-inflammatory function in BV2 microglial cells after LPS/INFγ administration. Wogonin not only inhibited LPS/ INFγ-induced PGE2 and NO production without affecting cell viability but also exhibited parallel inhibition on LPS/INFγ-induced expression of iNOS and COX-2 in the same concentration range. While LPS/INFγ-induced expression of P-p65 and P-IκB was inhibited by wogonin— only weak inhibition on P-p38 and P-JNK were observed, whereas it significantly attenuated the P-ERK1/2 and its upstream activators P-MEK1/2 and P-Src in a parallel concentration-dependent manner. These results indicated that the blockade of PGE2 and NO production by wogonin in LPS/INFγ-stimulated BV2 cells is attributed mainly to interference in the Src-MEK1/2-ERK1/2-NFκB-signaling pathway. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Ultrastructural changes during spermatogenesis, biochemical and hormonal evidences of testicular toxicity caused by TBT in freshwater prawn macrobrachium rosenbergii (De Man, 1879)
Abstract
The present investigation documents the impact of tributyltin (TBT) on the ultrastructural variation of spermatogenesis in freshwater prawn Macrobrachium rosenbergii . The environmentally realistic concentration of TBT can cause damages to the endocrine and reproductive physiology of crustaceans. In this context, three concentrations viz. 10, 100, and 1000 ng/L were selected and exposed to prawns for 90 days. The TBT exposed prawn exhibited decrease the reproductive activity as evidenced by sperm count and sperm length compared to control. Histopathological results revealed the retarded testicular development, abnormal structure of seminiferous tubule, decrease in the concentration of spermatozoa, diminution of seminiferous tubule membrane, abundance of spermatocytes and vacuolation in testis of treated prawns. Ultrastructural study also confirmed the impairment of spermatogenesis in treated prawns. Furthermore, radioimmunoassay (RIA) clearly documented the reduction of testosterone level in TBT exposed groups. Thus, TBT substantially reduced the level of male sex hormone as well as biochemical constituents which ultimately led to impairment of spermatogenesis in the freshwater male prawn M.rosenbergii . © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Heavy metal influence on BDE-47 uptake in the human KERTr keratinocyte cell line
Abstract
Significant correlations between concentrations of PBDEs and heavy metals were observed in the human body. However, there is a lack of evidence on the linkage between the uptake of heavy metals and PBDEs. This study is the first report on the BDE-47 uptake profile in a human cell line. Hg and As exposures to KERTr (human skin derived keratinocyte) did not significantly (p > 0.05) affect the uptake of BDE47, whereas Pb and Cd significantly (p < 0.05) affected the uptake of BDE-47 in KERTr. The change in K m was minor after exposure to all heavy metals. The maximum transport rate (V max ) after exposure to Pb (V max : 5.23 ± 0.49) and As (V max : 4.95 ± 0.60) was significantly increased when compared with the background of the KERTr cell line (V max : 4.07 ± 0.35). Real-time RT-PCR indicated that OATP-B, OATP-D, and OATP-E were expressed in the KERTr cell line. The upregulation or downregulation of OATP B and D genes were minor after exposure to heavy metals, but the OATP E gene was upregulated by three to fourfold in KERTr cell line after exposure to Pb an Cd, which may explain the significant increase of uptake of BDE-47 in KERTr after exposures to Pb and Cd. This study indicated that the uptake effects should be considered when performing risk assessment of human exposure to PBDEs and heavy metal. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
An “ex vivo†model to evaluate toxicological responses to mixtures of contaminants in cetaceans: Integumentum biopsy slices
Abstract
The need for powerful new tools to detect the effects of chemical pollution, in particular of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) on Mediterranean cetaceans led us to develop and apply a suite of sensitive biomarkers for integument biopsies of stranded and free-ranging animals. This multi-response ex vivo method has the aim to detect toxicological effects of contaminant mixtures. In the present study, we applied an ex vivo assay using skin biopsy and liver slices, combining molecular biomarkers [Western blot of Cytochrome P450 1A1 (CYP1A1) and Cytochrome P450 2B (CYP2B)] and gene expression biomarkers (Quantitative real-time PCR of CYP1A1, heat shock protein 70, estrogen receptor alpha and E2F transcription factor) in response to chemical exposure [organochlorines compounds (OCs), polybrominated diphenyl ethers (PBDEs), and PAHs] for stranded Mediterranean Stenella coeruleoalba. The main goal of this experiment was to identify the biomarker and/or a suite of biomarkers that could best detect the presence of a specific class of pollutants (OCs, PBDEs, and PAHs) or a mixture of them. This multi-response biomarker methodology revealed an high sensitivity and selectivity of responses (such as CYP1A and ER α mRNA variations after OCs and PAHs exposure) and could represent a valid future approach for the study of inter- and intra-species sensitivities to various classes of environmental contaminants. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Side-effects of thiamethoxam on the brain andmidgut of the africanized honeybee Apis mellifera (Hymenopptera: Apidae)
Abstract
The development of agricultural activities coincides with the increased use of pesticides to control pests, which can also be harmful to nontarget insects such as bees. Thus, the goal of this work was assess the toxic effects of thiamethoxam on newly emerged worker bees of Apis mellifera (africanized honeybee—AHB). Initially, we determined that the lethal concentration 50 (LC50 ) of thiamethoxam was 4.28 ng a.i./μL of diet. To determine the lethal time 50 (LT50 ), a survival assay was conducted using diets containing sublethal doses of thiamethoxam equal to 1/10 and 1/100 of the LC50. The group of bees exposed to 1/10 of the LC50 had a 41.2% reduction of lifespan. When AHB samples were analyzed by morphological technique we found the presence of condensed cells in the mushroom bodies and optical lobes in exposed honeybees. Through Xylidine Ponceau technique, we found cells which stained more intensely in groups exposed to thiamethoxam. The digestive and regenerative cells of the midgut from exposed bees also showed morphological and histochemical alterations, like cytoplasm vacuolization, increased apocrine secretion and increased cell elimination. Thus, intoxication with a sublethal doses of thiamethoxam can cause impairment in the brain and midgut of AHB and contribute to the honeybee lifespan reduction. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Protective role of silymarin against manganese-induced nephrotoxicity and oxidative stress in rat
Abstract
Metal toxicity may occur after exposure from many sources. Oxidative stress is thought to be involved in manganese-induced toxicity and leads to various health disorders. Silymarin (SIL), a natural flavonoid, has been reported to have many benefits and medicinal properties. The aim of this study was to assess the toxicity of manganese (Mn) on oxidative stress and DNA damage in the kidney of rats and its alleviation by SIL. Manganese was given orally in drinking water (20 mg MnCl2 /mL) with or without SIL administration (100 mg /kg intraperitoneally) for 30 days. Our data showed that SIL significantly prevented Mn induced nephrotoxicity, indicated by both diagnostic indicators of kidney injury like plasma urea, uric acid and creatinine and urinary electrolyte levels and by histopathological analysis. Moreover, Mn-induced profound elevation of the production of reactive oxygen species (ROS) and altered the levels of oxidative stress related biomarkers in kidney tissue. This is evidenced by the increase of lipid peroxidation, protein carbonylation, DNA fragmentation and urinary hydrogen peroxide, while, the activities of enzymatic antioxidant and glutathione level were decreased. Treatment with SIL reduced the alterations in the renal and urine markers, decreasing lipid peroxidation markers, increasing the antioxidant cascade and decreasing the Mn-induced damage. All these changes were supported by histopathological observations. These findings suggested that the inhibition of Mn-induced damage by SIL was due at least in part to its antioxidant activity and its capacity to modulate the oxidative damage. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Crude extract of rheum palmatum L induced cell death in LS1034 human colon cancer cells acts through the caspase-dependent and -independent pathways
Abstract
Crude extract of Rheum palmatum L (CERP) has been used to treat different diseases in the Chinese population for decades. In this study, we investigated the effects of CERP on LS1034 human colorectal cancer cells in vitro and also examined possible mechanisms of cell death. Flow cytometric assays were used to measure the percentage of viable cells, cell cycle distribution including the sub-G1 phase (apoptosis), the activities of caspase-8, -9, and -3, reactive oxygen species (ROS) and Ca2+ levels, and mitochondrial membrane potential (ΔΨm ). DNA damage, nuclei condensation, protein expression, and translocation were examined by Comet assay, 4′-6-diamidino-2-phenylindole (DAPI) staining, Western blotting, and confocal laser system microscope, respectively. CERP induced apoptosis as seen by DNA fragmentation and DAPI staining in a concentration- and time-dependent manner in cancer cells. CERP was associated with an increase in the Bax/Bcl-2 protein ratio and CERP promoted the activities of caspase-8, -9, and -3. Both ROS and Ca2+ levels were increased by CERP but the compound decreased levels of ΔΨm in LS1034 cells. Laser confocal microscope also confirmed that CERP promoted the expressions of AIF, Endo G, cytochrome c, and GADD153 to induce apoptosis through mitochondrial-dependent pathway. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Genetic and biochemical biomarkers in the macrophyte Bidens laevis L. Exposed to a commercial formulation of endosulfan
Abstract
Previous studies in the wetland macrophyte Bidens laevis L have demonstrated that the insecticide endosulfan induces a high frequency of somatic chromosome aberrations in anaphase–telophase (CAAT) but no DNA changes as determined by the single cell gel electrophoresis (Comet) assay. Thus, cytogenetic biomarkers appear to be more sensitive to the toxic effects of the insecticide than the DNA molecule in the studied species. For this reason, the goals of this study were to use cytogenetic biomarkers—CAAT and abnormal metaphase—and defense biomarkers such as the activity of the antioxidant enzymes—guaiacol peroxidases (POD), glutathione reductase, and microsomal and cytosolic (m- and c-) glutathione-S -transferase (GST)—to evaluate in B. laevis effects caused by a commercial formulation of endosulfan. The frequency of CAAT was increased at 5, 10, 50, and 100 μg/L endosulfan with respect to the negative controls by 3.1, 2.5, 2.5, and 3.2-fold, respectively while the frequency of abnormal metaphases was also increased at the same concentrations by 3.5, 2.8, 3.2, and 11.3-fold, respectively. In addition to these aneugenic effects, other abnormalities such as C-mitosis and chromosome clumping were observed at 10 μg/L endosulfan. On the other hand, POD induction at 0.02, 0.5, 5, and 10 μg/L and m-GST inhibition at 0.5, 10, and 50 μg/L in plants exposed during 24 h to endosulfan were observed but all of these responses were highly variable. In conclusion, only cytogenetic biomarkers like CAAT in B. laevis can serve potentially as early warning systems to detect environmentally relevant concentrations of endosulfan in aquatic ecosystems. © 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013.
The crude extract of Corni Fructus induces apoptotic cell death through reactive oxygen species-modulated pathways in U-2 OS human osteosarcoma cells
Abstract
Crude extract of Corni Fructus (CECF) has been used in Traditional Chinese medicine for the treatment of different diseases for hundreds of years. The purpose of this study was to investigate the cytotoxic effects of CECF on U-2 OS human osteosarcoma cells. Flow cytometry was used for measuring the percentage of viable cells, cell-cycle distribution, apoptotic cells in sub-G1 phase, reactive oxygen species (ROS), Ca2+ levels, and mitochondrial membrane potential (ΔΨm ). Comet assay and 4′-6-diamidino-2-phenylindole staining were used for examining DNA damage and condensation. Western blotting was used to examine apoptosis-associated protein levels in U-2 OS cells after exposed to CECF. Immunostaining and confocal laser system microscope were used to examine protein translocation after CECF incubation. CECF decreased the percentage of viability, induced DNA damage and DNA condensation, G0 /G1 arrest, and apoptosis in U-2 OS cells. CECF-stimulated activities of caspase-8, caspase-9, and caspase-3, ROS, and Ca2+ production, decreased ΔΨm levels of in U-2 OS cells. CECF increased protein levels of caspase-3, caspase-9, Bax, cytochrome c , GRP78, AIF, ATF-6α, Fas, TRAIL, p21, p27, and p16 which were associated with cell-cycle arrest and apoptosis. These findings suggest that CECF triggers apoptosis in U-2 OS cells via ROS-modulated caspase-dependent and -independent pathways. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effect of commercial grade endosulfan on growth and reproduction of the fighting fish Betta splendens
Abstract
To study the effects of endosulfan on survival, growth and reproduction of the obligate air-breathing male heterogametic fighting fish Betta splendens , posthatchlings of the fighting fish were discretely immersed for 3 h/day during the labile period on the 2nd , 5th , and 8th day posthatching (dph) at selected concentrations of commercial grade endosulfan ranging from 175 to 1400 ng/L. The immersions at 1,400 ng/L led to 21% mortality, among the 79% of surviving fry, 80% developed into females. The endosulfan reduced the air-breathing frequency of 5- and 8-day old hatchlings, and the reduction in the frequency persisted even after a depuration period of 172 days. In the ovary of the treated females, reduced number of vitellogenic oocytes with increased vacuolar cavities was observed. In the testis of the treated males, the reduced number of spermatogonia with increased vacuolar cavities was observed. The treated male induced the female to spawn a fewer eggs, which were subsequently incubated in his smaller bubble nest. The control females attained puberty on the 138th dph and spawned 120 eggs once in every 15 days, the females, which were previously treated at 1400 ng/L, postponed puberty to the 179th dph and spawned 70 eggs once in every 32 days. During the 240-day experiment, endosulfan is found to reduce significantly the cumulative progeny production from 760 to 144, reducing significantly to 19% of the control. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cytochrome P450 system expression and DNA adduct formation in the liver of Zacco platypus following waterborne Benzo(a)pyrene exposure: implications for biomarker determination
Abstract
Benzo(a )pyrene (Ba P) is a polycyclic aromatic hydrocarbon that causes mutations and tumor formation. Zacco platypus is a sentinel species that is suitable for monitoring aquatic environments. We studied cytochrome P450 system (CYP system) expression and DNA adduct formation in the liver of Z. platypus following waterborne exposure to Ba P. The results showed both dose and time dependency. The significant induction levels of CYP system mRNA and protein reached maximums at 2 days and 14 days, respectively, and hepatosomatic index was maximally induced at 4 days during 14 days Ba P exposure. DNA adduct formation was significantly induced compared to corresponding controls (t -test, p < 0.01) after 4 days of exposure in 100 μg/L Ba P. These results indicate that the only use of mRNA expression level of CYP system as a biomarker make us underestimate prolonged toxicity (4–14 days) of Ba P and the only use of protein expression level of CYP system make us underestimate acute toxicity (1–2 days) of Ba P. Therefore, we suggests that a combinational use of the mRNA expression level and protein expression level of CYP system, hepatosomatic index is a useful biomarker in risk assessment of waterborne Ba P exposure. In addition, DNA adduct formation was a useful biomarker in risk assessment of waterborne Ba P exposure at 4 days. CYP1A was a more sensitive biomarker than CYP reductase for Ba P exposure when considering both the mRNA and protein level. Furthermore, our results show that Z. platypus is a useful species for assessing the risk of waterborne Ba P exposure. 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Acute toxicity and biochemical effects of azinphos methyl in the amphipod Hyalella curvispina
Abstract
We evaluated the acute toxicity and biochemical effects of the organophosphorus pesticide azinphos methyl (AM) in the amphipod Hyalella curvispina that inhabits ponds and irrigation channels of an intensive fruit-producing region in Rio Negro and Neuquén valley, North Patagonia, Argentina. The analysis by nonlinear regression of data from the 96 h-acute toxicity tests indicated the coexistence of two subpopulations of H. curvispina with different susceptibilities to AM. The 96 h-LC50 for the resistant subpopulation (166 ± 56 μg/L) was 216-fold higher than the 96h-LC50 value for the susceptible one (0.77 ± 1.33 μg/L).The two subpopulations could not be distinguished based on the biochemical measurements in control amphipods. Cholinesterase activity was significantly inhibited in AM-exposed amphipods in a concentration-dependent manner. The IC50 value obtained after 96 h of exposure (2.18 ± 1.95 μg/L) was significantly lower than the 48 h-IC50 value (29.6 ± 17.4 μg/L). Carboxylesterase activity was significantly inhibited after 48 h of exposure to 12.5 and 62.5 μg/L AM (inhibition, 51%). This enzyme was thus able to protect cholinesterase from inhibition at 12.5 μg/L AM. Reduced glutathione and catalase showed a significant increase after 24 h of exposure as an adaptive response to AM, whereas glutathione S -transferase activity was not significantly modified. The analysis of species sensitivity distribution showed that both subpopulations of H. curvispina were more tolerant to AM than most amphipod species, and that the susceptible subpopulation was more sensitive to AM than the other local aquatic species analyzed. The maximum concentration of AM in drainage water within the fruit-producing area reported by other studies would affect most of the amphipod species (99%) and also a 44% of local aquatic ones. The results obtained in this study point out the usefulness of including amphipods like H. curvispina in ecotoxicity studies and monitoring programs to perform pesticide risk assessments. 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Response of bacterial isolates from Antarctic shallow sediments towards heavy metals, antibiotics and polychlorinated biphenyls
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivThe response of bacterial isolates from Antarctic sediments to polychlorinated biphenyls (Aroclor 1242 mixture), heavy metal
salts (cadmium, copper, mercury and zinc) and antibiotics (ampicillin, chloramphenicol, kanamycin and streptomycin) was investigated.
Overall, the ability to growth in the presence of Aroclor 1242 as a sole carbon source was observed for 22 isolates that mainly
belonged to iPsychrobacter/i spp. Tolerance to the heavy metals assayed in this study was in the order of Cdnbsp;gt;nbsp;Cunbsp;gt;nbsp;Znnbsp;gt;nbsp;Hg and appeared to be strictly
related to the metal concentrations, as determined during previous chemical surveys in the same area. With regards to antibiotic
assays, the response of the isolates to the tested antibiotics ranged from complete resistance to total susceptibility. In
particular, resistances to ampicillin and chloramphenicol were very pronounced in the majority of isolates. Our isolates differently
responded to the presence of toxic compounds primarily based on their phylogenetic affiliation and secondarily at strain level.
Moreover, the high incidence of resistance either to metal or antibiotics, in addition to the capability to grow on PCBs,
confirm that bacteria are able to cope and/or adapt to the occurrence pollutants even in low human-impacted environments.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-11/liliDOI 10.1007/s10646-012-1020-2/lilispanAuthors/spanul
liAngelina Lo Giudice, Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontrés 31, 98166 Messina, Italy/liliPatrizia Casella, Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontrés 31, 98166 Messina, Italy/liliVivia Bruni, Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontrés 31, 98166 Messina, Italy/liliLuigi Michaud, Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontrés 31, 98166 Messina, Italy/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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The effect of pyrogallic acid on growth, oxidative stress, and gene expression in Cylindrospermopsis raciborskii (Cyanobacteria)
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivIn order to investigate the effect of the allelopathic compound pyrogallic acid on iCylindrospermopsis raciborskii/i F2, the impact on growth, oxidative stress and expression of the ipsbA/i, igrpE/i, ifabZ/i, irecA/i, icmpA/i, iftsZ/i and icyrJ/i genes were studied. The results indicated significant decreases in Chl ia/i and cell number following a 24-h incubation with 4nbsp;mgnbsp;Lsup−1/sup pyrogallic acid. Additionally, malodialdehyde content, superoxide dismutase activity and catalase activity were enhanced
following treatment with 2 and 4nbsp;mgnbsp;Lsup−1/sup pyrogallic acid. Expressions of the genes ipsbA/i, igrpE/i, ifabZ/i, irecA/i and icyrJ/i were significantly up-regulated following exposure to 4nbsp;mgnbsp;Lsup−1/sup pyrogallic acid, while no changes were observed with concentrations of 1 or 2nbsp;mgnbsp;Lsup−1/sup. Expression of icmpA/i was significantly down-regulated following treatment with the lowest tested concentration of pyrogallic acid (1nbsp;mgnbsp;Lsup−1/sup), while iftsZ/i was only significantly down-regulated with concentrations of 2 and 4nbsp;mgnbsp;Lsup−1/sup. These results suggest that photosynthesis inhibition and oxidative damage are important modes of action for the allelopathic
effect of pyrogallic acid on iC. raciborskii/i.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1023-z/lilispanAuthors/spanul
liZhongxing Wu, Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, 400715 People’s Republic of China/liliJunqiong Shi, Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, 400715 People’s Republic of China/liliSongqi Yang, Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, 400715 People’s Republic of China/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Periphyton responses to nutrient and atrazine mixtures introduced through agricultural runoff
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivAgricultural runoff often contains pollutants with antagonistic impacts. The individual influence of nutrients and atrazine
on periphyton has been extensively studied, but their impact when introduced together and with multiple agricultural pollutants
is less clear. We simulated a field-scale runoff pulse into a riverine wetland that mimicked pollutant composition typical
of field runoff of the Mississippi River Alluvial Plain. Periphyton biomass and functional responses were measured for 2nbsp;weeks
along a 500nbsp;m section. Additionally, laboratory chamber assays were used to identify potential periphyton changes due to nutrients,
atrazine, and their interactions. Generally, nutrients stimulated, and atrazine reduced chlorophyll ia/i (Chl ia/i) in chambers. In the wetland, nutrient and atrazine relationships with periphyton were weaker, and when found, were often
opposite of trends in chambers. Total nitrogen (TN) was inversely related to Chl ia/i, and total phosphorus was inversely related to respiration (R) rates. Atrazine (10–20nbsp;μgnbsp;Lsup−1/sup in the wetland) had a positive relationship with ash-free dry mass (AFDM), and weakened the relationship between TN and AFDM.
Wetland periphyton biomass was better correlated to total suspended solids than nutrients or atrazine. Periphyton function
was resilient as periphyton gross primary production (GPP)/R ratios were not strongly impacted by runoff. However, whole-system
GPP and R decreased over the 2-week period, suggesting that although periphyton metabolism recovered quickly, whole-system
metabolism took longer to recover. The individual and combined impacts of nutrients and atrazine in complex pollutant mixtures
can vary substantially from their influence when introduced separately, and non-linear impacts can occur with distance downstream
of the pollutant introduction point.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-16/liliDOI 10.1007/s10646-012-1018-9/lilispanAuthors/spanul
liJustin N. Murdock, USDA-Agricultural Research Service, National Sedimentation Laboratory, Oxford, MS 38655, USA/liliF. Douglas Shields Jr., USDA-Agricultural Research Service, National Sedimentation Laboratory, Oxford, MS 38655, USA/liliRichard E. Lizotte Jr., USDA-Agricultural Research Service, National Sedimentation Laboratory, Oxford, MS 38655, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Hormesis on life-history traits: is there such thing as a free lunch?
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivThe term “hormesis†is used to describe dose–response relationships where the response is reversed between low and high doses
of a stressor (generally, stimulation at low doses and inhibition at high ones). A mechanistic explanation is needed to interpret
the relevance of such responses, but there does not appear to be a single universal mechanism underlying hormesis. When the
endpoint is a life-history trait such as growth or reproduction, a stimulation of the response comes with costs in terms of
resources. Organisms have to obey the conservation laws for mass and energy; there is no such thing as a free lunch. Based
on the principles of Dynamic Energy Budget theory, we introduce three categories of explanations for hormesis that obey the
conservation laws: acquisition (i.e., increasing the input of energy into the individual), allocation (i.e., rearranging the
energy flows over various traits) and medication (e.g., the stressor is an essential element or acts as a cure for a disease
or infection). In this discussion paper, we illustrate these explanations with cases where they might apply, and elaborate
on the potential consequences for field populations.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1022-0/lilispanAuthors/spanul
liTjalling Jager, Department of Theoretical Biology, VU University Amsterdam, de Boelelaan 1085, 1081 HV Amsterdam, the Netherlands/liliAlpar Barsi, INRA, Equipe Ecotoxicologie et Qualité des Milieux Aquatiques, UMR985 Ecologie et Santé des Ecosystèmes, INRA-Agrocampus Ouest, 65 rue de Saint Brieuc, 35000 Rennes, France/liliVirginie Ducrot, INRA, Equipe Ecotoxicologie et Qualité des Milieux Aquatiques, UMR985 Ecologie et Santé des Ecosystèmes, INRA-Agrocampus Ouest, 65 rue de Saint Brieuc, 35000 Rennes, France/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Apoptosis induced by para-phenylenediamine involves formation of ROS and activation of p38 and JNK in chang liver cells
Abstract
para -phenylenediamine (p -PD) is a suspected carcinogen, but it has been widely used as a component in permanent hair dyes. In this study, the mechanism of p -PD-induced cell death in normal Chang liver cells was investigated. The results demonstrated that p -PD decreased cell viability in a dose-dependent manner. Cell death via apoptosis was confirmed by enhanced DNA damage and increased cell number in the sub-G1 phase of the cell cycle, using Hoechst 33258 dye staining and flow cytometry analysis. Apoptosis via reactive oxygen species generation was detected by the dichlorofluorescin diacetate staining method. Mitogen-activated protein kinase (MAPK) activation was assessed by western blot analysis and revealed that p -PD activated not only stress-activated protein kinase (SAPK)/c-Jun N-terminal kinases (JNK) and p38 MAPK but also extracellular signal-regulated kinase (ERK). Cytotoxicity and apoptosis induced by p -PD were markedly enhanced by ERK activation and selectively inhibited by ERK inhibitor PD98059, thus indicating a negative role of ERK. In contrast, inhibition of p38 MAPK activity with the p38-specific inhibitor SB203580 moderately inhibited cytotoxicity and apoptosis induction by p -PD. Similarly, SP600125, an inhibitor of SAPK/JNK, moderately inhibited cytotoxicity and apoptosis induced by p -PD, thus implying that p38 MAPK and SAPK/JNK had a partial role in p -PD-induced apoptosis. Western blot analysis revealed that p -PD significantly increased phosphorylation of p38 and SAPK/JNK and decreased phosphorylation of ERK. In conclusion, the results demonstrated that SAPK/JNK and p38 cooperatively participate in apoptosis induced by p -PD and that a decreased ERK signal contributes to growth inhibition or apoptosis. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Exposure to bifenthrin causes immunotoxicity and oxidative stress in male mice
Abstract
Bifenthrin (BF) is one of the most commonly used pesticides among the synthetic pyrethroids. The effects of BF exposure on the induction of immunotoxicity and oxidative stress were studied both in adolescent and adult male ICR mice. Both the weights of the spleen and thymus decreased significantly in the adolescent mice when they were treated with 20 mg/kg BF for 3 weeks. We found that the 3-week oral administration of BF during puberty increased the transcriptional levels of the genes TNF and IL2 in the spleen and IL2 as well as IL4 in the thymus. The effect of BF exposure on the induction of oxidative stress was also studied in serum and liver samples. The total antioxidant capacity and activity of superoxide dismutase were altered significantly in the serum of the 20 mg/kg BF-treated adolescent mice, and the activity of glutathione peroxidase (GPX) decreased significantly in the serum of adolescent and adult mice after 3 weeks of oral administration of 20 mg/kg BF. Compared to serum, hepatic GSH content increased significantly in both the adolescent and adult mice exposed to 20 mg/kg BF; hepatic CAT and GPX activities were altered significantly, even in adolescent mice, after treatment with 10 mg/kg BF. Taken together, the results of this study suggest that exposure to BF, especially during puberty, has the potential to induce immunotoxicity accompanied by oxidative stress in male mice. These findings will help in elucidating the mechanism of toxicity induced by BF in mice. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Role of propolis (bee glue) in improving histopathological changes of the kidney of rat treated with aluminum chloride
Abstract
Humans are frequently exposed to aluminum from various food additives, therapeutic treatments and the environment, and it can be potentially toxic. This study is aimed to elucidate the protective effects of propolis against aluminum chloride (AlCl3 )-induced histopathological and immunohistochemical changes in kidney tissues of rats. Sixty Wistar Albino male rats (average weight 250–300 g) were divided into three equal groups. The first served as a negative control. The second received AlCl3 (34 mg/kg bw, 1/ 25 LD 50). The third were administered AlCl3 (34 mg/kg bw, 1/ 25 LD 50) plus propolis (50 mg/kg bw). Doses were given once daily via a gavage for 8 weeks every day. The results showed that shrunken glomeruli, intraglomerular congestion, loss of apical microvilli, degeneration of mitochondria and widened rough endoplasmic reticulum were also observed in the Proximal Convoluted Tubules of these animals. Treatment with propolis ameliorated the harmful effects of AlCl3 ; this was also proved histopathologically by the noticeable improvement in the renal tissues. There were also significant variations in the expressed of ki-67 and p53 proteins. It can be concluded that propolis may be promising as a natural therapeutic agent in AlCl3 -induced renal toxicity and oxidative stress in rat kidneys. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Chlorpyrifos induced testicular damage in rats: Ameliorative effect of glutathione antioxidant
Abstract
This study investigated the induction of oxidative stress in the testes of adult rats exposed to chlorpyrifos (CPF). CPF was administered orally, in a dose of 30 mg/kg body weight to male rats for 90 days, twice weekly. Coadministration of water-soluble nonenzymatic antioxidant glutathione (GSH) was performed in a dose of 100 mg/kg body weight, orally, for the same period. Another two groups of male rats were administered GSH and corn oil, respectively. The activities of superoxide dismutase and GSH reductase were decreased while the levels of lipid peroxidation were increased in the testicular tissues of the exposed animals. Testosterone level in the serum was significantly decreased. A decrease in the histochemical determination of testicular alkaline phosphatase was observed in CPF-treated rats. A significant decrease in all stages of spermatogenesis in the seminiferous tubules was recorded in the exposed animals. Coadministration of GSH restored these parameters. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Interspecific effects of 4A-DNT (4-amino-2,6-dinitrotoluene) and RDX (1,3,5-trinitro-1,3,5-triazine) in Japanese quail, Northern bobwhite, and Zebra finch
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivThe purpose of this study was to assess the toxicological effects of two munition compounds, 4-amino-2,6-dinitrotoluene (4A-DNT)
and 1,3,5-trinitro-1,3,5-triazine (RDX), on three different bird species: two common toxicological model species—the Northern
Bobwhite (iColinus virginianus/i) and the Japanese Quail (iCoturnix japonica/i), and a representative passerine—the Zebra Finch (iTaeniopygia guttata/i). Bobwhite were exposed to 4A-DNT at 0, 8, 15, 30, 60, or 150nbsp;mg/kg body weight (bw)nbsp;d by oral gavage for seven days; because
the high dose of 4A-DNT was lethal to bobwhite, the maximum dose was changed to 100nbsp;mg/kg bwnbsp;d for Japanese quail and finches
to ensure tissue could be used for future toxicogenomic work. RDX was similarly administered at 0, 0.5, 1.5, 3, 6, or 12nbsp;mg/kg
bwnbsp;d. Blood was drawn prior to euthanasia for blood cellularity and chemistry analyses. Finches were clearly least affected
by 4A-DNT as evidenced by a lack of observable effects. Bobwhite appeared to be the most sensitive species to 4A-DNT as observed
through changes in blood cellularity and plasma chemistry effects. Bobwhite appeared to be more sensitive to RDX than Japanese
Quail due to increased effects on measures of plasma chemistries. Finches exhibited the greatest sensitivity to RDX through
increased mortality and seizure activity. This study suggests that sensitivity among species is chemical-specific and provides
data that could be used to refine current avian sensitivity models used in ecological risk assessments.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-9/liliDOI 10.1007/s10646-012-1019-8/lilispanAuthors/spanul
liMichael J. Quinn, U.S. Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD 21010, USA/liliTerry L. Hanna, U.S. Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD 21010, USA/liliAlicia A. Shiflett, U.S. Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD 21010, USA/liliCraig A. McFarland, U.S. Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD 21010, USA/liliMichelle E. Cook, Oak Ridge Institute of Science and Education, Oak Ridge, TN 37830, USA/liliMark S. Johnson, U.S. Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD 21010, USA/liliKurt A. Gust, U.S. Army Corps of Engineers, Engineer Research Development Center, Vicksburg, MS 39180, USA/liliEdward J. Perkins, U.S. Army Corps of Engineers, Engineer Research Development Center, Vicksburg, MS 39180, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Effects of a bioassay-derived ivermectin lowest observed effect concentration on life-cycle traits of the nematode Caenorhabditis elegans
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivThe pharmaceutical ivermectin is used to treat parasitic infections, such as those caused by nematodes. While several studies
have demonstrated the severe effects of ivermectin on non-target organisms, little is known about the drug’s impact on free-living
nematodes. In the present work, a full life-cycle experiment was conducted to estimate how an ivermectin lowest observed effect
concentration derived from a iCaenorhabditis elegans/i bioassay (endpoint reproduction) might translate into effects at the population level of this free-living nematode. The results
showed that fecundity decreased to levels similar to those determined in the bioassay after a time of corresponding duration
(18.6nbsp;% inhibition compared to the control), but the impact then rather weakened until the end of the experiment, at which
point the net reproductive rate (Rsub0/sub) was still, but not significantly, reduced by 12.4nbsp;%. Moreover, the average lifespan, length of the reproductive period,
maximum daily reproduction rate, and intrinsic rate of increase (rsubm/sub) were significantly reduced by 30.0, 25.9, 11.2, and 3.5nbsp;%, respectively. The experiment revealed that a 4-day bioassay is
protective enough for iC. elegans/i with respect to ivermectin’s effects on fecundity. However, the pronounced effects of a low drug concentration on survival,
a highly elastic trait, may better account for the observed population-level response, i.e., a decrease of rsubm/sub, than the effects on fecundity. These results emphasize that full life-cycle experiments are valuable for assessment of pollutants,
because the effects on several life-cycle traits can be simultaneously measured and integrated into an ecologically relevant
parameter, the population growth rate, that reflects a population’s response to a specific pollutant.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1011-3/lilispanAuthors/spanul
liMarvin Brinke, Department of Animal Ecology, University of Bielefeld, Morgenbreede 45, 33615 Bielefeld, Germany/liliPeter Heininger, Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz, Germany/liliWalter Traunspurger, Department of Animal Ecology, University of Bielefeld, Morgenbreede 45, 33615 Bielefeld, Germany/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Toxic effects, uptake, and translocation of Cd and Pb in perennial ryegrass
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivCadmium (Cd) and lead (Pb) are regarded as the most toxic environmental pollutants because they are a threat not only to plants,
but also to humans. Better understanding of the growth response, uptake and translocation of Cd and Pb in perennial ryegrass
(iLolium perenne/i L.) would be helpful to evaluate the role of this grass species as a potential candidate used for phyto-remediation. Perennial
ryegrass seedlings were subjected to three Pb levels (0, 0.5, and 3.2nbsp;mM) for 6nbsp;days and three Cd levels (0, 0.2, and 0.5nbsp;mM)
for 7nbsp;days in a walk-in growth room. The Cd and Pb reduced the normalized transpiration and growth rate. Greater amount of
Cd and Pb accumulated in roots relative to shoots. The enrichment coefficient (EC) and translocation factor (TF) were greater
in plants treated with Cd than those with Pb. The dose of Cd had no effect on EC and TF. However, the plants subjected to
higher dose of Pb had a greater TF and a lower EC relative to that with lower dose of Pb. Meanwhile, removal rates were decreased
when the doses of Pb and Cd increased. The results indicated that perennial ryegrass preferred Cd assimilation to Pb, and
can be considered as one of the plant species which accumulate high levels of Cd and Pb.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1017-x/lilispanAuthors/spanul
liYanhong Lou, Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan, 430074 Hubei, People’s Republic of China/liliHongji Luo, Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan, 430074 Hubei, People’s Republic of China/liliTao Hu, Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan, 430074 Hubei, People’s Republic of China/liliHuiying Li, Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan, 430074 Hubei, People’s Republic of China/liliJinmin Fu, Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan, 430074 Hubei, People’s Republic of China/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Effects of pyrene exposure and temperature on early development of two co-existing Arctic copepods
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivOil exploration is expected to increase in the near future in Western Greenland. At present, effects of exposure to oil compounds
on early life-stages of the ecologically important iCalanus/i spp. are unknown. We investigated the effects of the oil compound pyrene, on egg hatching and naupliar development of the
calanoid copepods iCalanus glacialis/i and iC. finmarchicus/i, two key species in the Disko Bay, Western Greenland. At low temperature the nauplii of iC. glacialis/i experienced reduced growth when exposed to pyrene, and survival in both species decreased. Naupliar mortality increased with
temperature at high pyrene concentration in iC. finmarchicus/i. Both iCalanus/i species were affected by pyrene exposure but iC. finmarchicus/i was more sensitive compared to iC. glacialis/i. Lowered growth rate and increased mortality of the naupliar stages entail reduced recruitment to copepod populations. Exposure
to pyrene from an oil spill may reduce the standing stock of iCalanus/i, which can lead to less energy available to higher trophic levels in the Arctic marine food web.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-15/liliDOI 10.1007/s10646-012-1016-y/lilispanAuthors/spanul
liJulie Cornelius Grenvald, Section of Oceanecology and Climate, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920 Charlottenlund, Denmark/liliTorkel Gissel Nielsen, Section of Oceanecology and Climate, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920 Charlottenlund, Denmark/liliMorten Hjorth, Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Thyroid disruption in the lizard Podarcis bocagei exposed to a mixture of herbicides: a field study
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivPesticide exposure has been related with thyroid disrupting effects in different vertebrate species. However, very little
is known about the effects of these compounds in reptiles. In the Mediterranean area, lacertid lizards are the most abundant
vertebrate group in agroecosystems, and have been identified as potential model species for reptile ecotoxicology. The aim
of this study was to understand if the herbicides applied in corn fields have thyroid disruptive effects in the lizard iPodarcis bocagei/i. Adult male lizards were captured in north-western Portugal in corn fields treated with herbicides (exposed sites), and in
organic agricultural fields (reference sites). Thyroid and male gonad morphology and functionality, and testosterone levels
were investigated through histological, immunohistochemical and biochemical techniques. Lizards from exposed locations displayed
thyroid follicular lumens with more reabsorption vacuoles and significantly larger follicular area than those from reference
fields. Furthermore, testes of lizards from exposed locations had significantly larger seminiferous tubule diameters, significantly
higher number of spermatogenic layers and displayed an up-regulation of thyroid hormone receptors when compared with lizards
from reference areas. These findings strongly suggest that the complex mixture of herbicides that lizards are exposed to in
agricultural areas have thyroid disrupting effects which ultimately affect the male reproductive system. Alachlor, which has
demonstrated thyroid effects in mammals, may be largely responsible for the observed effects.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-10/liliDOI 10.1007/s10646-012-1012-2/lilispanAuthors/spanul
liRita C. Bicho, CESAM Departmento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliMaria José Amaral, CESAM Departmento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliAugusto M. R. Faustino, Departamento de Patologia e Imunologia Molecular, ICBAS, Universidade do Porto, 4050-123 Porto, Portugal/liliDeborah M. Power, Centro de Ciências do Mar (CCMAR), Campus de Gambelas, Universidade do Algarve, 8005-139 Faro, Portugal/liliAlexandra Rêma, Departamento de Patologia e Imunologia Molecular, ICBAS, Universidade do Porto, 4050-123 Porto, Portugal/liliMiguel A. Carretero, CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto Campus Agrário de Vairão, 4485-661 Vairão, Portugal/liliAmadeu M. V. M. Soares, CESAM Departmento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliReinier M. Mann, CESAM Departmento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Drosophila melanogaster as a model to characterize fungal volatile organic compounds
Abstract
Fungi are implicated in poor indoor air quality and may pose a potential risk factor for building/mold related illnesses. Fungi emit numerous volatile organic compounds (VOCs) as alcohols, esters, ethers, ketones, aldehydes, terpenoids, thiols, and their derivatives. The toxicity profile of these VOCs has never been explored in a model organism, which could enable the performance of high throughput toxicological assays and lead to a better understanding of the mechanism of toxicity. We have established a reductionist Drosophila melanogaster model to evaluate the toxicity of fungal VOCs. In this report, we assessed the toxicity of fungal VOCs emitted from living cultures of species in the genera, Trichoderma , Aspergillus , and Penicillium and observed a detrimental effect on larval survival. We then used chemical standards of selected fungal VOCs to assess their toxicity on larval and adult Drosophila . We compared the survival of adult flies exposed to these fungal VOCs with known industrial toxic chemicals (formaldehyde [37%], xylene, benzene, and toluene). Among the tested fungal VOC standards, the compounds with eight carbons (C8) caused greater truncation of fly lifespan than tested non-C8 fungal VOCs and industrial toxins. Our data validate the use of Drosophila melanogaster as a model with the potential to elucidate the mechanistic attributes of different toxic VOCs emitted by fungi and also to explore the potential link between reported human illnesses/symptoms and exposure to water damaged and mold contaminated buildings. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Gene expression profile in chronic mouse liver injury caused by long-term exposure to CeCl3
Abstract
Numerous studies have demonstrated lanthanide (Ln) accumulation in the liver, and the corresponding damage; however, very little work has been done to evaluate the relationship between Ln-induced liver injury and its gene expression profile in mice. In this study, liver injury and gene-expressed profiles in male mice induced by oral administration of CeCl3 (2 mg/kg) via gavage for 90 consecutive days were investigated. The results showed that cerium accumulation, liver inflammation, and hepatocyte necrosis were observed. CeCl3 exposure significantly decreased the counts of white blood cells, lymphocyte, and platelet, the reticulocyte count (Ret) and neutrophilic granulocyte percentages as well as A/G ratio, whereas markedly increased the activities of alkaline phosphatase, lactate dehydrogenase, and cholinesterase, and the concentrations of triglycerides and total cholesterol. Furthermore, microarray results of liver showed that the differential expression of 675 known function genes involved in immune/inflammation response, apoptosis, metabolic process, cell cycle, cell proliferation, cytoskeleton, oxidative stress, signal transduction, transcription, translation, and transportation in CeCl3 exposed livers, respectively. Specifically, the significant downregulation of Nt5e led to inflammation, overexpressed Cyp4a12a and great suppression of Cdkn1a resulted in hepatocyte apoptosis, marked elevation of Cel, and Cyp7b1 expression caused the metabolic disorders in mouse liver after long-term CeCl3 exposure. Therefore, these genes may be in great relation to liver damages induced by exposure to CeCl3 . © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Alleviation effects of magnesium on copper toxicity and accumulation in grapevine roots evaluated with biotic ligand models
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivCopper toxicity and accumulation in plants are affected by physicochemical characteristics of soil solutions such as the concentrations
of coexistent cations (e.g., Casup2+/sup, Mgsup2+/sup, Ksup+/sup, Nasup+/sup, and Hsup+/sup). The biotic ligand model (BLM) approach has been proposed to predict metal phyto-toxicity and -accumulation by taking into
account the effects of coexistent cations, given the assumption of the partition equilibrium of metal ions between soil solution
and solid phase. The alleviation effects of Mg on Cu toxicity and accumulation in grapevine roots were the main concerns in
this study and were investigated by using a hydroponic experiment of grapevine cuttings. The BLM approach, which incorporated
competition of Mgsup2+/sup with Cusup2+/sup to occupy the biotic ligands on root surfaces, was developed to predict Cu rhizotoxicity and accumulation by grapevine roots.
In the results, the effective activity of Cu, {iCu/i
sup2+/sup}, resulting in a 50nbsp;% reduction of root elongation (iEA/i
sub50/sub), linearly increased with increments of Mg activity, {iMg/i
sup2+/sup}. In addition, the Cu concentration in root, iCu/i
sub
iroot/i
/sub, was retarded by an increase of {iMg/i
sup2+/sup}. The linear model was significantly fitted to the relationship between {iCu/i
sup2+/sup}/iCu/i
sub
iroot/i
/sub and {iMg/i
sup2+/sup}. According to the concept of BLM, the present results revealed that the amelioration effects of Mg on Cu toxicity and accumulation
in roots could arise from competition between Mgsup2+/sup and Cusup2+/sup on the binding sites (i.e., the biotic ligands). Then, the developed Cu-BLMs incorporating the Mgsup2+/sup competition effectiveness were validated provide accurate predictions of Cu toxicity and accumulation in grapevine roots.
To our knowledge this is the first report of the successful development of BLMs for a woody plant. This BLM approach shows
promise of being widely applicable for various terrestrial plants.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-10/liliDOI 10.1007/s10646-012-1015-z/lilispanAuthors/spanul
liBo-Ching Chen, Department of Post-Modern Agriculture, MingDao University, No. 369, Wenhua Rd., Peetow, Changhua, 52345 Taiwan/liliPei-Chi Ho, Department of Agronomy, National Chiayi University, No. 300, Syuefu Rd., Chiayi, 60004 Taiwan/liliKai-Wei Juang, Department of Agronomy, National Chiayi University, No. 300, Syuefu Rd., Chiayi, 60004 Taiwan/li
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The effect of copper on different phototrophic microorganisms determined in vivo and at cellular level by confocal laser microscopy
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivMicrobial mats are coastal ecosystems that consist mainly of cyanobacteria, primary producers in these habitats that play
an important role in stabilising delta sediments. However, these ecosystems are subject to various kinds of pollution, including
metal contamination, placing their survival at risk. Among heavy metals, copper is an essential metal at low doses and toxic
at high doses. This metal is present in different pesticides used in rice production, a thriving agro-industry in the Ebro
Delta (Spain). For several years, our group has been studying the Ebro Delta microbial mats and has developed a method for
determining the effect that metals cause on cyanobacteria populations. This method is based on confocal laser microscopy coupled
to a spectrofluorometer, which rapidly provides simultaneous three-dimensional information on photosynthetic microorganisms
and their fluorescence spectra profiles. The current study determines the copper effect on different photosynthetic microorganisms
from culture collection (iChroococcus/i sp. PCC 9106 and iSpirulina/i sp. PCC 6313) and isolated from the environment (iMicrocoleus/i-like and the microalga DE2009). Comparing all results obtained it can be observed that the minimum dose of Cu that is capable
of significantly altering chlorophyll ia/i (chl ia/i) fluorescence intensity were 1nbsp;×nbsp;10sup−7/sup M in iChroococcus/i sp. PCC 9106; 1nbsp;×nbsp;10sup−7/sup M in iSpirulina/i sp. PCC 6313; 3nbsp;×nbsp;10sup−7/sup M in iMicrocoleus/i and 5nbsp;×nbsp;10sup−6/sup M in the microalga DE2009. Moreover, the sensitivity of the technique used was 1nbsp;×nbsp;10sup−7/sup M.
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lispanContent Type /spanspanJournal Article/span/liliCategory Technical Note/liliPages 1-7/liliDOI 10.1007/s10646-012-1014-0/lilispanAuthors/spanul
liM. Seder-Colomina, Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Bellaterra), Barcelona, Spain/liliA. Burgos, Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Bellaterra), Barcelona, Spain/liliJ. Maldonado, Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Bellaterra), Barcelona, Spain/liliA. Solé, Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Bellaterra), Barcelona, Spain/liliI. Esteve, Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Bellaterra), Barcelona, Spain/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Sensitivity of early life stages of white sturgeon, rainbow trout, and fathead minnow to copper
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivPopulations of white sturgeon (WS; iAcipenser transmontanus/i) are in decline in several parts of the United States and Canada, attributed primarily to poor recruitment caused by degradation
of habitats, including pollution with contaminants such as metals. Little is known about sensitivity of WS to contaminants
or metals such as copper (Cu). Here, acute (96nbsp;h) mortalities of WS early life stages due to exposure to Cu under laboratory
conditions are reported. Two standard test species, rainbow trout (iOncorhynchus mykiss/i) and fathead minnow (iPimephales promelas/i), were exposed in parallel to determine relative sensitivity among species. Swim-up larvae [15nbsp;days post-hatch (dph)] and
early juveniles (40–45nbsp;dph) of WS were more sensitive to Cu (LCsub50/subnbsp;=nbsp;10 and 9–17nbsp;μg/L, respectively) than were yolksac larvae (8nbsp;dph; LCsub50/subnbsp;=nbsp;22nbsp;μg/L) and the later juvenile life stage (100nbsp;dph; LCsub50/subnbsp;=nbsp;54nbsp;μg/L). WS were more sensitive to Cu than rainbow trout and fathead minnow at all comparable life stages tested. Yolksac
larvae of rainbow trout and fathead minnow were 1.8 and 4.6 times, respectively, more tolerant than WS, while swim-up and
juvenile life stages of rainbow trout were between 1.4- and 2.4-times more tolerant than WS. When plotted in a species sensitivity
distribution with other fishes, the mean acute toxicity value for early life stage WS was ranked between the 1st and 2nd centile.
The WS life stage of greatest Cu sensitivity coincides with the beginning of active feeding and close association with sediment,
possibly increasing risk. WS early life stages are sensitive to aqueous copper exposure and site-specific water quality guidelines
and criteria should be evaluated closely to ensure adequate protection.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-9/liliDOI 10.1007/s10646-012-1010-4/lilispanAuthors/spanul
liDavid W. Vardy, Toxicology Centre, University of Saskatchewan, 44 Campus Dr., Saskatoon, SK S7N 5B3, Canada/liliJohanna Oellers, Institute for Environmental Research, RWTH University, Aachen, Germany/liliJon A. Doering, Toxicology Centre, University of Saskatchewan, 44 Campus Dr., Saskatoon, SK S7N 5B3, Canada/liliHenner Hollert, Institute for Environmental Research, RWTH University, Aachen, Germany/liliJohn P. Giesy, Toxicology Centre, University of Saskatchewan, 44 Campus Dr., Saskatoon, SK S7N 5B3, Canada/liliMarkus Hecker, Toxicology Centre, University of Saskatchewan, 44 Campus Dr., Saskatoon, SK S7N 5B3, Canada/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Cadmium chelation by frustulins: a novel metal tolerance mechanism in Nitzschia palea (Kützing) W. Smith
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivThe ubiquity of diatom distribution, species richness, short generation time, and specific sensitivity to several environmental
stressors such as metals, make diatoms particularly useful for scientific studies. Anthropogenic activities have increased
the concentration of metals in air, soil and water. Due to their toxicity and persistent character, the effects of metals
on organisms have been extensively studied. In this work, the association of cadmium to different extracellular molecules
of iNitzschia palea/i cells was investigated. Cells were grown in the absence and presence (0.2nbsp;mgnbsp;lsup−1/sup) of cadmium in Chu no. 10 medium. Extracellular polysaccharides were extracted, and subsamples were used for polysaccharide
and Cd determination. The frustules were broken mechanically under liquid nitrogen and the intracellular and frustule fractions
separated. Frustulins, a protein family found on the outmost frustule layer, constituting a protection coating to environmental
stress, were extracted. In each fraction proteins were quantified by the BCA method and separated by gel electrophoresis (SDS-PAGE).
Cadmium associated to each fraction was quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis. Exposure
of iNitzschia palea/i to cadmium decreased extracellular polysaccharides by 52.8nbsp;% and increased 6 times the amount of frustulins. Cadmium was
mostly retained extracellularly: 85.4nbsp;% was bound to the frustulin fraction, and 11.1nbsp;% to polysaccharides. The ability of
iNitzschia palea/i to increase the production of frustulins due to the presence of Cd, the extracellular location of this frustulin coating
and the ability of these proteins to bind Cd, suggests a new cellular defense mechanism to metals unknown until now.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1013-1/lilispanAuthors/spanul
liJosé Santos, Biology Department, and CBC (Centro de Biologia Celular), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/liliSalomé F. P. Almeida, Biology Department, and GeoBioTec (GeoBioSciences, GeoTechnologies and GeoEngineering Research Center), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/liliEtelvina Figueira, Biology Department, and CBC (Centro de Biologia Celular), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Exposure of pregnant mice to chlorpyrifos-methyl alters embryonic H19 gene methylation patterns
Abstract
The aim of this study was to identify whether chlorpyrifos methyl (CPM) exposure during pregnancy leads to changes in the methylation patterns of H19 gene. CPM 4, 20, 100 mg/kg bw/day was administered to 4 pregnant mice per group between 7 and 12 days post coitum (d.p.c.). Pregnant mice were killed at 13 d.p.c. The genomic methylation in primordial germ cells (PGCs) and fetal organs (the liver, intestine, and placenta) was examined. Four polymorphism sites in the H19 alleles of maternal (C57BL/6J) and paternal (CAST/Ei) alleles were identified at nucleotide position 1407, 1485, 1566, and 1654. The methylation patterns of 17 CpG sites were analyzed. The methylation level in male and female PGCs was not altered by CPM treatment in the maternal allele H19 . The methylation level of the paternal H19 allele was altered in only male PGCs in response to the CPM treatment. The methylation level at a binding site for the transcriptional regulator CTCF2 was higher than that at the CTCF1 binding site in all CPM-treated groups. In the placenta, the aggregate methylation level of H19 was 56.89%in control group. But, those levels were ranged from 47.7% to 49.89% after treatment with increasing doses of CPM. H19 gene from the liver and intestine of 13 d.p.c. fetuses treated with CPM was hypomethylated as compared with controls, although H19 mRNA expression was unaltered. In the placenta, H19 expression was slightly increased in the CPM-treated group, although not significantly. IGF2 expression levels were not significantly changed in the placenta. In conclusion, CPM exposure during pregnancy alters the methylation status of the H19 gene in PGCs and embryonic tissues. We infer that these alterations are likely related to changes in DNA demethylase activity. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Comparative effect of technical and commercial formulations of methamidophos on sperm quality and dna integrity in mice
Abstract
Methamidophos (MET), widely used in developing countries, is a highly neurotoxic organophosphate pesticide that has been associated with male reproductive alterations. Commercial formulations of pesticides used by agricultural workers and urban sprayers are responsible for thousands of intoxications in developing countries and may not have the same effects as active pure ingredients. Therefore, we compared effects of MET technical (METt) and commercial (METc) grades on sperm quality and DNA integrity. Male mice were injected (intraperitoneal, i.p.) with METt or METc (3.75, 5, and 7 mg/kg bw/day/4 days) and sacrificed 24 h post-treatment. Sperm cells collected from epididymis–vas deferens were evaluated for quality parameters, DNA damage by the comet assay, and lipoperoxidation by malondialdehyde (MDA) production. Erythrocyte acetylcholinesterase (AChE) activity was evaluated by acetylthiocholine inhibition as an index of overall toxicity. A dose-dependent AChE inhibition was observed with both formulations. Sperm quality was decreased after treatment with both MET compounds, but the commercial formulation showed stronger effects; a similar profile was observed with the DNA damage, being METc more genotoxic. None MET formulation increased MDA, suggesting no peroxidative damage involved. In summary, the commercial formulation of MET was more reprotoxic and genotoxic than the active pure ingredient, highlighting that commercial formulations must be considered for more appropriate risk assessment of pesticide exposures. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Biomarker responses in caged carp (Cyprinuscarpio) and native collected fish (Leporinus obtusidens) in the rÃo de la plata estuary, argentina
Abstract
Punta Lara is located in the RÃo de la Plata estuary near industrial areas contaminated mainly by organic pollutants. In this work, the responses and status of hepatic biomarkers were studied in juvenile carp (Cyprinus carpio ) by means of a 21-day field exposure in cages and collection of juvenile native fish (Leporinus obtusidens ) at Punta Lara. The analyzed hepatic biomarkers were: enzymatic activity of glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD), lipid peroxidation level using the thiobarbituric acid reaction (TBARS), and CYP1A protein expression, condition factor (CF) and liver somatic (LSI) index. Taking into account oxidative stress responses, SOD activity was increased in both species, while CAT was increased in C. carpio and decreased in L. obtusidens ; TBARS levels indicated that oxidative damage was possibly exerted only in L. obtusidens . Biotransformation responses mediated by CYP1A were observed in both species, while GST activity was induced mainly in carps. Considering morphometric indices, CF and LSI were significantly increased in carps while CF decreased in native species. The anthropogenic pollution detected in this study in Punta Lara was associated with differences in biomarkers on both fish species, although a different pattern of response was observed. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Carbon and clay nanoparticles induce minimal stress responses in gram negative bacteria and eukaryotic fish cells
Abstract
We investigated in vitro the potential mutagenic and toxic effects of two clay-based nanoparticles, Cloisite® Na+ (Cloisite) and halloysite; and multi-walled carbon nanotubes (MWCNT), commonly used in the polymer composite industry. Using the Ames test, the three nanoparticles did not have a true mutagenic effect, although growth of Salmonella enterica var. Typhimurium (S. typhimurium ) was diminished at higher nanoparticle concentrations. We investigated the impact of nanoparticles on Escherichia coli and S. typhimurium including oxyR and rpoS mutants, which are susceptible to oxidative stress. The oxyR mutants were inhibited in the presence of nanoparticles, when grown aerobically with light. Toxicity was not observed in the absence of light or during anaerobic growth. E. coli rpoS mutants exhibited some toxicity when cultured with Cloisite and MWCNT only when grown aerobically with light. There was no effect with other nanoparticles, or with S. typhimurium rpoS mutants. MWCNT exhibited a slight toxic effect against Epithelioma papulosum cyprini (EPC) cells only at the highest concentration tested. There was no discernable toxicity to EPC cells caused by the clay nanoparticles. We conclude that clay-based nanoparticles and MWCNT do not exert a mutagenic effect and do not have a general toxic effect across all bacterial species or between prokaryotic and eukaryotic cells. Modest toxicity was only observed in eukaryotic EPC cells against MWCNT at the highest concentration tested. Limited species-specific toxicity to clay based and MWCNT nanoparticles was seen in bacterial strains primarily due to culture conditions and mutations that exacerbate oxidative stress. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Experimental exposure of red-legged partridges (Alectoris rufa) to seeds coated with imidacloprid, thiram and difenoconazole
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivPesticide coated seeds are commonly used in agriculture, and may be an important source of food for some birds in times of
scarcity, as well as a route of pesticide ingestion. We tested the lethal and sub-lethal effects of treated seed ingestion
by the red-legged partridge (iAlectoris rufa/i), a game bird of high socio-economic value in Spain. One year-old partridges (in/inbsp;=nbsp;42 pairs) were fed for 10nbsp;days in spring (prior to breeding) with wheat treated with difenoconazole (fungicide), thiram
(fungicide) or imidacloprid (insecticide), using two doses for each pesticide (the one recommended, and its double to represent
potential cases of abuse of pesticides). We investigated the direct and indirect effects on the body condition, physiology,
immunology, coloration and subsequent reproduction of exposed partridges. For the latter, eggs were collected, measured and
incubated and the growth and survival of chicks were monitored. Thiram and imidacloprid at high exposure doses produced mortalities
of 41.6 and 58.3nbsp;%, respectively. The first death was observed at day 3 for imidacloprid and at day 7 for thiram. Both doses
of the three pesticides caused sublethal effects, such as altered biochemical parameters, oxidative stress and reduced carotenoid-based
coloration. The high exposure doses of imidacloprid and thiram also produced a decrease in cellular immune response measured
by the phytohemagglutinin test in males. Bearing in mind the limitation of the small number of surviving pairs in some treatments,
we found that the three pesticides reduced the size of eggs and imidacloprid and difenoconazole also reduced the fertilization
rate. In addition, both thiram and imidacloprid reduced chick survival. These experiments highlight that the toxicity of pesticide-treated
seeds is a factor to consider in the decline of birds in agricultural environments.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-14/liliDOI 10.1007/s10646-012-1009-x/lilispanAuthors/spanul
liAna Lopez-Antia, Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13071 Ciudad Real, Spain/liliManuel E. Ortiz-Santaliestra, Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13071 Ciudad Real, Spain/liliFrançois Mougeot, Estación Experimental de Zonas Ãridas (EEZA), CSIC, Ctra. de Sacramento s/n La Cañada de San Urbano, 04120 AlmerÃa, Spain/liliRafael Mateo, Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13071 Ciudad Real, Spain/li
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Influence of dietary carbon on mercury bioaccumulation in streams of the Adirondack Mountains of New York and the Coastal Plain of South Carolina, USA
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivWe studied lower food webs in streams of two mercury-sensitive regions to determine whether variations in consumer foraging
strategy and resultant dietary carbon signatures accounted for observed within-site and among-site variations in consumer
mercury concentration. We collected macroinvertebrates (primary consumers and predators) and selected forage fishes from three
sites in the Adirondack Mountains of New York, and three sites in the Coastal Plain of South Carolina, for analysis of mercury
(Hg) and stable isotopes of carbon (δsup13/supC) and nitrogen (δsup15/supN). Among primary consumers, scrapers and filterers had higher MeHg and more depleted δsup13/supC than shredders from the same site. Variation in δsup13/supC accounted for up to 34nbsp;% of within-site variation in MeHg among primary consumers, beyond that explained by δsup15/supN, an indicator of trophic position. Consumer δsup13/supC accounted for 10nbsp;% of the variation in Hg among predatory macroinvertebrates and forage fishes across these six sites, after
accounting for environmental aqueous methylmercury (MeHg, 5nbsp;% of variation) and base-N adjusted consumer trophic position
(Δδsup15/supN, 22nbsp;% of variation). The δsup13/supC spatial pattern within consumer taxa groups corresponded to differences in benthic habitat shading among sites. Consumers
from relatively more-shaded sites had more enriched δsup13/supC that was more similar to typical detrital δsup13/supC, while those from the relatively more-open sites had more depleted δsup13/supC. Although we could not clearly attribute these differences strictly to differences in assimilation of carbon from terrestrial
or in-channel sources, greater potential for benthic primary production at more open sites might play a role. We found significant
variation among consumers within and among sites in carbon source; this may be related to within-site differences in diet
and foraging habitat, and to among-site differences in environmental conditions that influence primary production. These observations
suggest that different foraging strategies and habitats influence MeHg bioaccumulation in streams, even at relatively small
spatial scales. Such influence must be considered when selecting lower trophic level consumers as sentinels of MeHg bioaccumulation
for comparison within and among sites.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-12/liliDOI 10.1007/s10646-012-1003-3/lilispanAuthors/spanul
liKaren Riva-Murray, U.S. Geological Survey, 425 Jordan Road, Troy, NY 12180, USA/liliPaul M. Bradley, U.S. Geological Survey, Columbia, SC, USA/liliLia C. Chasar, U.S. Geological Survey, Tallahassee, FL, USA/liliDaniel T. Button, U.S. Geological Survey, Columbus, OH, USA/liliMark E. Brigham, U.S. Geological Survey, Mounds View, MN, USA/liliBarbara C. Scudder Eikenberry, U.S. Geological Survey, Middleton, WI, USA/liliCeleste A. Journey, U.S. Geological Survey, Columbia, SC, USA/liliMichelle A. Lutz, U.S. Geological Survey, Middleton, WI, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Costs of living in metal polluted areas: respiration rate of the ground beetle Pterostichus oblongopunctatus from two gradients of metal pollution
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivTo address the question about costs of living in polluted areas, biomarkers linked to metabolism were measured in iPterostichus oblongopunctatus/i (Coleoptera: Carabidae) collected along two metal-pollution gradients in the vicinity of the two largest Polish zinc smelters:
‘Bolesław’ and ‘Miasteczko Śląskie’ in southern Poland. Both gradients covered a broad range of Zn and Cd concentrations in
the humus layer (109–6151 and 1.48–71.4nbsp;mgnbsp;kgsup−1/sup, respectively) and body metal concentrations increased with increasing soil metal concentrations. The whole-organism respiration
rate was measured as oxygen consumption with Micro-Oxymax respirometer, and cellular energy consumption—as the activity of
electron transport system, which is linked to cellular respiration rate. The significant increase in the whole-organism respiration
rate with the body metal concentration was found when taking into account other factors such as body mass, gradient (or year
of sampling as the beetles were collected on the gradients in different years) and the interactions: body metal concentrationsnbsp;×nbsp;collection
date, body metal concentrationsnbsp;×nbsp;body mass, and body massnbsp;×nbsp;gradient/sampling year. However, no relationships between metal
concentrations in soil or body metal concentrations and the whole-organism or cellular respiration rate could be detected
when using mean values per site, underlining the crucial importance of incorporating individual variability in such analyses.
The observed increase of the whole-organism respiration rate with increasing body contamination with metals suggests that
iP. oblongopunctatus/i incurs energetic expenditures resulting from the necessity to facilitate metal elimination or repair of toxicant-induced
damage.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-7/liliDOI 10.1007/s10646-012-1008-y/lilispanAuthors/spanul
liAgnieszka J. Bednarska, Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland/liliIzabela Stachowicz, Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland/li
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Assessing bioavailability and toxicity of permethrin and DDT in sediment using matrix solid phase microextraction
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivMatrix solid phase microextraction (matrix-SPME) was evaluated as a surrogate for the absorbed dose in organisms to estimate
bioavailability and toxicity of permethrin and dichlorodiphenyltrichloroethane (DDT) in laboratory-spiked sediment. Sediments
were incubated for 7, 28, and 90nbsp;days at room temperature to characterize the effect of aging on bioavailability and toxicity.
Sediment toxicity was assessed using two freshwater invertebrates, the midge iChironomus dilutus/i and amphipod iHyalella azteca/i. Disposable polydimethylsiloxane fibers were used to estimate the absorbed dose in organisms and to examine bioavailability
and toxicity. The equilibrium fiber concentrations substantially decreased with an increase in sediment aging time, indicating
a reduction in bioavailability. Based on median lethal fiber concentrations (fiber LC50), toxicity of permethrin was not significantly
different among the different aging times. Due to the substantial degradation of DDT to dichlorodiphenyldichloroethane (DDD)
in sediment, sediment toxicity to iC. dilutus/i increased, while it decreased for iH. azteca/i with extended aging times. A toxic unit-based fiber LC50 value represented the DDT mixture (DDT and DDD) toxicity for both
species. Significant linear relationships were found between organism body residues and the equilibrium fiber concentrations
for each compound, across aging times. The study suggested that the matrix-SPME fibers mimicked bioaccumulation in the organisms,
and enabled estimation of body residues, and could potentially be used in environmental risk assessment across matrices (e.g.
sediment and water) to measure bioavailability and toxicity of hydrophobic pesticides.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-9/liliDOI 10.1007/s10646-012-1007-z/lilispanAuthors/spanul
liYuping Ding, Fisheries and Illinois Aquaculture Center, Department of Zoology, Southern Illinois University, Carbondale, IL 62901, USA/liliPeter F. Landrum, Fisheries and Illinois Aquaculture Center, Department of Zoology, Southern Illinois University, Carbondale, IL 62901, USA/liliJing You, State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640 China/liliMichael J. Lydy, Fisheries and Illinois Aquaculture Center, Department of Zoology, Southern Illinois University, Carbondale, IL 62901, USA/li
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Use of transgenic GFP reporter strains of the nematode Caenorhabditis elegans to investigate the patterns of stress responses induced by pesticides and by organic extracts from agricultural soils
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivAs a free-living nematode, iC. elegans/i is exposed to various pesticides used in agriculture, as well as to persistent organic residues which may contaminate the
soil for long periods. Following on from our previous study of metal effects on 24 GFP-reporter strains representing four
different stress-response pathways in iC. elegans/i (Anbalagan et al. Ecotoxicology 21:439–455, 2012), we now present parallel data on the responses of these same strains to
several commonly used pesticides. Some of these, like dichlorvos, induced multiple stress genes in a concentration-dependent
manner. Unusually, endosulfan induced only one gene (icyp/i-34A9) to very high levels (8–10-fold) even at the lowest test concentration, with a clear plateau at higher doses. Other
pesticides, like diuron, did not alter reporter gene expression detectably even at the highest test concentration attainable,
while others (such as glyphosate) did so only at very high concentrations. We have also used five responsive GFP reporters
to investigate the toxicity of soil pore water from two agricultural sites in south-east Spain, designated P74 (used for cauliflower
production, but significantly metal contaminated) and P73 (used for growing lettuce, but with only background levels of metals).
Both soil pore water samples induced all five test genes to varying extents, yet artificial mixtures containing all major
metals present had essentially no effect on these same transgenes. Soluble organic contaminants present in the pore water
were extracted with acetone and dichloromethane, then after evaporation of the solvents, the organic residues were redissolved
in ultrapure water to reconstitute the soluble organic components of the original soil pore water. These organic extracts
induced transgene expression at similar or higher levels than the original pore water. Addition of the corresponding metal
mixtures had either no effect, or reduced transgene expression towards the levels seen with soil pore water only. We conclude
that the main toxicants present in these soil pore water samples are organic rather than metallic in nature. Organic extracts
from a control standard soil (Lufa 2.2) had negligible effects on expression of these genes, and similarly several pesticides
had little effect on the expression of a constitutive imyo/i-3::GFP transgene. Both the P73 and P74 sites have been treated regularly with (undisclosed) pesticides, as permitted under
EU regulations, though other (e.g. industrial) organic residues may also be present.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-14/liliDOI 10.1007/s10646-012-1004-2/lilispanAuthors/spanul
liCharumathi Anbalagan, School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD UK/liliIvan Lafayette, School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD UK/liliMelissa Antoniou-Kourounioti, School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD UK/liliCarmen Gutierrez, Department of Environmental Contamination, Instituto de Ciencias Agrarias (ICA)-CSIC, Serrano 115B, 28006 Madrid, Spain/liliJose Rodriguez Martin, Department of Forest Ecology and Genetics, Centro de Investigación Forestal (CIFOR)-INIA, Crta. de La Coruña, km 7,5, 28040 Madrid, Spain/liliDebapratim K. Chowdhuri, Indian Institute of Toxicology Research, Lucknow, 226001 India/liliDavid I. De Pomerai, School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD UK/li
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Mercury concentrations in tropical resident and migrant songbirds on Hispaniola
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivDespite growing concerns over mercury (Hg) exposure to humans and wildlife on a global scale, little is known about Hg bioaccumulation
in the New World tropics. From 2005 to 2011, we monitored Hg concentrations in blood of nine avian species occupying a geographic
range of tropical wet broadleaf sites on the island of Hispaniola, including eight passerines (two Nearctic–Neotropical migrant
and six resident species) and one top order predatory accipiter. Invertivorous songbirds were further differentiated by foraging
guild, with six species of ground-foragers and two species of foliage-gleaners. Blood Hg concentrations were orders of magnitude
higher in birds sampled in central and southern cloud forest sites (1,000–1,800nbsp;m elevation) than in northern and northeastern
rainforest sites (50–500nbsp;m elevation), with migratory and resident species both showing 2–20× greater blood Hg concentrations
in cloud forests than in rainforests. Within cloud forest sites, ground-foraging species had higher Hg concentrations than
foliage-gleaning species. Top order predatory sharp-shinned hawks (iAccipiter striatus/i) had the highest blood Hg concentrations among all species, suggesting that Hg biomagnification is occurring in terrestrial
forests of Hispaniola. Two migrant songbird species overwintering on the island had higher blood Hg concentrations than have
been recorded on their North American breeding grounds. Future studies should seek to elucidate sources of variation in atmospheric
Hg deposition on Hispaniola and to quantify the dynamics of Hg cycling in tropical forest ecosystems, which may differ in
important ways from patterns documented in temperate forest ecosystems.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1005-1/lilispanAuthors/spanul
liJason M. Townsend, Conservation Science Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA/liliChristopher C. Rimmer, Vermont Center for Ecostudies, P.O. Box 420, Norwich, VT 05055, USA/liliCharles T. Driscoll, Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244, USA/liliKent P. McFarland, Vermont Center for Ecostudies, P.O. Box 420, Norwich, VT 05055, USA/liliEduardo Iñigo-Elias, Conservation Science Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Contamination, parasitism and condition of Anguilla anguilla in three Italian stocks
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivIn conjunction with habitat loss and overfishing, pollution and parasitism are believed to be relevant causes of collapse
of iAnguilla/i, as these can affect eel swimming ability and the development of gonads and embryos. The present study investigated Persistent
Organic Pollutant (POP) concentrations, infection levels of iAnguillicoloides crassus/i, lipid content and gonad abnormalities in eels sampled in 2007–2008 in three Italian water bodies (Caprolace Lake, Lesina
Lagoon and Tevere River) that vary in salinity, trophic condition, contamination level and fishing pressure. Our analysis
revealed that low-to-moderate levels of contamination and parasitism were not associated with gonad abnormalities in Caprolace
Lake and Lesina Lagoon. On the contrary, POP concentrations and abundances of swim bladder nematodes were remarkably high
in eels from the heavily urbanized Tevere River and were associated with significant gonad and swim bladder alterations. Contamination
and infestation levels were so high to potentially impair spawner successful migration and reproduction. POP concentrations
in Tevere eels also exceeded levels considered safe for food consumption. Though marginally contaminated, eels from the oligotrophic
Caprolace Lake were in critical health condition: their lipid reserve was so low as to be considered insufficient to sustain
the energetic costs of the transoceanic migration. Lesina eel stock was the only one displaying relatively good quality but
here spawner abundance is likely limited by overfishing. Our results suggest that multiple stressors may potentially affect
eel reproductive success. More definitive studies are needed to assess whether health effects caused by these multiple stressors
are additive, compensatory or synergistic.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-15/liliDOI 10.1007/s10646-012-1006-0/lilispanAuthors/spanul
liSilvia Quadroni, Department of Theoretical and Applied Sciences (Environmental Section), University of Insubria, Via Dunant 3, 21100 Varese, Italy/liliSilvana Galassi, Department of Biology, University of Milan, Via Celoria 26, 20133 Milan, Italy/liliFabrizio Capoccioni, Department of Biology, University of Rome “Tor Vergataâ€, Via della Ricerca Scientifica 1, 00133 Rome, Italy/liliEleonora Ciccotti, Department of Biology, University of Rome “Tor Vergataâ€, Via della Ricerca Scientifica 1, 00133 Rome, Italy/liliGilberto Grandi, Department of Biology and Evolution, University of Ferrara, Via L. Borsari 46, 44100 Ferrara, Italy/liliGiulio A. De Leo, Hopkins Marine Station and Woods Institute for the Environment, Stanford University, Pacific Grove, CA, USA/liliRoberta Bettinetti, Department of Theoretical and Applied Sciences (Environmental Section), University of Insubria, Via Dunant 3, 21100 Varese and Via Valleggio 11, 22100 Como, Italy/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Mitochondrial gene expression, antioxidant responses, and histopathology after cadmium exposure
Abstract
The present study investigates cadmium effects on the transcription of mitochondrial genes of Procambarus clarkii after acute (0.05, 0.5, and 5 mg Cd/L; 4–10 days) and chronic exposures (10 μg Cd/L; 30–60 days). Transcriptional responses of cox1 , atp6 , and 12S using quantitative real-time RT-PCR were assessed in gills and hepatopancreas. Additionally, the expression levels of genes involved in detoxification and/or oxidative stress responses [mt , sod (Mn )] and enzymatic activities of antioxidants (SOD, CAT, GPX, and GST) were analyzed. The histopathological effects in hepatopancreas of crayfish were evaluated by light microscopy. Relationships between endpoints at different levels of biological organization and Cd bioaccumulation were also examined. Cd induced high levels of bioaccumulation, which was followed by mitochondrial dysfunction and histological alterations in both experiments. Moreover, perturbations in the defence mechanisms against oxidative stress tended to increase with time. Results also showed that molecular responses can vary depending on the intensity and duration of the chemical stress applied to the organisms and that the study of mt gene expression levels seemed to be the best tool to assess Cd intoxication. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effects of phytoplankton cell size and chloride concentration on the bioaccumulation of methylmercury in marine phytoplankton
Abstract
In the current study, the effects of phytoplankton cell size and methylmercury (MeHg) speciation on the bioaccumulation of MeHg by marine phytoplankton were investigated. Volume concentration factors (VCFs) of MeHg were determined in relation to the surface area to volume ratio of the cells for four species of diatom and a cyanobacteria species cultured in unenriched seawater. The VCFs of MeHg, ranging from 7.3 × 104 to 1.6 × 106 , increased linearly as the cell surface area-to-volume ratio increased. It suggests that pico- and nano-dominated phytoplankton communities may lead to larger MeHg accumulation than the one dominated by microphytoplankton. MeHg VCFs increased with increasing chloride concentration from 0.47 to 470 mM, indicating that MeHg bioaccumulation is enhanced under conditions that facilitate membrane permeability by the formation of neutral MeHgCl species. Overall results suggest that the size distributions of the planktonic community as well as the seawater chemistry affect MeHg bioaccumulation by marine phytoplankton. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Acrolein induction of oxidative stress and degranulation in mast cells
Abstract
Increases in asthma worldwide have been associated epidemiologically with expanding urban air pollution. The mechanistic relationship between airway hyper-responsiveness, inflammation, and ambient airborne triggers remains ambiguous. Acrolein, a ubiquitous aldehyde pollutant, is a product of incomplete combustion reactions. Acrolein is abundant in cigarette smoke, effluent from industrial smokestacks, diesel exhaust, and even hot oil cooking vapors. Acrolein is a potent airway irritant and can induce airway hyper-responsiveness and inflammation in the lungs of animal models. In the present study, we utilized the mast cell analog, RBL-2H3, to interrogate the responses of cells relevant to airway inflammation and allergic responses as a model for the induction of asthma-like conditions upon exposure to acrolein. We hypothesized that acrolein would induce oxidative stress and degranulation in airway mast cells. Our results indicate that acrolein at 1 ppm initiated degranulation and promoted the generation of reactive oxygen species (ROS). Introduction of antioxidants to the system significantly reduced both ROS generation and degranulation. At higher levels of exposure (above 100 ppm), RBL-2H3 cells displayed signs of severe toxicity. This experimental data indicates acrolein can induce an allergic inflammation in mast cell lines, and the initiation of degranulation was moderated by the application of antioxidants. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells
Abstract
Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects. It was found that 50 mg/L HA showed cytotoxicity, which we considered to be mediated by apoptosis through the mitochondrial pathway because of an increase in the expression of caspases 6 and 9 in response to HA administration. In addition, this cytotoxicity was enhanced when cells in this experimental system were exposed to oxidative stress, while it was decreased by the addition of vitamin C. Thus, we conclude that the apoptosis induced by HA depends upon oxidative stress. Furthermore, an iron chelator, DFO, showed a tendency to decrease HA-induced cytotoxicity, suggesting that iron may potentially mediate HA-induced oxidative stress. In conclusion, long-term consumption of HA-rich water obtained from our study area may cause damage to endothelial cells and subsequent chronic health problems. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Environmentally relevant concentrations of a common insecticide increase predation risk in a freshwater gastropod
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivEcological receptors are faced with a multitude of stressors that include abiotic and biotic factors creating a challenge
for assessing risk of chemical exposure. Of particular interest and importance are the effects of contaminants on inter-species
interactions such as competition and predator–prey relationships. The objective of this study was to determine whether environmentally
relevant concentrations of the commonly used insecticide, malathion, would alter predator avoidance behavior in a freshwater
gastropod that could translate to increased predation risk. We exposed adult iPhysa pomilia/i snails to 0, 0.25, or 1.0nbsp;mg/L malathion for 2, 24, or 48nbsp;h and evaluated predator avoidance using a behavioral assay in
which snails were exposed to cues from predatory crayfish. We found a significant reduction in predator avoidance in snails
exposed to both concentrations of malathion after 48nbsp;h of exposure. To evaluate whether observed effects of malathion on predator
avoidance actually increased susceptibility of snails to predators, we conducted a predator challenge experiment. Snails exposed
to 0.25nbsp;mg/L malathion for 48nbsp;h were significantly more susceptible to predation. That increased predation risk was evident
48nbsp;h after initial malathion exposures is a unique result because most studies have evaluated behavioral responses soon after
(lt;12nbsp;h) initiation of pesticide exposure. The extent to which the observed interactions affect natural populations, and the
mechanisms through which they are mediated are largely unexplored. However, our study is the first to show that a commonly
used insecticide decreases predator avoidance and may actually increase predation susceptibility in gastropods at concentrations
several orders of magnitude below acute toxicity levels.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-8/liliDOI 10.1007/s10646-012-1001-5/lilispanAuthors/spanul
liChristopher J. Salice, The Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, P.O. Box 41163, Lubbock, TX 79409, USA/liliDavid A. Kimberly, The Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, P.O. Box 41163, Lubbock, TX 79409, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Contamination by metals and pharmaceuticals in northern Taihu Lake (China) and its relation to integrated biomarker response in fish
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivTaihu Lake is the largest shallow freshwater lake in eastern China and is suffering not only from an increasingly serious
threat of eutrophication but also potential ecological risk due to the input of emerging contaminants. Active biomonitoring
was conducted in Taihu Lake using transplanted goldfish (iCarassius auratus/i) to determine the contamination by pharmaceuticals and metals and to assess the potential ecological risk. A suite of biomarkers
including acetylcholinesterase, ethoxyresorufin iO/i-deethylase, glutathione iS/i-transferase, glutathione peroxidase and superoxide dismutase activities in fish after 7, 14, 21 and 28nbsp;days of exposure in
situ, as well as pharmaceuticals and metals in water, were determined during the field exposure period. The results indicate
that pharmaceuticals exist mainly in Zhushan Bay and Meiliang Bay, while metals are present mainly in Gong Bay. An integrated
biomarker response (IBR) was calculated and used to evaluate the ecological risk of the polluted area of Taihu Lake. It was
found that Zhushan Bay might present higher risk to fish, followed by Meiliang Bay. IBR values were in good agreement with
copper and caffeine concentrations.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-10/liliDOI 10.1007/s10646-012-1002-4/lilispanAuthors/spanul
liGuanghua Lu, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 People’s Republic of China/liliXiaofan Yang, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 People’s Republic of China/liliZhihua Li, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 People’s Republic of China/liliHaizhou Zhao, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 People’s Republic of China/liliChao Wang, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 People’s Republic of China/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Designing ionic liquids: the chemical structure role in the toxicity
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivIonic liquids (ILs) are a novel class of solvents with interesting physicochemical properties. Many different applications
have been reported for ILs as alternatives to organic solvents in chemical and bioprocesses. Despite the argued advantage
of having low vapor pressure, even the most hydrophobic ILs show some degree of solubility in water, allowing their dispersion
into aquatic systems and raising concerns on its pollutant potential. Moreover, nowadays most widespread notion concerning
the ILs toxicity is that there is a direct relationship with their hydrophobicity/lipophilicity. This work aims at enlarging
the currently limited knowledge on ILs toxicity by addressing negative impacts in aquatic ecosystems and investigating the
possibility of designing hydrophobic ILs of low ecotoxicity, by the manipulation of their chemical structures. The impact
of aromaticity on the toxicity of different cations (pyridinium, piperidinium, pyrrolidinium and imidazolium) and hydrophobic
anions (bis(trifluoromethylsulfonyl)imide [NTfsub2/sub] and hexafluorophosphate [PFsub6/sub]) was analysed. Concomitantly, several imidazolium-based ILs of the type [Csub
in/i
/subCsub
im/i
/subCsub
ij/i
/subim][NTfsub2/sub] were also studied to evaluate the effects of the position of the alkyl chain on the ILs’ toxicity. For that purpose, standard
assays were performed using organisms of different trophic levels, iVibrio fischeri/i, iPseudokirchneriella subcapitata/i and iDaphnia magna/i, allowing to evaluate the consistency of the structure–activity relationships across different biological targets. The results
here reported suggest the possibility of designing ILs with an enhanced hydrophobic character and lower toxicity, by elimination
of their aromatic nature.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-12/liliDOI 10.1007/s10646-012-0997-x/lilispanAuthors/spanul
liSónia P. M. Ventura, Departamento de QuÃmica, CICECO, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/liliAna M. M. Gonçalves, Departamento de Biologia CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliTânia Sintra, Departamento de QuÃmica, CICECO, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/liliJoana L. Pereira, Departamento de Biologia CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliFernando Gonçalves, Departamento de Biologia CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, 3810-193 Aveiro, Portugal/liliJoão A. P. Coutinho, Departamento de QuÃmica, CICECO, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Influence of pH, light cycle, and temperature on ecotoxicity of four sulfonylurea herbicides towards Lemna gibba
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivIn chemical regulation, e.g. the EU Water Framework Directive, REACH, or the Pesticide Directive, standardized ecotoxicological
tests are applied to evaluate and rank the hazard of compounds and for deriving environmental quality standards (EQS). Standardized
test methods prescribe fixed testing conditions e.g. specific temperature, pH, light intensity etc. However, environmental
conditions under which the organisms live are rarely identical to the standard conditions. Thus, the ecotoxicity of compounds
found in standard test is not only a function of the compounds inherent physico-chemical properties but is also affected by
test conditions. It is therefore important to study the effect of changes in test conditions in order to get reliable input
ecotoxicity data for assessing the potential risk posed by a compound. The objective of this study was to investigate the
implications of changing test conditions on the toxicity of four sulfonylurea herbicides (SUs). The toxicity of the four SUs
towards iLemna gibba/i was investigated at three pH levels (6, 7.5 and 9), at two temperatures (15 and 24nbsp;°C) and two light regimes (continuous
and 12:12nbsp;h light:dark cycle) The EC50 increased twofold to tenfold for the four SUs when pH was increased from 6 to 9. Decreasing
the temperature from 24 to 15nbsp;°C or introducing a dark:light cycle did not cause any trends in changes in toxicity. The results
show that test conditions can have an effect on the toxicity and this should be considered when the standard test results
are used for derivation of EQS.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-9/liliDOI 10.1007/s10646-012-1000-6/lilispanAuthors/spanul
liRikke T. Rosenkrantz, Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark/liliNina Cedergreen, Department of Basic Sciences and Environment, University of Copenhagen, Copenhagen, Denmark/liliAnders Baun, Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark/liliK. Ole Kusk, Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Nondestructive indices of mercury exposure in three species of turtles occupying different trophic niches downstream from a former chloralkali facility
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivTurtles are useful for studying bioaccumulative pollutants such as mercury (Hg) because they have long life spans and feed
at trophic levels that result in high exposure to anthropogenic chemicals. We compared total Hg concentrations in blood and
toenails of three species of turtles (iChelydra serpentina/i, iSternotherus odoratus/i, and iGraptemys geographica/i) with different feeding ecologies from locations up- and downstream of a superfund site in Virginia, USA. Mercury concentrations
in turtle tissues were low at the reference site (averagenbsp;±nbsp;1SE: bloodnbsp;=nbsp;48nbsp;±nbsp;6nbsp;ngnbsp;gsup−1/sup; nailnbsp;=nbsp;2,464nbsp;±nbsp;339nbsp;ngnbsp;gsup−1/sup FW) but rose near the contamination source to concentrations among the highest ever reported in turtles [up to 1,800nbsp;ngnbsp;gsup−1/sup (blood) and 42,250nbsp;ngnbsp;gsup−1/sup (nail) FW]. Tissue concentrations remained elevated ~130nbsp;km downstream from the source compared to reference concentrations.
Tissue Hg concentrations were higher for iC. serpentina/i and iS. odoratus/i than iG. geographica/i, consistent with the feeding ecology and our stable isotope (δsup13/supC and δsup15/supN) analyses of these species. In addition, we suggest that toenails were a better indication of Hg exposure than blood, probably
because this keratinized tissue represents integrated exposure over time. Our results demonstrate that downstream transport
of Hg from point sources can persist over vast expanses of river thereby posing potential exposure risks to turtles, but relative
exposure varies with trophic level. In addition, our study identifies turtle toenails as a simple, cost-efficient, and minimally
invasive tissue for conservation-minded sampling of these long-lived vertebrates.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-11/liliDOI 10.1007/s10646-012-0999-8/lilispanAuthors/spanul
liWilliam A. Hopkins, Wildlife Ecotoxicology and Physiological Ecology, Department of Fish and Wildlife Conservation, Virginia Tech University, 106 Cheatham Hall, Blacksburg, VA 24061-0321, USA/liliCathy Bodinof, Wildlife Ecotoxicology and Physiological Ecology, Department of Fish and Wildlife Conservation, Virginia Tech University, 106 Cheatham Hall, Blacksburg, VA 24061-0321, USA/liliSarah Budischak, Wildlife Ecotoxicology and Physiological Ecology, Department of Fish and Wildlife Conservation, Virginia Tech University, 106 Cheatham Hall, Blacksburg, VA 24061-0321, USA/liliChristopher Perkins, Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT 06269-4210, USA/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Chronic toxicity of tire and road wear particles to water- and sediment-dwelling organisms
pdiv lang="en"a name="Abs1"/aspanAbstractnbsp;nbsp;/spandivTire and road wear particles (TRWP) consist of a complex mixture of rubber, and pavement released from tires during use on
road surfaces. Subsequent transport of the TRWP into freshwater sediments has raised some concern about the potential adverse
effects on aquatic organisms. Previous studies have shown some potential for toxicity for tread particles, however, toxicity
studies of TRWP collected from a road simulator system revealed no acute toxicity to green algae, daphnids, or fathead minnows
at concentrations up to 10,000nbsp;mg/kg under conditions representative of receiving water bodies. In this study, the chronic
toxicity of TRWP was evaluated in four aquatic species. Test animals were exposed to whole sediment spiked with TRWP at concentrations
up to 10,000nbsp;mg/kg sediment or elutriates from spiked sediment. Exposure to TRWP spiked sediment caused mild growth inhibition
in iChironomus dilutus/i but had no adverse effect on growth or reproduction in iHyalella azteca/i. Exposure to TRWP elutriates resulted in slightly diminished survival in larval iPimephales promelas/i but had no adverse effect on growth or reproduction in iCeriodaphnia dubia./i No other endpoints in these species were affected. These results, together with previous studies demonstrating no acute toxicity
of TRWP, indicate that under typical exposure conditions TRWP in sediments pose a low risk of toxicity to aquatic organisms.
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lispanContent Type /spanspanJournal Article/span/liliPages 1-9/liliDOI 10.1007/s10646-012-0998-9/lilispanAuthors/spanul
liJulie M. Panko, ChemRisk, 20 Stanwix Street, Suite 505, Pittsburgh, PA 15222, USA/liliMarisa L. Kreider, ChemRisk, 20 Stanwix Street, Suite 505, Pittsburgh, PA 15222, USA/liliBritt L. McAtee, ChemRisk, 20 Stanwix Street, Suite 505, Pittsburgh, PA 15222, USA/liliChristopher Marwood, NovaTox Inc., 10 Crane Avenue, Guelph, ON N1G 2R2, Canada/li
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lispanJournal /spanspana href="http://www.springerlink.com/content/100168/"Ecotoxicology/a/span/lilispanOnline ISSN /spanspan1573-3017/span/lilispanPrint ISSN /spanspan0963-9292/span/li
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Depletion of Kupffer cells modulates ethanol-induced hepatocyte DNA synthesis in C57Bl/6 mice
Abstract
Kupffer cells (KCs) are important in hepatic homeostasis and responses to xenobiotics. KCs are activated on interaction with endotoxin, releasing cytokines, and reactive oxygen species normally associated with increased gene expression, cellular growth, or hepatic injury. Ethanol-induced endotoxemia is one means of KC activation. We propose that KC depletion attenuates the effect of EtOH-induced endotoxemia to impact the hepatic growth response. Hepatic DNA synthesis was examined in KC competent (KC+) or KC-depleted (KC−) C57BL/6 mice fed EtOH-containing diet in the presence or absence of polyphenol-60 antioxidant. KC depletion was assessed by F4/80 antigen, and DNA synthesis was assessed by 5-bromo-2′-deoxyuridine incorporation. Tumor necrosis factor alpha (TNF-α) messenger RNA released was quantified by RT-PCR/electrophoresis. ERK1/2 phosphorylation was evaluated by Western blotting, and Nrf2 and CYP2E1protein were also assayed. Apoptosis and hepatic injury were examined by the Tunnel assay and hepatic transaminases in serum, respectively. Hepatic transaminases in serum (AST and ALT) were within normal range. Over 90% of KC was depleted by clodronate treatment. KC depletion decreased TNF-α mRNA release, ERK1/2 phosphorylation, and hepatocyte DNA synthesis. KC depletion is associated with increased numbers of apoptotic cells bodies in KC− mice. Antioxidant treatment decreased DNA synthesis, Nrf2, and CYP2E1 protein expression in EtOH-consuming mice. Our data indicate that upon ethanol exposure, KC participates in hepatic DNA synthesis and growth responses. Collectively, these observations suggest that KC depletion attenuates the downstream effect of ethanol-induced endotoxemia by reduced cytokine and reactive oxygen species production with its concomitant effect on MAPK-signaling pathway on hepatocyte DNA synthesis. © 2012 Wiley Periodicals, Inc.
Lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) causes hyperactivity in male rat pups by aberrant increase in dopamine and its receptor
Abstract
Polychlorinated biphenyls (PCBs) are recognized as persistent environmental pollutants that may cause adverse health problems. Despite extensive investigations of PCB in neural function, little is known about behavioral traits by PCB exposure and its neurochemical mechanism. Here, we report the behavioral study of a rat pup that was exposed to hydroxylated-PCB 106 (OH-PCB 106; 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl) through maternal milk. The different groups of mothers received via gavage corn oil vehicle, 0.5, 5, or 50 mg/kg body weight of OH-PCB 106 every second day from day 3 to 13 after delivery. The exposure did not affect the body weight of the dams or the physical development of the newborn pups in both sexes. Male rats exposed to OH-PCB 106 showed hyperactivity that was characterized by increased locomotor activity in novel environment and circadian period. Interestingly, OH-PCB 106-exposed rat pups displayed abnormally high levels of dopamine and D2 dopamine receptor (D2DR), but not D1DR and D5DR, in the striatum, an important center for the coordination of behavior. These findings indicate that OH-PCB 106 has a significant neurotoxic effect on rat behavior, which may be associated with increased D2DR mediated signals. © 2012 Wiley Periodicals, Inc.
Comparative evaluation in vitro of the herbicide flurochloridone by cytokinesis-block micronucleus cytome and comet assays
Abstract
The in-vitro effects of flurochloridone and its formulations Twin Pack Gold® (25% a.i.) and Rainbow® (25% a.i.) were evaluated in Chinese Hamster Ovary K1 (CHO-K1) cells. The cytokinesis-block micronucleus cytome (CBMN-cyt) and single-cell gel electrophoresis (SCGE) assays were used. The activities were tested within the range of final concentrations of 0.25–15 μg flurochloridone/mL. The results demonstrated that both the flurochloridone and Rainbow® were not able to induce micronuclei (MN). On the other hand, Twin Pack Gold® only increased the frequency of MN at 5 μg/mL. Furthermore, 10 and 15 μg/mL of both formulations resulted in a cellular cytotoxicity demonstrated by alterations in the nuclear division index and cellular death. SCGE assay appeared to be a more sensitive bioassay for detecting primary DNA strand breaks at lower concentrations of flurochloridone than MN did. A marked increase in the genetic damage index was observed when 5 and 15 μg/mL of both flurochloridone and Rainbow® but only when 15 μg/mL of Twin Pack Gold® were used. This is the first report demonstrating that flurochloridone and its two commercial formulations are able to induce single-strand DNA breaks in vitro on mammalian cells. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Responsiveness of hepatic and cerebral cytochrome P450 in rat offspring prenatally and lactationally exposed to a reconstituted PCB mixture
Abstract
Perinatal polychlorinated biphenyl (PCB) exposures still remain a serious health concern because offspring receive PCB burden from mother during vulnerable processes of development. Since cytochrome P450 (CYP) represents a toxicological endpoint, in the present study, representing an extended investigation of a previous multitasked one, we explored the long-term responsiveness of CYP1A and CYP2B isoforms by Western blot analysis in liver and whole brain of lactating (PN12), weaning (PN21), and adult offspring (PN60) rats prenatally and lactationally exposed to a reconstituted PCB mixture (RM) of noncoplanar PCB138, 153, 180, and coplanar PCB126 congeners. We chose highly chlorinated PCBs instead of lower chlorinated one, because their recalcitrance to biotransformation makes easy their accumulation/persistence in tissues and breast milk. Dioxin-like congener PCB126 binding aryl hydrocarbon receptor (AHR) is responsible of many toxic effects. Pregnant Sprague–Dawley dams with high affinity AHR received subcutaneous injection of RM (10 mg/kg body weight) daily during gestation (days 15–19) and twice a week during breast-feeding. The results evidenced a transfer of PCBs to neonates through milk and a significant responsiveness of hepatic CYP in both mothers and offspring. In liver of exposed progeny, CYP isoforms exhibited a significant increment at PN12 (70% over control) and at PN21 (270% over control). Contrary to dams, in adult PCB offspring CYP levels showed a decline up to values similar to those of control. This transient developmental responsiveness of CYP isoforms in offspring liver reflects roughly the time course of hepatic PCB levels previously reported. Even if congeners were detected in brain, we failed in evidencing a responsiveness of CYP isoforms probably because of region-specific CYP expression in this organ. In conclusion, induction of offspring hepatic CYP is index of liver PCB burden, and despite the insensitivity of whole brain CYP we cannot exclude brain vulnerability toward PCB. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Developmental iodine deficiency delays the maturation of newborn granule neurons associated with downregulation of p35 in postnatal rat hippocampus
Abstract
We evaluated the role of p35 in the maturation of hippocampal granule neurons in offspring caused by developmental iodine deficiency. Two developmental rat models were established with either an iodine-deficient diet, or propylthiouracil-adulterated water (5 ppm) to impair thyroid function, in pregnant rats from gestational day 6 until postnatal day 28. The protein levels of p35, cyclin-dependent kinase 5, β-catenin, and N-cadherin were assessed on postnatal day 14, 21, and 28. Dendritic morphogenesis of newborn granule neurons in dentate gyrus was examined. Developmental hypothyroidism induced by iodine deficiency and PTU treatment delayed the maturation of hippocampal granule neurons in the offspring and decreased the percentage of Dcx-positive neurons that expressed β-catenin on postnatal day 21 and 28. In addition, downregulation of p35 was observed in dentate gyrus of hypothyroid groups. Developmental hypothyroidism induced by iodine deficiency and PTU treatment could delay the maturation of newborn granule neurons in dentate gyrus, and this deficit may be attributed to the downregulation of p35. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Persistent hexavalent chromium exposure impaired the pubertal development and ovarian histoarchitecture in wistar rat offspring
Abstract
Hexavalent chromium (CrVI) is a highly toxic metal and a major environmental pollutant. Several studies indicate that CrVI exposure adversely affects reproductive function. We reported that maternal Cr exposure resulted in Cr accumulation in the reproductive organs of female offsprings. CrVI can cross the placental barrier and also can be passed through breastfeeding. The present investigation aimed to determine the persistent (in utero through puberal period) CrVI exposure-induced toxic effects on the reproductive functions of mother and the offspring. Induction of oxidative stress is one of the plausible mechanisms behind Cr-induced cellular deteriorations. Mother rats exposed to CrVI showed reduced reproductive outcome, while the offsprings showed higher accumulation of Cr in ovary, altered steroid, and peptide hormones. Specific activities of antioxidant enzymes were decreased and associated with increased levels of H2 O2 , and lipid peroxidation. CrVI exposure also damaged the ovarian histoarchitecture in various age groups studied. CrVI exposure also delayed the sexual maturation. Results from the present investigation suggest that CrVI exposure from in utero through puberal period significantly damaged the pubertal development through altered antioxidants, anemia, and altered hormone levels. These changes were associated with damaged ovarian histoarchitecture and extended estrous cycle in developing Wistar rats. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Induction of oxidative stress and histological changes in liver by subacute doses of butyl cyclohexyl phthalate
Abstract
Phthalates are esters of phthalic acid and are mainly used as plasticizers in a wide variety of products and applications. There is no information on butyl cyclohexyl phthalate (BCP) toxicity. This study was performed to evaluate the histopathological effects and to determine oxidative stress inducing potential in liver by subacute exposure of BCP. The animals of the treatment groups were orally administered 100, 200, and 400 mg/kg/day BCP for 5 consecutive days per week during 28 days. As a result, no significant changes were observed in body weight gains, and absolute and relative liver weights of liver of BCP treated mice, when compared with control group. Although the degree of lipid peroxidation in the liver tissue of all BCP exposure groups were significantly higher than those of the control (p < 0.01), SOD and CAT activities in liver tissue of mice of 200 and 400 mg/kg exposure groups were significantly lower than those of the controls (p < 0.01). Moreover, BCP caused dose-dependent histological changes in the liver of mice such as congestions in vena centralis, an enlargement of the sinusoids, degeneration in hepatocytes, vacuole formations and presence of lipid droplets in hepatocytes, eosinophilic cytoplasm. While iNOS immunoreactivity was increased in all treatment groups, Type IV collagen and Connexin 43 immunoreactivities were decreased in all treatment groups compared with the control group. Significant decrease was observed in the number of TUNEL-positive liver cells of BCP treated mice. These results suggested that BCP exposure induces oxidative stress in liver and exposure of BCP during long time period could lead to hepatocarcinogenesis. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Comparison of speciated arsenic levels in the liver and brain of mice between arsenate and arsenite exposure at the early life
Abstract
The aim of this study was to compare the risk from exposure to arsenate (iAsV ) or arsenite (iAsIII ) at the early life. Mother mice were exposed to equimolar dose of iAsV and iAsIII via drinking water during gestation and lactation. Their offspring continually drank the same water after weaning. Levels of speciated arsenic in both liver and brain were analyzed by hydride generation of volatile arsines and atomic absorption spectrophotometry (HG-AAS). In the liver, inorganic arsenic (iAs) levels significantly increased from postnatal day (PND) 15, and those on PND 35 were significantly higher than on PND 15 and 21 in iAsIII exposed mice, but iAs levels did not significantly differ until PND 35 in iAsV exposed mice; Furthermore, all speciated arsenic levels on PND 35 and dimethylarsinic acid (DMA) levels on PND 1 were significantly higher in iAsIII exposed mice than those in iAsV exposed mice. In the brain, iAs levels increased significantly on PND 21, but those declined sharply on PND 35 in either iAsIII or iAsV exposed mice, however the mean difference between the two exposure groups was not significant; whereas DMA levels in iAsIII exposed mice were significantly higher than those in iAsV exposed mice on both PND 1 and 35. In conclusion, findings from this study suggested that iAsIII was preferentially accumulated into liver, and expected to result in more efficient methylation capacity than iAsV ; either iAsV or iAsIII might be accumulated in the brain readily, when immature blood brain barrier can not limit it into brain. Hence, exposure to either iAsV or iAsIII at the early life may increase the risk of iAs exposure in the brain. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Genotoxic, cytotoxic, and apoptotic effects of Hypogymnia physodes (L.) Nyl. on breast cancer cells
Abstract
The aim of this study is to determine the chemical composition, and evaluate the genotoxic, and anti-growth potency of the methanol extracts of lichen species Hypogymnia physodes (L.) Nyl. (HPE). Anti-growth effect was tested in two different human breast cancer cell lines (MCF-7 and MDA-MB-231) by the MTT and ATP viability assays and apoptosis was assayed by the caspase-cleaved cytokeratin 18 (M30-antigen). Genotoxic activity of HPE was studied using chromosome aberration and micronuclei tests in human lymphocytes culture in vitro . The chemical composition of H. physodes was analyzed by using direct thermal desorption method coupled with comprehensive gas chromatography–time of flight mass spectrometry (GCXGC-TOF/MS). Our results indicate that HPE has an anti-growth effect at relatively lower concentrations, while relatively higher concentrations are required for genotoxic activity. HPE, therefore, seems to represent a therapeutic potential and poses new challenges for medicinal chemistry. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Acute and chronic toxic effects of bisphenol a on Chlorella pyrenoidosa and Scenedesmus obliquus
Abstract
The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa ) and Scenedesmus obliquus (S. obliquus ) were not well understood. The indoor experiments were carried out to observe and analyze the BPA-induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short-term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose-dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa , whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
The first evidence of cholinesterases in skin mucus of carps and its applicability as biomarker of organophosphate exposure
Abstract
The presence of cholinesterase (ChE) activity in skin mucus of three carps, Cirrhinus mrigala , Labeo rohita , and Catla catla and its applicability as biomarker of the organophosphorus insecticide exposure were investigated. Biochemical characterization, using specific substrates and inhibitors, indicated that measured esterase activity in skin mucus was mainly owing to ChEs. Significant difference in the proportion of acetylcholinesterase and butyrylcholinesterase activities was observed in skin mucus of three carps. Enzyme kinetic analysis, using the substrate acetylthiocholine iodide revealed significantly high V max value in C. catla compared to that in L. rohita and C. mrigala . In contrast, V max value using the substrate butyrylthiocholine iodide was significantly high in C. mrigala than in L. rohita and C. catla . In vitro treatment of skin mucus of three carps, with the organophosphorus insecticide Nuvan®, showed strong inhibition of ChE activities. In vivo experiments conducted using C. mrigala and exposing the fish to the sublethal test concentrations (5 and 15 mg/L) of the insecticide also revealed significant inhibition of ChE activity in mucus. In C. mrigala , exposed to the sublethal test concentrations of the insecticide for 4 days and then kept for recovery for 16 days, mucus ChE activity recovered to the control level. Thus, ChE activity in skin mucus could be considered a good biomarker of the organophosphorus insecticide exposure to fish and a useful tool in monitoring environmental toxicity. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Reproductive toxicity and histopathological changes induced by lambda-cyhalothrin in male mice
Abstract
Lambda-cyhalothrin (LCT) is a widely used broad-spectrum pyrethroid insecticide. Oral LCT administration to adult male mice at 3 doses (0.2, 0.4, and 0.8 mg/kg/day) for 6 weeks caused a significant reduction in the weight of the seminal vesicles. The epididymal sperm count was lower in mice that received at the highest dose than in control mice. However, the proportions of live and motile spermatozoa were reduced at both the medium and the high doses compared with control mice. All doses induced an increase in the number of morphologically abnormal spermatozoa. Histopathological observations of the testes, liver, kidneys, and spleen showed dose-related degenerative damage in LCT-treated mice. The results indicate that LCT has reproductive toxicity, hepatotoxicity, nephrotoxicity, and splenotoxicity in male mice at the tested doses. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Downregulation of nuclear respiratory factor-1 contributes to mitochondrial events induced by benzo(a)pyrene
Abstract
Environmental carcinogen benzo(a )pyrene (BaP) has been shown to be a genotoxicant that affects both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). Nuclear respiratory factor 1 (NRF-1) is a transcriptional activator of nuclear genes that encode a range of mitochondrial proteins including mitochondrial transcription factor A (mtTFA). However, the role of NRF-1 in BaP-induced mitochondrial event is not clear. We investigated the change of NRF-1 and mtTFA in human bronchial epithelial cells (16HBE) elicited by BaP. The results indicated that BaP induced cell apoptosis, total mitochondrial enzymes activities and ATP levels decrease in dose- and time-dependent manners, respectively. The transcription and protein levels of NRF-1 and mtTFA decreased at 48 h after 16 μM BaP treatment. Our results indicated downregulation of NRF-1 and mtTFA is involved in BaP-induced mitochondrial events. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Responses of PTTH-producing neurosecretory neurons in Lymantria dispar caterpillars exposed to cadmium
Abstract Lymantria dispar, as most invasive insect species, is very adaptable and reacts quickly to changing environment. Neuroendocrine system first reacts to stress in insects, and specific neurohormonal reorganization may be used in early heavy metal risk assessment. Prothoracicotropic neurohormones (PTTH) control ecdysteroid synthesis (morphogenetic and stress hormones) in insects. In this article, we report the presence of PTTH immunoreactive molecules in L2′ dorsolateral neurosecretory neurons (nsn) in caterpillar brains and changes after exposure to pollutant stress of different intensity. For 3 days, after molting into the 4th instar, caterpillars of Lymantria dispar were fed with a high wheat germ diet without (control) or with added cadmium (experimental groups: 10, 30, 100, 250 μg Cd/g dry food weight). Changes in PTTH producing L2′ nsn and differences in the intensity of protein bands in the region of PTTH molecular mass (Mr 11–15 kDa) were analyzed. The number of L2′ neurons tended to decrease except in the group given the highest cadmium concentration (250 μg). The neurons were enlarged after acute treatment especially in the group given the highest cadmium concentration. The size of L2′ nsn nuclei was decreased only in the group fed with 30 μg Cd. Protein band intensity in the Mr region of PTTH remained unchanged in all groups except for the group given the diet with the highest Cd concentration. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
β-catenin involvement in arsenite-induced VEGF expression in neuroblastoma SH-SY5Y cells
Abstract Arsenic is a widespread contaminant in the environment especially in drinking water. Although it is a known carcinogen in human, the mechanism by which arsenic induces carcinogenesis is not well understood. Among several effects of arsenic, it has been suggested that arsenic-induced vascular endothelial growth factor (VEGF) expression plays a critical role in arsenic carcinogenesis. In the present study, we demonstrated that arsenite induced VEGF expression in neuroblastoma SH-SY5Y cells without induction of HIF-1α, a well-known transcriptional activator for VEGF suggesting that arsenite-induced VEGF expression in SH-SY5Y cells may not require HIF-1α activation. It has been reported that VEGF expression is regulated by multiple transcription factors including β-catenin. We therefore investigated whether β-catenin was involved in arsenite-induced VEGF expression in SH-SY5Y cells. Treatment of arsenite caused β-catenin accumulation in the nucleus. Additionally, arsenite treatment decreased the activity of GSK3, an enzyme that phosphorylates and targets β-catenin for degradation by proteasome, without activation of its upstream kinase, Akt. Inhibition of PI3K/Akt which negatively regulates GSK3 activity by LY294002 resulted in a decrease in arsenite-mediated β-catenin nuclear accumulation, and VEGF expression. These results suggested that β-catenin plays a role in arsenite-induced VEGF in SH-SY5Y cells, and the induction of β-catenin by arsenite is mediated by inhibition of GSK3 without activating its upstream kinase Akt. © © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Ptaquiloside-induced early-stage urothelial lesions show increased cell proliferation and intact β-catenin and e-cadherin expression
Abstract Bracken (Pteridium aquilinum ) is a carcinogenic plant whose main toxin, ptaquiloside, causes cancer in farm and laboratory animals. Ptaquiloside contaminates underground waters as well as meat and milk from bracken-grazing animals and is a suspected human carcinogen. A better understanding of the underlying mechanisms of carcinogenesis can be achieved by studying the early stages of this process. Unfortunately, most research on ptaquiloside has focused on the late, malignant, lesions, so the early changes of ptaquiloside-induced carcinogenesis remain largely unknown. This study aims to characterize early-stage ptaquiloside-induced urinary bladder lesions both morphologically and immunohistochemically. 12 male CD-1 mice were administered 0.5 mg ptaquiloside intraperitoneally, weekly, for 15 weeks, followed by 15 weeks without treatment. 12 control animals were administered saline. Bladders were tested immunohistochemically for antibodies against a cell proliferation marker (Ki-67), and two cell adhesion markers (E-cadherin and β-catenin). Two exposed animals died during the work. Six ptaquiloside-exposed mice developed low-grade and two developed high grade urothelial dysplasia. No lesions were detected on control animals. Significantly, increased (p < 0.05) Ki-67 labeling indices were found on dysplastic urothelium from ptaquiloside-exposed mice, compared with controls. No differences were found concerning E-cadherin and β-catenin expression. Early-stage ptaquiloside-induced urothelial lesions show increased cell proliferation but there is no evidence for reduced intercellular adhesiveness, though this may be a later event in tumor progression. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Modulation of microrna expression by volatile organic compounds in mouse lung
Abstract Volatile organic compounds (VOCs) are one of main pollutants indoors. Exposure to VOCs is associated with cancer, asthma disease, and multiple chemical allergies. Despite the adverse health effects of VOCs, the molecular mechanisms underlying VOCs-induced disease remain largely unknown. MicroRNAs (miRNAs), as key post-transcriptional regulators of gene expression, may influence cellular disease state. To investigate whether lung miRNA expression profiles in mice are modified by VOCs mixture exposure, 44 male Kunming mice were exposed in 4 similar static chambers, 0 (control) and 3 different doses of VOCs mixture (groups 1–3). The concentrations of VOCs mixture were as follows: formaldehyde, benzene, toluene, and xylene 3.0 + 3.3 + 6.0 + 6.0 mg/m3 , 5.0 + 5.5 + 10.0 + 10.0 mg/m3 , 10.0 + 11.0 + 20.0 + 20.0 mg/m3 , respectively, which corresponded to 30, 50, and 100 times of indoor air quality standard in China, after exposure to 2 weeks (2 h/day, 5 days/week). Small RNAs in lung and protein isolated from bronchoalveolar lavage fluid (BALF) were collected and analyzed for miRNA expression using microarray analysis and for interleukin-8 (IL-8) protein levels by enzyme-linked immunosorbent assay, respectively. VOCs exposure altered the miRNA expression profiles in lung in mice. Specifically, 69 miRNAs were significantly differentially expressed in VOCs-exposed samples versus controls. Functional annotation analysis of the predicted miRNA transcript targets revealed that VOCs exposure potentially alters signaling pathways associated with cancer, chemokine signaling, Wnt signaling, neuroactive ligand-receptor interaction, and cell adhesion molecules. IL-8 isolated from BALF and nitric oxide synthase of lung increased significantly, whereas GSH of lung decreased significantly in mice exposed to VOCs. These results indicate that inhalation of VOCs alters miRNA patterns that regulate gene expression, potentially leading to the initiation of cancer and inflammatory diseases. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Altered sperm chromatin structure in mice exposed to sodium fluoride through drinking water
Abstract This study investigated the effects of sodium fluoride (NaF) on sperm abnormality, sperm chromatin structure, protamine 1 and protamine 2 (P1 and P2 ) mRNA expression, and histones expression in sperm in male mice. NaF was orally administrated to male mice at 30, 70, and 150 mg/l for 49 days (more than one spermatogenic cycle). Sperm head and tail abnormalities were significantly enhanced at middle and high doses. Similarly, sperm chromatin structure was also adversely affected by NaF exposure, indicating DNA integrity damage. Furthermore, middle and high NaF significantly reduced the mRNA expressions of P1 and P2 , and P1/P2 ratio, whereas the sperm histones level was increased, suggesting the abnormal histone-protamine replacement. Therefore, we concluded that the mechanism by which F induced mice sperm abnormality and DNA integrity damage may involved in the alterations in P1 , P2 , and histones expression in sperm of mice. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
The embryonic and postembryonic developmental toxicity of imidazolium-based ionic liquids on Physa acuta
Abstract The embryonic and postembryonic developmental toxicity of imidazolium-based ionic liquids (ILs) to the snail Physa acuta was evaluated in this study. The results of embryonic toxicity tests showed that lower concentrations of 1-octyl-3-methylimidazolium bromide ([C8 mim]Br) (1.5 and 2.1 mg/L) inhibited the hatching rate of snail embryos, and partial snails hatched normally and died, while all of the treated embryos died when the exposure concentration was higher than 4.16 mg/L, at which IL caused the deformation, death, and decay of snail embryos. Statistical analyses revealed obvious differences in the hatching rates between three developmental stages in the 2.1 and 2.94 mg/L groups, indicating that the veliger stage is more sensitive to [C8 mim]Br exposure than the blastula and gastrula stages. Furthermore, the 96 h LC50 values of [C8 mim]Br on the tested snails at three developmental stages (juvenile, subadult, and adult) were 70.83 ± 2.99, 97.59 ± 4.05, and 109.3 ± 2.22 mg/L, respectively, indicating that young snails were more sensitive to [C8 mim]Br toxicity than adults. In addition, the 96 h LC50 values of ILs with different alkyl chain lengths, that is, [C12 mim], [C10 mim], [C8 mim], and [C6 mim], in adult snails were 1.35 ± 0.24, 8.96 ± 5.66, 109.3 ± 4, and 359.6 ± 11.6 mg/L, respectively, suggesting that longer alkyl chains can increase the toxicity of imidazolium ILs on snails. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Protective effect of melatonin on propoxur-induced impairment of memory and oxidative stress in rats
Abstract Propoxur (a carbamate pesticide) has been shown to adversely affect memory and induce oxidative stress on both acute and chronic exposure. This study was designed to explore the modulation of the effects of propoxur over cognitive function by melatonin (MEL). Cognitive function was assessed using step-down latency (SDL) on a passive avoidance apparatus, and transfer latency (TL) on an elevated plus maze. Oxidative stress was assessed by examining brain malondialdehyde (MDA) and reduced glutathione (GSH) levels and catalase (CAT) activity. A significant reduction in SDL and prolongation of TL was observed for the propoxur (10 mg/kg/d; p.o.) treated group at weeks 6 and 7 when compared with control. One week treatment with MEL (50 mg/kg/d; i.p.) antagonized the effect of propoxur on SDL, as well as TL. Propoxur produced a statistically significant increase in the brain MDA levels and decrease in the brain GSH levels and CAT activity. Treatment with MEL attenuated the effect of propoxur on oxidative stress. The results of the present study thus show that MEL has the potential to attenuate cognitive dysfunction and oxidative stress induced by toxicants like propoxur in the brain. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Acute spill-mimicking exposure effect of hexavalent chromium on the pituitary-ovarian axis of a teleost, Channa punctatus (Bloch)
Abstract Acute exposure to hexavalent chromium (as 10, 20, and 40 mg/L potassium dichromate for 96 h) adversely affected the pituitary-ovarian axis of a teleost Channa punctatus . The toxic impact of metal exposure on fish ovary was revealed in the form of increased percentage of atretic follicles, significantly in 20 mg/L and 40 mg/L exposure groups. The follicular atresia mostly occurred in vitellogenic (stage II and stage III) oocytes. Reduction of serum level of 17β-estradiol was also significant in 20 mg/L and 40 mg/L exposure groups. The increase of LH-immunointensity of pituitary gonadotrophs (LHβ-immunoreactive cells) and their hypertrophy was evident, significantly in fish of 40 mg/L exposed group. Thus, the present acute metal spill-mimicking laboratory study clearly demonstrated that short-term exposures to high doses of hexavalent chromium may disrupt reproduction of the fish and affect their population. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Chrysophanol-induced cell death (necrosis) in human lung cancer A549 cells is mediated through increasing reactive oxygen species and decreasing the level of mitochondrial membrane potential
Abstract Chrysophanol (1,8-dihydroxy-3-methylanthraquinone) is one of the anthraquinone compounds, and it has been shown to induce cell death in different types of cancer cells. The effects of chrysophanol on human lung cancer cell death have not been well studied. The purpose of this study is to examine chrysophanol-induced cytotoxic effects and also to investigate such influences that involved apoptosis or necrosis in A549 human lung cancer cells in vitro . Our results indicated that chrysophanol decreased the viable A549 cells in a dose- and time-dependent manner. Chrysophanol also promoted the release of reactive oxygen species (ROS) and Ca2+ and decreased the levels of mitochondria membrane potential (ΔΨm ) and adenosine triphosphate in A549 cells. Furthermore, chrysophanol triggered DNA damage by using Comet assay and DAPI staining. Importantly, chrysophanol only stimulated the cytocheome c release, but it did not activate other apoptosis-associated protein levels including caspase-3, caspase-8, Apaf-1, and AIF. In conclusion, human lung cancer A549 cells treated with chrysophanol exhibited a cellular pattern associated with necrotic cell death and not apoptosis in vitro . © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Inflammatory airway responses by nasal inoculation of suspended particulate matter in NC/Nga mice
Abstract To evaluate the allergic effect of airborne particulate matter (PM) on the airway, separated soluble supernatant (Sup) and insoluble precipitate (Pre) in suspended PM were inoculated into NC/Nga mice with a high sensitivity for mite allergens. Sup, Pre, or both Sup and Pre with or without pronase treatment were inoculated via the nasal route five times for sensitization and a challenge inoculation on the 11th day in NC/Nga mice. On the 14th day, mice were examined for airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th1 and Th2 cytokines in the lung tissue, and histopathology. Synergistic effects of Sup and Pre were observed as increases in AHR and a histopathological change of Periodic acid-Schiff (PAS) staining. Increases in neutrophils, macrophages, and lymphocytes of BALF cells were dependent on Pre. The expression of IL-4 mRNA was increased by Sup, and those of IL-5 mRNA and Il-13 mRNA was increased by Sup and Pre. Augmented AHR, mRNA expression of IL-4, peribronchial inflammation, and PAS staining by Sup plus Pre were attenuated by treatment of Sup with pronase to digest proteins. These results suggest that some proteins of ambient PM may be important environmental factors for AHR and airway inflammation with the aid of insoluble particulates, although some soluble factors such as endotoxins cannot be ruled out. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
4-chloro-1,2-phenylenediamine Induces Apoptosis in Mardin–Darby canine kidney cells via activation of caspases
Abstract 4-Chloro-1,2-phenylenediamine (4-Cl-o -PD) is a halogenated aromatic diamine that was used as a precursor for manufacturing permanent hair dyes. Despite its well-documented mutagenic and carcinogenic effects in a number of in vitro and in vivo models, its cytotoxicity and mode of action have not received similar attention. Here, we investigated the effect of 4-Cl-o -PD on Mardin–Darby canine kidney cells. It induced apoptosis and the evidence suggests its initiation by reactive oxygen species (ROS). The results of various assays used show a dose-dependent (i) decrease in cell viability, (ii) increase in cells at sub-G1 phase and the G0/G1 phase arrested in cell cycle, (iii) increase in intracellular ROS accompanied by depletion of glutathione, and (iv) that apoptotic cell death probably involves activation of both intrinsic and extrinsic pathways. © 2012 Wiley Periodicals, Inc. Environ Toxicol 2012.
Diphenyl diselenide protects against metabolic disorders induced by acephate acute exposure in rats
Abstract The present study investigated the effect of diphenyl diselenide [(PhSe)2 ] on metabolic disorders induced by acephate acute exposure in rats. We also investigated a possible mechanism of action of (PhSe)2 against hyperglycemia induced by acephate. (PhSe)2 was administered to rats at a dose of 10 or 30 mg/kg by oral gavage (p.o.) 1 hour prior to acephate administration (140 mg/kg; p.o.). Glucose and corticosterone levels as well as the lipid status were determined in plasma of rats. Cardiovascular risk factors and the atherogenic index were calculated. Glycogen levels as well as tyrosine aminotransferase (TAT) and glucose-6-phosphatase (G6Pase) activities were determined in livers of rats. Cerebral acetylcholinesterase (AChE) activity was assayed. Acephate induced an increase in glucose and corticosterone levels as well as in TAT and G6Pase activities. AChE activity was inhibited by acephate. Triglyceride (TG) levels and the cardiovascular risk factor TG/high-density lipoprotein-cholesterol (HDL) were increased by acephate. (PhSe)2 was effective against the metabolic disorders induced by acephate acute exposure in rats. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
A semiquinone glucoside derivative provides protection to male reproductive system of the mice against gamma radiation toxicity
Abstract Present investigation was carried out to evaluate the radioprotective efficacy of a novel Semiquinone glucoside derivative (SQGD), isolated from Bacillus sp. INM-1, in the male reproductive system of BALB/c mice. Animals were administered 50 mg/kg b.wt. (i.p.) SQGD 2 h before whole body γ-irradiation (10 Gy). Radiation-induced cellular toxicity and its modulation by SQGD pretreatment was evaluated in the mice testes by quantitative histological and protein expression analysis. SQGD pretreatment protects irradiated mice from radiation-induced testicular atrophy and germ cells degeneration, which may lead to emptiness of seminiferous tubules. Significant decrease in P53 and P21(Cip/WAF-1) expression was observed in the irradiated mice pretreated (2 h) by SQGD at 6 h compared with only irradiated mice. However, contrary to P53, expressions of P21 at latter time, that is, 24–72 h was found to be increased significantly in the irradiated mice pretreated by SQGD. Significant increase in the intact PARP-1 protein expression were observed in the testes of the mice pretreated by SQGD 2 h before irradiation at 24–72 h compared with the only irradiated mice, whereas significant increase in PARP-1 cleaved fragment was noticed at 24 h. Similarly, significant increase in NF-kB and BCL-2/BAX expressions ratio was noticed in SQGD-treated mice (± irradiation) compared with irradiated mice, suggested a role of SQGD in the activation of prosurvival signaling in the testicular germinal cells population of the irradiated mice and thus contributed to protection against lethal γ-irradiation. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Micronuclei, nucleoplasmic bridges, and nuclear buds induced in human lymphocytes by the fungicide signum and its active ingredients (boscalid and pyraclostrobin)
Abstract The aim of this study was to investigate the genotoxic and cytotoxic potential of the Signum fungicide and its active ingredients (boscalid and pyraclostrobin) on human peripheral blood lymphocytes using the cytokinesis-block micronucleus (CBMN) assay. Micronuclei (MNi), nucleoplasmic bridges (NPBs), nuclear bud (NBUDs) formations, and the cytokinesis-block proliferation index (CBPI) were evaluated in treated lymphocytes in Go (cells were treated and then kept in culture without stimulation for 24 h) and proliferation phases (cells were treated after 44 h culture in medium containing phytohemagglutinin). MN formation in lymphocytes treated in G 0 statistically increased at doses of 2, 6, and 25 μg/mL signum; 0.5 and 2 μg/mL boscalid; and 0.5, 1.5, and 2 μg/mL pyraclostrobin; while NPB formation increased at a dose of 0.25 μg/mL pyraclostrobin. All concentrations of each fungicide did not statistically increase NBUD formation, while the cytotoxicity increased the dependent on concentration in lymphocytes treated in G 0 . Doses of 0.5, 1, 1.5, and 3 μg/mL signum; 0.5, 1, and 1.5 μg/mL boscalid; and 0.75 μg/mL pyraclostrobin statistically increased the MN formation in proliferating lymphocytes. NPB formation increased in proliferating lymphocytes at doses of 1, 1.5, 2, and 3 μg/mL signum and at a dose of 0.75 μg/mL pyraclostrobin. In addition, a dose of 0.75 μg/mL pyraclostrobin increased NBUD frequencies. Cytotoxicity increased with increasing concentrations of each fungicide. It is concluded that signum, boscalid, and pyraclostrobin may be genotoxic and cytotoxic in vitro human peripheral blood lymphocytes in consideration of each of the two protocols. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
In vitro investigation of the genotoxic and cytotoxic effects of thiacloprid in cultured human peripheral blood lymphocytes
Abstract Thiacloprid, a neonicotinoid insecticide, is widely used for controlling various species of pests on many crops. The potential genotoxic effects of thiacloprid on human peripheral blood lymphocytes (PBLs) were investigated in vitro by the chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and cytokinesis-block micronucleus (MN) assays. The human PBLs were treated with 75, 150, and 300 μg/mL thiacloprid in the absence and presence of an exogenous metabolic activator (S9 mix). Thiacloprid increased the CAs and SCEs significantly at all concentrations (75, 150, and 300 μg/mL) both in the absence and presence of the S9 mix and induced a significant increase in MN and nucleoplasmic bridge formations at all concentrations for 24 h and at 75 and 150 μg/mL for 48-h treatment periods in the absence of the S9 mix; and at all concentrations in the presence of the S9 mix when compared with the control and solvent control. Thiacloprid was also found to significantly induce nuclear bud (NBUD) formation at 300 μg/mL for 24 h and at 150 μg/mL for 48-h treatment times in the absence of the S9 mix and at the two highest concentrations (150 and 300 μg/mL) in the presence of the S9 mix. Thiacloprid significantly decreased the mitotic index, proliferation index, and nuclear division index for all concentrations both in the absence and presence of the S9 mix. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effects of Hg(II) Exposure on MAPK Phosphorylation and Antioxidant System in D. melanogaster
Abstract The heavy metal mercury is a known toxin, but while the mechanisms involved in mercury toxicity have been well demonstrated in vertebrates, little is known about toxicological effects of this metal in invertebrates. Here, we present the results of our study investigating the effects associated with exposure of fruit fly Drosophila melanogaster to inorganic mercury (HgCl2 ). We quantify survival and locomotor performance as well as a variety of biochemical parameters including antioxidant status, MAPK phosphorylation and gene expression following mercury treatment. Our results demonstrate that exposure to Hg(II) through diet induced mortality and affected locomotor performance as evaluated by negative geotaxis, in D. melanogaster . We also saw a significant impact on the antioxidant system including an inhibition of acetylcholinesterase (Ache), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities. We found no significant alteration in the levels of mRNA of antioxidant enzymes or NRF-2 transcriptional factor, but did detect a significant up regulation of the HSP83 gene. Mercury exposure also induced the phosphorylation of JNK and ERK, without altering p38MAPK and the concentration of these kinases. In parallel, Hg(II) induced PARP cleavage in a 89 kDa fragment, suggesting the triggering of apoptotic cell death in response to the treatment. Taken together, this data clarifies and extends our understanding of the molecular mechanisms mediating Hg(II) toxicity in an invertebrate model. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Basic apoptotic and necrotic cell death in human liver carcinoma (HepG2) cells induced by synthetic azamacrocycle
Abstract Treatment of diseases with synthetic materials has been an aspiration of mankind since the dawn of human development. In this research, three complex compounds of azamacrocycle (TD1, TD2, and TD3) were synthesized, and experiments were conducted to determine whether their toxicity to human liver carcinoma (HepG2 ) cells is associated with apoptotic and/or necrotic cell death. Cell survival was determined by MTT assay. Apoptosis and necrosis were measured by annexin V FITC/PI assay using the flow cytometry and by propidium iodide (PI) assay using the cellometer vision. HepG2 cells were treated with different concentrations of azamacrocycles for 48 h. Results from MTT assay indicated that all the three azamacrocycles significantly (p < 0.05) reduce cell viability in a dose-dependent manner, showing 48 h-LD50 values of about 37.97, 33.60, and 19.29 μM, for TD3, TD1 and TD2, respectively. Among the three compounds tested, TD2 showed the most pronounced cytotoxic activity against HepG2 cells, being about twofold more potent than TD3. The order of toxicity was TD2 > TD1 > TD3. Because TD2 exerted the most cytotoxic activity against HepG2 cells, it was used in the subsequent apoptosis and necrosis-related experiments. The flow cytometry assessment showed a strong dose-response relationship with regard to TD2 exposure and annexin V/PI positive cells. PI assay data indicated that TD2 exposure increased the proportion of fluorescence positive cells. Overall, our results indicate that azamacrocycle toxicity to HepG2 cells is associated with apoptotic and necrotic cell death resulting from phosphatidylserine externalization and loss of membrane integrity. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Genotoxic effects of glyphosate or paraquat on earthworm coelomocytes
Abstract The potential genotoxicity (nuclear anomalies, damage to single-strand DNA) and pinocytic adherence activity of two (glyphosate-based and paraquat-based) commercial herbicides to earthworm coelomocytes (immune cells in the coelomic cavity) were assessed. Coelomocytes were extracted from earthworms (Pheretima peguana ) exposed to concentrations <LC50 of glyphosate-based or paraquat-based herbicides on filter paper for 48 h. Three assays were performed: Micronucleus (light microscopy count of micronuclei, binuclei, and trinuclei), Comet (epifluorescent microscope and LUCIA image analyzer measure of tail DNA %, tail length, and tail moment), and Neutral Red (to detect phagocytic or pinocytic activity). The LC50 value for paraquat was 65-fold lower than for glyphosate indicating that paraquat was far more acutely toxic to P. peguana. There were significant (P < 0.05) differences from the control group in total coelomocyte micronuclei, binuclei, and trinuclei frequencies of earthworms exposed to glyphosate at 25 × 10–1 (10–3 LC50) and paraquat at 39 × 10–5 (10–4 LC50) μg cm–2 filter paper. In earthworms exposed to glyphosate, no differences in tail DNA%, tail length, and tail moment of coelomocytes were detected. In contrast, for paraquat at 10–1 LC50 concentration, there were significant (P < 0.05) differences between tail DNA % and tail length, and at LC50 concentration, tail moment was also significantly different when compared with controls. A decline in pinocytic adherence activity in coelomocytes occurred on exposure to glyphosate or paraquat at 10–3 LC50 concentration. This study showed that, at concentrations well below field application rates, paraquat induces both clastogenic and aneugenic effects on earthworm coelomocytes whereas glyphosate causes only aneugenic effects and therefore does not pose a risk of gene mutation in this earthworm. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Benzo[a]pyrene modulation of acute immunologic responses in red Sea bream pretreated with lipopolysaccharide
Abstract The effects of polycyclic aromatic hydrocarbons (PAHs) have been reported to modulate the immune response in aquatic animals, but the collected information of their effects on fish immunity is so far ambiguous. This study demonstrated that Benzo[a ]pyrene (BaP) exposure altered the expression pattern of an antimicrobial peptide hepcidin (PM-hepc) gene and the activities of some immune-associated parameters in the lipopolysaccharide (LPS)-challenged red sea bream (Pagrus major ). It was observed that LPS could increase respiratory burst, lysozyme and antibacterial activity in P. major . However when the P. major was exposed to different concentrations of BaP (1, 4, or 8 μg L−1 ) for 14 days and then challenged with LPS there was no significant change in the lysozyme and antibacterial activity. It was further observed that LPS could induce the PM-hepc mRNA expression at 3, 6, and 12-h post-LPS challenge. However, when P. major was exposed first to BaP for 14 days and then challenged with LPS, the expression of PM-hepc mRNA was delayed in the liver until 24 h and not significantly induced until 48 and 96 h. The mRNA expression pattern was completely different from that only with LPS challenge, showing that BaP exposure changed the PM-hepc mRNA expression pattern of fish with LPS challenge. This study demonstrated that BaP exposure can weaken or inhibit the induction of lysozyme and antibacterial activity in the LPS-challenged P. major ; conversely BaP exposure could enhance the mRNA expression of PM-hepc gene, indicating that the effect of BaP has different modulatory mechanism on hepcidin genes and immune-associated parameters. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Responses of biomarkers of a standardized (Cyprinus carpio) and a native (Pimelodella laticeps) fish species after in situ exposure in a periurban zone of Luján river (Argentina)
Abstract The Luján River basin, which is located in the northwest area of the province of Buenos Aires, Argentina, receives different anthropogenic inputs before reaching the RÃo de la Plata estuary. The aim of this study was to assess the adverse impact of the river in the middle part of the basin. To this end, an in situ cage assay was conducted in two sites of the river (S1 and S2) near Luján city, and the responses of hepatic biomarkers of both a standardized (Cyprinus carpio ) and a native (Pimelodella laticeps ) species were evaluated. The biomarkers studied were the condition factor and liver somatic indices (LSI), the enzymatic activities of catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST), lipid peroxidation levels (thiobarbituric acid reactive substances, TBARS) and the induction of hepatic cytochrome P450 1A (CYP1A) and vitellogenin (Vtg) proteins. After 14 days, LSI and GST activity increased, and TBARS levels decreased in both species exposed at S1 and S2. In addition, exposure at both sites promoted an increase in SOD activity and CYP1A induction in C. carpio , while Vtg expression was observed only at S1. A shorter exposure period (7 days) caused an initial response only at S2 mediated only by CAT in P. laticeps . Finally, our results demonstrate that a 14-day period of in situ exposure in Luján River could lead to antioxidant and biotransformation processes in C. carpio and to phase II biotransformation responses in P. laticeps . © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Human dna damage by the synergistic action of 4-aminobiphenyl and nitric oxide: An immunochemical study
Abstract 4-Aminobiphenyl (4-ABP), an aromatic amine is a major environmental carcinogen found mainly in cigarette smoke. It has been vastly implicated in mutagenesis and cancer development. In this study, commercially available human placental DNA was exposed to 4-ABP (1.3 mM) in presence of sodium nitroprusside (SNP; 8 mM) at 37°C for 3 h. The 4-ABP + SNP-mediated structural changes in human DNA were studied by ultraviolet, circular dichroism and fluorescence spectroscopy, thermal melting profile, agarose gel electrophoresis, and nuclease S1 digestibility assay. Spectroscopical analysis and melting temperature studies suggest structural perturbations in the DNA as a result of modification. This might be due to generation of single-stranded regions and destabilization of hydrogen bonds. Modification was also visualized in agarose gel electrophoresis. Furthermore, nuclease S1 digestibility confirmed the generation of single strand breaks. Rabbits challenged with 4-ABP-SNP-modified human DNA-induced high-titer immunogen-specific antibodies, which showed Cross-reaction with modified/unmodified DNA bases and ss-DNA in competitive inhibition assay. The immunogen specificity of induced antibodies against 4-ABP-SNP-modified human DNA was further confirmed in gel retardation assay. It may be concluded that induction of anti-modified DNA antibodies could be due to perturbation in the DNA structure and its subsequent recognition by immunoregulatory cells as a foreign molecule. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Assessment of the genotoxic effects of organophosphorus insecticides phorate and trichlorfon in human lymphocytes
Abstract In vitro genotoxic effects of organophosphorus insecticides Phorate (PHR) and Trichlorfon (TCF) were investigated using four genotoxicity endpoints. Different concentration ranges between 0.25–2.00 μg mL−1 of PHR and 2.34–37.50 μg mL−1 of TCF were applied to lymphocytes. PHR and TCF significantly increased the frequency of chromosomal aberrations (except 2.34 μg mL−1 for TCF) and sister chromatid exchanges at all treatment times and concentrations. Most of the used concentrations induced a significant increase in the frequency of micronuclei. Furthermore, PHR and TCF significantly decreased the mitotic index at the higher concentrations after 24- and 48-h treatments. In the comet assay, PHR and TCF significantly increased the comet tail at all concentrations. However, the comet tail intensity was significantly increased at only the highest concentration of PHR and at all concentrations of TCF. According to these results, PHR and TCF possess clastogenic, mutagenic, and DNA damaging effects in human lymphocytes in vitro . © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Fluoride decreased osteoclastic bone resorption through the inhibition of NFATc1 gene expression
Abstract Over the past two decades, fluoride effects on osteoclasts have been evaluated; however, its molecular mechanisms remain unclear. In this study, we investigated the effect of fluoride on osteoclast formation, function, and regulation using osteoclasts formed from mice bone marrow macrophages treated with the receptor activator of NF-κB ligand and macrophage colony-stimulating factor. Our data showed that fluoride levels ≤ 8 mg/L had no effect on osteoclast formation; however, it significantly reduced osteoclast resorption at 0.5 mg/L. Fluoride activity on bone resorption occurred through the inhibition of nuclear factor of active T cells (NFAT) c1 expression. Furthermore, the expression of its downstream genes, including the dendritic cell-specific transmembrane protein, c-Src, the d2 isoform of vacuolar (H+) ATPase v0 domain, matrix metalloproteinase 9, and cathepsin K were decreased, leading to impaired osteoclast acidification, reduced secretion of proteolytic enzymes, and decreased bone resorption. In summary, our results suggested that fluoride has different roles in osteoclast formation and function. Fluoride ≤ 8 mg/L did not impact osteoclast formation; however, it significantly decreased the resorption activity of newly formed osteoclasts. The molecular mechanism of fluoride action may involve inhibition of NFATc1 and its downstream genes. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Perinatal exposure to di-(2-ethylhexyl)-phthalate leads to cognitive dysfunction and phospho-tau level increase in aged rats
Abstract Di-(2-ethylhexyl)-Phthalate (DEHP) can affect glucose and insulin homeostasis in periphery and lead to insulin resistance, especially exposure of DEHP during critical developmental period. Given the potential relationship between insulin resistance and pathogenesis of Alzheimer's disease (AD) in elderly life, we investigated the relationship between perinatal DEHP exposure and AD pathogenesis. Our results suggested that perinatal exposure to DEHP can affect the expression of insulin and insulin-Akt- GSK-3β signal pathway in hippocampus. Furthermore, impaired cognitive ability and increased level of phospho-Tau was observed in DEHP-exposed rat offspring (1.25 ± 0.11 vs. 0.47 ± 0.07, P < 0.05). The present study demonstrates that perinatal exposure to DEHP may be a potential risk factor for AD pathogenesis associated with insulin resistance and insulin metabolism disorder in the hippocampus. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Hydrogen peroxide induces adaptive response and differential gene expression in human embryo lung fibroblast cells
Abstract Hydrogen peroxide (H2 O2 ), a substance involved in cellular oxidative stress, has been observed to induce an adaptive response, which is characterized by a protection against the toxic effect of H2 O2 at higher concentrations. However, the molecular mechanism for the adaptive response remains unclear. In particular, the existing reports on H2 O2 -induced adaptive response are limited to animal cells and human tumor cells, and relatively normal human cells have never been observed for an adaptive response to H2 O2 . In this study, a human embryo lung fibroblast (MRC-5) cell line was used to model an adaptive response to H2 O2 , and the relevant differential gene expressions by using fluoro mRNA differential display RT-PCR. The results showed significant suppression of cytotoxicity of H2 O2 (1100 μM, 1 h) after pretreatment of the cells with H2 O2 at lower concentrations (0.088–8.8 μM, 24 h), as indicated by cell survival, lactate dehydrogenase release, and the rate of apoptotic cells. Totally 60 mRNA components were differentially expressed compared to untreated cells, and five of them (sizing 400–600 bp) which demonstrated the greatest increase in expression were cloned and sequenced. They showed identity with known genes, such as BCL-2, eIF3S5, NDUFS4, and RPS10. Real time RT-PCR analysis of the five genes displayed a pattern of differential expression consistent with that by the last method. These five genes may be involved in the induction of adaptive response by H2 O2 in human cells, at least in this particular cell type. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cytotoxicity and genotoxicity of chlorhexidine on macrophages in vitro
Abstract Chlorhexidine (CHX) is the most widely used antiseptic for wound, skin disinfection, and dental hygiene. The aim of this study is to investigate the possible correlation between CHX-induced cytogenotoxicity and alterations in normal cell cycle on RAW264.7 macrophages. The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis-block proliferation index, and superoxide dismutase-inhibitable reduction of ferricytochrome c , respectively. The genotoxicity was measured using comet assay and cytokinesis-block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose- and time-dependent manner (p < 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown DNA damage in a dose-dependent manner (p < 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose-dependent manner (p < 0.05). Taken together, the data suggested that CHX-induced cytotoxicity and genotoxicity on macrophages may be via ROS generation. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Inhibition of polyisoprenylated methylated protein methyl esterase by synthetic musks induces cell degeneration
Abstract Synthetic fragrances are persistent environmental pollutants that tend to bioaccumulate in animal tissues. They are widely used in personal care products and cleaning agents. Worldwide production of Galaxolide and Tonalide are in excess of 4500 tons annually. Because of their widespread production and use, they have been detected in surface waters and fish in the US and Europe. Consumption of contaminated water and fish from such sources leads to bioaccumulation and eventual toxicity. Since fragrances and flavors bear structural similarities to polyisoprenes, it was of interest to determine whether toxicity by Galaxolide and Tonalide may be linked with polyisoprenylated methylated protein methyl esterase (PMPMEase) inhibition. A concentration-dependent study of PMPMEase inhibition by Galaxolide and Tonalide as well as their effects on the degeneration of cultured cells were conducted. Galaxolide and Tonalide inhibited purified porcine liver PMPMEase with K i 50 values of 26 and 98 μM (neuroblastoma SH-SY5Y cells) and 58 and 14 μM (lung cancer A549 cells), respectively. The effects on cell viability correlate well with the inhibition of PMPMEase activity in the cultured cells. Molecular docking analysis revealed that the binding interactions are most likely between the fragrance molecules and hydrophobic amino acids in the active site of the enzyme. These results appear to suggest that the reported neurotoxicity of these compounds may be associated with their inhibition of PMPMEase. Exposure to fragrances may pose a significant risk to individuals predisposed to developing degenerative disorders. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Toxicity thresholds for juvenile freshwater mussels Echyridella menziesii and crayfish Paranephrops planifrons, after acute or chronic exposure to Microcystis sp.
Abstract Survival of juvenile freshwater mussels (Echyridella menziesii (Gray, 1843) formerly known as Hyridella menziesi ) and crayfish (Paranephrops planifrons , White, 1842) decreased after four days exposure to microcystin-containing cell-free extracts (MCFE) of Microcystis sp. at concentrations typical of severe cyanobacterial blooms. Crayfish survival was 100, 80, and 50% in microcystin concentrations of 1339, 2426, and 11146 μg L−1 respectively, and shade- and shelter-seeking behavior was negatively affected when concentrations were ≥2426 μg L−1 . Mussel survival decreased to 92% and reburial rates decreased to 16% after exposure for 96 h to MCFE containing microcystins at concentrations of 5300 μg L−1 . Crayfish survival was 100% when fed freeze-dried Microcystis sp. incorporated into an artificial diet (6–100 μg microcystin kg−1 ww) at dietary doses from 0.03 to 0.55 μg g−1 body weight d−1 for 27 days. Specific growth rate was significantly lower in crayfish fed ≥0.15 μg g−1 body weight day−1 compared with controls, but not compared with a diet incorporating nontoxic cyanobacteria. Microcystins accumulated preferentially in crayfish hepatopancreas and mussel digesta as MCFE or dietary concentrations increased. These laboratory data indicate that, assuming dissolved oxygen concentrations remain adequate, and no simultaneous exposure to live Microcystis sp. cells, cell-free microcystins will only be a significant stressor to juvenile crayfish and mussels in severe Microcystis sp. blooms. In contrast, crayfish were negatively affected by relatively low concentrations of microcystins in artificial diets compared with those measured locally in benthic cyanobacterial mats. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Extensive Ace2 duplication and multiple mutations on Ace1 and Ace2 are related with high level of organophosphates resistance in Aphis gossypii
Abstract Aphis gossypii (Glover) has been found to possess multiple mutations in the acetylcholinesterase (AChE) gene (Ace ) that might involve target site insensitivity. In vitro functional expression of AChEs reveals that the resistant Ace1 (Ace1R) and Ace2 (Ace2R) were significantly less inhibited by eserine, omethoate, and malaoxon than the susceptible Ace1 (Ace1S) and Ace2 (Ace2S). Furthermore, in both the mutant and susceptible AChEs, Ace2 was significantly less sensitive to eserine, omethoate, and malaoxon than Ace1. These results suggested that both the mutant Ace1 and Ace2 were responsible for omethoate resistance, while the mutant Ace2 played a major role in insecticide resistance. The DNA copy number and transcription level of Ace2 were 1.52- and 1.88-fold higher in the ORR strain than in the OSS strain. Furthermore, the DNA copy number and transcription level of Ace2 were significantly higher than that of Ace1 in either OSS or ORR strains, demonstrating the involvement of Ace2 gene duplication in resistance. Thus, the authors conclude that omethoate resistance in cotton aphids appears to have evolved through a combination of multiple mutations and extensive Ace2R gene duplication. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Prenatal di-n-butyl phthalate exposure alters reproductive functions at adulthood in male rats
Abstract This study was aimed to investigate the reproductive health in adult male rats exposed to di-n -butyl phthalate (DBP) during embryonic development. Pregnant rats were injected with DBP and F1 male rats were weaned and on postnatal day 100, used for mating with normal cycling females to assess reproductive performance. After completion of cohabitation period, rats were analyzed for other reproductive end points. Transplacental exposure to DBP significantly decreased fertility in adult male rats. Prenatal exposure to DBP significantly decreased sperm density, number of motile sperms, viable sperms, and hypoosmotic swelling tail coiled sperms with an increase in morphological abnormalities in sperms. Testicular steroidogenic enzyme activity levels and serum testosterone levels were significantly decreased in rats exposed to DBP during embryonic development. In conclusion, transplacental exposure to DBP impairs male reproductive performance by decreasing steroidogenesis and spermatogenesis. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Synergistic interactions between PBDEs and PCBs in human neuroblastoma cells
Abstract Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants. Exposure to these chemicals has been associated with developmental neurotoxicity, endocrine dysfunction, and reproductive disorders. Humans and wildlife are generally exposed to a mixture of these environmental pollutants, highlighting the need to evaluate the potential effects of combined exposures. In this study, we investigated the cytotoxic effects of the combined exposure to two PBDEs and two PCBs in a human neuronal cell line. 2,2′,4,4′-Tetrabromodiphenyl ether, 2,2′,4,4′,5-pentabromodiphenyl ether, PCB-126 (3,3′,4,4′,5-pentachlorobiphenyl; a dioxin-like PCB), and PCB-153 (2,2′,4,4′,5,5′-hexachlorobiphenyl; a non-dioxin-like PCB) were chosen, because their concentrations are among the highest in human tissues and the environment. The results suggest that the nature of interactions is related to the PCB structure. Mixtures of PCB-153 and both PBDEs had a prevalently synergistic effect. In contrast, mixtures of each PBDE congener with PCB-126 showed additive effects at threshold concentrations, and synergistic effects at higher concentrations. These results emphasize the concept that the toxicity of xenobiotics may be affected by possible interactions, which may be of significance given the common coexposures to multiple contaminants. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
The roles of endoplasmic reticulum stress and mitochondrial apoptotic signaling pathway in quercetin-mediated cell death of human prostate cancer PC-3 cells
Abstract Prostate cancer has its highest incidence and is becoming a major concern. Many studies have shown that traditional Chinese medicine exhibited antitumor responses. Quercetin, a natural polyphenolic compound, has been shown to induce apoptosis in many human cancer cell lines. Although numerous evidences show multiple possible signaling pathways of quercetin in apoptosis, there is no report to address the role of endoplasmic reticulum (ER) stress in quercetin-induced apoptosis in PC-3 cells. The purpose of this study was to investigate the effects of quercetin on the induction of the apoptotic pathway in human prostate cancer PC-3 cells. Cells were treated with quercetin for 24 and 48 h and at various doses (50–200 μM), and cell morphology and viability decreased significantly in dose-dependent manners. Flow cytometric assay indicated that quercetin at 150 μM caused G0/G1 phase arrest (31.4–49.7%) and sub-G1 phase cells (19.77%) for 36 h treatment and this effect is a time-dependent manner. Western blotting analysis indicated that quercetin induces the G0/G1 phase arrest via decreasing the levels of CDK2, cyclins E, and D proteins. Quercetin also stimulated the protein expression of ATF, GRP78, and GADD153 which is a hall marker of ER stress. Furthermore, PC-3 cells after incubation with quercetin for 48 h showed an apoptotic cell death and DNA damage which are confirmed by DAPI and Comet assays, leading to decrease the antiapoptotic Bcl-2 protein and level of ΔΨm , and increase the proapoptotic Bax protein and the activations of caspase-3, -8, and -9. Moreover, quercetin promoted the trafficking of AIF protein released from mitochondria to nuclei. These data suggest that quercetin may induce apoptosis by direct activation of caspase cascade through mitochondrial pathway and ER stress in PC-3 cells. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Monitoring toxigenic Microcystis strains in the Missisquoi bay, Quebec, by PCR targeting multiple toxic gene loci
Abstract The increasing incidence of mixed assemblages of toxic and nontoxic cyanobacterial blooms in Quebec's freshwater bodies over the last decade, coupled with inherent inadequacies of current monitoring approaches, warrants development of sensitive and reliable tools for assessing the toxigenic potential of these water blooms. In this study, we applied three independent polymerase chain reaction (PCR) assays that simultaneously target the microcystin synthetase (mcy ) genes A, E, and G to rapidly and reliably detect and quantify potentially toxic Microcystis genotypes in the Missisquoi bay, Quebec, Canada. Linear regressions of quantitative PCR threshold cycles (C t ) against the logarithm of their respective Microcystis cell number equivalents resulted in highly significant linear curves with coefficients of determination (R 2 ) greater than 0.99 (p < 0.0001, n = 6) and reaction efficiencies of 91.0, 95.8, and 92.7%, respectively, for the mcy A, mcy E, and mcy G-based quantitative real-time PCR (qPCR) assays. The three assays successfully estimated potential microcystin-producing Microcystis genotypes from all field samples. The proportions of Microcystis mcy A, mcy E, and mcy G genotypes to total Microcystis cell counts showed substantial spatial variability ranging between 1.7–21.6%, 1.9–11.2%, and 2.2–22.6%, respectively. Correlation of microscopically determined total Microcystis counts to qPCR-based Microcystis mcy A, mcy E, or mcy G cell number equivalents resulted in highly significant associations with R 2 > 0.90. Thus, PCR-based assays targeting the mcy A, mcy G, and/or mcy E genes can serve as powerful screening tools for rapid and sensitive estimation of microcystin-producing Microcystis genotypes in freshwater water bodies. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effects of 4-nonylphenol on balance of steroid and thyroid hormones in sexually immature male yellowfin seabream (Acanthopagrus latus)
Abstract Nonylphenol (NP) is an endocrine disrupting chemical which has been shown to be able to modulate the endocrine system of various organisms by different mechanisms. The objective of this study was to investigate the potential effects of 4-NP on steroid and thyroid hormone levels in sexually immature male yellowfin seabream (Acanthopagrus latus ), a protandrous hermaphrodite species. For this, the fish were injected with ascending doses (10, 50, 100, and 200 μg g−1 body weight) of 4-nonylphenol (4-NP) or vehicle during 2 weeks. After 7 and 14 days the fish were anesthetized, blood sample were collected and plasma steroid and thyroid hormone concentrations were quantified by radioimmunoassay. The result showed that 4-NP induced a significant increase in 17β-etradiol levels at dose 10 μg g−1 , while the levels of this hormone in the higher doses decreased compared with the control group. However, 4-NP treatment did not have any significant effect on plasma levels of testosterone. In addition, it was observed that 4-NP affect the level of thyroid hormones in fish. Plasma thyroxine levels increased in a dose-dependent manner after 7 and 14 days of the exposure. In contrast, a significant decrease in triiodothyronine levels was observed during the experiment period. Moreover, no significant change was detected for thyroid stimulating hormone levels in 4-NP-treated fish. These results indicated that 4-NP could lead to disturb the balance of steroid and thyroid hormones with potential consequences for sexually immature male yellowfin seabream. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
The surface reactivity and implied toxicity of ash produced from sugarcane burning
Abstract Sugarcane combustion generates fine-grained particulate that has the potential to be a respiratory health hazard because of its grain size and composition. In particular, conversion of amorphous silica to crystalline forms during burning may provide a source of toxic particles. In this study, we investigate and evaluate the toxicity of sugarcane ash and bagasse ash formed from commercial sugarcane burning. Experiments to determine the main physicochemical properties of the particles, known to modulate biological responses, were combined with cellular toxicity assays to gain insight into the potential reactions that could occur at the particle-lung interface following inhalation. The specific surface area of the particles ranged from ∼16 to 90 m2 g−1 . The samples did not generate hydroxyl- or carbon-centered radicals in cell-free tests. However, all samples were able to ‘scavenge’ an external source of hydroxyl radicals, which may be indicative of defects on the particle surfaces that may interfere with cellular processes. The bioavailable iron on the particle surfaces was low (2–3 μmol m−2 ), indicating a low propensity for iron-catalyzed radical generation. The sample surfaces were all hydrophilic and slightly acidic, which may be due to the presence of oxygenated (functional) groups. The ability to cause oxidative stress and membrane rupture in red blood cells (hemolysis) was found to be low, indicating that the samples are not toxic by the mechanisms tested. Cytotoxicity of sugarcane ash was observed, by measuring lactate dehydrogenase release, after incubation of relatively high concentrations of ash with murine alveolar macrophage cells. All samples induced nitrogen oxide release (although only at very high concentrations) and reactive oxygen species generation (although the bagasse samples were less potent than the sugarcane ash). However, the samples induced significantly lower cytotoxic effects and nitrogen oxide generation when compared with the positive control. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Protective role of zinc during aluminum-induced hepatotoxicity
Abstract The study was carried out to assess the role of zinc (Zn) in mitigating the biochemical alterations induced by aluminum (Al) in rat liver. Rats were divided into four groups: normal control, Al treated (AlCl3 , 100 mg/kg b.wt./day), Zn treated (ZnSO4 , 227 mg/L drinking water), and combined Al + Zn treated. Al and zinc treatments were given for a total duration of 2 months. Al treatment caused a significant increase in the activity of alkaline phosphatase (ALP), but decreased aspartate aminotransferase (AST) and alanine aminotranferase (ALT) activities, which showed the reverse trend following Zn supplementation. Levels of lipid peroxidation (LPx) and activities of catalase and glutathione-S -transferase (GST) were significantly decreased following Al treatment, which, however, were increased significantly in Zn co-treated rats. Further Al exposure showed a significant increase in reduced glutathione (GSH) content as well as activities, of superoxide dismutase (SOD) and glutathione reductase (GR). However, Zn supplementation to Al-treated rats brought down the raised levels of reduced (GSH) and SOD to within normal limits, but caused no effect on GR activity. Furthermore, Al treatment also resulted in alterations in liver histoarchitecture with disruption of hepatic cords and increased vacuolization, which were close to normal following Zn supplementation. The present study reveals that Zn is effective in attenuating the liver damage inflicted by Al toxicity. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effects of carbofuran and deltamethrin on acetylcholinesterase activity in brain and muscle of the common carp
Abstract This work investigated the effect from exposure to insecticides carbofuran and deltamethrin on acetylcholinesterase (AChE) activity in the brain and muscle of common carp (Cyprinus carpio ). Both pesticides were evaluated through two separate experiments, and carp were exposed in a semi-static system to three different concentrations of carbofuran (10, 50, and 100 μg/L) and deltamethrin (0.08, 0.4, and 0.8 μg/L) during a month with sampling times at 0, 4, 15, and 30 days (n = 7 from each aquarium). AChE activity was significantly inhibited in both organs of carps exposed to carbofuran at all sampling times depending on dose and time, reaching inhibition values of 73.5 and 67.1%, in brain and muscle tissues respectively, after 30 days with the highest concentration. On the contrary, AChE activity was not significantly affected after deltamethrin exposure at all concentrations and times of the assay. This study shows that the measurement of brain and muscle AChE activity in Cyprinus carpio is a useful biomarker of carbamates exposure and/or effects, but has no application with pyrethroids. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Tissue-specific copper accumulation, zinc levels, induction, and purification of metallothionein in freshwater crab Sinopotamon henanense exposed to subacute waterborne copper
Abstract Copper (Cu) is one of the most important essential metals for crustaceans, but toxic in excess. Metallothioneins (MT) are a family of low molecular weight, cysteine-rich, metal-binding proteins, which play important roles in metal homeostasis, detoxification, and cytoprotection. In the present study, Sinopotamon henanense were exposed to 0 (controls), 2.86, and 14.3 mg L−1 waterborne Cu, Cu accumulation, zinc (Zn) levels and MT induction in gills and hepatopancreas were determined with Cd/Hemoglobin saturation assay and atomic absorption spectrophotometry method. Results showed that Cu accumulation and MT levels were both tissue-specific and revealed some time-dependent and dose-dependent, respectively. The highest Cu accumulations of 82.10 ± 16.38 μg g−1 w wt were observed in the gill after 15 days of 14.3 mg L−1 Cu exposure, the peak MT induction of 136.16 ± 19.39 μg g−1 w wt were observed in the hepatopancreas after 3 day of 14.3 mg L−1 Cu exposure.In addition, the essential metal homeostasis of Zn was disturbed in some ways by subacute Cu exposure. The calculated ratios of actual Cu to theoretical maximum metal bound by MT indicating that the hepatopancreas had much greater Cu-binding potentials than the gills. Positive correlation were shown between MT induction and Cu accumulation both in hepatopancreas and gills, indicating that MT induction in S. henanense can be considered as a biomarker for subacute waterborne Cu pollution. Furthermore, the Cu induced MT (CuMT) from S. henanense was purified using acetone precipitation (50–80%), followed by gel filtration chromatography and anion exchange chromatography. SDS-PAGE and time-of-flight mass spectrometry analysis showed that S. henanense CuMT possess two isoforms and both mainly existed as monomer and dimmer forms. These present studies will be helpful to increase the database information of heavy metal-induced MT in terms of crustaceans. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Toxicity of pamam-coated gold nanoparticles in different unicellular models
Abstract Polyamidoamine (PAMAM) dendrimers are used for many pharmaceutical and biomedical applications. However, the toxicological risks of several PAMAM-based compounds are still not fully evaluated, despite evidences of PAMAM deleterious effects on biological membranes, leading to toxicity. In this report, we investigated the toxicity of generation 0 PAMAM-coated gold nanoparticles (AuG0 NPs) in four different models to determine how different cellular systems are affected by PAMAM-coated NPs. Toxicity was evaluated in two mammalian cell lines, Neuro 2A and Vero, in the green alga Chlamydomonas reinhardtii and the bacteria Vibrio fischeri . AuG0 NP treatments reduced cell metabolic activity in algal and bacterial cells, measured by esterase enzymatic activity (C. reinhardtii ) and luminescence emission (V. fischeri ). EC50 value after 30 min of treatment was similar in both organisms, with 0.114 and 0.167 mg mL−1 for C. reinhardtii and V. fischeri , respectively. On the other hand, AuG0 NPs induced no change of mitochondrial activity in mammalian cells after 24 h of treatment to up to 0.4 mg mL−1 AuG0 NPs. Change in the absorption spectra of AuG0 NP in the mammalian cell culture media may indicate an alteration of NP properties that contributed to the low toxicity of AuG0 NPs in mammalian cells. For a safe development of PAMAM-based nanomaterials, the difference of sensitivity between mammalian and microbial cells, as well as the modulation of NPs toxicity by medium properties, should be taken into account when designing PAMAM NPs for applications that may lead to their introduction in the environment. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cell death in relation to DNA damage after exposure to the jellyfish Pelagia noctiluca nematocysts
Abstract Studies on the toxicity of Mediterranean jellyfish have gained attention owing to their weak toxic properties. Our research has been mainly performed on the Scyphomedusae. Pelagia noctiluca is a scyphozoan jellyfish which causes a danger to sea bathers and fishery damages in the Mediterranean Sea. To check whether the cytotoxicity of Pelagia noctiluca nematocysts was associated to DNA lesions, we have looked for DNA fragmentation by means of the Comet and chromosome aberration assays. To specify cell death pathway, we have investigated caspase-3 activation. Our results have shown that nematocysts reduced cell viability and induced DNA fragmentation in a concentration-dependent manner with a maximum effect at 150 000 nematocysts mL−1 . The high percentage of chromosome aberrations also emphasized the genotoxic character of Pelagia noctiluca nematocysts in Vero cells. This fragmentation was correlated to apoptosis induction which was confirmed by caspase-3 activation. In conclusion, the present report has suggested that Pelagia noctiluca nematocysts were able to promote apoptosis in Vero cells and therefore may be useful in cancer therapy. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Scutellaria barbata inhibits angiogenesis through downregulation of HIF-1 α in lung tumor
Abstract Hypoxia, a hallmark of many solid tumors, is associated with angiogenesis and tumor progression. Hypoxia-inducible factor-1 (HIF-1) plays a significant role in tumor angiogenesis. In this study, the authors constructed a selective platform to screen the traditional Chinese medicine as anti-angiogenic agent. The authors examined the molecular mechanism by which Scutellaria barbata regulates HIF-1-dependent expression of vascular endothelial growth factor (VEGF), which is an important angiogenic factor. Hypoxia promotes angiogenesis by increasing VEGF expression and secretion. Herein, the expression of VEGF was decreased by treatment with S. barbata in tumor cells. Meanwhile, S. barbata reduced the migration and proliferation of endothelial cells under hypoxic condition. S. barbata inhibited the expression of HIF-1α, as well as phosphorylated their upstream signal mediators AKT. S. barbata significantly inhibited the tumor growth in vivo and immunohistochemical studies in the tumors revealed decreased intratumoral microvessel density. These results suggest that the traditional Chinese medicine therapy using S. barbata , which exerts anti-angiogenic activities, represents a promising strategy for the treatment of tumors. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Water-insoluble fraction of airborne particulate matter (PM10) induces oxidative stress in human lung epithelial A549 cells
Abstract Exposure to ambient airborne particulate matter (PM) with an aerodynamic diameter less than 10 μm (PM10 ) links with public health hazards and increases risk for lung cancer and other diseases. Recent studies have suggested that oxidative stress is a key mechanism underlying the toxic effects of exposure to PM10 . Several components of water-soluble fraction of PM10 (sPM10 ) have been known to be capable of inducing oxidative stress in in vitro studies. In this study, we investigated if water-insoluble fraction of PM10 (iPM10 ) could be also capable of inducing oxidative stress and oxidative damage. Human lung epithelial A549 cells were exposed to 10 μg/mL of sPM10 , iPM10 or total PM10 (tPM10 ) preparation for 24 h. Here, we observed that all three PM10 preparations reduced cell viability and induced apoptotic cell death in A549 cells. We further found that, similar to the exposure to sPM10 and tPM10 , the intracellular level of hydrogen peroxide (H2 O2 ) in the iPM10 -exposed cells was increased significantly; meanwhile the activity of catalase was decreased significantly as compared with the unexposed control cells, resulting in significant DNA damage. Our data obtained from inductively coupled plasma-mass spectrometry (ICP-MS) assays showed that iron is the most abundant metal in all three PM10 preparations. Thus, we have demonstrated that, similar to sPM10 , iPM10 is also capable of inducing oxidative stress by probably inducing generation of H2 O2 and impairing enzymatic antioxidant defense, resulting in oxidative DNA damage and even apoptotic cell death through the iron-catalyzed Fenton reaction. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Effects of cadmium alone and in combination with low molecular weight chitosan on metallothionein, glutathione-S-transferase, acid phosphatase, and ATPase of freshwater crab Sinopotamon yangtsekiense
Abstract Cadmium (Cd) is an environmental contaminant showing a variety of deleterious effects, including the potential threat for the ecological environment and human health via food chains. Low molecular weight chitosan (LMWC) has been demonstrated to be an effective antioxidant. Metallothionein (MT) mRNA levels and activities of glutathione-S -transferase (GST), superoxide dismutase (SOD), acid phosphatase (ACP), Na+ ,K+ -ATPase, and Ca2+ -ATPase as well as malondialdehyde (MDA) contents in the gills of the freshwater crab Sinopotamon yangtsekiense were analyzed in vivo in order to determine the injury of Cd exposure on the gill tissues as well as the protective effect of LMWC against this injury. The results showed that there was an apparent accumulation of Cd in the gills, which was lessened by the presence of LMWC. Moreover, Cd2+ significantly increased the gill MT mRNA levels, ACP activity and MDA content while decreasing the activities of SOD, GST, Na+ ,K+ -ATPase, and Ca2+ -ATPase in the crabs relative to the control. Cotreatment with LMWC reduced the levels of MT mRNA and ACP but raised the activities of GST, Na+ ,K+ -ATPase, and Ca2+ -ATPase in gill tissues compared with the crabs exposed to Cd2+ alone. These results suggest that LMWC may exert its protective effect through chelating Cd2+ to form LMWC-Cd2+ complex, elevating the antioxidative activities of GST, Na+ ,K+ -ATPase, and Ca2+ -ATPase as well as alleviating the stress pressure on MT and ACP, consequently protecting the cell from the adverse effects of Cd. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Evaluation of the cytotoxicity of organic dust components on THP1 monocytes-derived macrophages using high content analysis
Abstract Organic dust contains pathogen-associated molecular patterns (PAMPs) which can induce significant airway diseases following chronic exposure. Mononuclear phagocytes are key protecting cells of the respiratory tract. Several studies have investigated the effects of PAMPs and mainly endotoxins, on cytokine production. However the sublethal cytotoxicity of organic dust components on macrophages has not been tested yet. The novel technology of high content analysis (HCA) is already used to assess subclinical drug-induced toxicity. It combines the capabilities of flow cytometry, intracellular fluorescence probes, and image analysis and enables rapid multiple analyses in large numbers of samples. In this study, HCA was used to investigate the cytotoxicity of the three major PAMPs contained in organic dust, i.e., endotoxin (LPS), peptidoglycan (PGN) and β-glucans (zymosan) on THP-1 monocyte-derived macrophages. LPS was used at concentrations of 0.005, 0.01, 0.02, 0.05, 0.1, and 1 μg/mL; PGN and zymosan were used at concentrations of 1, 5, 10, 50, 100, and 500 μg/mL. Cells were exposed to PAMPs for 24 h. In addition, the oxidative burst and the phagocytic capabilities of the cells were tested. An overlap between PGN intrinsic fluorescence and red/far-red fluorescent dyes occurred, rendering the evaluation of some parameters impossible for PGN. LPS induced sublethal cytotoxicity at the lowest dose (from 50 ng/mL). However, the greatest cytotoxic changes occurred with zymosan. In addition, zymosan, but not LPS, induced phagosome maturation and oxidative burst. Given the fact that β-glucans can be up to 100-fold more concentrated in organic dust than LPS, these results suggest that β-glucans could play a major role in macrophage impairment following heavy dust exposure and will merit further investigation in the near future. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Acute exposure to pure cylindrospermopsin results in oxidative stress and pathological alterations in tilapia (Oreochromis niloticus)
Abstract Cylindrospermopsin (CYN) is increasingly recognized as a potential threat to drinking water safety, due to its ubiquity. This cyanotoxin has been found to cause toxic effects in mammals, and although fish could be in contact with this toxin, acute toxicity studies on fish are nonexistent. This is the first study showing that single doses of CYN pure standard (200 or 400 μg CYN/kg fish bw) by oral route (gavage) generate histopathological effects in fish (Tilapia—Oreochromis niloticu s) exposed to the toxin under laboratory condition. Among the morphological changes, disorganized parenchymal architecture in the liver, dilated Bowman's space in the kidney, fibrolysis in the heart, necrotic enteritis in the intestines, and hemorrhages in the gills, were observed. Moreover, some oxidative stress biomarkers in the liver and kidney of tilapias were altered. Thus, CYN exposure induced increased protein oxidation products in both organs, NADPH oxidase activity was significantly increased with the kidney being the most affected organ, and decreased GSH contents were also detected in both organs, at the higher dose assayed. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cytotoxicity and apoptosis induction by nanoscale talc particles from two different geographical regions in human lung epithelial cells
Abstract We have characterized the physicochemical properties of nanotalc particles from two different geographical regions and examined their toxicity mechanisms in human lung epithelial (A549) cells. Indigenous nanotalc (IN) of Indian origin and commercial nanotalc (CN) of American origin were used in this study. Physicochemical properties of nanotalc particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Brunauer-Emmet-Teller (BET), and dynamic light scattering (DLS). Results showed that both IN and CN particles significantly induce cytotoxicity and alteration in cell cycle phases. Both IN and CN particles were found to induce oxidative stress indicated by induction of reactive oxygen species (ROS), lipid peroxidation, and depletion of antioxidant levels. DNA fragmentation and caspase-3 enzyme activation due to IN and CN particles exposure were also observed. We further showed that after iron chelation, IN and CN particles produce significantly less cytotoxicity, oxidative stress, and genotoxicity to A549 cells as compared with nonchelated particles. In conclusion, this study demonstrated that redox active iron plays significant role in the toxicity of IN and CN particles, which may be mediated through ROS generation and oxidative stress. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cloperastine rescues impairment of passive avoidance response in mice prenatally exposed to diethylstilbestrol
Abstract We previously reported that prenatal exposure to diethylstilbestrol (DES) impaired passive avoidance responses in mice. Apart from the above, we also found that cloperastine, a centrally acting antitussive, ameliorated depression-like and anxiety-like behaviors in rodents at antitussive-effective doses. In this study, we investigated whether or not cloperastine rescues impairment of passive avoidance responses in mice prenatally exposed to DES. Male DES-exposed mice were subcutaneously administered cloperastine at 10 or 30 mg/kg twice a day from 32 to 41 days after birth and subjected to behavioral testing 42 to 46 days after birth. Cloperastine at 10 and 30 mg/kg ameliorated DES-induced impairment of passive avoidance responses. In addition, cloperastine affected the levels of 5-HT1A receptors, GIRK and BDNF in the hippocampus of DES-exposed mice. However, the number of BrdU-positive cells in the hippocampus of DES-exposed mice was not changed by chronic administration of cloperastine. These findings suggest that the action of endocrine disruptors in the brain may not always be irreversible, and that the symptoms caused by endocrine disruptors might be curable with drugs such as cloperastine. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Exposure to 17α-ethinylestradiol decreases motility and ATP in sperm of male fighting fish Betta splendens
Abstract The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine-disrupting chemical released into aquatic environments from sewage treatment facilities. We tested the effects of two environmentally relevant concentrations of waterborne EE2, 10 and 100 ng L−1 , on reproductive endpoints in the teleost fish Betta splendens . In the first experiment, testes were removed from males and sperm were exposed to EE2 directly through the activation water. Direct exposure to EE2 had no effect on any measure of sperm swimming performance. In the second experiment, we exposed sexually mature male B. splendens to EE2 using a semi-static exposure protocol for 4 weeks. There were no significant treatment effects in the 10 ng L−1 treatment group, but at the 100 ng L−1 dose we found that fish had smaller gonads and reduced sperm swimming velocity. When allowed to interact freely with female conspecifics, males exposed to 100 ng L−1 EE2 built smaller nests and showed a nonsignificant decrease in fertilization success. To investigate further the potential mechanism underlying the decrease in sperm quality, we repeated the chronic exposure experiment and analyzed the ATP content of sperm from fish in each treatment group. We found that males exposed to 100 ng L−1 of EE2 had fewer moles of ATP per sperm than did fish in the other two treatment groups, suggesting that a decrease in intracellular ATP caused a reduction in sperm swimming velocity. The current study adds to the growing body of literature that indicates the risks to aquatic organisms of exposure to environmentally relevant concentrations of EE2. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Organic insecticide spinosad causes in vivo oxidative effects in the brain of Oreochromis niloticus
Abstract Spinosad is an organic insecticide derived from a naturally occurring soil bacterium and is used in organic farming worldwide. The aim of this study was to evaluate in vivo toxic effects of spinosad in the brain of Oreochromis niloticus as a model organism. The fish were exposed to sublethal spinosad concentrations (25, 50, 75 mg L−1 ) for 24–48–72 h to determine tGSH, GSH, GSSG, and TBARS contents, GSH/GSSG ratio, and GPx, GR, GST enzymes activities using spectrophotometrical methods, and Hsp70 content by an ELISA technique. Spinosad caused elevations in the contents of tGSH, GSH, GSSG, Hsp70, and reductions in the ratio of GSH/GSSG and GPx activity and an induction in the GR activity. The results indicated that spinosad had oxidative effects in the brain tissue by altering the parameters in GSH-related antioxidant system and Hsp70. It was also suggested that spinosad-induced free-radicals were eliminated by GSH-related antioxidant system in the brain of Oreochromis niloticus . © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Affinity purification using recombinant PXR as a tool to characterize environmental ligands
Abstract Many environmental endocrine disrupting compounds act as ligands for nuclear receptors. The human pregnane X receptor (hPXR), for instance, is activated by a variety of environmental ligands such as steroids, pharmaceutical drugs, pesticides, alkylphenols, polychlorinated biphenyls and polybromo diethylethers. Some of us have previously reported the occurrence of hPXR ligands in environmental samples but failed to identify them. The aim of this study was to test whether a PXR-affinity column, in which recombinant hPXR was immobilized on solid support, could help the purification of these chemicals. Using PXR ligands of different affinity (10 nM < EC50 < 10 μM), we demonstrated that the PXR-affinity preferentially column captured ligands with medium to high affinities (EC50 < 1 μM). Furthermore, by using the PXR-affinity column to analyze an environmental sample containing ERα, AhR, AR, and PXR activities, we show that (i) half of the PXR activity of the sample was due to compounds with medium to high affinity for PXR and (ii) PXR shared ligands with ERα, AR, and AhR. These findings demonstrate that the newly developed PXR-affinity column coupled to reporter cell lines represents a valuable tool for the characterization of the nature of PXR active compounds and should therefore guide and facilitate their further analysis. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Cell cycle deregulation by methyl isocyanate: Implications in liver carcinogenesis
Abstract Liver is often exposed to plethora of chemical toxins. Owing to its profound physiological role and central function in metabolism and homeostasis, pertinent succession of cell cycle in liver epithelial cells is of prime importance to maintain cellular proliferation. Although recent evidence has displayed a strong association between exposures to methyl isocyanate (MIC), one of the most toxic isocyanates, and neoplastic transformation, molecular characterization of the longitudinal effects of MIC on cell cycle regulation has never been performed. Here, we sequentially delineated the status of different proteins arbitrating the deregulation of cell cycle in liver epithelial cells treated with MIC. Our data reaffirms the oncogenic capability of MIC with elevated DNA damage response proteins pATM and γ-H2AX, deregulation of DNA damage check point genes CHK1 and CHK2, altered expression of p53 and p21 proteins involved in cell cycle arrest with perturbation in GADD-45 expression in the treated cells. Further, alterations in cyclin A, cyclin E, CDK2 levels along with overexpression of mitotic spindle checkpoints proteins Aurora A/B, centrosomal pericentrin protein, chromosomal aberrations, and loss of Pot1a was observed. Thus, MIC impacts key proteins involved in cell cycle regulation to trigger genomic instability as a possible mechanism of developmental basis of liver carcinogenesis. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Excitotoxicity and oxidative damages induced by methylmercury in rat cerebral cortex and the protective effects of tea polyphenols
Abstract Methylmercury (MeHg) is a highly neurotoxic environmental pollutant that has a high appetency to the central nervous system. The underlying mechanisms of MeHg-induced neurotoxicity have not been elucidated clearly until now. Therefore, to explore the mechanisms contribute to MeHg-induced neurotoxicity, rats were exposed to different dosage of methylmercury chloride (CH3 ClHg) (0, 4, and 12 μmol kg−1 ) for 4 weeks to evaluate the neurotoxic effects of MeHg. In addition, considering the antioxidative properties of tea polyphenols (TP), 1 mmol kg−1 TP was pretreated to observe the possible protective effects on MeHg-induced neurotoxicity. Then Hg, glutamate (Glu) and glutamine (Gln) levels, glutamine synthetase (GS), phosphate-activated glutaminase (PAG), Na+ -K+ -ATPase, and Ca2+ -ATPase activities, intracellular Ca2+ level were examined, glutathione (GSH), malondialdehyde (MDA), protein sulfhydryl, carbonyl, 8-hydroxy-2-deoxyguanosine (8-OHdG), and reactive oxygen species (ROS) levels, N -methyl-D -aspartate receptors (NMDARs) mRNA and protein expressions, apoptosis level and morphological changes in the cerebral cortex were also investigated. Study results showed that compared with those in control, exposure to CH3 ClHg resulted in excitotoxicity in a concentration-dependent manner, which was shown by the Glu-Gln cycle disruption and intracellular Ca2+ homeostasis disturbance. On the other hand, CH3 ClHg exposure resulted in oxidative damages of brain, which were supported by the significant changes on GSH, MDA, sulfhydryl, carbonyl, 8-OHdG, and ROS levels. Moreover, apoptosis rate increased obviously and many morphological changes were found after CH3 ClHg exposure. Furthermore, this research indicated that TP pretreatment significantly mitigated the toxic effects of MeHg. In conclusion, findings from this study indicated that exposure to MeHg could induce excitotoxicity and oxidative damage in cerebral cortex while TP might antagonize the MeHg-induced neurotoxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol 21:, 2011.
Spatial learning and memory impairment and pathological change in rats induced by acute exposure to microcystin-LR
Abstract Microcystin-LR (MCLR) is a commonly encountered blue–green algal hepatotoxin and a known inhibitor of cellular protein phosphatase. However, little is known about its neurotoxicity. By using Morris water maze, histopathological and biochemical analysis, we investigated MCLR-induced neurotoxicity on the hippocampus of rat brain. After rats were intrahippocampally injected with MCLR (1 and 10 μg/L), their learning and memory function was greatly impaired, suggesting the neurotoxic potential of MCLR. Meanwhile, obvious histological and ultrastructural injuries and serious oxidative damage were also observed in the hippocampus. These results suggested that oxidative stress might be involved in the MCLR-induced pathological damage in hippocampus, subsequently leading to the spatial learning and memory deficit of rat. Taken together, our results highlighted the MCLR-induced neurotoxicity in the rat, as well as the importance of oxidative stress and pathological impairment in this procedure. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Protein phosphatases 2A as well as reactive oxygen species involved in tributyltin-induced apoptosis in mouse livers
Abstract Tributyltin (TBT), a highly toxic environmental contaminant, has been shown to induce caspase-3-dependent apoptosis in human amniotic cells through protein phosphatase 2A (PP2A) inhibition and consequent JNK activation. This in vivo study was undertaken to further verify the results derived from our previous in vitro study. Mice were orally dosed with 0, 10, 20, and 60 mg/kg of body weight TBT, and levels of PP2A, reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), Bax/Bcl-2, and caspase-3 were detected in the mouse livers. Apoptosis was also evaluated using the TUNEL assay. The results showed that PP2A activity was inhibited, ROS levels were elevated, and MAPKs including ERK, JNK, and p38 were activated in mouse livers treated with the highest dose of TBT. Additionally, the ratio of Bax/Bcl-2 was increased, caspase-3 was activated, and apoptosis in mouse livers could be detected in the highest dose group. Therefore, a possible signaling pathway in TBT-induced apoptosis in mouse livers involves PP2A inhibition and ROS elevation serving a pivotal function as upstream activators of MAPKs; activation of MAPKs in turn leads to an increase in the Bax/Bcl-2 ratio, ultimately leading to the activation of caspase-3. The results give a comprehensive and novel description of the mechanism of TBT-induced toxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Acetaminophen increases the risk of arsenic-mediated development of hepatic damage in rats by enhancing redox-signaling mechanism
Abstract We evaluated whether the commonly used analgesic-antipyretic drug acetaminophen can modify the arsenic-induced hepatic oxidative stress and also whether withdrawal of acetaminophen administration during the course of long-term arsenic exposure can increase susceptibility of liver to arsenic toxicity. Acetaminophen was co-administered orally to rats for 3 days following 28 days of arsenic pre-exposure (Phase-I) and thereafter, acetaminophen was withdrawn, but arsenic exposure was continued for another 28 days (Phase-II). Arsenic increased lipid peroxidation and reactive oxygen species (ROS) generation, depleted glutathione (GSH), and decreased superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) activities. Acetaminophen caused exacerbation of arsenic-mediated lipid peroxidation and ROS generation and further enhancement of serum alanine aminotransferase and aspartate aminotransferase activities. In Phase-I, acetaminophen caused further GSH depletion and reduction in SOD, catalase, GPx and GR activities, but in Phase-II, only GPx and GR activities were more affected. Arsenic did not alter basal and inducible nitric oxide synthase (iNOS)-mediated NO production, but decreased constitutive NOS (cNOS)-mediated NO release. Arsenic reduced expression of endothelial NOS (eNOS) and iNOS genes. Acetaminophen up-regulated eNOS and iNOS expression and NO production in Phase-I, but reversed these effects in Phase-II. Results reveal that acetaminophen increased the risk of arsenic-mediated hepatic oxidative damage. Withdrawal of acetaminophen administration also increased susceptibility of liver to hepatotoxicity. Both ROS and NO appeared to mediate lipid peroxidation in Phase-I, whereas only ROS appeared responsible for peroxidative damage in Phase-II. © 2011 Wiley-Liss, Inc. Environ Toxicol, 2011.
Molecular and cellular effects of chemicals disrupting steroidogenesis during early ovarian development of brown trout (Salmo trutta fario)
Abstract A range of chemicals found in the aquatic environment have the potential to influence endocrine function and affect sexual development by mimicking or antagonizing the effects of hormones, or by altering the synthesis and metabolism of hormones. The aim of this study was to evaluate whether the effects of chemicals interfering with sex hormone synthesis may affect the regulation of early ovarian development via the modulation of sex steroid and insulin-like growth factor (IGF) systems. To this end, ex vivo ovary cultures of juvenile brown trout (Salmo trutta fario ) were exposed for 2 days to either 1,4,6-androstatriene-3,17-dione (ATD, a specific aromatase inhibitor), prochloraz (an imidazole fungicide), or tributyltin (TBT, a persistent organic pollutant). Further, juvenile female brown trout were exposed in vivo for 2 days to prochloraz or TBT. The ex vivo and in vivo ovarian gene expression of the aromatase (CYP19), responsible for estrogen production, and of IGF1 and 2 were compared. Moreover, 17β-estradiol (E2) and testosterone (T) production from ex vivo ovary cultures was assessed. Ex vivo exposure to ATD inhibited ovarian E2 synthesis, while T levels accumulated. However, ATD did not affect ex vivo expression of cyp19 , igf1 , or igf2 . Ex vivo exposure to prochloraz inhibited ovarian E2 production, but did not affect T levels. Further prochloraz up-regulated igf1 expression in both ex vivo and in vivo exposures. TBT exposure did not modify ex vivo synthesis of either E2 or T. However, in vivo exposure to TBT down-regulated igf2 expression. The results indicate that ovarian inhibition of E2 production in juvenile brown trout might not directly affect cyp19 and igf gene expression. Thus, we suggest that the test chemicals may interfere with both sex steroid and IGF systems in an independent manner, and based on published literature, potentially lead to endocrine dysfunction and altered sexual development. © 2011 Wiley-Liss, Inc. Environ Toxicol, 2011.
Antioxidant effect of propolis against exposure to chromium in Cyprinus carpio
Abstract The aim of the present study was to investigate the ameliorative properties of propolis against the toxic effects of chromium (VI) by examining oxidative damage markers such as lipid peroxidation and the antioxidant defence system components in carp (Cyprinus carpio ). The fish were exposed to sublethal concentrations of chromium. Propolis was simultaneously administered to chromium-exposed fish. Treatment was continued for 28 days, and at the end of this period, blood and tissue (liver, kidney, spleen, and gill) samples were collected. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were determined in blood and tissues for measurement of oxidant–antioxidant status. The levels of MDA, as an index of lipid peroxidation, increased in blood and tissues. Antioxidant enzyme activities in blood and tissues were modified in chromium groups compared to controls. Simultaneous administration of propolis ameliorated these parameters. The present results suggest that administration of propolis might alleviate chromium-induced oxidative stress. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Silymarin prevents the toxicity induced by benzo(a)pyrene in human erythrocytes by preserving its membrane integrity: An in vitro study
Abstract Silymarin, the purified extract from milk thistle Silybum marianum (L.) Gaertn, consists mainly of four isomeric flavonolignans: silibinin, isosilibinin, silidianin, and silichristin. The present study was carried out to evaluate the protective potential of silymarin in human erythrocytes against in vitro exposure to the carcinogen benzo(a)pyrene (B(a)P). Erythrocytes isolated from human blood were divided into four groups and treated with Vehicle [Group I], B(a)P (300 μM ) [Group II], Silymarin (500 μM ) + B(a)P (300 μM ) [Group III], and Silymarin alone (500 μM )] [Group IV]. Silymarin treatment maintains the integrity of erythrocytes by preventing hemolysis, protein thiol oxidation and by decreasing the activity of AChE. SEM observations indicate that B(a)P induced significant alteration in the morphology of erythrocytes to echinocytes, which may be due to the interaction of B(a)P with the membrane's outer phopholipid monolayer. The light microscopic and SEM images show that silymarin treatment maintains the normal discocytic morphology of erythrocytes. The protective effect of silymarin might be attributed to its chemical structure and membranotrophic nature. The components silibinin, silydianin, and silychristin have OH in the 3rd, 5th, and 7th carbon atoms that may account for its increased antioxidant activity and removal of ROS formed during B(a)P metabolism. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Stage-dependent toxicity of bisphenol a on Rhinella arenarum (anura, bufonidae) embryos and larvae
Abstract The acute and chronic toxicity of bisphenol A (BPA) was evaluated on the common South American toad Rhinella arenarum embryos and larvae by means of continuous and pulse exposure treatments. Embryos were treated continuously from early blastula (S.4) up to complete operculum (S.25), during early larval stages and by means of 24 h pulse exposures of BPA in concentrations ranging between 1.25 and 40 mg L−1 , in order to evaluate the susceptibility to this compound in different developmental stages. For lethal effects, S.25 was the most sensitive and gastrula was the most resistant to BPA. The Teratogenic Index for neurula, the most sensitive embryonic stage for sublethal effects was 4.7. The main morphological alterations during early stages were: delayed or arrested development, reduced body size, persistent yolk plug, microcephaly, axial/tail flexures, edemas, blisters, waving fin, underdeveloped gills, mouth malformations, and cellular dissociation. BPA caused a remarkable narcotic effect from gill circulation stage (S.20) onwards in all the organisms exposed after 3 h of treatment with 10 mg L−1 BPA. After recovering, the embryos exhibited scarce response to stimuli, erratic or circular swimming, and spasmodic contractions from 5 mg L−1 onwards. Our results highlight the lethal and sublethal effectsof BPA on R. arenarum embryos and larvae, in the last case both at structural and functional levels. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Acute and chronic toxicity of chromium and cadmium to the tropical cladoceran pseudosida ramosa and the implications for ecotoxicological studies
Abstract In this study, the acute and chronic toxicity of the metals chromium and cadmium were tested against the tropical freshwater cladoceran Pseudosida ramosa . Acute tests showed that the 48-h LC50 of chromium was 29 μg L−1 , while that of cadmium was 12 μg L−1 . P. ramosa had a similar sensitivity to those of other cladoceran species cultured in the same conditions as in this study, or a higher sensitivity when water hardness was raised. Long-term chronic exposure of P. ramosa to chromium decreased maternal survival, fecundity, and fertility at a concentration of 10 μg L−1 . For cadmium, reductions in the same endpoints were observed at a concentration of 3 μg L−1 . Moreover, the degree of toxicity of the chromium and cadmium to P. ramosa after release of the first brood was similar to the result obtained after 21 days, using reproduction as the endpoint. Brazilian water bodies located near industrial areas already show concentrations of chromium and cadmium higher than levels causing acute and chronic toxicity to P. ramosa in our study. Many water quality criteria in tropical regions are based on ecotoxicological tests with non-native species and, consequently, this may lead to errors of interpretation when the permitted maximum levels of for each toxic substance are established. Therefore, we reinforce the idea of using native species to establish the maximum concentrations of toxic substances in water quality criteria, especially for metals, since their effects are related to water hardness, pH, and temperature specific to each region. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Potassium bromate causes cell lysis and induces oxidative stress in human erythrocytes
Abstract In the present study, we have studied the effect of KBrO3 on human erythrocytes under in vitro conditions. Erythrocytes were isolated from the blood of healthy nonsmoking volunteers and incubated with different concentrations of KBrO3 at 37°C for 60 min. This resulted in marked hemolysis in a KBrO3 -concentration dependent manner. Lysates were prepared from KBrO3 -treated and control erythrocytes and assayed for various parameters. KBrO3 treatment caused significant increase in protein oxidation, lipid peroxidation, hydrogen peroxide levels, and decrease in total sulfhydryl content, which indicates induction of oxidative stress in human erythrocytes. Methemoglobin levels and methemoglobin reductase activity were significantly increased while the total antioxidant power of lysates was greatly reduced upon KBrO3 treatment. Intracellular production of reactive oxygen species increased in a dose dependent manner. Exposure of erythrocytes to KBrO3 also caused decrease in the activities of catalase, glutathione peroxidase, thioredoxin reductase, glucose 6-phosphate dehydrogenase and glutathione reductase whereas the activities of Cu-Zn superoxide dismutase and glutathione-S -transferase were increased. These results show that KBrO3 induces oxidative stress in human erythrocytes through the generation of reactive oxygen species and alters the cellular antioxidant defense system. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
DNA damage and repair following In vitro exposure to two different forms of titanium dioxide nanoparticles on trout erythrocyte
Abstract TiO2 has been widely used to promote organic compounds degradation on waste aqueous solution, however, data on TiO2 nanotoxicity to aquatic life are still limited. In this in vitro study, we compare the toxicity of two different families of TiO2 nanoparticles on erythrocytes from Oncorhynchus mykiss trout. The crystal structure of the two TiO2 nanoparticles was analyzed by XRD and the results indicated that one sample is composed of TiO2 in the anatase crystal phase, while the other sample contains a mixture of both the anatase and the rutile forms of TiO2 in a 2:8 ratio. Further characterization of the two families of TiO2 nanoparticles was determined by SEM high resolution images and BET technique. The toxicity results indicate that both TiO2 nanoparticles increase the hemolysis rate in a dose dependent way (1.6, 3.2, 4.8 μg mL−1 ) but they do not influence superoxide anion production due to NADH addition measured by chemiluminescence. Moreover, TiO2 nanoparticles (4.8 μg mL−1 ) induce DNA damage and the entity of the damage is independent from the type of TiO2 nanoparticles used. Modified comet assay (Endo III and Fpg) shows that TiO2 oxidizes not only purine but also pyrimidine bases. In our experimental conditions, the exposure to TiO2 nanoparticles does not affect the DNA repair system functionality. The data obtained contribute to better characterize the aqueous environmental risks linked to TiO2 nanoparticles exposure. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Effects of low-dose exposure to pesticide mixture on physiological responses of the pacific oyster, Crassostrea gigas
Abstract This study investigated the effects on the physiology of Pacific oyster, Crassostrea gigas , of a mixture of pesticides containing 0.8 μg L−1 alachlor, 0.6 μg L−1 metolachlor, 0.7 μg L−1 atrazine, 0.6 μg L−1 terbuthylazine, 0.5 μg L−1 diuron, 0.6 μg L−1 fosetyl aluminum, 0.05 μg L−1 carbaryl, and 0.7 μg L−1 glyphosate for a total concentration of 4.55 μg L−1 . The total nominal concentration of pesticides mixture corresponds to the pesticide concentrations in the shellfish culture area of the Marennes-Oleron basin. Two varieties of C. gigas were selected on the foreshore, based on their characteristics in terms of resistance to summer mortality, to assess the effects of the pesticide mixture after 7 days of exposure under controlled conditions. The early effects of the mixture were assessed using enzyme biomarkers of nitrogen metabolism (GS, glutamine synthetase), detoxification metabolism (GST, glutathione S -transferase), and oxidative stress (CAT, catalase). Sublethal effects on hemocyte parameters (phagocytosis and esterase activity) and DNA damages (DNA adducts) were also measured. Changes in metabolic activities were characterized by increases in GS, GST, and CAT levels on the first day of exposure for the “resistant†oysters and after 3–7 days of exposure for the “susceptible†oysters. The formation of DNA adducts was detected after 7 days of exposure. The percentage of hemocyte esterase-positive cells was reduced in the resistant oysters, as was the hemocyte phagocytic capacity in both oyster varieties after 7 days of exposure to the pesticide mixture. This study highlights the need to consider the low doses and the mixture of pesticides to evaluate the effects of these molecules on organisms. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Comparison of the protective effects of antioxidant compounds in the liver and kidney of Cd- and Cr-exposed common carp
Abstract The aim of this study was to see whether the taurine (TAU), alpha-lipoic acid (LA), curcumin (CUR), and N -acetylcysteine (NAC) protection against oxidative stress caused by heavy metals is owed to the metal-decreasing or antioxidative effect. In this context, liver and kidney tissues of common carp (Cyprinus carpio carpio L.) were exposed in vivo to model toxicants cadmium (Cd) and chromium (Cr). The tissues were dissected 96 h after intraperitoneal injection of the metals and antioxidant substances. Cd and Cr levels were determined in the liver using the ICP-OES, but we could not obtain enough kidney tissue to make the same measurements in the kidney. The enzymatic activities of SOD, CAT, and GPx, and the GSH redox status and lipid peroxidation levels were analyzed using spectrophotometric methods. Of all investigated antioxidants, only NAC decreased metal levels in the liver. Cd had little effect on oxidative stress parameters, while Cr showed a weak prooxidative effect. Cotreatment with TAU/LA/CUR/NAC and Cr significantly increased liver SOD activity. Chromium induced kidney SOD and CAT, but all antioxidants lowered CAT activity. Cadmium reduced liver and increased kidney GSSG. NAC increased liver GSH, but the increase did not correlate with decrease in Cd. Curcumin given with Cd increased kidney and decreased liver lipid peroxidation, whereas TAU with Cr increased lipid peroxidation in both tissues. N -Acetylcysteine was the most effective antioxidative agent, owing to its metal-decreasing function as well as to its effects on the GSH redox status. We believe that the investigated antioxidant substances which may have been involved in the reduction of Cr caused an increase in SOD activity and a decrease in CAT activity. Changes in the GSSG levels in both tissues might be an adaptive response to the prooxidative potential of Cd. Because of their respective tissue- and metal-dependent prooxidative effects, CUR and TAU deserve particular attention in regard to their use against metal toxicity, Cr in particular. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Pesticide induced alterations in marrow physiology and depletion of stem and stromal progenitor population: An experimental model to study the toxic effects of pesticide
Abstract Long-term exposure of agriculturally used organochloride and organophosphate pesticides have been shown to cause long-lasting hematotoxicity and increased incidence of aplastic anemia in humans. The mechanisms involved in pesticide induced hematotoxicity and the features of toxicity that may play a major role in bone marrow suppression are not known. The aim of the present study was to investigate the hematological consequences of pesticide exposure in swiss albino mice exposed to aqueous mixture of common agriculturally used pesticides for 6 h/day, 5 days/week for 13 weeks. After the end of last exposure, without a recovery period, the strong hematotoxic effect of pesticide was assessed in mice with long-term bone marrow explant culture (LTBMC-Ex) system and cell colony forming assays. Bone marrow explant culture from the pesticide exposed group of mice failed to generate a supportive stromal matrix and did not produce adequate number of hematopoietic cells and found to contain largely the adipogenic precursors. The decreased cell colony numbers in the pesticide exposed group indicated defective maturational and functional status of different marrow cell lineages. As a whole, exposure of mice to the mixture of pesticides reduced the total number of bone marrow cells (granulocytes are the major targets of pesticide toxicity), hematopoietic, and non-hematopoietic progenitor cells and most of the hematological parameters. Replication of primitive stem/progenitor cells in the marrow was decreased following pesticide exposure with G0/G1-phase arrest of most of the cells. The progenitor cells showed decreased percentage of cells in S/G2/M-phase. The increased apoptosis profile of the marrow progenitors (Increased CD95 expression) and primitive stem cells (High Annexin-V positivity on Sca1+ cells) with an elevated intracellular cleaved caspase-3 level on the Sca1+ bone marrow cells provided the base necessary for explaining the deranged bone marrow microenvironmental structure which was evident from scanning electron micrographs. These results clearly indicate a strong, long lasting toxic effect of pesticides on the bone marrow microenvironment and different microenvironmental components which ultimately leads to the formation of a degenerative disease like aplastic anemia. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Attenuation of low dose methylmercury and glutamate induced-cytotoxicity and tau phosphorylation by an N-methyl-D-aspartate antagonist in human neuroblastoma (SHSY5Y) cells
Abstract Methylmercury (MeHg), a known neurotoxin, has been reported to alter glutamate homeostasis in the neuronal environment resulting in excitotoxicity. This study was conducted to investigate whether, and if so, under what conditions, that low dose MeHg would enhance the toxicity of glutamate and to what extent that blockade of NMDA receptors would alter MeHg and glutamate's toxicity in cultured neuroblastoma cells. Neuroblastoma cells (SH-SY5Y) were used in a cell culture model to study effects of MeHg, glutamate (glu), a calcium chelator (BAPTA-AM), and a noncompetitive NMDA antagonist, MK-801 on cell growth, cell survival, and phosphorylation of tau protein, as a measure of cellular events associated with tauopathies. Exposure of cells to a combination of MeHg (50 nM) and glutamate (1 mM) resulted in both a greater decrease in cell viability as well as a greater induction in tau phosphorylation, as compared to exposures with MeHg and glutamate alone. MK-801, an NMDA receptor antagonist, and the intracellular calcium chelator, BAPTA-AM, both significantly inhibited tau hyperphosphorylation and protected cells from the effects of combination exposures to glutamate and MeHg. These results may indicate that exposure to even nontoxic levels of MeHg may prime neuronal cells to be more susceptible to neuronal injury from excitotoxicants such as glutamate and thus may increase the likelihood of neurological disease states. In conclusion, low-dose MeHg-induced toxicity may be related to an increase in the cellular response to glutamate and that NMDA receptor antagonists may provide a potential treatment for MeHg-associated neurological diseases. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Effects of di(2-ethylhexyl)phthalate on testicular oxidant/antioxidant status in selenium-deficient and selenium-supplemented rats
Abstract Di(ethylhexyl)phthalate (DEHP), the most widely used plasticizer, was investigated to determine whether an oxidative stress process was one of the underlying mechanisms for its testicular toxicity potential. To evaluate the effects of selenium (Se), status on the toxicity of DEHP was further objective of this study, as Se is known to play a critical role in testis and in the modulation of intracellular redox equilibrium. Se deficiency was produced in 3-weeks-old Sprague–Dawley rats feeding them ≤0.05 mg Se /kg diet for 5 weeks, and Se-supplementation group was on 1 mg Se/kg diet. DEHP-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the feeding period. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR)], catalase (CAT), superoxide dismutase (SOD), and glutathione S -transferase (GST); concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), and thus the GSH/GSSG redox ratio; and thiobarbituric acid reactive substance (TBARS) levels were measured. DEHP was found to induce oxidative stress in rat testis, as evidenced by significant decrease in GSH/GSSG redox ratio (>10-fold) and marked increase in TBARS levels, and its effects were more pronounced in Se-deficient rats with ∼18.5-fold decrease in GSH/GSSG redox ratio and a significant decrease in GPx4 activity, whereas Se supplementation was protective by providing substantial elevation of redox ratio and reducing the lipid peroxidation. These findings emphasized the critical role of Se as an effective redox regulator and the importance of Se status in protecting testicular tissue from the oxidant stressor activity of DEHP. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
The impact of paracetamol on selected biomarkers of the mollusc species Corbicula fluminea
Abstract The Asian clam Corbicula fluminea is an invasive bivalve that has recently spread in Europe and currently represents a large portion of the aquatic biomass in specific areas. Because of the impacts that the species may have in invaded ecosystems, increased knowledge on the physiologic features of the species life-cycle under different environmental scenarios (e.g., contamination events) is critical to understand the dynamics of the invasion and resulting ecosystem imbalance. The presence of pharmaceutical residues in the aquatic environment has recently received great attention since high levels of contamination have been found, not only in sewage treatment plant effluents, but also in open waters. The present article reports toxicological biochemical effects of paracetamol to Corbicula fluminea following short- and long-term exposures. Oxidative stress parameters were specially focused namely catalase (CAT), glutathione S-transferases (GSTs), and glutathione reductase (GRed). The effect of tested substances on lipid peroxidation was also investigated. Paracetamol did not induce alterations on CAT activity, caused a significant decrease of GSTs activity following short- and long-term exposure (LOEC values of 532.78 mg L−1 and 30.98 μg L−1 , respectively), and was responsible for a significant and dose-dependent decrease of GRed activity in short- and long-term exposures. These results indicate that exposure to paracetamol can provoke significant alterations on the cellular redox status of C. fluminea . 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Exogenous application of salicylic acid to alleviate the toxic effects of insecticides in Vicia faba L
Abstract The present study investigated the possible mediatory role of salicylic acid (SA) in protecting plants from insecticides toxicity. The seeds of Vicia faba var IIVR Selection-1 were treated with different concentrations (1.5, 3.0, and 6.0 ppm) of the insecticides alphamethrin (AM) and endosulfan (ES) for 6 h with and without 12 h conditioning treatment of SA (0.01 mM). Insecticides treatment caused a significant decrease in mitotic index (MI) and induction of different types of chromosomal abnormalities in the meristematic cells of broad bean roots. Pretreatment of seeds with SA resulted in increased MI and significant reduction of chromosomal abnormalities. SA application also regulated proline accumulation and carotenoid content in the leaf tissues. SA resulted in the decrement of insecticides induced increase in proline content and increased the carotenoids content. These results illustrate the ameliorating effect of SA under stress conditions and reveal that SA is more effective in alleviating the toxic effects of insecticides at higher concentrations than that at lower concentrations. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Effects of benzene and its metabolites on global DNA methylation in human normal hepatic l02 cells
Abstract Benzene is an important industrial chemical that is also widely present in cigarette smoke, automobile exhaust, and gasoline. It is reported that benzene can cause hematopoietic disorders and has been recognized as a human carcinogen. However, the mechanisms by which it increases the risk of carcinogenesis are only partially understood. Aberrant DNA methylation is a major epigenetic mechanism associated with the toxicity of carcinogens. To understand the carcinogenic capacity of benzene, experiments were designed to investigate whether exposure to benzene and its metabolites would change the global DNA methylation status in human normal hepatic L02 cells and then to evaluate whether the changes would be induced by variation of DNA methyltransferase (DNMT) activity in HaeIII DNMT-mediated methylation assay in vitro . Our results showed that hydroquinone and 1,4-benzoquinone could induce global DNA hypomethylation with statistically significant difference from control (p < 0.05), but no significant global DNA methylation changes were observed in L02 cells with benzene, phenol, and 1,2,4-trihydroxybenzene exposure. Benzene metabolites could not influence HaeIII DNMT activity except that 1,4-benzoquinone shows significantly inhibiting effect on enzymatic methylation reaction at concentrations of 5 μM (p < 0.05). These results suggest that benzene metabolites, hydroquinone, and 1,4-benzoquinone can disrupt global DNA methylation, and the potential epigenetic mechanism by which that global DNA hypomethylation induced by 1,4-benzoquinone may work through the inhibiting effects of DNMT activity at 10 μM (p < 0.05). © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
A subchronic in situ exposure method for evaluating effects in small-bodied fish at contaminated sites
Abstract In situ fish-caging studies at contaminated sites can provide information that is more realistic compared to traditional laboratory-based studies. However, few methods have been developed for exposing sentinel fish species for subchronic durations, and fewer still are optimized for exposing small-bodied fish while maintaining fish health and growth throughout the caging trial. Those methods typically lack a feeding regimen during the fish caging trial. While that may be acceptable or even appropriate for typical short-term toxicity testing, it does limit the duration of the exposure, and may not be suitable when post-caging trials or observations are necessary. Returning healthy fish to the lab following the in situ exposure would be important, for example, in studies designed to examine long-term or multigenerational effects following an in situ exposure. In this article we describe a subchronic method for caging small fish at contaminated sites while maintaining growth and reproductive development. Fathead minnow (Pimephales promelas ) were caged in situ for 6 weeks, after which time they were returned to the lab where they were evaluated for health and reproductive performance. Growth and reproductive endpoints revealed no adverse effect on fish due to fish caging and related handling, demonstrating the suitability of our caging and feeding method for long-term caging studies. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Immune dysfunction and liver damage of mice following exposure to lanthanoids
Abstract In an effort to investigate the effects of exposure to lanthanoids (Ln) on the immune response and liver function, mice were orally exposed to LaCl3 , CeCl3 , and NdCl3 at 2, 10, and 20 mg/kg doses for 30 days, respectively; lymphocyte counts, serum IgM level, hematological indices, biochemical parameters of liver functions, and histopathological changes in Ln3+ -treated mice were assessed. Indeed, 20 mg/kg Ln3+ significantly inhibited mice growth and reduced the counts of white blood cells, platelets, and reticulocyte in mice blood. Specifically, in these Ln3+ -treated mice, CD3+, CD4+, CD8+, CD19+ and NK cells, and CD4+/CD8+ ratio as well as serum IgM level were decreased. Furthermore, liver function was disrupted, as evidenced by the increased alanine aminotransferase, total bilirubin, total bile acid and triglycerides, and the decreased glucose and ratio of albumin to globulin. The cytoarchitecture damage and fatty degeneration in liver caused by Ln3+ at 20 mg/kg dose were also observed. Our findings showed that exposure to Ln affected the cell and humoral immunity and disturbed liver function in mice. In addition, Ce3+ was found to exhibit higher toxicity than La3+ and Nd3+ . © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Developmental toxicity of benzyl benzoate in rats after maternal exposure throughout pregnancy
Abstract The maternal and fetal toxicity of benzyl benzoate, commonly used as antiparasitic insecticide, was evaluated in pregnant rats after a daily oral dose of 25 and 100 mg/kg. Biochemical, histopathological, and morphological examinations were performed. Dams were observed for maternal body weights and food and water consumption and subjected to caesarean section on (GD) 20. Maternal and fetal liver, kidney, heart, brain, and placenta were examined histopathologically under light microscope. Maternal and fetal liver and placenta were stained immunohistochemically for vascular endothelial growth factor (VEGF). Morphometric analysis of fetal body lengths, placental measurements, and fetal skeletal stainings was performed. Statistically significant alterations in biochemical parameters and placental and skeletal measurements were determined in treatment groups. In addition to histopathological changes, considerable differences were observed in the immunolocalization of VEGF in treatment groups. These results demonstrated that benzyl benzoate and its metabolites can transport to the placenta and eventually enter the fetuses. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Bufalin-inhibited migration and invasion in human osteosarcoma U-2 OS cells is carried out by suppression of the matrix metalloproteinase-2, ERK, and JNK signaling pathways
Abstract Bufalin has been shown to exhibit multiple pharmacological activities, including induction of apoptosis in many types of cancer cell lines. Osteosarcoma is a type of cancer which is difficult to treat and the purpose of this study was to investigate the effects of bufalin on the migration and invasion of human osteosarcoma U-2 OS cells. The wound healing assay and Boyden chamber transwell assay were used for examining the migration of U-2 OS cells. Western blotting and gelatin zymography assays were used for theexpression and activities of metalloproteinase (MMP)-2, MMP-7 or MMP-9 levels. Western blotting analysis also was used for measuring the levels of growth factor receptor-bound protein 2 (GRB2), son of sevenless homolog 1 (SOS1), c-Jun N-terminal kinases 1/2 (JNK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 in bufalin-treated U-2 OS cells. Bufalin inhibited the cell migration and invasion of U-2 OS cells in vitro . Moreover, bufalin reduced MMP-2 and MMP-9 enzyme activities of U-2 OS cells. Bufalin also suppressed the protein level of MMP-2 and reduced the levels of mitogen-activated protein kinases (MAPKs) such as JNK1/2 and ERK1/2 signals in U-2 OS cells. Our results suggest that signaling pathways for bufalin-inhibited migration and invasion of U-2 OS cells might be mediated through blocking MAPK signaling and resulting in the inhibition of MMP-2. Bufalin could be a useful agent to develop as a novel antitumor agent by virtue of its ability to inhibit tumor cell migration and invasion. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011..
Ecotoxicological study of arsenic and lead contaminated soils in former orchards at the Hanford site, USA
Abstract The purpose of this study was to assess ecotoxicity of former orchard soils contaminated with lead arsenate pesticides at the Hanford Site in Washington state (USA). Surface soil, plant, and invertebrate samples were collected from 11 sites in former orchard areas. Mean (standard deviation [SD]) for As and Pb in soil were 39.5 (40.6) and 208 (142) mg/kg dry wt, respectively (n = 11). These concentrations exceeded Hanford background levels but were similar to orchard soils elsewhere. In our study, As and Pb soil concentrations were positively and significantly correlated (r = 0.87, Bonferroni P < 0.05). Speciation of total inorganic As in soil (n = 6) demonstrated that As+5 was the dominant form (>99%). Mean (SD) for As and Pb in cheatgrass were 3.9 (7.9) and 12.4 (20.0) mg/kg dry wt, respectively (n = 11), while mean (SD) for As and Pb in darkling beetles were 5.4 (2.6) and 3.9 (3.0) mg/kg dry wt, respectively (n = 8). Linear regressions were constructed to estimate soil to cheatgrass and soil to darkling beetle uptake for As and Pb. These were significant (Bonferroni P < 0.05) only for cheatgrass versus soil (As) and darkling beetle versus soil (Pb). Standardized lettuce seedling and earthworm bioassays were performed with a subset of soil samples (n = 6). No significant effects (P > 0.05) were observed in lettuce survival or growth nor in earthworm survival or sublethal effects. Based on these bioassays, unbounded no observed effect concentrations (NOECs) in soil for As and Pb were 128 and 390 mg/kg dry wt, respectively. However, our range of soil concentrations generally overlapped a set of ecotoxicological benchmarks reported in the literature. Given uncertainty and limited sampling related to our NOECs, as well as uncertainty in generic benchmarks from the literature, further study is needed to refine characterization of As and Pb ecotoxicity in former orchard soils at the Hanford Site. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Sublethal toxicity of esbiothrin relationship with total antioxidant status and in vivo genotoxicity assessment in fish (Cyprinus carpio L., 1758) using the micronucleus test and comet assay
Abstract Esbiothrin, synthetic pyrethroid with quick activity against insects, is widely used against household pests and in public health. Despite widespread use, data on ecotoxicity and genotoxic effects are extremely scarce. The aim of the present study is to evaluate the genotoxic potential of esbiothrin on a model fish species Cyprinus carpio L., 1758 (Pisces: Cyprinidae, koi) using the micronucleus test and comet assay in peripheral blood erythrocytes. Effects of two sublethal exposure concentrations on plasma total antioxidant status (TAS mmol/L), and Hct values were examined. On the basis of the 96 h LC50 data from U.S. EPA ecotox database (32 μg/L) two sublethal exposure concentrations (5 and 10 μg/L) were used together with ethyl methanesulfonate (EMS) (5 mg/L) as positive control. Five fish were used for each dose/duration group (24, 48, and 72 h) under controlled laboratory conditions. The fish showed behavioral changes at the higher dose. Plasma TAS (mmol/L) levels decreased in 24 h; an increase was observed slightly for 48 and obviously for 72 h in both exposure doses. Similarly, hematocrit (Hct) values differed between exposure duration but no significant differences in mean values were found between groups of the same exposure time. The general trend was a rise after 48 h, which decreased afterwards. Our results revealed significant increases in the frequencies of micronuclei and levels of DNA strand breaks and thus demonstrated the genotoxic potential of this pesticide on fish, a nontarget organism of the aquatic ecosystem. To our knowledge this is the first study to report observable genotoxic effects of esbiothrin on fish. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Impairment of the mitochondrial oxidative phosphorylation system and oxidative stress in liver of crucian carp (Carassius auratus L.) exposed to microcystins
Abstract Hepatotoxic microcystins (MCs) are produced by cyanobacteria in diverse water bodies and the pathophysiology includes induction of reactive oxygen species and adenosine triphosphate (ATP) depletion in cells. In this study, we evaluated MCs induced changes in the oxidative phosphorylation (OXPHOS) system in mitochondria of crucian carp liver. Fish were subdivided into two groups that were intraperitoneally injected with two doses of MCs (50 and 200 MC-LReq μg/kg bw) and were sacrificed at 1, 3, 12, 24, and 48 h postinjection. The activities of five enzyme complexes of electron transport chain and mRNA expression of mitochondrial-encoded genes (cox1, cox2, cox3, and atp6 ) were significantly reduced in a time-dependent pattern after injection. There were also changes in mitochondrial ultrastructure, decreases in ATPase activities and reduction in antioxidant level after MCs exposure. Disorder in the OXPHOS system and decreased activities of antioxidative enzymes might contribute to bioenergy deficiency and consequent hepatocyte damage induced by MCs. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Effects of decabromodiphenyl ether (BDE-209) on mRNA transcription of thyroid hormone pathway and spermatogenesis associated genes in Chinese rare minnow (Gobiocypris rarus)
Abstract Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants, which are ubiquitous environmental contaminant found in both abiotic and biotic environmental samples. Deca-BDE (BDE-209) is the principal component, which is currently used worldwide. In this study, the effect of BDE-209 on the mRNA levels of thyroid hormone (TH) related genes and spermatogenesis associated genes were determined from larvae and adult rare minnow (Gobiocypris rarus ) exposed to concentrations 0.01, 0.1, 1, and 10 μg/L for 21 days. The results showed that the type II deiodinase (dio2 ) and sodium iodide symporter (nis ) mRNA levels were significantly up-regulated in the larvae at 10 μg/L treatment. In adult, histopathological observations showed that liver of female fish were degenerated at 10 μg/L treatment, and inhibition of spermatogenesis were observed in testis of male fish. In addition, the thyroid hormone receptor α (trα ), dio2 , and nis mRNA levels in the liver of male and female fish were significantly up-regulated, whereas dio2 and nis mRNA levels were significantly down-regulated in the brain. These results indicate that exposure to BDE-209 could result in tissue-specific alternations of TH-related genes expression in adults. Moreover, the mRNA levels of the testis-specific apoptosis genes, the spermatogenesis-associated 4 (spata4 ) and spermatogenesis-associated 17 (spata17 ), were down-regulated at 10 μg/L treatment in testis of male fish. Our results suggest that BDE-209 may pose threat to normal thyroid and reproductive function in fish. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Metals (Ag+, Cd2+, Cr6+) affect ATPase activity in the gill, kidney, and muscle of freshwater fish Oreochromis niloticus following acute and chronic exposures
Abstract Freshwater fish Oreochromis niloticus were individually acutely exposed to different concentrations (0, 0.1, 0.5, 1.0, and 1.5 μg/mL) of Cd2+ , Cr6+ , and Ag+ for 96 h and 0.05 μg/mL concentration of the same metals for different periods (0, 5, 10, 20, and 30 days) chronically. Following each experimental protocol, Na+ /K+ -ATPase, Mg2+ -ATPase, and Ca2+ -ATPase activities were measured in the gill, kidney, and muscle of O. niloticus . In vitro experiments were also performed to determine the direct effects of metal ions (0, 0.1, 0.5, 1.0, and 1.5 μg/mL) on ATPases. Except Ag+ , none of the metals caused fish mortality within 30 days. Silver killed all the fishes within 16 days. Metal exposures generally decreased Na+ /K+ -ATPase and Ca2+ -ATPase activities in the tissues of O. niloticus , although there were some fluctuations in Mg2+ -ATPase activity. Ag+ and Cd2+ were found to be more toxic to ATPase activities than Cr6+ . It was also observed that metal efficiency was higher in the gill than in the other tissues. Results indicated that the response of ATPases varied depending on metals, exposure types, and tissues. Because ATPases are sensitive to metal toxicity, their activity can give valuable data about fish physiology. Therefore, they may be used as a sensitive biomarker in environmental monitoring in contaminated waters. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Quercetin attenuates lambda cyhalothrin-induced reproductive toxicity in male rats
Abstract The aim of this study was to evaluate the possible protective effects of Quercetin (Qe) against oxidative stress induced by λ cyhalothrin (LTC) in reproductive system. Thirty-two male rats were divided into four groups. First group was allocated as the control group. Second group was given a Qe alone while the third group received a LTC alone. Animals in the fourth group were given a Qe with LTC. Caudae epididymis was removed for sperm analysis. Lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and reduced glutathione (GSH) were determined in the testis. Additionally, the different histopathologic changes were observed in the testis of animals. LTC exposure significantly increased the abnormal morphology and LPO. On the contrary, sperm motility, viability and count, levels of GSH, and activities of SOD, CAT, GPx, and GST were significantly decreased compared to controls. Qe with LTC offset the decrease in functional sperm parameters, antioxidants enzymatic activities, and nonenzymatic antioxidant levels when compared with LTC-treated rats. Furthermore, LTC showed irregular seminiferous tubules containing only Sertoli cells and Qe with LTC caused regular seminiferous tubules showing spermatogenesis at level of spermatocytes. We conclude that LTC-induced oxidative stress and functional sperm parameters in male rats, and dietary of Qe attenuates the reproductive toxicity of LTC to restore the antioxidant system and sperm parameters in male rats. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Classification of polycyclic aromatic hydrocarbons based on mutagenicity in lung tissue through DNA microarray
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced in the combustion of organic matter. Exposure to PAHs raises the risk of lung cancer and inflammatory and allergic disorders such as asthma. DNA microarray technologies have been applied to research on toxicogenomics in the recent years. To evaluate the mutagenicity of PAHs and constituents of environmental pollutants in lung tissue, including metabolic activation, human alveolar epithelial type II cells (A549) were treated with nonmutagenic PAH pyrene and with the mutagenic PAHs benzo-[a]-pyrene, 1-nitropyrene, or 1,8-dinitropyrene. Comparison of genome-wide microarray expression profiles between a nonmutagenic and a mutagenic PAH-treated group revealed that xenobiotic response genes such as CYP1B1 were commonly upregulated in two groups and that DNA damage induced genes, especially p53-downstream genes such as p21 (CDKN1A) were upregulated only in the mutagenic PAH-treated group. Pretreatment with cytochrome P450 inhibitor α-naphthoflavone or p53 inhibitor pifithrin-α inhibited the benzo-[a]-pyrene-induced p21 expression. These data suggest that when PAHs enter the cells, lung epithelium induces PAH metabolic activating enzymes, and then the DNA damages-recognition signal is converged with p53 downstream genes. This metabolic activation and DNA damage is induced in lung epithelium, and the mutagenicity of PAHs can be classified by DNA microarray expression profiles. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Protective effects of vitamin E and selenium against dimethoate-induced cardiotoxicity in vivo: Biochemical and histological studies
Abstract There is considerable interest in the study of free radical-mediated damage to biological systems due to pesticide exposure. However, there is a lack of consensus as to which determinations are best used to quantify future risks arising from xenobiotic exposure and natural antioxidant interventions. Our study investigated the potential ability of selenium and/or vitamin E, used as nutritional supplements, to alleviate cardiotoxicity induced by dimethoate. Female Wistar rats were exposed for 30 days either to dimethoate (0.2 g L−1 of drinking water), dimethoate+selenium (0.5 mg kg−1 of diet), dimethoate+vitamin E (100 mg kg−1 of diet), or dimethoate+selenium+vitamin E. The exposure of rats to dimethoate promoted oxidative stress with a rise in malondialdehyde, advanced protein oxidation, and protein carbonyl levels. An increase of glutathione peroxidase, superoxide dismutase, and catalase activities was also noted. A fall in acetylcholinesterase and Na+ K+ -ATPase activities, glutathione, nonprotein thiols, vitamins C and E levels was observed. Plasma levels of cholesterol, triglycerides, and low density lipoprotein-cholesterol increased and those of high density lipoprotein-cholesterol decreased. Coadministration of selenium or vitamin E to the diet of dimethoate-treated rats ameliorated the biochemical parameters cited above. The histopathological findings confirmed the biochemical results and the potential protective effects of selenium and vitamin E against cardiotoxicity induced by dimethoate. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Estrogen-like response of perfluorooctyl iodide in male medaka (Oryzias latipes) based on hepatic vitellogenin induction
Abstract Using the in vivo male medaka model, we investigated the estrogen-like response of perfluorooctyl iodide (PFOI) which is a potential source of perfluorinated carboxylic acids. Using real-time quantitative polymerase chain reaction, the expression levels of related estrogenic genes including estrogenic receptor α (ERα), ERβ, vitellogenin I (VTG I), and VTG II in the livers of male medaka exposed to PFOI were analyzed. The results showed that PFOI upregulated the expression levels of the tested genes in a dose-dependent manner. VTG protein levels increased in both dose- and time-dependent manners due to PFOI exposure. The results suggested that PFOI is a potential estrogenic compound. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Gallic acid provokes DNA damage and suppresses DNA repair gene expression in human prostate cancer PC-3 cells
Abstract Our earlier studies have demonstrated that gallic acid (GA) induced cytotoxic effects including induction of apoptosis and DNA damage and inhibited the cell migration and invasion in human cancer cells. However, GA-affected DNA damage and repair gene expressions in human prostate cancer cells are still unclear. In this study, we investigated whether or not GA induces DNA damage and inhibits DNA repair gene expression in a human prostate cancer cell line (PC-3). The results from flow cytometric assay indicated that GA decreased the percentage of viable PC-3 cells in a dose- and time-dependent manner. PC-3 cells after exposure to different doses (50, 100, and 200 μM) of GA and various periods of time (12, 24, and 48 h) led to a longer DNA migration smear (comet tail) occurred based on the single cell gel electrophoresis (comet assay). These observations indicated that GA-induced DNA damage in PC-3 cells, which also confirmed by 4,6-diamidino-2-phenylindole dihydrochloride staining and DNA agarose gel electrophoresis. Alternatively, results from real-time polymerase chain reaction assay also indicated that GA inhibited ataxia telangiectasia mutated, ataxia-telangiectasia and Rad3-related, O 6 -methylguanine-DNA methyltransferase, DNA-dependent serine/threonine protein kinase, and p53 mRNA expressions in PC-3 cells. Taken together, the present study showed that GA caused DNA damage and inhibited DNA repair genes as well as both effects may be the critical factors for GA-inhibited growth of PC-3 cells in vitro . © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Cadmium impairment of reproduction in the female wall lizard Podarcis sicula
Abstract The exposure to environmental toxicants such cadmium (Cd) is an important research area in wildlife protection. In this study, the effect of Cd oral administration on the ovarian structure and function and on reproductive performance of the Italian wall lizard Podarcis sicula was studied. In vivo , adult female lizards were randomly assigned to three groups. Cd was given with food in single dose and in multiple doses 3 days/week for 4 weeks at dose of 1.0 μg/g body weight. Following euthanasia, the ovaries were removed and analyzed for morpho-functional changes. Results demonstrated that Cd increases prefollicular germ cells number; the evaluation of the number of follicles detects significantly higher number of atretic growing follicles, whereas primary follicles remain unchanged with respect to controls. After Cd treatments, follicles are deformed by the presence of large protrusions and a general dysregulation in the follicle organization is observed. The zona pellucida is also affected. Cd causes alteration in sugar metabolism and in metallothionein gene expression. Finally, Cd administration significantly reduces clutch size and dramatically increases embryo mortality. In conclusion, data here described show that Cd induces morpho-functional alterations in lizard follicles and indicates that these are responsible for a significant impairment of oogenesis. The effects of the dose are time independent, persisting essentially unchanged regardless of single or multiple administration, so it can be concluded that even occasional, sublethal Cd contamination may significantly impair reproductive performance in these animals. © 2011 Wiley Periodicals, Inc.Environ Toxicol, 2011.
The antioxidant effects of pumpkin seed oil on subacute aflatoxin poisoning in mice
Abstract This study was aimed at the investigation of the antioxidant effect of pumpkin seed oil against the oxidative stress-inducing potential of aflatoxin. For this purpose, 48 male BALB/c mice were used. Four groups, each comprising 12 mice, were established. Group 1 was maintained as the control group. Group 2 was administered with pumpkin seed oil alone at a dose of 1.5 mL/kg.bw/day (∼1375mg/kg.bw/day). Group 3 received aflatoxin (82.45% AFB1 , 10.65% AFB2 , 4.13% AFG1, and 2.77% AFG2 ) alone at a dose of 625 μg/kg.bw/day. Finally, group 4 was given both 1.5 mL/kg.bw/day pumpkin seed oil and 625 μg/kg.bw/day aflatoxin. All administrations were oral, performed with the aid of a gastric tube and continued for a period of 21 days. At the end of day 21, the liver, lungs, kidneys, brain, heart, and spleen of the animals were excised, and the extirpated tissues were homogenized appropriately. Malondialdehyde (MDA) levels and catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were determined in tissue homogenates. In conclusion, it was determined that aflatoxin exhibited adverse effects on most of the oxidative stress markers. The administration of pumpkin seed oil diminished aflatoxin-induced adverse effects. In other words, the values of the group, which was administered with both aflatoxin and pumpkin seed oil, were observed to have drawn closer to the values of the control group. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Protective effect of lycopene on oxidative stress and antioxidant status in Cyprinus carpio during cypermethrin exposure
Abstract The aim of this study was to investigate the ameliorative properties of lycopene against the toxic effects of cypermethrin (CYP) by examining oxidative damage markers such as lipid peroxidation and the antioxidant defense system components in carp (Cyprinus carpio ). The fish were divided into seven groups of 10 fish each and received the following treatments: group 1, no treatment; group 2, orally administered corn oil; group 3, oral lycopene (10 mg/kg body weight); group 4, exposure to 0.202 μg/L CYP; group 5, exposure to 0.202 μg/L CYP plus oral administration of 10 mg/kg lycopene; group 6, exposure to 0.404 μg/L CYP; and group 7, exposure to 0.404 μg/L CYP plus oral administration of 10 mg/kg lycopene. Treatment was continued for 28 days, and at the end of this period, blood and tissue (liver, kidney, and gill) samples were collected. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were determined in blood and tissues for measurement of oxidant-antioxidant status. MDA level, as an index of lipid peroxidation, increased in blood and tissues. Antioxidant enzyme activities in blood and tissues were modified in CYP groups compared with controls. Administration of lycopene ameliorated these parameters. The present results suggest that administration of lycopene might alleviate CYP-induced oxidative stress. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Indium chloride-induced micronuclei via reactive oxygen species in Chinese hamster lung fibroblast V79 cells
Abstract We study the cytotoxicity of indium chloride (InCl3 ) in Chinese hamster lung fibroblasts, the V79 cells, using MTT assay. The results showed that InCl3 did not induce significant cytotoxicity at various concentrations tested. In addition, the frequency of micronuclei (MN) was assayed to evaluate the genotoxic effects of InCl3 in V79 cells. InCl3 at concentrations ranged 0.1–1 μM significantly increased MN frequency in a concentration-dependent manner. Both catalase and superoxide dismutase at concentrations of 75 and 150 μg/mL significantly inhibited InCl3 -induced MN. Similarly, Germanium oxide (GeO2 ) and dimercaprol expressed antigenotoxic effects. From these findings, it is concluded that InCl3 is a potent genotoxic chemical, which may be mediated partly by inducing oxidative stress. The significance of this study shows that the workers in the semiconductor factories should be cautious in exposing to the hazardous genotoxic InCl3. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Glucose and lipid homeostasis in adult rat is impaired by early-life exposure to perfluorooctane sulfonate
Abstract Perfluorooctane sulfonate (PFOS), which belongs to the degradation product of many perfluorinated compounds, is on the list of persistent organic pollutants (POPs) and is currently detected in both wildlife and humans. The consequence of gestational and lactational exposure to PFOS on prediabetes effect in offspring was investigated in rats in the present study. Maternal rats were treated with vehicle, 0.5 mg/kg/day or 1.5 mg/kg/day PFOS respectively from gestation day 0 to postnatal day 21. The glucose and lipid metabolism effects were investigated on the offspring in adulthood. The gestational and lactational exposure to PFOS led to low body weight from birth to weaning, and evoked signs of a prediabetic state, with elevated fasting serum insulin and leptin level, impaired glucose tolerance, though the fasting serum glucose and glycosylated serum protein level were normal. Abnormal lipid homeostasis was also observed by the phenomenon of hepatic steatosis and increased gonadal fat pad weight. However, the circulating serum level of fasting triglyceride and cholesterol level were no different from controls. Our results suggested that developmental exposure to PFOS may contribute to glucose and lipid metabolic disorder in adulthood. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Prenatal exposure to permethrin influences vascular development of fetal brain and adult behavior in mice offspring
Abstract Pyrethroids are one of the most widely used classes of insecticides and show neurotoxic effects that induce oxidative stress in the neonatal rat brain. However, little is still known about effects of prenatal exposure to permethrin on vascular development in fetal brain, central nervous system development, and adult offspring behaviors. In this study, the effects of prenatal exposure to permethrin on the development of cerebral arteries in fetal brains, neurotransmitter in neonatal brains, and locomotor activities in offspring mice were investigated. Permethrin (0, 2, 10, 50, and 75 mg/kg) was orally administered to pregnant females once on gestation day 10.5. The brains of permethrin-treated fetuses showed altered vascular formation involving shortened lengths of vessels, an increased number of small branches, and, in some cases, insufficient fusion of the anterior communicating arteries in the area of circle of Willis. The prenatal exposure to permethrin altered neocortical and hippocampus thickness in the mid brain and significantly increased norepinephrine and dopamine levels at postnatal day 7 mice. For spontaneous behavior, the standing ability test using a viewing jar and open-field tests showed significant decrease of the standing ability and locomotor activity in male mice at 8 or 12 weeks of age, respectively. The results suggest that prenatal exposure to permethrin may affect insufficient development of the brain through alterations of vascular development. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Safrole suppresses murine myelomonocytic leukemia WEHI-3 cells in vivo, and stimulates macrophage phagocytosis and natural killer cell cytotoxicity in leukemic mice
Abstract Many anticancer drugs are obtained from phytochemicals and natural products. However, some phytochemicals have mutagenic effects. Safrole, a component of Piper betle inflorescence, has been reported to be a carcinogen. We have previously reported that safrole induced apoptosis in human oral cancer cells in vitro and inhibited the human oral tumor xenograft growth in vivo . Until now, there is no information addressing if safrole promotes immune responses in vivo . To evaluate whether safrole modulated immune function, BALB/c mice were intraperitoneally injected with murine myelomonocytic WEHI-3 leukemia cells to establish leukemia and then were treated with or without safrole at 4 and 16 mg/kg. Animals were sacrificed after 2 weeks post-treatment with safrole for examining the immune cell populations, phagocytosis of macrophages and the natural killer (NK) cells' cytotoxicity. Results indicated that safrole increased the body weight, and decreased the weights of spleen and liver in leukemic mice. Furthermore, safrole promoted the activities of macrophages phagocytosis and NK cells' cytotoxicity in leukemic mice when compared with untreated leukemic mice. After determining the cell marker population, we found that safrole promoted the levels of CD3 (T cells), CD19 (B cells) and Mac-3 (macrophages), but it did not affect CD11b (monocytes) in leukemic mice. In conclusion, safrole altered the immune modulation and inhibited the leukemia WEHI-3 cells in vivo . © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
In vivoexamination of the genotoxicity of the urban air and surface soil pollutant, 3,6-dinitrobenzo[e]pyrene, with intraperitoneal and intratracheal administration
Abstract 3,6-Dinitrobenzo[e ]pyrene (3,6-DNBeP) was identified as a new potent mutagen toward Salmonella strains in surface soil and airborne particles. Because data of in vivo examination of the genotoxicity of 3,6-DNBeP are limited, micronucleus test was performed in peripheral blood and bone marrow, and comet assay in the lungs of mice treated with 3,6-DNBeP. In male ICR mice intraperitoneally (i.p.) injected with 3,6-DNBeP, the frequency of micronuclated polychromatic erythrocytes (MNPCEs) was increased in the peripheral blood and bone marrow after 24 h in a dose-dependent manner. Compared to controls, the highest dose of 3,6-DNBeP (40 mg/kg B.W.) induced 7.3- and 8.7-fold increases of MNPCE frequency in the peripheral blood and bone marrow, respectively. Furthermore, when 3,6-DNBeP was intratracheally (i.t.) instilled to male ICR mice, 3,6-DNBeP at the highest dose of 0.1 mg/kg body exhibited 3.1-fold increase of DNA tail moment in the lungs at 3 h after the instillation compared to controls. The values of DNA tail moment at 9 and 24 h after the instillation were increased up to 3.5 and 4.2-fold, respectively. These data indicate that 3,6-DNBeP is genotoxic to mammalians in in vivo and suggest that 3,6-DNBeP may be a carcinogenic compound present in the human environment. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Nerium indicum, a botanical pesticide affects ultimobranchial gland of the catfish Heteropneustes fossilis
Abstract Heteropneustes fossilis were subjected to 11.27 mg L−1 (80% of 96 h LC50 ) and 2.81 mg L−1 (20% of 96 h LC50 ) of Nerium indicum leaf extract for short-term and long-term, respectively. After sacrificing the fish, blood was collected on 24, 48, 72, and 96 h in short-term and after 7, 14, 21, and 28 days in long-term experiment and analyzed for plasma calcium levels. Also, ultimobranchial glands (UBG) were fixed on these intervals. Serum calcium levels of H. fossilis exhibited a decline after 48 h following exposure to Nerium indicum leaf extract. This decrease continued till the end of the experiment (96 h). Ultimobranchial cells exhibited a decrease in the cytoplasmic staining response after 72 h following the treatment. The nuclear volumes of these cells were slightly decreased. These changes were exaggerated after 96 h following the treatment. Chronically exposed fish exhibited a decline in serum calcium levels of H. fossilis on day 14. The level progressively declined till the end of the experiment. Up to day 14 following the treatment there was no change in the histological structure of UBG. A decrease in the nuclear volume of ultimobranchial cells was noticed on day 21. Moreover, the cytoplasm of these cells displayed weakstaining response. The nuclear volume of these cells recorded a further decrease following 28-day treatment. Also there was noticed vacuolization and degeneration at certain places. To the best of our knowledge, the effects of any botanical pesticides on fish UBG have not been reported yet. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Is cell death induced by nematocysts extract of medusa Pelagia noctiluca related to oxidative stress?
Abstract Pelagia noctiluca , a jellyfish widely distributed in the Mediterranean waters, especially in coastal areas of Tunisia, has garnered attention because of its stinging capacity and the resulting public health hazard. Crude extracts of P. noctiluca nematocysts have been tested for their cytotoxicity on Vero cells. Our results clearly showed that nematocysts induced cell mortality in a dose- and time-dependent manner. A cytoprotective effect against cell mortality was obtained when Vero cells were treated with Vitamin E. This process was further confirmed by the generation of reactive oxygen species (ROS) and the induction of Hsp 70 and 27 protein expressions. Thus, our findings suggested that oxidative stress is involved in the toxicity of pelagia nematocysts and may therefore constitute the major mechanism of this medusa nematocysts toxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Sodium arsenite induced reactive oxygen species generation, nuclear factor (erythroid-2 related) factor 2 activation, heme oxygenase-1 expression, and glutathione elevation in Chang human hepatocytes
Abstract Liver is one of the major target organs of arsenic toxicity and carcinogenesis. Nuclear factor (erythroid-2 related) factor 2 (Nrf2) is a redox-sensitive transcription factor, regulating critically cellular defense responses against the toxic metallic arsenic in many cell types and tissues. This study was conducted to evaluate the hepato-cellular Nrf2 and Nrf2-regulated antioxidant reactions of sodium arsenite exposure in Chang human hepatocytes. Nrf2 and heme oxygenase-1 (HO-1) protein levels were detected by Western blot, and Nrf2-regulated HO-1 mRNA expressions were determined using semiquantitative RT-PCR by 0∼50 μmol/L of sodium arsenite exposure for 2, 6, 12, and 24 h. We also observed the changes of intracellular reactive oxygen species (ROS) and total cellular glutathione (GSH) by flow cytometry and spectrophotometry, respectively. Our results showed that intracellular ROS were both dose- and time-dependent induced by inorganic arsenic; Cellular Nrf2 protein levels increased rapidly after 2 h of exposure, elevated significantly at 6 h, and reached the maximum at 12 h. The endogenous Nrf2-regulated downstream HO-1 mRNA and protein were also induced dramatically and lasted for as long as 24 h. In addition, intracellular GSH levels elevated in consistent with Nrf2 activation. Our findings here suggest that inorganic arsenic alters cellular redox balance in hepatocytes to trigger Nrf2-regulated antioxidant responses promptly, which may represent an adaptive cell defense mechanism against inorganic arsenic induced liver injuries and hepatoxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Maternal exposure to the mixture of organophosphorus pesticides induces reproductive dysfunction in the offspring
Abstract Organophosphorus pesticide residues are found in many food samples due to increasing use of multiple organophosphorus pesticides (OPs) in agriculture. Toxicity of individual organophosphorus has been well-studied in previous epidemiological and laboratory investigations. This study focused on reproductive toxicity of perinatal exposure to the mixture of organophosphorus pesticides (MOPs). The MOPs consists of three most commonly used pesticides, i.e., Dichlorovos, Dimethoate, and Malathion which individually does not cause significant effects on the reproductive system at the similar concentration levels based on previous studies. Using the Sprague-Dawley rats, we established a perinatal exposure model by oral gavage and observed significant endometrial hyperplasia and thickened uterine walls in the F0 rats after administration of high doses of the MOPs. We further monitored several key developmental and behavioral indices in the F1 generation after maternal exposure to the MOPs, and observed significantly delayed physical development and weakened mental development. Moreover, we found increased weights of the reproductive organs (the uterus and the testis) and abnormal levels of key sex hormones (progestin and testosterone) in the MOPs groups. It is more important that we observed a significantly lower pregnancy rate and live birth rate in the high-dose MOPs group. These results indicate that the MOPs may be more detrimental to the maternal endometria and the reproductive functions in the offspring than individual organophosphorus. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Lanthanum chloride promotes mitochondrial apoptotic pathway in primary cultured rat astrocytes
Abstract Population surveys and animal experiments have shown that rare earth elements (REEs) cause neurological defects. However, the detailed mechanisms underlying these effects are still unclear. Given that lanthanum is commonly used for investigating into REEs-induced neurological defects, this study chose lanthanum chloride (LaCl3 ) to show that LaCl3 promotes mitochondrial apoptotic pathway in primary cultured rat astrocytes by regulating expression of Bcl-2 family proteins. The main findings of this study are (1) LaCl3 treatment (0.25, 0.5, and 1.0 mM for 12–48 h) induced the astrocytes damages with a concentration-dependent manner, which were confirmed with methyl thiazolyl tetrazolium and lactate dehydrogenase release assays, and morphological examination. (2) A 24 h treatment of LaCl3 concentration-dependently decreased mitochondrial membrane potential, increased cytochrome c release from mitochondria into cytosol, elevated caspase 9 and 3 expression, and promoted astrocyte apoptosis. (3) LaCl3 treatment increased the ratio of pro-apoptotic Bax and antiapoptotic Bcl-2 proteins, which in turn broke the balance among pro-apoptotic and antiapoptotic Bcl-2 family proteins, leading to astrocyte apoptosis. Our results indicate that LaCl3 alters Bcl-2 family protein expressions, which in turn promote mitochondrial apoptotic pathway, and thus astrocytic damage. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Resveratrol protects against methylglyoxal-induced apoptosis and disruption of embryonic development in mouse blastocysts
Abstract Methylglyoxal (MG) is a glucose metabolite. Diabetic patients have increased serum levels of MG, and MG is also implicated in tissue injury during embryonic development. In the present work, we show that MG induces apoptosis in the inner cell mass of mouse blastocysts and inhibits cell proliferation. Both effects are suppressed by resveratrol, a grape-derived phytoalexin with known antioxidant and anti-inflammatory properties. MG-treated blastocysts displayed lower levels of implantation (compared to controls) when plated on culture dishes in vitro and a reduced ability to proceed to later stages of embryonic development. Pretreatment with resveratrol prevented MG-induced disruption of embryonic development, both in vitro and in vivo . Further investigation of these processes revealed that MG directly promotes reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (MMP), and activation of caspase-3, whereas resveratrol effectively blocks MG-induced ROS production and the accompanying apoptotic biochemical changes. Our results collectively imply that MG triggers the mitochondrion-dependent apoptotic pathway via ROS generation, and the antioxidant activity of resveratrol prevents MG-induced toxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Evaluation of factors associated with cadmium exposure and kidney function in the general population
Abstract Cadmium (Cd) is a nonessential toxic metal which is widely distributed in the environment. The general population is exposed to low levels of Cd and the kidney is the organ most sensitive to Cd toxicity. This study was performed to simultaneously evaluate Cd exposure, kidney function, and oxidative stress biomarkers in the general population. A total of 643 adults were interviewed to document demographic characteristics, lifestyles, past-medical history, and diet during the last 24 h. We estimated daily Cd intake based on the diet of study subjects who had not been exposed to Cd occupationally. Whole blood and urine samples were collected and analyzed to determine Cd concentrations and kidney function indices (β2 -microglobulin [β2 -MG], N -acetyl-β-D -glucosaminidase [NAG], metallothionein [MT]). The oxidative stress index (malondialdehyde [MDA]) was determined from the urine. The daily Cd intake from diet was established as 7.07 μg/day. The mean concentration of Cd measured in the blood was 1.22 μg/L and urine was 0.95 μg/g creatinine. The concentrations of Cd in blood and urine were higher in females than in males. The blood levels of Cd were affected by sex, age, and smoking, and urine Cd was influenced by sex, age, and blood Cd. The urine Cd was positively correlated with MT, NAG activity, and MDA in females, but with NAG only in males. The blood Cd was associated with MT in males. Increased NAG activity was observed when Cd in urine reached 1.0 μg Cd/g creatinine and was also affected by age, hypertension, and diabetes mellitus. Urinary MT only responded to Cd in urine or blood. In summary, exposure to Cd in the general population was influenced by various factors including sex, age, and smoking habits. Such exposure might eventually cause tubular damage in the kidneys through the oxidative stress mechanism, and females might be more susceptible than males to Cd exposure under the environment. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011
Evaluation of DNA damage and cytotoxicity induced by three commonly used organophosphate pesticides individually and in mixture, in rat tissues
Abstract Organophosphate pesticides are among the most widely used synthetic chemicals for controlling a wide variety of pests. Chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) are among the most extensively used organophosphate (OP) pesticides. The main target of action of OP compounds is the central and peripheral nervous system, although it has also been postulated that these compounds in both acute and chronic intoxication, disturb the redox processes and thus induce oxidative stress. The excessive generation of reactive oxygen species (ROS) causes damage to all vital macromolecules including lipids, proteins, and DNA. This study was aimed to investigate the genotoxicity and cytotoxicity of CPF, MPT, and MLT when given singly or in combination. The DNA damage was measured by alkaline single-cell gel electrophoresis or comet assay and expressed as DNA damage index. The results showed that both acute and chronic exposure with CPF, MPT, and MLT, caused significantly marked DNA damage in rat tissues namely, liver, brain, kidney, and spleen, when measured 24 hour posttreatment. It was also observed that MPT caused highest level of DNA damage and brain was maximally affected by these OP compounds. When these pesticides were given in mixture, the damage was not the sum of damage caused by individual pesticide, confirming that these pesticides do not potentiate the toxicity of each other. When the DNA damage was measured 48 and 72 hour posttreatment, the damage was partially repaired. Pesticide exposure also caused histopathological changes in rat tissues. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011
Cytogenetic effects of commercial formulations of deltamethrin and/or thiacloprid on Wistar rat bone marrow cells
Abstract Deltamethrin (DEL) and thiacloprid (THIA) are two insecticides that are widely used in agriculture either separately or in combination. Studies on genotoxicity and cytotoxicity of TIA and the mixture of DEL and THIA insecticides have not been reported so far. Therefore, we investigated the cytotoxic and genotoxic effects of commercial formulations DEL and/or THIA in rat bone marrow cells, using mitotic index (MI), micronucleus (MN) and chromosome aberrations (CA) assay. In vivo cytokinesis-block micronucleus ( CBMN) assay using cytochalasin-B in bone marrow cells was performed for the first time in this study. Rats were orally gavaged with a single dose of DEL (15 mg/kg), THIA (112.5 mg/kg) or DEL + THIA (15 + 112.5 mg/kg) for 24 h (acute treatments), or DEL (3 mg/kg/day), THIA (22.5 mg/kg/day) or DEL + THIA (3 + 22.5 mg/kg/day) for 30 days (subacute treatments). A corn oil vehicle control group and cyclophosphamide (50 mg/kg) positive control group were also included. All DEL and/or THIA treatments significantly decreased MI and binucleated (BN) cell numbers, and significantly increased CA, as compared to the vehicle control group. The results of CBMN assay indicated that the combination of DEL and THIA for both treatment times and the 30-day treatment with THIA alone caused a significant increase in micronucleus formation in BN cells. The present findings indicated the combined exposure of DEL and THIA showed genotoxic and cytotoxic effects more than those of individual exposure of DEL or THIA in rat bone marrow cells. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Induction of reactive oxygen species in Chlamydomonas reinhardtii in response to contrasting trace metal exposures
Abstract The toxicity of metals to organisms is, in-part, related to the formation of reactive oxygen species (ROS) in cells and subsequent oxidative stress. ROS are by-products of normal respiration and photosynthesis processes in organisms, but environmental factors, like metal exposure, can stimulate excess production. Metals involved in several different mechanisms such as Haber-Weiss cycling and Fenton-type reactions can produce ROS. Some metals, such as Cd, may contribute to oxidative stress indirectly by depleting cellular antioxidants. We investigated the measurement of ROS as a sensitive biomarker of metal toxicity (that could possibly be implemented in a biotic ligand model for algae) and we compared ROS induction in response to several contrasting transition metals (Cu, V, Ni, Zn, and Cd). We also compared the ROS response to glutathione and growth toxicity endpoints measured in a previous study. The cell-permeable dye, 2′7′dichlorodihydrofluorescein diacetate, was used as a probe to detect formation of ROS in Chlamydomonas reinhardtii cells. Metal-exposed cells were incubated with the fluorescent dye in a 96-well plate and monitored over 5.5 h. A dose-response of ROS formation was observed with Cu exposure in the range of 20–500 nM. Cu produced more ROS compared with either Zn or Cd (both nonredox active metals). The redox-active metal V produced increased ROS with increased concentration. The measurement of ROS may be a useful indicator of Cu toxicity, but the signal to noise ratio was better for the glutathione endpoint assay. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
cDNA microarray analysis of the gene expression of murine leukemia RAW 264.7 cells after exposure to propofol
Abstract Propofol (2,6-diisopropylphenol) is the most extensively used general anesthetic-sedative agent and it is employed in clinical patients. It has been shown that propofol exhibits anticancer activities. However, there is no available information to address propofol-induced cytotoxic effects and affected gene expressions on murine leukemia cells. Therefore, we investigated the effects of propofol on the levels of protein and gene expression, which are associated with apoptotic death in mouse leukemia RAW 264.7 cells in vitro . Results indicated that propofol induced cell morphological changes, cytotoxicity, and induction of apoptosis in RAW 264.7 cells in vitro . Western blot analysis demonstrated that propofol promoted Fas, cytochrome c , caspase-9 and −3 active form and Bax levels, but inhibited Bcl-xl protein level which led to cell apoptosis. Furthermore, cDNA microarray assay indicated that propofol significantly enhanced 5 gene expressions (Gm4884; Gm10883; Lce1c; Lrg1; and LOC100045878) and significantly suppressed 26 gene expressions (Gm10679; Zfp617; LOC621831; LOC621831; Gm5929; Snord116; Gm3994; LOC380994; Gm5592; LOC380994; Gm4638; LOC280487; Gm4638; Tex24; A530064D06Rik; BC094916; EG668725; Gm189; Hist2h3c2; Gm8020; Snord115; Gm3079; Olfr198; Tdh; Snord115; and Olfr1249). Based on these observations, propofol-altered apoptosis-related proteins might result from induction of apoptotic gene expression and inhibition of cell growth gene expression, which finally led to apoptosis in a mouse leukemia cell line (RAW 264.7) in vitro . © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Relationship between intracellular Ca2+ and ROS during fluoride-induced injury in SH-SY5Y cells
Abstract
The mechanisms underlying the neurotoxicology of endemic fluorosis still remain obscure. To explore lactate dehydrogenase (LDH) leakage, intracellular Ca2+ concentration ([Ca2+ ]i ) and reactive oxygen species (ROS) production induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with sodium fluoride (NaF, 20, 40, 80 mg/L) for 24 h, with 40 mg/L NaF for 3, 6, 12, 18, 24 h, and N -acetyl-L -cysteine (NAC), ethyleneglycol-bis-(β-aminoethyl ether)-N ,N ,N ′,N ′-tetraacetic acid (EGTA), 1,2-bis(O -aminophenoxy)ethane-N ,N ,N ′,N ′-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM) alone or combined with fluoride (40 mg/L) respectively for 12 h in vitro . The results showed that the LDH levels in the 40 and 80 mg/L fluoride-treated groups were significantly higher than that of the control group (in the test level of 0.05, the difference were statistical significance). [Ca2+ ]i and ROS reached a peak at 3 h and 12 h respectively after exposure to 40 mg/L fluoride. Fluoride coincubated with NAC (antioxidant) dramatically decreased ROS and LDH levels compared with the fluoride only group (in the test level of 0.05, the difference were statistical significance). However, fluoride-induced increase in [Ca2+ ]i was not affected by NAC. BAPTA-AM (intracellular calcium chelator) markedly lowered fluoride-induced increase of [Ca2+ ]i , ROS and LDH levels while EGTA (extracellular calcium chelator) have no effects on them. These results indicate that fluoride-related Ca2+ release from the site of intracellular calcium storage causes the elevation of ROS contributing to the cytotoxicity in SH-SY5Y cells. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Bioaccumulation of algal toxins and changes in physiological parameters in Mediterranean mussels from the North Adriatic Sea (Italy)
Abstract The Northwestern Adriatic Sea is a commercially important area in aquaculture, accounting for about 90% of the Italian mussel production, and it was subjected to recurring cases of mussel farm closures due to toxic algae poisoning. A spatial and temporal survey of four sites along the North Adriatic Sea coasts of Emilia Romagna (Italy) was undertaken to study the possible impairments of physiological parameters in Mytilus galloprovincialis naturally exposed to algal toxins. The sites were selected as part of the monitoring network for the assessment of algal toxins bioaccumulation by the competent Authority. Samples positive to paralytic shellfish toxins and to lipophilic toxins were detected through the mouse bioassay. Lipophilic toxins were assessed by HPLC. Decreasing yessotoxins (YTX) levels were observed in mussels from June to December, while homo-YTX contents increased concomitantly. Lysosome membrane stability (LMS), glutathione S-transferase and catalase activities, and multixenobiotic resistance (MXR)-related gene expressions were assessed as parameters related to the mussel health status and widely utilized in environmental biomonitoring. Levels of cAMP were also measured, as possibly involved in the algal toxin mechanisms of action. Low LMS values were observed in hemocytes from mussels positive to the mouse bioassay. MXR-related gene expressions were greatly inhibited in mussels positive to the mouse bioassay. Clear correlations were established between increasing homo-YTX contents (and decreasing YTX) and increasing cAMP levels in the tissues. Similarly, significant correlations were established between the increase of homo-YTX and cAMP levels, and the expressions of three MXR-related genes at submaximal toxin concentrations. In conclusion, YTXs may affect mussel physiological parameters, including hemocyte functionality, gene expression and cell signaling. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2011.
Diallyl sulfide, diallyl disulfide, and diallyl trisulfide inhibit migration and invasion in human colon cancer colo 205 cells through the inhibition of matrix metalloproteinase-2, -7, and -9 expressions
Abstract Diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS) are major organosulfur compounds exiting in garlic (Allium sativum ). These compounds are reported to exhibit various pharmacological properties such as antibacteria, antiangiogenesis, anticancer, and anticoagulation, and they also induce cytotoxicity and induction of apoptosis in human cancer cells. Although these compounds show wide spectrum of biological activities, there are no reports to show that DAS, DADS, and DATS affected migration and invasion of human colon cancer cells, and their exact molecular mechanisms are not well investigated. Therefore, the purpose of this study was to determine whether DAS, DADS, and DATS affected the invasion and migration abilities of colo 205 human colon cancer cells. The results indicate that DAS, DADS, and DATS at 10 and 25 μM inhibited the migration and invasion of colo 205 cells in the order of DATS < DADS < DAS. DATS is the highest for inhibition of migration and invasion of colo 205 cells. DAS, DADS, and DATS induce downregulation expression of PI3K, Ras, MEKK3, MKK7, ERK1/2, JNK1/2, and p38 and then lead to the inhibition of MMP-2, -7, and -9. DAS, DADS, and DATS inhibited NF-κB and COX-2 for leading to the inhibition of cell proliferation. Taken together, these results demonstrated that application of DAS, DADS, and DATS might serve as potential antimetastatic drugs. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2011.
Antioxidative and antigenotoxic effect of vitamin E against patulin cytotoxicity and genotoxicity in HepG2 cells
Abstract
Patulin (PAT) is a mycotoxin produced in fruits, mainly in apples, by certain species of Penicillium , Aspergillus , and Byssochlamys . It has been shown that PAT is cytotoxic, genotoxic, and mutagenic in different cell types. Several studies incriminate the oxidative stress as a mechanism of PAT-mediated toxicity. In this context, our aim was to investigate the protective role of Vitamin E (Vit E), an antioxidant agent, against PAT induced cytotoxicity and genotoxicity in cultured HepG2 cells. The obtained results showed that addition of Vit E in cells treated with PAT significantly reduce cell mortality induced by this toxin. In the same conditions, Vit E decreased the intracellular level of ROS, reduced PAT induced p53 expression, and reversed PAT induced DNA damage. In addition, Vit E prevented significantly the percentage of chromosome aberrations induced by PAT in HepG2 cells in a concentration dependant manner. These results suggest that Vit E, an exogenous antioxidant agent, plays an important role in defense against PAT-induced cytotoxicity and genotoxicity, which confirms the involvement of oxidative stress in the induction of DNA damage by PAT in HepG2 cells. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Catalase activity and innate immune response of Caenorhabditis elegans against the heavy metal toxin lead
Abstract
The heavy metal lead-induced oxidative stress on Caenorhabditis elegans was examined at the level of catalase activity and on innate immunity. Stress-induced C. elegans was exposed to Pseudomonas aeruginosa PA14::GFP for monitoring the impact at the physiological level. Role of catalase on the innate-immune responses of C. elegans was examined. PA14::GFP did not colonize lead pretreated C. elegans intestinal cells significantly compared to untreated controls, indicating stress-mediated upregulation of host-immunity. Semiquantitative PCR analyses of lead-exposed and PA14-infected C. elegans mRNA showed significant upregulation of candidate antimicrobial enzyme gene lys-7 after 24 h of exposures. Upregulation of metallothionein(mtl-1 ) when compared to mtl-2 in response to the lead suggesting active detoxification of metal by mtl-1 . Exogenously provided Catalase (0.4–3.2 U) induced significant upregulation of lys-7 compared to controls. lys-7 upregulation during lead exposure was reconfirmed by real-time PCR. Confocal microscopy and fluorescence spectrophotometer analyses indicated that the lead pretreated C. elegans was significantly less colonized by PA14::GFP when compared to controls. Relative expression of ctl-1 and ctl-2 mRNA was measured using real time PCR and found to be regulated during lead exposures. Over all, the upregulation of antimicrobial gene expression appears to be correlated with the level of catalase during stress emphasizing their key roles in defensive mechanism(s). These results provide a link between the stress and related immune responses which can be explored in higher systems. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Molecular mechanism of inflammatory response in mouse liver caused by exposure to CeCl3
Abstract
To investigate the molecular mechanism of inflammatory response in the mouse liver caused by exposure to CeCl3 , we measured the liver indices, and cerium content, evaluated the liver histopathological section, detected serum biochemical parameters of liver function, and the immunoglobulin M (IgM) content, analyzed the liver mRNA and protein expression levels of Toll-like receptor 2, 4 (TLR2, TLR4), and inflammatory cytokines in liver using real-time quantitative reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that exposure to CeCl3 decreased body weight and caused cerium accumulation in the mouse liver and histopathological changes of liver (such as inflammatory cell infiltration). Furthermore, biochemical assays suggested that CeCl3 could promote the activities of alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, pseudocholinesterase, and leucine aminopeptidase, decrease serum IgM, upregulate the levels of TLR2, TLR4, nuclear factor-κB (NF-κB), NF-κBp52, NF-κBp65, NF-κB-inducing kinase (NIK), IκB kinase α (IKK-α), IκB kinase β (IKK-β), and tumor necrosis factor-α (TNF-α) expression, and suppress NF-κB-inhibiting factor (IκB) and interleukin-2 (IL-2) expression in liver. Taken together, the inflammation of mice liver caused by exposure to CeCl3 might be closely associated with the alteration of inflammatory cytokine expressions in the mouse liver, the signal-transducing events happening in CeCl3 -induced macrophages of liver sequentially might occur via activation of TLRs→TNF-α→NIK→IκB kinase (including IKK1, IKK2)→NF-κB (including NF-κBP52, NF-κBP65)→ inflammation. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Investigation of biochemical responses of Bacopa monnieri L. upon exposure to arsenate
Abstract Widespread contamination of arsenic (As) is recognized as a global problem due to its well-known accumulation by edible and medicinal plants and associated health risks for the humans. In this study, phytotoxicity imposed upon exposure to arsenate [As(V); 0–250 μM for 1–7 days] and ensuing biochemical responses were investigated in a medicinal herb Bacopa monnieri L. vis-à -vis As accumulation. Plants accumulated substantial amount of As (total 768 μg g−1 dw at 250 μM As(V) after 7 days) with the maximum As retention being in roots (60%) followed by stem (23%) and leaves (17%). The level of cysteine and total nonprotein thiols (NP-SH) increased significantly at all exposure concentrations and durations. Besides, the level of metalloid binding ligands viz., glutathione (GSH) and phytochelatins (PCs) increased significantly at the studied concentrations [50 and 250 μM As(V)] in both roots and leaves. The activities of various enzymes viz., arsenate reductase (AR), glutathione reductase (GR), superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), and catalase (CAT) showed differential but coordinated stimulation in leaves and roots to help plants combat As toxicity up to moderate exposure concentrations (50 μM). However, beyond 50 μM, biomass production was found to decrease along with photosynthetic pigments and total soluble proteins, whereas lipid peroxidation increased. In conclusion, As accumulation potential of Bacopa may warrant its use as a phytoremediator but if Bacopa growing in contaminated areas is consumed by humans, it may prove to be toxic for health. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Adverse influence of coumestrol on secretory function of bovine luteal cells in the first trimester of pregnancy
Abstract Coumestrol is one of a few biologically active substances present in leguminous plants, which are widely used as fodder for ruminants. Depending on the doses, coumestrol acts on the reproductive processes as an estrogen-like factor or antiestrogen to evoke a decrease in ovulation frequency, elongation of estrous cycle duration. The aim of the current investigations was to study the influence of coumestrol on secretory function of luteal cells obtained from first trimester of pregnant cows. Luteal cells (2.5 × 105 /mL) from 3rd to 5th, 6th to 8th, and 9th to 12th week of pregnancy were preincubated for 24 h and incubated with coumestrol (1 × 10−6 M) for successive 48 h and the medium concentrations of progesterone (P4), oxytocin (OT), prostaglandin (PG) E2 and F2α were determined. Moreover, the expression of mRNA for neurophysin-I/oxytocin (NP-I/OT; precursor of OT) and peptidyl-glycine-α-amidating mono-oxygenase (PGA, an enzyme responsible for post-translational OT synthesis) was determined after 8 h of treatment. Coumestrol did not affect P4 secretion but increased the secretion of OT from the cells collected at all stages of gestation studied. Hence, the ratio of P4 to OT was markedly decreased. Simultaneously, coumestrol increased the expression of NP-I/OT mRNA during 9th to 12th weeks of pregnancy, and mRNA for PGA during 3rd to 5th and 9th to 12th weeks of gestation. Furthermore, coumestrol decreased PGE2 secretion from luteal cells in all studied stages of pregnancy, while it affected PGF2α metabolite (PGFM) concentration only from week 3 to 5 of pregnancy. Obtained results suggest that coumestrol impairs secretory function of the corpus luteum (CL) and this way it can affect the maintenance of pregnancy in the cow. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Multiwall carbon nano-onions induce DNA damage and apoptosis in human umbilical vein endothelial cells
Abstract Growing evidence has indicated the potential adverse effects on cardiovascular system of some nanomaterials, including fullerenes. In this study, we have evaluated the biological effects of multiwall carbon nano-onions (MWCNOs) (average size of 31.2 nm, ζ potential of 1.6 mV) on human umbilical vein endothelial cells (HUVECs). It was found that MWCNOs exhibited a dose-dependent inhibitory effect on cell growth; EC50 was 44.12 μg/mL. Thus, three concentrations were chosen (0.2, 1, and 5 μg/mL) for further experiments. Flow cytometry analysis revealed that 1 and 5 μg/mL MWCNOs could induce apoptosis in HUVECs, the apoptotic rates were 12% and 24% at 24 h after exposure. On the other hand, MWCNOs did not affect the cell cycle distribution during 24 h period. Using γH2AX foci formation as an indicator for DNA damage, it was shown that 5 μg/mL MWCNOs can induce γH2AX foci formation in HUVECs at 6, 12, and 24 h after treatment, whereas 0.2 μg/mL MWCNOs induced γH2AX foci formation only at 6 h after treatment. In addition, all three concentrations of MWCNOs induced the generation of reactive oxygen species (ROS), and inhibition of ROS generation can partially decrease the γH2AX foci formation induced by MWCNOs. Taken together, these data first suggested that MWCNOs can induce DNA damage and apoptosis in HUVECs, and that ROS might be involved in this process. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Excessive fluoride induces endoplasmic reticulum stress and interferes enamel proteinases secretion
Abstract
Protein retention in the enamel layer during tooth formation is well known to be associated with dental fluorosis but the underlying mechanism is unclear. The functions of the endoplasmic reticulum (ER) correlate directly with secreted protein metabolism. We used an ameloblast-derived cell line to determine whether excessive amounts of fluoride cause ER stress, and whether this interferes with the secretion of enamel matrix proteinases. ER stress activates a signaling network called the unfolded protein response (UPR). Here, we used real-time RT-PCR and immunofluorescence to study the effect of fluoride on the expression, translation, and secretion of UPR transcription factors in ameloblast-like cells. Measurement of both the gene and protein expression of UPR transcription factors indicated that high-dose fluoride increases the expression of UPR transcription factors in a dose-dependent manner. We also used ELISA to detect and quantify the enamel proteinases secreted by ameloblasts. We found a corresponding decrease in extracellular secretion of the enamel proteinases matrix metalloproteinase-20 and kallikrein-4, after exposure to fluoride. Furthermore, correlation analysis indicated that the expression of UPR transcription factors showed a strong inverse correlation with that of enamel proteinases. The results suggest that high-dose fluoride initiates an ER stress response in ameloblasts and induces the UPR, which interferes with the synthesis and secretion of enamel proteinases. Taken together, these results suggest that excessive ingestion of fluoride during tooth formation can decrease the secretion of proteinases, thus causing protein retention in the enamel layer, indicating that the ER stress response may be responsible for dental fluorosis. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Influence of increasing temperature and salinity on herbicide toxicity in estuarine phytoplankton
Abstract Ecological risk assessments are, in part, based on results of toxicity tests conducted under standard exposure conditions. Global climate change will have a wide range of effects on estuarine habitats, including potentially increasing water temperature and salinity, which may alter the risk assessment of estuarine pollutants. We examined the effects of increasing temperature and salinity on the toxicity of common herbicides (irgarol, diuron, atrazine, and ametryn) to the phytoplankton species Dunaliella tertiolecta . Static 96-h algal bioassays were conducted for each herbicide under four exposure scenarios: standard temperature and salinity (25°C, 20 ppt), standard temperature and elevated salinity (25°C, 40 ppt), elevated temperature and standard salinity (35°C, 20 ppt), and elevated temperature and elevated salinity (35°C, 40 ppt). The endpoints assessed were algal cell density at 96 h, growth rate, chlorophyll a content, lipid content, and starch content. Increasing exposure temperature reduced growth rate and 96-h cell density but increased the cellular chlorophyll and lipid concentrations of the control algae. Exposure condition did not alter starch content of control algae. Herbicides were found to decrease growth rate, 96 h cell density, and cellular chlorophyll and lipid concentrations, while starch concentrations increased with herbicide exposure. Herbicide effects under standard test conditions were then compared with those observed under elevated temperature and salinity. Herbicide effects on growth rate, cell density, and starch content were more pronounced under elevated salinity and temperature conditions. To encompass the natural variability in estuarine temperature and salinity, and to account for future changes in climate, toxicity tests should be conducted under a wider range of environmental conditions. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Developmental exposure to decabrominated diphenyl ether (BDE-209): Effects on sperm oxidative stress and chromatin dna damage in mouse offspring
Abstract Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants and have been found in human milk in recent years. This study investigates whether prenatal exposure to decabrominated diphenyl ether (BDE-209) induces sperm dysfunction in male offspring. Pregnant CD-1 mice were gavaged once daily with corn oil (control), 10, 500, and 1500 mg kg−1 body weight of BDE-209 from day 0 of gestation to day 17. The outcomes of male reproductive parameters were assessed on postnatal day 71. Anogenital distance, sperm-head abnormalities, and testicular histopathology were significantly affected in male offspring prenatally exposed to 1500 mg kg−1 . Significant increases in the tendency for sperm DNA denaturation (αT) induction and the DNA fragmentation index (DFI) were found in those exposed to 10, 500, and 1500 mg kg−1 (P < 0.05). We observed a significant increase of sperm hydrogen peroxide (H2 O2 ) generation in the 10 and 1500 mg/kg/day groups compared to the control group (P < 0.05). Although our findings suggested that the mechanisms underlying BDE-209-induced sperm DNA damage and H2 O2 generation might not be represented as a dose-response relationship, we found that the greater the excess production of sperm H2 O2 , the greater the sperm αT (r = 0.65, P = 0.0155) and DFI (r = 0.53, P = 0.002). In conclusion, developmental exposure to BDE-209 induced sperm-head abnormality, oxidative stress, chromatin DNA damage, and testicular histopathological changes. These findings suggest that BDE-209-induced male reproductive effects might involve the formation of sperm H2 O2 which attacks nucleic acids via H2 O2 generation. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Inhibition of PP2A and the consequent activation of JNK/c-Jun are involved in tributyltin-induced apoptosis in human amnionic cells
Abstract Tributyltin (TBT), a highly toxic environmental contaminant, has been shown to induce mitochondrial-dependent apoptosis in several mammalian cells. However, the upstream signal transduction pathways involved in TBT-induced apoptosis are still not fully elucidated. In this study, the protein phosphatase (PP) 2A, microtubule organization, and mitogen-activated protein kinases (MAPKs), including JNK, p38 and their downstream transcription factors, c-Jun and ATF-2, respectively, were investigated in human amnionic cells treated by TBT. Furthermore, the activation of procaspase-3 after blocking either one of these MAPK pathways was also observed. The results showed that TBT effectively induced apoptosis characterized by caspase-3 activation. In apoptotic cells, the inhibition of PP2A activity and microtubule depolymerization was detected. Additionally, JNK and p38, as well as their downstream targets, c-Jun and ATF-2, were activated. Moreover, a JNK inhibitor, but not p38 inhibitor, significantly reduced caspase-3 activation. It can be concluded that the inhibition of PP2A may (1) play as a role in the activation of JNK and c-Jun and the concomitant promotion of microtubule depolymerization and (2) lead to the activation of caspase-3 in TBT-induced apoptotic cells. The results of this study suggest a critical role of PP2A in the TBT toxicity mechanism. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Metiram-induced nephrotoxicity in albino mice: Effect of licorice aqueous extract
Abstract The present study was designed to estimate the effect of aqueous extract of licorice on metiram toxicity in mice. Treating mice with metiram at a dose level of [1/2] LD50 daily for 3 weeks induced many histological changes in the kidney cortex. The renal tubules lost their characteristic appearance and their lining epithelial cells were degenerated. The glomeruli were atrophied and the renal blood vessels were congested. The intertubular spaces infiltrated by inflammatory leukocytic cells. Metiram caused an increase in proliferating cell nuclear antigen (PCNA) expression in nuclei of tubular epithelial cells. Metiram also caused marked elevation in serum creatinine and blood urea nitrogen. Treating animals with metiram and licorice aqueous extract led to an improvement, in both biochemical and histopathological alterations. These results proved that licorice had an ameliorative effect against kidney injury induced by metiram and this effect may be attributed to its antioxidant activity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2011.
PFOS and PCB 153 have direct adverse effects on neonatal testis modeled using a coculture of primary gonocyte and sertoli cells
Abstract
Perfluorooctane sulfonate (PFOS) is widely used in industry; it is nonbiodegradable and persistent in the human body and in the environment. Although reports have indicated that young people might have higher PFOS levels in serum or blood than do older people, its adverse effects on neonatal testicular cells had not been investigated previously. PCB 153 is one of the most prevalent polychlorinated biphenyl (PCB) congeners in biological tissues, but the direct adverse effect of PCB 153 on neonatal testis remains unclear. In this study, we exposed a neonatal Sertoli cell/gonocyte coculture system to PFOS and PCB 153 individually at concentrations of 0, 1, 10, 50, and 100 μM for 24 h. Exposure to either compound reduced the cell viability and induced the production of reactive oxygen species (ROS) in dose-dependent manners, with PCB 153 having a greater effect than PFOS. Whereas PCB 153 induced apoptosis significantly from 10 μM, PFOS induced no obvious change. Morphologically, both PCB 153 and PFOS induced changes in the vimentin and actin filaments in the Sertoli cells, as investigated using confocal argon ion laser scanning microscopy; here, PFOS exhibited a more dramatic effect than did PCB 153. Furthermore, doses of 50 μM for PFOS and 10 μM for PCB 153 were the key concentrations that produced significant differences between the control and exposure groups. We suggest that both PCB 153 and PFOS directly affect neonatal gonocyte and Sertoli cells; the production of ROS and the change in the cytoskeleton in Sertoli cells might be causes. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Involvement of oxidative stress in methyl parathion and parathion-induced toxicity and genotoxicity to human liver carcinoma (HepG2) cells
Abstract
Methyl parathion (C8 H10 NO5 PS) and parathion (C10 H14 NO5 PS) are both organophosphate insecticides (OPI) widely used for household and agricultural applications. They are known for their ability to irreversibly inhibit acetylcholinesterase which often leads to a profound effect on the nervous system of exposed organisms. Many recently published studies have indicated that human exposure to OPI may be associated with neurologic, hematopoietic, cardiovascular, and reproductive adverse effects. Studies have also linked OPI exposure to a number of degenerative diseases including Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Also, oxidative stress (OS) has been reported as a possible mechanism of OPI toxicity in humans. Hence, the aim of the present investigation was to use human liver carcinoma (HepG2 ) cells as a test model to evaluate the role of OS in methyl parathion- and parathion-induced toxicity. To achieve this goal, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell viability, lipid peroxidation assay for malondialdehyde (MDA) production, and Comet assay for DNA damage, respectively. Results from MTT assay indicated that methyl parathion and parathion gradually reduce the viability of HepG2 cells in a dose-dependent manner, showing 48 h-LD50 values of 26.20 mM and 23.58 mM, respectively. Lipid peroxidation assay resulted in a significant increase (P < 0.05) of MDA level in methyl parathion- and parathion-treated HepG2 cells compared with controls, suggesting that OS plays a key role in OPI-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of OPI exposure. Overall, we found that methyl-parathion is slightly less toxic than parathion to HepG2 cells. The cytotoxic effect of these OPI was found to be associated, at least in part, with oxidative cell/tissue damage. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Retracted: Long-term copper toxicity in apple trees (Malus pumila Mill) and bioaccumulation in fruits
Abstract The following article from Environmental Toxicology , ‘Long-term Copper Toxicity in Apple Trees (Malus pumila Mill) and Bioaccumulation in Fruits’ by Bai-Ye Sun, Shi- Hong Kan, Yan-Zong Zhang, Jun Wu, Shi-Huai Deng, Chun-Sheng Liu and Gang Yang, published online on January 15, 2010 in Wiley InterScience (www.interscience.wiley.com; DOI: 10.1002/tox.20565), has been retracted by agreement between the authors, the journal Editor in Chief, Dr. Paul Tchounwou, and Wiley Periodicals, Inc. The retraction has been agreed at the request of the authors due to overlap with ‘Copper Toxicity and Bioaccumulation in Chinese Cabbage (Brassica pekinensis Rupr.)’ by Zhi-Ting Xiong and Hai Wang, published in Environmental Toxicology , Volume 20, pages 188–194, 2005.
