Antioxidant effect of ascorbic acid on PCB (Aroclor 1254) induced oxidative stress in hypothalamus of albino rats

Melatonin and Vitamins as Protectors against the Reproductive Toxicity of Bisphenols: Which Is the Most Effective? A Systematic Review and Meta-Analysis

Bisphenols such as bisphenol A (BPA), S (BPS), C (BPC), F (BPF), AF (BPAF), tetrabromobisphenol, nonylphenol, and octylphenol are plasticizers used worldwide to manufacture daily-use articles. Exposure to these compounds is related to many pathologies of public health importance, such as infertility. Using a protector compound against the reproductive toxicological effects of bisphenols is of scientific interest. Melatonin and vitamins have been tested, but the results are not conclusive. To this end, this systematic review and meta-analysis compared the response of reproductive variables to melatonin and vitamin administration as protectors against damage caused by bisphenols. We search for controlled studies of male rats exposed to bisphenols to induce alterations in reproduction, with at least one intervention group receiving melatonin or vitamins (B, C, or E). Also, molecular docking simulations were performed between the androgen (AR) and estrogen receptors (ER), melatonin, and vitamins. About 1234 records were initially found; finally, 13 studies were qualified for review and meta-analysis. Melatonin plus bisphenol improves sperm concentration and viability of sperm and increases testosterone serum levels compared with control groups; however, groups receiving vitamins plus bisphenols had lower sperm concentration, total testis weight, and testosterone serum levels than the control. In the docking analysis, vitamin E had the highest negative MolDock score, representing the best binding affinity with AR and ER, compared with other vitamins and melatonin in the docking. Our findings suggest that vitamins could act as an endocrine disruptor, and melatonin is most effective in protecting against the toxic effects of bisphenols.

Ascorbic acid as antioxidant

Ascorbic acid, as one of the basic exogenous vitamins, is known for its tremendous antioxidant properties. This review has been prepared to show not only the importance of ascorbic acid as a free radical scavenger, but also to summarize its antioxidant action based on other mechanisms, including activation of intracellular antioxidant systems. Ascorbic acid interacts with small molecule antioxidants, including tocopherol, glutathione and thioredoxin, but also can stimulate the biosynthesis and activation of antioxidant enzymes, such as superoxide dismutase, catalase or glutathione peroxidase. Moreover, ascorbic acid promotes the activity of several transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this connection, both DNA, protein and lipids are protected against oxidation. Although ascorbic acid has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in prevention of DNA mutation and cellular apoptosis, especially in relation to cancer cells is controversial.

Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid

Ascorbic acid, as a one of the basic exogenous vitamins, occurs in the body in the form of ascorbate, known for its strong antioxidant and anti-inflammatory properties. The presented review shows not only the importance of ascorbate as a free radical scavenger but also summarizes its antioxidant action based on other mechanisms, including the activation of intracellular antioxidant systems and its effect on the NFκB/TNFα pathway and apoptosis. Ascorbate interacts with small-molecule antioxidants, including tocopherol, glutathione, and thioredoxin; it can also stimulate biosynthesis and the activation of antioxidant enzymes, such as superoxide dismutase, catalase, or glutathione peroxidase. Moreover, ascorbate promotes the activity of transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this regard, both DNA, proteins, and lipids are protected against oxidation, leading to an inflammatory reaction and even cell death. Although ascorbate has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in the prevention of DNA mutation, inflammation, and cell apoptosis, especially in relation to cancer cells, is controversial.

A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals

Over the years, the vaste expansion of plastic manufacturing has dramatically increased the environmental impact of microplastics [MPs] and nanoplastics [NPs], making them a threat to marine and terrestrial biota because they contain endocrine disrupting chemicals [EDCs] and other harmful compounds. MPs and NPs have deleteriouse impacts on mammalian endocrine components such as hypothalamus, pituitary, thyroid, adrenal, testes, and ovaries. MPs and NPs absorb and act as a transport medium for harmful chemicals such as bisphenols, phthalates, polybrominated diphenyl ether, polychlorinated biphenyl ether, organotin, perfluorinated compounds, dioxins, polycyclic aromatic hydrocarbons, organic contaminants, and heavy metals, which are commonly used as additives in plastic production. As the EDCs are not covalently bonded to plastics, they can easily leach into milk, water, and other liquids affecting the endocrine system of mammals upon exposure. The toxicity induced by MPs and NPs is size-dependent, as smaller particles have better absorption capacity and larger surface area, releasing more EDC and toxic chemicals. Various EDCs contained or carried by MPs and NPs share structural similarities with specific hormone receptors; hence they interfere with normal hormone receptors, altering the hormonal action of the endocrine glands. This review demonstrates size-dependent MPs' bioaccumulation, distribution, and translocation with potential hazards to the endocrine gland. We reviewed that MPs and NPs disrupt hypothalamic-pituitary axes, including the hypothalamic-pituitary-thyroid/adrenal/testicular/ovarian axis leading to oxidative stress, reproductive toxicity, neurotoxicity, cytotoxicity, developmental abnormalities, decreased sperm quality, and immunotoxicity. The direct consequences of MPs and NPs on the thyroid, testis, and ovaries are documented. Still, studies need to be carried out to identify the direct effects of MPs and NPs on the hypothalamus, pituitary, and adrenal glands.

Co-administration of Selenium Nanoparticles and Metformin Abrogate Testicular Oxidative Injury by Suppressing Redox Imbalance, Augmenting Sperm Quality and Nrf2 Protein Expression in Streptozotocin-Induced Diabetic Rats

Selenium nanoparticles (SeNPs) and metformin (Met) elicit individually protective effects against testicular oxidative injury in diabetic rats. However, the combined effects of both compounds have not been investigated. We investigated the effects of SeNPs and Met individual/co-treatment on testicular oxidative injury in diabetic rats. Diabetes was induced by a single intraperitoneal administration of streptozotocin (STZ-40 mg/kg bwt). The rats were equally divided into 6 groups: Group one-non-diabetic; group two-diabetic untreated; and group six-non-diabetic received citrate buffer (2 mL/kg bwt), while group three, four, and five received SeNPs (0.1 mg/kg bwt), Met (50 mg/kg bwt), and SeNPs/Met combined respectively, for 42 days. Results revealed that SeNPs, as well as Met treatment significantly (p < 0.001), lowered blood glucose levels and improved relative organ weights in treated rats than those of the untreated group. Moreover, a synergistic effect was observed in the co-administration group. Additionally, combined treatment elicited better effect, in augmenting the pituitary and testicular hormone (LH, FSH, prolactin, and testosterone) levels, marker enzymes/protein associated with steroidogenesis (3-βHSD, 17-βHSD, and StAR protein), and sperm functional parameters than those of individual treatment groups, when compared with control. Furthermore, the combinatorial effects of SeNPs and Met surpassed their influence in attenuating testicular oxidative stress/inflammation and upregulation of Nrf2 protein expression in diabetic rats when compared with control. Overall, normal rats, co-treated with SeNPs and Met, did not reveal any deleterious effect. Therefore, SeNPs and Met combined treatment may better improve testes function in diabetic conditions than an individual regimen.

Neurobiology of vitamin C: Expanding the focus from antioxidant to endogenous neuromodulator

Ascorbic acid (AA) is a water-soluble vitamin (C) found in all bodily organs. Most mammals synthesize it, humans are required to eat it, but all mammals need it for healthy functioning. AA reaches its highest concentration in the brain where both neurons and glia rely on tightly regulated uptake from blood via the glucose transport system and sodium-coupled active transport to accumulate and maintain AA at millimolar levels. As a prototype antioxidant, AA is not only neuroprotective, but also functions as a cofactor in redox-coupled reactions essential for the synthesis of neurotransmitters (e.g., dopamine and norepinephrine) and paracrine lipid mediators (e.g., epoxiecoisatrienoic acids) as well as the epigenetic regulation of DNA. Although redox capacity led to the promotion of AA in high doses as potential treatment for various neuropathological and psychiatric conditions, ample evidence has not supported this therapeutic strategy. Here, we focus on some long-neglected aspects of AA neurobiology, including its modulatory role in synaptic transmission as demonstrated by the long-established link between release of endogenous AA in brain extracellular fluid and the clearance of glutamate, an excitatory amino acid. Evidence that this link can be disrupted in animal models of Huntington´s disease is revealing opportunities for new research pathways and therapeutic applications (e.g., epilepsy and pain management). In fact, we suggest that improved understanding of the regulation of endogenous AA and its interaction with key brain neurotransmitter systems, rather than administration of AA in excess, should be the target of future brain-based therapies.

Neuroprotective effects of Withania somnifera in BPA induced-cognitive dysfunction and oxidative stress in mice

BACKGROUND

Bisphenol A (BPA), a major endocrine disruptor and a xenobiotic compound is used abundantly in the production of polycarbonate plastics and epoxy resins. Human exposure to this compound is primarily via its leaching from the protective internal epoxy resin coatings of containers into the food and beverages. In addition, the plastics used in dental prostheses and sealants also contain considerable amount of BPA and have a high risk of human exposure. Since it is a well-known endocrine disruptor and closely mimics the molecular structure of human estrogen thereby impairing learning and memory. Withania somnifera (Ws), commonly known as Ashwagandha is known for its varied therapeutic uses in Ayurvedic system of medicine. The present study was undertaken to demonstrate the impairment induced by BPA on the spatial learning, working memory and its alleviation by Ws in Swiss albino mice. The study was conducted on thirty Swiss albino mice, randomly distributed among three groups: control, BPA and BPA + Ws. The behavioral recovery after treatment with Ws was investigated using the Y-maize and Morris water maize test. Whereas, for the estimation of recovery of NMDA receptor which is related to learning and memory in hippocampus region by western blot and immunohistochemistry. Furthermore, the oxidative stress and antioxidant level was assessed by biochemical tests like MDA, SOD and catalase.

RESULTS

The study revealed that administration of Ws alleviated the behavioral deficits induced by BPA. Alongside, Ws treatment reinstated the number of NMDA receptors in hippocampus region and showed anti-oxidative property while ameliorating the endogenous anti-oxidant level in the brain.

CONCLUSION

These findings suggest that Ws significantly ameliorates the level of BPA intoxicated oxidative stress thereby potentially treating cognitive dysfunction which acts as the primary symptom in a number of neurodegenerative diseases.

Acetylcholinesterase Is a Potential Biomarker for a Broad Spectrum of Organic Environmental Pollutants

Acetylcholinesterase (AChE, EC 3.1.1.7) is a classical biomarker for monitoring contamination and intoxication of organophosphate (OP) and carbamate pesticides. In addition to these classical environmental AChE inhibitors, other organic toxic substances have been found to alter AChE activity in various species. These emerging organic AChE disruptors include certain persistent organic pollutants (POPs), polycyclic aromatic hydrocarbons (PAHs), and wildly used chemicals, most of which have received considerable public health concern in recent years. It is necessary to re-evaluate the environmental significances of AChE in terms of these toxic substances. Therefore, the present review is aiming to summarize correlations of AChE activity of certain organisms with the level of the contaminants in particular habitats, disruptions of AChE activity upon treatment with the emerging disruptors in vivo and in vitro, and action mechanisms underlying the effects on AChE. Over 40 chemicals belonging to six main categories were reviewed, including 12 POPs listed in the Stockholm Convention. AChE activity in certain organisms has been found to be well correlated with the contamination level of certain persistent pesticides and PAHs in particular habitats. Moreover, it has been documented that most of the listed toxic chemicals could inhibit AChE activity in diverse species ranging from invertebrates to mammals. Besides directly inactivating AChE, the mechanisms in terms of interference with the biosynthesis have been recognized for some emerging AChE disruptors, particularly for dioxins. The collected evidence suggests that AChE could serve as a potential biomarker for a diverse spectrum of organic environmental pollutants.

Ameliorating effect of kisspeptin-10 on methotrexate-induced sperm damages and testicular oxidative stress in rats

The purpose of this study was to determine the kisspeptin-10 (Kiss) administration on the damages in testicular oxidant-antioxidant system, reproductive organ weights and some spermatological characteristics resulted from methotrexate (MTX) exposure. Group 1 (n:6) received saline only; group 2 (n:6) received 50 nmol/kg kisspeptin-10 for 10 days; group 3 (n:10) received single-dose methotrexate 20 mg/kg; and group 4 (n:10) received MTX 20 mg/kg single dose and, after 3 days, received kisspeptin-10, 50 nmol/kg, lasted for 10 days by intraperitoneal injection. At the end of the study, malondialdehyde levels were found to have increased following the application of MTX while showing a significant reduction in group 4 with Kiss administration. With respect to the spermatological parameters, administering MTX decreased motility and increased the rates of abnormal spermatozoa in group 2, while improvements were observed in group 4 in the form of increased motility in the spermatozoa and fewer abnormal spermatozoa. In addition, Kiss treatment provided statistically significant increases in the absolute weight of the seminal vesicles and the relative weights of the right cauda epididymis and seminal vesicles resulting from MTX administration. MTX administration damaged some spermatological parameters and increased oxidative stress when compared to the control group. However, Kiss treatment was observed to mitigate these adverse effects as demonstrated by the improvements in coadministration of Kiss and MTX when compared to the MTX group. It is concluded that Kiss treatment may reduce MTX-induced reproductive toxicity as a potential antioxidant compound.

Taurine reverses sodium fluoride-mediated increase in inflammation, caspase-3 activity, and oxidative damage along the brain-pituitary-gonadal axis in male rats

Excessive exposure to fluoride is associated with male reproductive dysfunction in humans and animals. Taurine (2-aminoethane sulfonic acid) is a free intracellular β-amino acid with antioxidant, anti-inflammatory, and neuroprotective properties. However, the effect of taurine on fluoride-induced reproductive toxicity has not been reported. The present study investigated the influence of taurine on sodium fluoride (NaF)-induced functional changes along the brain-pituitary-gonadal axis in male rats. NaF was administered singly in drinking water at 15 mg·L^-1 alone or orally co-administered by gavage with taurine at 100 and 200 mg·(kg body mass)^-1 for 45 consecutive days. Results showed that taurine significantly prevented NaF-induced increase in oxidative stress indices as well as augmented antioxidant enzymes activities and glutathione level in the brain, testes, and epididymis of the treated rats. Moreover, taurine reversed NaF-induced elevation in inflammatory biomarkers and caspase-3 activity as well as histological damage in the brain, testes, and epididymis of the treated rats. The significant reversal of NaF-induced decreases in testosterone level and testicular activities of acid phosphatase, alkaline phosphatase, and lactate dehydrogenase by taurine was accompanied by enhancement of sperm functional characteristics in the treated rats. Taurine may be a possible chemopreventive candidate against reproductive dysfunction resulting from fluoride exposure.

Investigation of the effects of kisspeptin-10 in methionine-induced lipid peroxidation in testicle tissue of young rats

Disruption of the balance oxidants, antioxidants cause various pathophysiological conditions such as lipid peroxidation, protein degradation, or DNA damage. We have examined possible effects of kisspeptin-10 on the structural damage produced by methionine-induced lipid peroxidation in testicle tissue of young rats. Kisspeptin-10 did not significantly affect spermatogenic cells in seminiferous tubules. Testosterone levels decreased in the methionine group as compared with the control group but without statistical significance. Luteinizing hormone levels decreased in the methionine group as compared with the control group (P < 0.001). Catalase enzyme activity increased in the kisspeptin-10 group (P < 0.01) as compared with the other groups. Catalase mRNA expression was decreased in the methionine group as compared with the kisspeptin group (P < 0.001). Total superoxide dismutase enzyme activity and superoxide dismutase mRNA expression were increased in the kisspeptin group as compared with the methionine group (P < 0.05). In conclusion, kisspeptin treatment may protect the structure of spermatogenic cells against methionine-induced damage.

Vitamin C intervention may lower the levels of persistent organic pollutants in blood of healthy women - A pilot study

Emerging evidence suggests that exposure to endocrine-disrupting chemicals including persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) has a long term impact on human health. The goal of this pilot study was to test whether antioxidant intervention by vitamin C supplementation may be a remedial approach to decrease body burden of POPs in humans. Using solid phase extraction coupled with a triple quadrupole mass spectrometer and a gas chromatography high resolution mass spectrometry, we measured 18 PCBs, 7 OCPs, and 5 PBDEs in the blood of 15 healthy California women (8 were obese/overweight and 7 had normal weight) before and after 2 months of vitamin C supplementation (1000 mg/day). We observed higher PBDE levels than PCBs and OCPs, but only PCB and OCP levels were strongly and positively correlated with participant's BMI and age. We also found statistically significant decreases in 6 PCBs (PCB-74, PCB-118, PCB-138, PCB-153, PCB-180, and PCB-187), and 2 OCPs (4,4'-DDE, and 4,4'-DDT), but not PBDEs after vitamin C supplementation. Pending confirmation of this pilot finding in a larger study of both sexes, vitamin C intervention may have important public health implications in protecting health by reducing body burdens of POPs.

Antioxidant properties of Artemisia herba-alba and Eucalyptus camaldulensis essentials oils on malathion-induced reproductive damage in rat

Malathion (M) is an organophosphorus pesticide of utmost concern because of its adverse effects on non-targeted organisms.

Acetylcholinesterase in zebrafish embryos as a tool to identify neurotoxic effects in sediments

In order to clarify the suitability of zebrafish (Danio rerio) embryos for the detection of neurotoxic compounds, the acetylcholinesterase assay was adapted and validated with a series of priority pollutants listed as relevant for the European water policy (Aroclor 1254, 2,3-benzofuran, bisphenol A, chlorpyrifos, paraoxon-methyl, quinoline, and methyl mercury chloride) as well as acetonic extracts from three sediments of known contamination. The acute toxicities of the model substances and the sediment extracts were determined by means of the fish embryo test as specified in OECD TG 236, and concentrations as low as the effective concentration at 10% inhibition (EC10) were used as the highest test concentration in the acetylcholinesterase test in order to avoid nonspecific systemic effects mimicking neurotoxicity. Among the model compounds, only the known acetylcholinesterase inhibitors paraoxon-methyl and chlorpyrifos produced a strong inhibition to about 20 and 33%, respectively, of the negative controls. For the sediment extracts, a reduction of acetylcholinesterase activity to about 60% could only be shown for the Vering Canal sediment extracts; this could be correlated to high contents of acetylcholinesterase-inhibiting polycyclic aromatic hydrocarbons (PAHs) as identified by chemical analyses. Co-incubation of the Vering Canal sediment extracts with chlorpyrifos at EC10 concentrations each did not significantly increase the inhibitory effect of chlorpyrifos, indicating that the mode of action of acetylcholinesterase inhibition by the sediment-borne PAHs is different to that of the typical acetylcholinesterase blocker chlorpyrifos. Overall, the study documents that zebrafish embryos represent a suitable model not only to reveal acetylcholinesterase inhibition, but also to investigate various modes of neurotoxic action.

Garcinia kola seed ameliorates renal, hepatic, and testicular oxidative damage in streptozotocin-induced diabetic rats

CONTEXT

In Africa, Garcinia kola Heckel (Guttiferae) seed is commonly recommended in folklore medicine for the treatment of diabetes and its associated complications.

OBJECTIVE

The present study evaluated this traditional claim by mechanistic investigation into the effect of G. kola seed administration on renal, hepatic, and testicular oxidative damage in streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Diabetes mellitus was induced in adult male Wistar rats by an intraperitoneal injection of STZ (50 mg/kg). The diabetic rats were thereafter treated orally once per day with G. kola seed (250 mg/kg) and monitored for 14 d. Clinical observations, plasma biochemistry, hormonal profile, oxidative stress indices, sperm characteristics, and histopathological examination of the kidney, liver, and testes were evaluated to monitor treatment-related effects of G. kola seed in STZ-induced diabetic rats.

RESULTS AND DISCUSSION

Garcinia kola seed administration significantly ameliorated hyperglycemia mediated damage by decreasing the blood glucose level (72.8% and 84.6% on the 7th and 14th post-treatment days, respectively), enhancement of the antioxidant system, inhibition of lipid peroxidation, and improving the architecture of the kidney, liver, and testes in STZ-induced diabetic rats. In addition, G. kola seed intervention restored the kidney and liver function biomarkers, the sperm characteristics as well as the plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, triiodothyronine (T3), and thyroxine (T4) to normal in STZ-induced diabetic rats.

CONCLUSION

The findings from this investigation provide persuasive scientific support for the traditional use of G. kola seed in the treatment of diabetes and its associated complications.

The effect of glyphosate, its metabolites and impurities on erythrocyte acetylcholinesterase activity

Glyphosate [N-(phosphonomethyl)glycine] is used all over the world to protect agricultural and horticultural crops. According to initial reports, glyphosate has been considered to be safe for humans and animals; nevertheless, recent investigations had proven its toxicity. Extensive use of glyphosate and the conviction of its low toxicity leads to a situation in which it is used in excessive amounts in agriculture. That is why, we have investigated the effect of the most commonly used pesticide: glyphosate, its metabolites and impurities on acetylcholinesterase (AChE) activity (in vitro) in human erythrocytes, which is biochemically similar to acetylcholinesterase present in neural synapses. The analysis of noxious effects of metabolites and impurities of pesticides seems to be very important to evaluate toxicological risk that is associated with the effect of pesticide formulations (requirement of the EU regulations 1107/200/EC). The erythrocytes were incubated with xenobiotics at concentrations range from 0.01 to 5 mM for 1 and 4 h. Statistically significant decrease in AChE activity (about 20%) was observed only at high concentrations of the compounds (0.25-5 mM), which enter body only as a result of acute poisoning. There were no statistically significant differences in the effect of the investigated compounds, while the changes caused by them were similar after 1 and 4 h incubation. The investigated metabolites and impurities did not cause stronger changes in AChE activity than glyphosate itself. It may be concluded that the compounds studied (used in the concentrations that are usually determined in the environment) do not disturb function of human erythrocyte acetylcholinesterase.

New evidences of neurotoxicity of aroclor 1254 in mice brain: potential of coenzyme q10 in abating the detrimental outcomes

OBJECTIVES

The present subacute study was designed to evaluate the effect of coenzyme Q 10 (CoQ10) in the 28 days aroclor 1254 exposure induced oxidative stress in mice brain.

METHODS

Biochemical estimations of brain lipid peroxidation (LPO), reduced glutathione (GSH), and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetyl cholinesterase (AChE), and histopathological investigations of brain tissue were carried out.

RESULTS

Oral exposure of aroclor 1254 (5 mg/kg) led to significant decrease in levels of GSH, and activities of SOD, CAT, GPx, and AChE, and increase in LPO. These aberrations were restored by CoQ10 (10 mg/kg, intraperitoneal injection [IP]). This protection offered was comparable to that of L-deprenyl (1 mg/kg, IP) which served as a reference standard.

CONCLUSIONS

Aroclor 1254 exposure hampers the activities of various antioxidant enzymes and induces oxidative stress in the brains of Swiss albino mice. Supplementation of CoQ10 abrogates these deleterious effects of aroclor 1254. CoQ10 also apparently enhanced acetyl cholinesterase activity which reflects its influence on the cholinergic system.

Modulatory effect of lycopene on deltamethrin-induced testicular injury in rats

Aim of the current study was to investigate the ability of deltamethrin to induce testicular injury in rats and its possible attenuation with lycopene. Rats were divided into three groups: Group I (DEL) received deltamethrin, 5 mg/kg b.w./day orally, in corn oil. Group II (DEL + Lyc) received oral dose of lycopene (4 mg/kg b.w./day) in corn oil concurrently with deltamethrin following the same regimen as in group I. Group III (Control) received appropriate volume of corn oil. After 4 weeks, deltamethrin-treated rats showed decreased body weight, serum testosterone, luteinizing hormone and follicle-stimulating hormone levels. Testicular total oxidant capacity (TOC), nitrite/nitrate (NOx), poly (ADP-ribose) polymerase (PARP), and DNA damage were significantly increased. RT-PCR demonstrated significant up-regulation in testicular mRNA for glutathione-S-transferase and heat-shock protein-70 (HSP-70), whereas steroidogenic acute regulatory (StAR) protein was down-regulated after deltamethrin exposure. Lycopene was able to restore body weight, serum testosterone, StAR mRNA, TOC, NOx levels, and PARP activity with significant decrease in HSP-70 mRNA, and DNA damage. In conclusion, lycopene was able to counteract the deleterious effect of deltamethrin.

The effects of vitamin C on DDP-induced anemia in rats

The aim of this study was to investigate the effects of vitamin C on cisplatin (DDP)-induced anemia and explore its possible mechanisms in rats. Adult male Sprague-Dawley rats were randomly divided into six groups: control, vitamin C 50, vitamin C 100, DDP, DDP plus vitamin C 50 and DDP plus vitamin C 100-treated groups. DDP was intravenous injected as a single dose and vitamin C was administered by gavage. Serum erythropoietin (Epo), hemoglobin (Hb) and blood urea nitrogen (BUN) concentration were measured 4 and 14 days after DDP treatment. The changes of renal tissue were examined by light microscope. Administration of DDP to rats induced anemia and nephrotoxicity, characterized with a significant decrease in serum Epo and Hb and increase in BUN concentrations. Pathological examination revealed that DDP caused significant renal damage in rats. Vitamin C administration produced amelioration in biochemical indices of anemia and nephrotoxicity and in histological change when compared to group DDP alone; concurrent administration of vitamin C at doses of 100 mg/kg being more effective. Results from this study indicate that the novel natural antioxidant vitamin C might have protective effect against DDP-induced anemia in rats.

Transcriptome-wide gene expression in a rat model of attention deficit hyperactivity disorder symptoms: rats developmentally exposed to polychlorinated biphenyls

Polychlorinated biphenyls (PCB) exposure in rodents provides a useful model for the symptoms of Attention deficit hyperactivity disorder (ADHD). The goal of this study is to identify genes whose expression levels are altered in response to PCB exposure. The brains from 48 rats separated into two age groups of 24 animals each (4 males and 4 females for each PCB exposure level (control, PCB utero, and PCB lactational)) were harvested at postnatal days 23 and 35, respectively. The RNA was isolated from three brain regions of interest and was analyzed for differences in expression of a set of 27,342 transcripts. Two hundred seventy-nine transcripts showed significant differential expression due to PCB exposure mostly due to the difference between PCB lactational and control groups. The cluster analysis applied to these transcripts revealed that significant changes in gene expression levels in PFC area due to PCB lactational exposure. Our pathway analyses implicated 27 significant canonical pathways and 38 significant functional pathways. Our transcriptome-wide analysis of the effects of PCB exposure shows that the expression of many genes is dysregulated by lactational PCB exposure, but not gestational exposure and has highlighted biological pathways that might mediate the effects of PCB exposure on ADHD-like behaviors seen in exposed animals. Our work should further motivate studies of fatty acids in ADHD, and further suggests that another potentially druggable pathway, oxidative stress, may play a role in PCB induced ADHD behaviors.

Vitamin C down-regulates VEGF production in B16F10 murine melanoma cells via the suppression of p42/44 MAPK activation

It is known that vitamin C induces apoptosis in several kinds of tumor cells, but its effect on the regulation of the angiogenic process of tumors is not completely studied. Vascular endothelial growth factor (VEGF) is the most well-known angiogenic factor, and it has a potent function as a stimulator of endothelial survival, migration, as well as vascular permeability. Therefore, we have investigated whether vitamin C can regulate the angiogenic process through the modulation of VEGF production from B16F10 melanoma cells. VEGF mRNA expression and VEGF production at protein levels were suppressed by vitamin C. In addition, we found that vitamin C suppressed the expression of cyclooxygenase (COX)-2 and that decreased VEGF production by vitamin C was also restored by the administration of prostaglandin E2 which is a product of COX-2. These results suggest that vitamin C suppresses VEGF expression via the regulation of COX-2 expression. Mitogen-activated protein kinases are generally known as key mediators in the signaling pathway for VEGF production. In the presence of vitamin C, the activation of p42/44 MAPK was completely inhibited. Taken together, our data suggest that vitamin C can down-regulate VEGF production via the modulation of COX-2 expression and that p42/44 MAPK acts as an important signaling mediator in this process.

Effects of anesthetics and terminal procedures on biochemical and hormonal measurements in polychlorinated biphenyl treated rats

This investigation reports the effects of various terminal procedures, and how they modified the responses to a toxicant (polychlorinated biphenyls [A1254], 130 mg/kg/day × 5 days) administered by gavage to Sprague-Dawley male rats. Terminal procedures included exsanguination via the abdominal aorta under anesthesia (isoflurane inhalation or Equithesin injection), decapitation with or without anesthesia, or narcosis induced by carbon dioxide inhalation. Effects of repeated anesthesia were also tested. Terminal procedures induced confounding stress responses, particularly when Equithesin was used. The terminal procedures modified the conclusions about effects of A1254 on the concentrations of corticosterone, insulin, glucagon, glucose, alkaline phosphatase, lactate dehydrogenase, uric acid, and blood urea nitrogen, from nonstatistically significant to significant changes, and in the case of luteinizing hormone from a statistically significant increase to a significant decrease. Investigations of effects of toxicants should be designed and interpreted considering potential changes induced by the selection of a terminal procedure.

Effects of chronic dietary exposure to a low-dose of Malathion, Aroclor-1254 and 3-methylcholanthrene on three biomarkers in male mice

The aim of this research was to examine the applicability of some chronic toxicological tests in the determination of exposure to xenobiotics present in concentrations below No Observed Adverse Effect Level (NOAEL) and below the detection limit of analytical instruments. In the present experiment tested chemicals (Malathion, Aroclor-1254 and 3-methylcholanthrene (3-MC)) were mixed with wheat grains and given to male mice as feed over a period of 12 months. 7-ethoxyresorufin-O-deethylase (EROD) activity with the 3-MC and Aroclor-1254 treatments reached the peak at 9th month of exposure (26.7 and 42.4 pmol⁻¹ mg(prot)-⁻¹, respectively), while malathion did not have significant influence. Glutathione (GSH) level depletion was highest after three months of exposure. Unexpectedly, acetylcholinesterase (AChE) activity increased after treatment with malathion, an organophosphorous insecticide. In conclusion, low-level concentrations chronically administered exert certain effects on the levels of selected enzymes, e.g. biomarkers.

Direct and indirect effects of kisspeptin on liver oxidant and antioxidant systems in young male rats

Kisspeptin is a recently discovered hypothalamic peptide which plays an important role in the central control of reproductive functions. We have investigated direct and indirect effects of kisspeptin on the liver oxidative stress in young male rats. Twenty-four rats were divided into four groups (n = 6/group). First group served as control and received saline. Kisspeptin-10 was administered to the animals in the second group (20 nmol/rat/day), for a period of 7 days. Rats were given only one dose gosereline (0.9 mg/rat), a GnRH agonist in the third group. The last group received kisspeptin-10 with gosereline. The activities of catalase, superoxide dismutase (SOD), xanthine oxidase (XO), adenosine deaminase (AD) and level of malondialdehyde were studied in liver tissue. Serum samples were separated for total antioxidant capacity (TAC), total oxidant status (TOS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, blood urea nitrogen (BUN), colesterol, high-density lipoprotein (HDL) and triglyceride. Kisspeptin increased the activities of SOD and catalase (p < 0.05). When compared to the control group, the levels of malondialdehyde, TOS and AST were lower, but levels of BUN, cholesterole, HDL and AD were higher in the other three groups (p < 0.05). In conclusion, our findings suggest that kisspeptin may have antioxidant and thus protective effects on the liver tissue.

Pro-oxidant effect of vitamin C coadministration with bisphenol A, nonylphenol, and octylphenol on the reproductive tract of male rats

This study was performed to investigate whether bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) induce oxidative stress on the reproductive tract of male rats and if coadministration of vitamin C can prevent any possible oxidative stress. Wistar male rats were divided into seven groups as control (vehicle; olive oil), BPA, NP, OP, BPA+C, NP+C, and OP+C. BPA, OP, and NP groups (25 mg/kg/day) were administered orally to rats three times a week for 45 days. In BPA+C, NP+C, and OP+C groups, vitamin C (60 mg/kg/day) was administered orally along with BPA, OP, and NP (25 mg/kg/day) treatments. Malondialdehyde (MDA) appeared at significantly higher concentrations in BPA-, NP-, and OP-treated groups, when compared to control group. No significant decrease was observed in testes MDA levels of vitamin C coadministrated groups, compared with BPA, NP, and OP treatment groups. Decreased levels of reduced glutathione (GSH) were found in testes of BPA-, NP-, OP-treated rats. No significant increase was observed in testes GSH levels of BPA+C, NP+C, and OP+C groups, compared with BPA, NP, and OP treatment groups. Histological examination showed that vitamin C coadministrated groups had much more congestion areas, atrophy, and germinal cell debris in testes than those observed in other groups. Abnormal sperm percentages of BPA, BPA+C, NP+C, and OP+C groups were increased. In conclusion, the present results demonstrated that BPA, NP, and OP generate reactive oxygen species that cause oxidative damage in testes of rats. Coadministration of vitamin C aggravates this damage.

Combined effects of repeated administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyls on kidneys of male rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent environmental contaminants that exist as complex mixtures in the environment, but the possible interactions of TCDD and PCBs have not been systematically investigated. The main objective of this study was to investigate the combined nephrotoxic effects of TCDD and PCBs on rats and to reveal the potential interactions between TCDD and PCBs. Male Sprague-Dawley rats were intragastrically administered TCDD (10 microg/kg), PCBs (Aroclor 1254, 10 mg/kg), or the combination (10 microg/kg TCDD + 10 mg/kg Aroclor 1254). After 12 consecutive days of exposure, all treatments induced nephrotoxicity, as evidenced by significant increases in the levels of serum creatinine and blood urea nitrogen, changes of kidney histopathology, and significant renal oxidative stress. Most of these effects were more remarkable in the combined-exposure group. Furthermore, all treatments induced renal cytochrome P450 1A1 (CYP1A1) protein expression, and the induction was more conspicuous in the combined-exposure group. These findings suggested that the nephrotoxicity induced by TCDD and PCBs in the present study might be attributable to the high expression of CYP1A1. In addition, the result of the two-way analysis of variance revealed that the combined effects of TCDD and PCBs were complicated, being additive, synergistic, or antagonistic depending on the selection of toxicity end points under the present experimental condition. This study demonstrates that combined exposure to TCDD and PCBs induced significant nephrotoxicity in rats, and there were complicated interactions between the two pollutants on the nephrotoxicity.

The antioxidant effects of vitamin A, C, and E on aflatoxin B1-induced oxidative stress in human lymphocytes

The aim of this study was to investigate the possible protective role of vitamin A, C, and E on aflatoxin B1-induced in human lymphocytes using biochemical approaches. The control group received dimethyl sulfoxide, the second group of cultures were administered aflatoxin B1 (AFB1) at a dose of 5 μM. The other group of cultures were treated with AFB1+vitamin A (0.5 and 1.0 and 1.5 μM) and AFB1+vitamin C (25, 50, and 100 μM) and AFB1+vitamin E (40, 100, and 200 μM). The results of this experiment show that AFB1 significantly decreased the level of GSH and the activities of superoxide dismutase and GPx and increased level of malondialdehyde. Simultaneous supplementation with vitamin A, C, and E restored these parameters to that of normal range. In conclusion, vitamin A, C, and E exhibited protective effects in human lymphocytes by inhibiting AFB1-induced ROS generation.

Assessing noxious effects of dietary exposure to methylmercury, PCBs and Se coexisting in environmentally contaminated rice in male mice

Polychlorinated biphenyls and methylmercury are two of the most ubiquitous environmental contaminants in Guizhou province. Rice is eaten with almost every meal and provides more calories than any single food in Guizhou province. The estimated tolerable daily intake of total mercury, MeHg, Se and PCBs from Guizhou contaminated rice by Chinese people showed that MeHg and/or PCBs exceeded the corresponding limits. The aim of this study was to characterize the effects of exposure to environmental contaminated rice on neurobehavioral development and neurobiological disruptions in mice. Animals were treated from postnatal day (PND) 22 to 91. At PND 26-91 days of age, mice were tested for neurobehavioural development and neurochemical level changes. We showed that dietary exposure to environmentally contaminated rice gave rise to different changes in antioxidants. Reduced superoxide dismutase (SOD) activity and excess increased nitric oxide (NO) indicated aggravation of oxidative status after long-term dietary intake of Hg and PCBs. Neurobehavioral derangement in the central nervous system and significant delay in the Morris water maze test response on PND 91 are correlated with the increased of c-fos/c-jun expression levels in the cerebral cortex. These results suggest that MeHg neurotoxicity might be a greater hazard than that associated with PCB, but PCB may augment the neurobehavioral deficits caused by increased levels of mercury exposure. The simultaneous intake of selenium might have a protective effect on Hg accumulation in the body, and vitamin C might protect mice against the toxic effects of PCBs. However, the protective role of Se and vitamin C is very limited for multiple-agent pollution. Immediately early genes in the brain response to contaminated rice might be dependent on interaction among NO, NO synthase (NOS), SOD and reduced glutathione (GSH). We should be alert to mental health problems in human beings when any kind of Hg- and PCB-polluted food is consumed.

Oxidative stress alters creatine kinase system in serum and brain regions of polychlorinated biphenyl (Aroclor 1254)-exposed rats: protective role of melatonin

Polychlorinated biphenyls are one of the environmental toxicants and neurotoxic compounds which induce the production of free radicals. Creatine kinase plays a key role in energy metabolism of nervous tissue and might be one of the targets for reactive oxygen species. Melatonin, an indoleamine, plays an important role in neurodegenerative diseases as an antioxidant and neuroprotector. The objective of the present study was to investigate the protective role of melatonin on polychlorinated biphenyl (Aroclor 1254)-induced oxidative stress and the changes in creatine kinase activity in brain regions of adult rats. Group I: rats were intraperitoneally (i.p.) administered with corn oil (vehicle) for 30 days. Group II: rats injected i.p. with Aroclor 1254 at 2 mg/kg body weight (bw)/day for 30 days. Groups III and IV: rats i.p. received melatonin (5 or 10 mg/kg bw/day) simultaneously with Aroclor 1254 for 30 days. After 30 days, rats were killed and the brain regions were dissected to cerebral cortex, cerebellum and hippocampus. Lipid peroxidation, hydroxyl radical and hydrogen peroxide (H2O2) levels were determined. The activity of creatine kinase was assayed in serum and brain regions, and its isoenzymes in serum were separated electrophoretically. Activity of creatine kinase was decreased while an increase in H2O2, hydroxyl radical and lipid peroxidation was observed in brain regions of polychlorinated biphenyl-treated rats. Also polychlorinated biphenyl exposure showed a significant increase in serum creatine kinase level and its isoforms such as BB-creatine kinase, MB-creatine kinase, and MM-creatine kinase. Administration of melatonin prevented these alterations induced by polychlorinated biphenyl by its free radical scavenging mechanism. Thus, polychlorinated biphenyl alters creatine kinase activity by inducing oxidative stress in brain regions, which can be protected by melatonin.

Effects of Aroclor 1254 on oxidative stress in developing Xenopus laevis tadpoles

Over the last decades, amphibians decline has been reported worldwide. Exposure to polychlorinated biphenyls (PCBs) is one of the possible causes in addition to climate changes, UV-radiation or habitat destruction. In the present study, we tested the hypothesis that PCBs could induce oxidative stress in young tadpoles. Developing Xenopus laevis were exposed from 2- to 5-d postfertilization (pf) to 0.1 or 1 mg/l of Aroclor 1254. Lipid peroxidation and antioxidant systems (SOD, CAT, GST, GPx, GR activities and t-GSH level) were investigated in whole organisms. Exposure to both concentrations did not impact on the survival and development whereas the average body weight decreased. Exposure to 1 mg/l of Aroclor 1254 induced a significant (p<0.05) increase of GST activity when compared to controls 0 and DMSO. The other antioxidant enzymes and LPO evaluation remained unchanged. Our results demonstrate that exposure of X. laevis tadpoles to environmental concentrations of Aroclor 1254 interfere with normal growth. They also highlight that very young X. laevis tadpoles express antioxidant systems.

Protein expression profiling in the African clawed frog Xenopus laevis tadpoles exposed to the polychlorinated biphenyl mixture aroclor 1254

Exposure to environmental pollutants such as polychlorinated biphenyls (PCBs) is now taken into account to partly explain the worldwide decline of amphibians. PCBs induce deleterious effects on developing amphibians including deformities and delays in metamorphosis. However, the molecular mechanisms by which they express their toxicity during the development of tadpoles are still largely unknown. A proteomics analysis was performed on developing Xenopus laevis tadpoles exposed from 2 to 5 days postfertilization to either 0.1 or 1 ppm Aroclor 1254, a PCB mixture. Two-dimensional DIGE with a minimal labeling method coupled to nanoflow liquid chromatography-tandem mass spectrometry was used to detect and identify proteins differentially expressed under PCBs conditions. Results showed that 59 spots from the 0.1 ppm Aroclor 1254 condition and 57 spots from the 1 ppm Aroclor 1254 condition displayed a significant increase or decrease of abundance compared with the control. In total, 28 proteins were identified. The results suggest that PCBs induce mechanisms against oxidative stress (peroxiredoxins 1 and 2), adaptative changes in the energetic metabolism (enolase 1, glycerol-3-phosphate dehydrogenase, and creatine kinase muscle and brain types), and the implication of the unfolded protein response system (glucose-regulated protein, 58 kDa). They also affect, at least at the highest concentration tested, the synthesis of proteins involved in normal cytogenesis (alpha-tropomyosin, myosin heavy chain, and alpha-actin). For the first time, proteins such as aldehyde dehydrogenase 7A1, CArG binding factor-A, prolyl 4-hydroxylase beta, and nuclear matrix protein 200 were also shown to be up-regulated by PCBs in developing amphibians. These data argue that protein expression reorganization should be taken into account while estimating the toxicological hazard of wild amphibian populations exposed to PCBs.

Anzer honey prevents N-ethylmaleimide-induced liver damage in rats

N-ethylmaleimide (NEM) is a sulphydryl blocker which impairs the sulphydryl dependent antioxidant system (mainly glutathione) in the body by alkylating endogenous sulphydryls. This study was designed to investigate the effects of Anzer honey on NEM-induced liver injury in rats. Thirty female Wistar albino rats were divided equally into three groups. Group 1: control; Group 2: NEM; Group 3: Anzer honey+NEM. NEM (0.075mg kg(-1)) was given to both group 2 and 3 administered subcutaneously (s.c.) for 30 days. The animals in the Anzer honey+NEM group were treated with Anzer honey at a dose of 0.275g kg(-1), (p.o.) at 1h prior to every NEM injection. At the end of the 30 day treatment period, liver samples were taken for determination of the glutathione levels and histological examination. NEM treatment alone caused a significant reduction of the liver glutathione levels in group 2. Furthermore, NEM treatment caused congestion and mononuclear cell infiltration in the liver when compared to the control group. In group 3, Anzer honey treatment reversed all the changes in glutathione level, as well as histopathological alterations, normally induced by NEM. The findings imply that depletion of glutathione concentration plays a causal role in NEM-induced liver injury, and that the hepatoprotective effect of Anzer honey may be mediated through sulfhydryl-sensitive processes. They further imply that it may also possess antioxidant properties.

The effect of vitamin C on bisphenol A, nonylphenol and octylphenol induced brain damages of male rats

Bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) are endocrine-disrupting chemicals that has been shown to exert both toxic and estrogenic effects on mammalian cells. The aim of this study was to investigate if BPA, NP and OP induce oxidative stress on the brain tissue of male rats and if co-administration of vitamin C, an antioxidant, can prevent any possible oxidative stress. The male rats were divided into seven groups as control (vehicle), BPA, NP, OP, BPA+C, NP+C, OP+C. BPA, OP and NP (25 mg/(kg day)) were administrated orally to male Wistar rats for 45 days. In vitamin C co-administration groups (BPA+C, NP+C, OP+C), vitamin C (60 mg/(kg day)) were administrated orally along with BPA, OP and NP (25 mg/(kg day)) treatments. The rats in the control group received olive oil orally. The final body and absolute organ weights of treated rats did not show any significant difference when compared with the control group. Also, there were no significant difference in relative organ weights of BPA, NP, OP, BPA+C and NP+C groups when compared with control group. Only, relative organ weights were increased significantly in OP+C group compared with control group. Decreased levels of reduced glutathione (GSH) were found in the brains of BPA, NP, OP treated rats. The end product of lipid peroxidation, malondialdehyde (MDA), appeared at significantly higher concentrations in the BPA, NP, and OP treated groups when compared to the control group. On the other hand, there were no changes in the brain MDA and GSH levels of BPA+C, NP+C and OP+C groups compared with BPA, NP and OP treatment groups, respectively. In histopathologic examination, the vitamin C co-administrated groups had much more hyperchromatic cells in the brain cortex than that observed in the groups treated with only BPA, NP, and OP. The results of this study demonstrate that BPA, NP and OP generate reactive oxygen species that caused oxidative damage in the brain of male rats. In addition, vitamin C co-administration along with BPA, NP, and OP aggravates this oxidative damage in the brain of rats.

Polychlorinated biphenyl-induced oxidative stress in organotypic co-cultures: experimental dopamine depletion prevents reductions in GABA

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that have been demonstrated to be toxic to the dopamine (DA) systems of the central nervous system. One proposed mechanism for PCB-induced DA neurotoxicity is inhibition of the vesicular monoamine transporter (VMAT); such inhibition results in increased levels of unsequestered DA and DA metabolism leading to oxidative stress. We have used an organotypic co-culture system of developing rat striatum and ventral mesencephalon (VM) to determine whether alterations in the vesicular storage of DA, resulting from PCB exposure and consequent induction of oxidative stress, leads to GABA and DA neuronal dysfunction. Twenty-four-hour exposure to an environmentally relevant mixture of PCBs reduced tissue DA and GABA concentrations, increased medium levels of DA and measures of oxidative stress in both the striatum and VM. Alterations in neurochemistry and increases in measures of oxidative stress were blocked in the presence of n-acetylcysteine (NAC). Although NAC treatment did not alter PCB-induced changes in DA neurochemistry, it did protect against reductions in GABA concentration. To determine whether alterations in the vesicular storage of DA were responsible for PCB-induced oxidative stress and consequent reductions in GABA levels, we depleted DA from the co-cultures using alpha-methyl-p-tyrosine (AMPT). AMPT reduced striatal and VM DA levels by 90% and 70%, respectively. PCB exposure, following DA depletion, neither increased levels of oxidative stress nor resulted in GABA depletion. These results suggest that PCB-induced alterations in the vesicular storage of DA, resulting in increased levels of unsequestered DA, leads to increased oxidative stress, depletion of tissue glutathione, and consequent reductions in tissue GABA concentrations.

Alterations in human red blood cell properties induced by 3-(dimethylamino)phenol (in vitro)

3-(Dimethylamino)phenol (3-DMAP) exists in the environment as a transformation product of ureic herbicides and may also be considered as a derivative of phenoxyherbicides. In this study, the activity of glutathione peroxidase, catalase and superoxide dismutase, as well as the level of free radicals and changes in cell morphology were measured in human erythrocytes exposed (in vitro) to 3-(dimethylamino)phenol. Human erythrocytes were incubated for 1 h in 3-DMAP at concentrations of 10-500 microg per 1 ml erythrocytes of 5% haematocrit. The results show that 3-(dimethylamino)phenol increased the level of free radicals and changed the activity of glutathione peroxidase, catalase, superoxide dismutase and acetylcholinesterase. It also changed cell morphology. All these results corroborated the thesis that 3-DMAP induces oxidative stress in cells. 3-DMAP changed the properties of the cell membrane, caused strong oxidation of haemoglobin, inhibited the levels of enzymatic and non-enzymatic antioxidants, which, in result, lead to generation of free radicals (ROS and semiquinones) that occurred in the exposed cells, predisposing them to oxidative damage.

Oxidative stress modulates membrane bound ATPases in brain regions of PCB (Aroclor 1254) exposed rats: Protective role of α-tocopherol

Polychlorinated biphenyls (PCBs) are a class of widely dispersed and environmentally persistent organic compounds. PCBs exhibit a wide range of toxicological effects including neurotoxicity. Vitamin E (alpha-tocopherol) is an important lipid soluble antioxidant placed in a special region of membranes. Large amounts of energy are required to maintain the signaling activities of the cells in the central nervous system (CNS). Membrane proteins that control ion gradients across organellar and plasma membranes appear to be particularly susceptible to oxidation-induced changes. The aim of this study was to determine the protective role of vitamin E on Aroclor 1254 induced modulation in membrane bound ATPases in brain regions of rats. One group of rats received corn oil as vehicle for 30days as control. The other group of rats were administered Aroclor 1254 at a dose of 2mgkg(-1) bwday(-1) intraperitoneally for 30days. One group of rats received vitamin E (50mgkg(-1) bwday(-1)) orally simultaneously with Aroclor 1254 for 30days. After 30days, the animals were euthanized and the brain was dissected to hypothalamus and hippocampus to determine the following parameters. Hydrogen peroxide (H2O2), Lipid peroxidation (LPO) and the activities of Na+K+-ATPase, Ca2+-ATPase and Mg2+-ATPase were determined. Reduced glutathione (GSH) level was also determined. Activities of all the enzymes were decreased while an increase in H2O2 and LPO were observed in selected brain regions of PCB treated animals. Simultaneous vitamin E treatment in PCB exposed animals restored all the parameters significantly. These results suggest that oxidative stress is involved in the inhibitory effect of PCB (Aroclor 1254) on membrane bound ATPases in selected brain regions. alpha-tocopherol acts against PCB induced neurotoxicity by decreasing oxidative stress.