Effects of methiocarb on lipid peroxidation and glutathione level in rat tissues

Methiocarb is an N-methylcarbamate insecticide used worldwide in agriculture and health programs. The aim of this study was to investigate the possible effects of methiocarb to induce lipid peroxidation (LPO) in tissues of male Wistar rats following single and repeated oral exposures. Animals were divided into six different groups, and methiocarb was administered by orally at doses 25, 10, and 2?mg/kg body weight for 1, 5, and 28 days, respectively. Liver, kidney, brain, and testis tissues were taken from the rats for the biochemical examinations. LPO and reduced glutathione (GSH) levels were determined in the tissues. LPO was significantly increased in liver, kidney, brain, and testis after 1-, 5-, and 28-day treatments of methiocarb. GSH levels were significantly increased in the 1-day period and significantly decreased in the 5- and 28-day periods in all tissues after methiocarb administration. It is concluded that methiocarb may induce LPO and produce disturbances on the GSH levels in liver, kidney, testis, and brain of rats. This suggests that methiocarb-induced toxicity may be associated with oxidative stress to cellular membranes. Further studies are required to better understand the role of oxidative stress on methiocarb-induced toxicity.     

Preventive effects of a purified extract isolated from Salvia miltiorrhiza enriched with tanshinone I,tanshinone IIA and cryptotanshinone on hepatocyte injury in vitro and in vivo

Salvia miltiorrhiza is traditionally used to treat liver disease in Asia. In this study, we tested the ability of a purified extract of S. miltiorrhiza (PF2401-SF) and its constituents, tanshinone I, tanshinone IIA, and cryptotanshinone, to protect against acute and subacute liver damage induced by carbon tetrachloride by measuring serum transaminase levels, the reduced form of glutathione (GSH), antioxidant enzyme activities, and lipid peroxidation levels in the liver. We also evaluated their ability to protect primary cultured rat hepatocytes from tertiary-butylhydroperoxide (tBH) or d-galactosamine (GalN). PF2401-SF was protective at 50–200 mg/kg per day in acute liver injury and 25–100 mg/kg per day in subacute liver injury. Tanshinone I, tanshinone IIA, and cryptotanshinon (40 μM), inhibited lactate dehydrogenase leakage, GSH depletion, lipid peroxidation and free radical generation in vitro. PF2401-SF and its major constituents, tanshinone I, tanshinone IIA and cryptotanshinone, can protect against liver toxicity in vivo and in vitro due to its antioxidant effects.     

Effects of dietary vitamin E,C and soybean oil supplementation on antioxidant enzyme activities in liver and muscles of rats

The effect of elevated levels of dietary vitamin E, C and a combination of vitamin E and C (E & C) with soybean oil on activities of antioxidant (AOE) enzymes important in the protection against lipid peroxidation was studied in male rats fed with vitamin C (12 mg/g), vitamin E (3.68 mg/g) or E & C (3.68 mg/kg + 12 mg/g) supplemented diets for 28 days. Catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activity in liver, pectoralis major (PM) and sartorius (S) muscles was increased significantly in rats fed with dietary vitamin C, E separately, and vitamin C & E combination, except, superoxide dismutase (SOD), which showed no alterations. These results clearly indicated that vitamin E & C separately and E & C together increased AOE activity in liver, PM and S muscle of rats. However, vitamin E and C combination enhanced AOE activity more significantly and our findings suggest the possible role of vitamin C & E and their combination in reducing the risk of chronic diseases related to oxidative stress.     

Taurine has a protective effect against thioacetamide-induced liver cirrhosis by decreasing oxidative stress

Thioacetamide (TAA) administration (0.3 g/l of tap water for a period of 3 months) to rats resulted in hepatic cirrhosis as assessed by biochemical and histopathological findings. This treatment caused an increase in the levels of malondialdehyde (MDA) and diene conjugates (DCs) and a decrease in the levels of glutathione (GSH), vitamin E, vitamin C and the activities of glutathione peroxidase (GSH-Px) in the liver of rats. Superoxide dismutase (SOD) activities were unchanged. Taurine (2% w/w, added to the chow diet) was administered together with TAA (0.3 g/l of drinking water) for 3 months. Taurine was found to decrease TAA-induced hepatic lipid peroxidation and to increase TAA-depleted vitamin E levels and GSH-Px activities. Histopathological findings also suggested that taurine has an inhibitive effect on TAA-induced hepatic cirrhosis. These results indicate that taurine treatment has a protective effect against TAA-induced liver cirrhosis by decreasing oxidative stress.     

The physiological stress response and oxidative stress biomarkers in rainbow trout and brook trout from selenium‐impacted streams in a coal mining region

Selenium (Se) is an essential element that can be toxic at concentrations slightly greater than those required for homeostasis. The main chronic toxic effects of Se in fish are teratogenic deformities, but Se can also activate the physiological stress response and redox cycle with reduced glutathione causing oxidative damage. Rainbow trout, Oncorhynchus mykiss, appear to be more sensitive to Se than brook trout, Salvelinus fontinalis. The objective of this study was to compare the physiological stress response (plasma cortisol, glucose, triiodothyronine, thyroxine, gill Na⁺/K⁺ ATPase, cortisol secretory capacity, K and liver somatic index) and oxidative stress biomarkers (liver GSH, GPx, lipid peroxidation, vitamin A and vitamin E) in rainbow trout (RNTR) and brook trout (BKTR) collected from reference and Se‐exposed streams. The physiological stress response was not impaired (cortisol secretory capacity unchanged); although there were species differences in plasma cortisol and plasma glucose levels. Liver GSH, GPx and vitamin levels were higher in RNTR than BKTR, but lipid peroxidation levels were not different. The elevated GSH reserves may make RNTR more sensitive to Se‐induced lipid peroxidation, but this may be offset by the RNTR's higher antioxidant (GPx and vitamin) levels. Species‐specific biochemical differences may mediate differences in Se sensitivity and be used in aquatic Se risk assessments. Copyright © 2009 John Wiley & Sons, Ltd.     

Vitamin E protects Wistar rats from chlorpyrifos-induced increase in erythrocyte osmotic fragility

The aim of the present study was to evaluate the effect of chronic chlorpyrifos (CPF) exposure on erythrocyte osmotic fragility, the role of lipid peroxidation and the ameliorative effect of vitamin E on the erythrocyte fragility. Twenty young adult male Wistar rats divided into four groups of five animals each served as subjects for this study. Groups I (control) and II were exposed to soya oil (2 ml/kg) and vitamin E (75 mg/kg), respectively. Rats in group III were exposed to CPF (10.6 mg/kg 1/8th of the previously determined LD50 of 85 mg/kg over a period of 48 h), while those in group IV were pretreated with vitamin E (75 mg/kg) and then exposed to CPF, 30 min later. The regimens were administered orally by gavage once daily for a period of 17 weeks. Blood samples collected at the end of the test period were analyzed for erythrocyte osmotic fragility, while the washed erythrocytes were used to evaluate malondialdehyde (MDA) concentration, as an index of lipid peroxidation. The study showed that repeated CPF exposure caused increased erythrocyte fragility and MDA concentration. Pretreatment with vitamin E ameliorated CPF-induced increase in erythrocyte fragility and lipoperoxidative changes in Wistar rats.     

Effects of prochloraz on DNA damage,lipid peroxidation and antioxidant system in vitro

Prochloraz is a broad-spectrum contact imidazol fungicide used against several diseases in wheat, barley and oleaginous plants but also for treatment of flower production. Although prochloraz has endocrine disrupting and hepatocarcinogenic effects, there is lack of data on toxic effects of prochloraz. Therefore, we aimed to investigate the DNA damage effects of prochloraz in NRK-52E cells by using Ames and Comet assay. By using a standard alkaline Comet assay procedure, there was no DNA damage observed after 24?h prochloraz exposure. It also showed that prochloraz caused neither base-pair substitution nor frame shift mutations by using TA98, TA100 strains, respectively, with/without metabolic activation in Ames assay. Both Comet and Ames assays, the exposure concentrations were 12.5, 25, 50 and 100?µM. IC₅₀ value of prochloraz was determined as 110.76?µM in NRK-52E cells by MTT cytotoxicity test. Also, we evaluated possible effects of prochloraz on lipid peroxidation, reduced glutathione (GSH), oxidized glutathione (GSSG) and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in NRK-52E cells at 1–50?µM concentrations. Prochloraz induced lipid peroxidation and altered glutathione contents and antioxidant enzyme activities in NRK-52E cells. Our results indicated that prochloraz showed no evidence of mutagenicity and DNA damage; however, some alterations were observed on lipid peroxidation and antioxidant systems in prochloraz treatment.     

Combined effects of vitamin C, vitamin E, and sodium selenate supplementation on absolute ethanol-induced injury in various organs of rats

In this study, the effect of combination of vitamin C (ascorbic acid), vitamin E (alpha -tocopherol), and selenium (sodium selenate) on ethanol-induced liver and intestine injury in rats was investigated. The ethanol-induced injury was produced by the administration of 1 ml of absolute ethanol to each rats. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and sodium selenate (Se) (0.5 mg/kg) for 3 days; 1 h after the final antioxidant administration, they were sacrificed. Lipid peroxidation and glutathione levels, catalase (CAT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase (GP(x)) activities were determined in liver and intestine tissues. Myeloperoxidase (MPO), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) were determined in liver tissue. Also, CAT activity, urea, creatinine, uric acid, and total lipid levels were determined in serum samples. In the ethanol group, serum urea, creatinine, uric acid, and total lipid levels; liver and intestine LDH; liver MPO, AST, ALP, ALT, and GGT activities; and liver and intestine LPO levels increased, whereas serum CAT activity, liver and intestine GSH levels, and CAT, SOD, and GP(x) activities decreased. On the other hand, treatment with vitamin C, vitamin E, and Se reversed these effects. As a result of these findings, we can say that the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced changes in lipid peroxidation, glutathione levels, and antioxidant enzyme activities in liver and intestine tissues, and in some serum parameters of rats.     

Caffeic acid phenethyl ester protects against tamoxifen-induced hepatotoxicity in rats

Tamoxifen (TAM) is widely used in the treatment and prevention of breast cancer. Adverse effects of TAM include hepatotoxicity. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been used in folk medicine for diverse ailments. In the current study, the protective effects of CAPE against TAM-induced hepatotoxicity in female rats were evaluated. TAM (45 mg/kg/day, i.p., for 10 consecutive days) resulted in an elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), depletion of liver reduced glutathione (GSH) and accumulation of oxidized glutathione (GSSG) and lipid peroxidation (LPO). Also, TAM treatment resulted in inhibition of hepatic activity of glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Further, it raised liver tumor necrosis factor-alpha (TNF-α) level and induced histopathological changes. Pretreatment with CAPE (2.84 mg/kg/day; i.p., for 20 consecutive days, starting 10 days before TAM injection) significantly prevented the elevation in serum activity of the assessed enzymes. CAPE significantly inhibited TAM-induced hepatic GSH depletion and GSSG and LPO accumulation. Consistently, CAPE normalized the activity of GR, GPx, SOD and CAT, inhibited the rise in TNF-α and ameliorated the histopathological changes. In conclusion, CAPE protects against TAM-induced hepatotoxicity.     

Antioxidant effects of Panax ginseng C.A. Meyer in healthy subjects: A randomized, placebo-controlled clinical trial

We investigated the antioxidant effects of Panax ginseng C.A. Meyer on healthy volunteers. In a double-blind randomized controlled design, 82 participants (21 men and 61 women) who were considered healthy by both objective and subjective health standard were divided into three groups, the control group and the groups received P. ginseng extract (1 or 2 g/day) for 4 weeks. Serum level of reactive oxygen species (ROS), malondialdehyde (MDA), total antioxidant capacity (TAC), the activities of catalase, superoxide dismutase (SOD), glutathione reductase (GSH-Rd), and peroxidase (GSH-Px), and total glutathione content were determined before and after the trial. Administration of P. ginseng led to significant decreases in the levels of serum ROS and MDA. Notably, the total glutathione content and GSH-Rd activity considerably improved in the groups that received 2 g of P. ginseng. No significant alterations were observed in TAC, catalase, SOD, and GSH-Px activities. In conclusion, our findings indicate that P. ginseng was shown to have antioxidant property. It enhanced the antioxidant defense mechanism in healthy populations and the results may reinforce the use of P. ginseng as a potential antioxidant supplement.     

Lipid peroxidation: A possible mechanism of cephaloridine-induced nephrotoxicity

Cephloridine produces renal cortical injury, but the precise mechanism responsible for this nephrotoxicity remains unclear. Recently cephaloridine has been shown to deplete reduced glutathione (GSH) concentration selectively in renal cortex. Cephaloridine nephrotoxicity can be potentiated by diethyl maleate (a GSH depletor), but no glutathione conjugate can be detected. Thus, it was of interest to investigate further the mechanism of depletion of renal cortical GSH by cephaloridine. In the present study, cephaloridine markedly decreased GSH in rat and rabbit renal cortex while concomitantly increasing oxidized glutathione (GSSG). Furthermore, cephaloridine increased lipid peroxidation specifically in renal cortical cells. Conjugated diene formation (an index of lipid peroxidation) was increased in renal cortex but not in the liver shortly following administration of cephaloridine. Removal of selenium and/or vitamin E from the diet, which should enhance lipid peroxidation, potentiated cephaloridine nephrotoxicity and enhanced cephaloridine-induced morphological damage in the kidney. These findings are consistent with a major role of lipid peroxidation in the etiology of cephaloridine nephrotoxicity.     

低剂量无机汞宫内及哺乳期暴露对仔大鼠肝、肾和脑组织中谷胱甘肽抗氧化物酶系统的影响

目的　研究低剂量无机汞子宫内及哺乳期暴露对仔大鼠肝脏、肾脏及脑组织中谷胱甘肽抗氧化物酶系统的影响 ,探讨低剂量无机汞对子代发育潜在的毒性。方法　对怀孕d 0的母大鼠进行 0 .2mg·L- 1Hg2 +饮水染毒直至仔鼠出生后d 2 0断乳期。研究仔鼠肝脏、肾脏及脑区 (大脑、小脑、脑干、海马及其余脑组织 )中汞的分布及汞暴露对上述组织中总巯基含量、还原型谷胱甘肽 (GSH)水平及谷胱甘肽过氧化物酶 (GSH Px)活性的影响。结果汞暴露后仔鼠肾脏中汞的含量最高 ,其次是肝脏和脑组织。在所研究的仔鼠各脑区中 ,海马汞含量最高 ,其次是小脑和大脑。汞暴露组仔鼠肝脏和肾脏中巯基含量比对照组升高了 2倍 ,而脑区中汞暴露组巯基含量与对照组相比则降低至 1/ 2～ 1/ 3。汞暴露组仔鼠肝脏中GSH水平与对照组相比升高了6 5 % ,而在肾脏和脑组织中GSH的水平与对照组相比则显著降低 ,其中 ,汞暴露组仔鼠各脑区中GSH水平降低幅度与对照组相比均超过了 5 8%。除肝脏外 ,汞暴露组仔鼠肾脏和脑区中GSH Px活性明显下降。在脑组织中 ,除海马外 ,GSH Px活性在汞暴露组其他 4个脑区中的下降幅度均超过 80 %。结论　低剂量无机汞子宫内及哺乳期暴露对仔鼠肾脏 ,特别是对脑组织的正常发育造成了一定程度的危害 ;但上述指标对肝脏的     

Effect of vitamin E on the balance between pro- and antioxidant activity of ascorbic acid in microsomes from rat heart, kidney and liver

The effect of the vitamin E status of membranes on the balance between pro- and antioxidant activity of ascorbic acid was studied in microsomes from rat heart, kidney and liver. Lipid peroxidation was initiated by 5 microM ferrous ions, in combination with amounts of ascorbic acid ranging from 0-4 mM. Lipid peroxidation was assessed after 1 h of incubation as production of thiobarbituric acid reactive material. It was found that the vitamin E status of the microsomal membranes had little effect on the balance between pro- and antioxidant activity of vitamin C. The sensitivity of the membranes to ferrous ions/ascorbic acid-induced lipid peroxidation, however, was highly dependent on the vitamin E content of the membranes. Vitamin E depletion, in combination with different ascorbic acid concentrations, showed that vitamin E deficiency is not an incontestable model system for enhanced sensitivity to lipid peroxidation in all organs.     

Effect of taurine supplementation on cytochrome P450 2E1 and oxidative stress in the liver and kidneys of rats with streptozotocin-induced diabetes

To investigate whether diabetes-induced alterations of CYP2E1 and oxidative stress can be modulated by dietary taurine supplementation, male Wistar rats were divided into non-diabetic, diabetic, and diabetic taurine-supplemented groups (administered at 2% in the drinking water). Increased levels of CYP2E1-catalyzed p-nitrophenol hydroxylation were found in liver and kidney microsomes of rats with STZ-induced diabetes compared to those of non-diabetic control rats. Immunoblot and RT-PCR analyses of CYP2E1 protein and mRNA levels in the liver and kidneys showed the same trend as with enzyme activities. Taurine supplementation significantly decreased the enzyme activity and expression (protein and mRNA) of CYP2E1 in diabetic rat kidneys. Plasma β-hydroxybutyrate concentration was significantly reduced in taurine-treated diabetic rats. The induction of heme oxygenase-1 mRNA was suppressed by taurine treatment in diabetic rat kidneys. An increase in reduced glutathione (GSH) and a higher ratio of reduced to oxidized glutathione (GSH/GSSG) together with lower values of thiobarbituric acid-reactive substances (TBARS) were observed in the kidneys of taurine-treated diabetic rats. However, taurine supplementation caused only a slight or insignificant effect on these alternations in the liver of diabetic rats. Our results show dietary taurine may reduce CYP2E1 expression and activity, and oxidative stress in kidneys of diabetic rats.     

Protective effects of Forsythia suspensa extract against oxidative stress induced by diquat in rats

Forsythia suspensa extract has been proved as a potential antioxidant in the recent years. The present study was undertaken to obtain the optimal antioxidant fraction in vitro and examine its antioxidative potential against diquat-induced oxidative stress in male Sprague Dawley rats in vivo. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging experiment indicated that the CH₂Cl₂ fraction of F. suspensa (FSC) exerted the strongest scavenging activities; forsythoside A, forythialan A and phillygenin from it might be the major antioxidant constituents. In vivo, pretreatment of rats with different doses of FSC (25, 50 and 100 mg/kg bw) and vitamin C (100 mg/kg bw, positive control) for 15 days significantly lowered the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in plasma compared to the negative control group. Also, FSC significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of glutathione (GSH) in plasma, liver and kidney whereas it decreased the levels of malondialdehyde (MDA) in plasma and kidney. Moreover, the protective effect of FSC (100 mg/kg bw) was better than vitamin C. These results revealed that FSC exerted a protective effect against diquat-induced oxidative stress and is worthy of becoming a potential dietary antioxidant.     

Effect of nitroheterocyclic drugs on lipid peroxidation and glutathione content in rat liver extracts

Incubation of rat liver cell-free extracts with an NADPH-generating system and with nifurtimox or benznidazole (two nitroheterocyclic drugs used in the treatment of Chagas' disease) produced oxidation of reduced glutathione (GSH) and increased lipid peroxidation, as shown by the generation of thiobarbituric-acid-reacting intermediates. Nifurtimox and benznidazole inhibited GSSG-reductase, but not GSH-peroxidase, the former inhibition contributing to GSH depletion. In every case, nifurtimox was more effective than benznidazole. Addition of GSH or free-radical scavengers (catalase, superoxide dismutase, mannitol, sodium benzoate or L-histidine) prevented the effect of nifurtimox on lipid peroxidation reactions. These results support the assumption [M. Dubin, S. N. J. Moreno, E. E. Martino, R. Docampo and A. O. M. Dubin, Biochem. Pharmac.32, 483 (1983)] that, in the rat liver, GSH exerts a protective action against oxygen radicals generated by the nitroheterocyclic drugs.     

氯丙烯诱导的大鼠坐骨神经传导速度和脂质过氧化相关性

目的探讨氯丙烯(AC)诱导的大鼠坐骨神经传导速度(NCV)改变和脂质过氧化之间是否存在相关性。方法W istar雄性大鼠ig AC 200 mg.kg-1,每周3次,分别给药3,6,9和12周。用电生理仪测定对照组与染毒组大鼠坐骨神经NCV;用生物化学方法测定坐骨神经匀浆丙二醛(MDA)和谷胱甘肽(GSH)含量、抗氧化能力(H2O2降低)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)和超氧化物岐化酶(SOD)活性等指标。结果随染毒时间的延长,GSH含量,抗氧化能力,SOD活性从染毒3周开始呈进行性下降;NCV,GSH-Px和CAT活性从染毒6周开始进行性下降;MDA含量则从染毒3周开始呈进行性升高,与对照组相比差异均有统计学意义(P<0.05)。经分层多元回归分析抗氧化能力,MDA含量和GSH-Px活性是影响NCV的主要脂质过氧化指标。随染毒时间的延长,NCV与MDA含量呈显著负相关(r=-0.9080,P<0.05),与抗氧化能力,GSH-Px活性呈显著正相关(r=0.7112,0.8943,P<0.05)。结论NCV和脂质过氧化的改变随染毒时间延长呈进行性加重;NCV改变和脂质过氧化之间存在密切的相关性,脂质过氧化可能是AC诱导的NCV改变的原因之一。     

Effect of garlic-derived organosulfur compounds on mitochondrial function and integrity in isolated mouse liver mitochondria

The objectives of this work were to evaluate the direct effects of diallysulfide (DAS) and diallyldisulfide (DADS), two major organosulfur compounds of garlic oil, on mitochondrial function and integrity, by using isolated mouse liver mitochondria in a cell-free system. DADS produced concentration-dependent mitochondrial swelling over the range 125–1000 μM, while DAS was ineffective. Swelling experiments performed with de-energized or energized mitochondria showed similar maximal swelling amplitudes. Cyclosporin A (1 μM), or ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA, 1 mM) were ineffective in inhibiting DADS-induced mitochondrial swelling. DADS produced a minor (12%) decrease in mitochondrial membrane protein thiols, but did not induce clustering of mitochondrial membrane proteins. Incubation of mitochondria with DADS (but not DAS) produced an increase in the oxidation rate of 2′,7′ dichlorofluorescein diacetate (DCFH-DA), together with depletion of reduced glutathione (GSH) and increased lipid peroxidation. DADS (but not DAS) produced a concentration-dependent dissipation of the mitochondrial membrane potential, but did not induce cytochrome c release. DADS-dependent effects, including mitochondrial swelling, DCFH-DA oxidation, lipid peroxidation and loss of mitochondrial membrane potential, were inhibited by antioxidants and iron chelators. These results suggest that DADS causes direct impairment of mitochondrial function as the result of oxidation of the membrane lipid phase initiated by the GSH- and iron-dependent generation of oxidants.     

Antioxidant enzyme activity and lipid peroxidation in liver and kidney of rats exposed to microcystin-LR administered intraperitoneally.

The effect of acute exposure of intraperitoneal injection of microcystin-LR (MCLR) on antioxidant enzymes and lipid peroxidation has been studied in liver and kidney of rats. Rats were treated with two doses, i.e. 100 and 150 microg of pure MCLR/kg body weight or saline solution. The enzyme activities of glutathione peroxidase (GSH-Px), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in the liver were significantly decreased in MCLR-treated rats. The decrease of GR activity in the liver was 60%, followed by GSH-Px, SOD and CAT. Similarly, a decrease in the antioxidant enzymes was found in the kidney of MCLR-treated rats, such as GSH-Px (27-31%), GR (22%), SOD (42%) and CAT (25-28%). Concomitantly, significant increases in lipid peroxidation levels were recorded in liver (121 and 196% for 100 and 150 microg/kg, respectively) and kidney (48 and 58% for 100 and 150 microg/kg, respectively) from MCLR-treated rats. In conclusion, acute exposure to MCLR results in a decrease in the antioxidant enzymes and an increase in lipid peroxidation in liver and kidney rats, suggesting the oxidative stress as an important role in the pathogenesis of MCLR-induced toxicity. Antioxidant enzymes were significantly consumed in the liver and a minor decrease was found in kidney, confirming the organ-specific effects of MCLR.     

The effects of organophosphate insecticide methidathion on lipid peroxidation and anti-oxidant enzymes in rat erythrocytes: role of vitamins E and C

The effects of organophosphate insecticide methidathion (MD) on lipid peroxidation and anti-oxidant enzymes and the ameliorating effects of a combination of vitamins E and C against MD toxicity were evaluated in rat erythrocytes. Experimental groups were: control group, MD-treated group (MD), and MD + vitamin E + vitamin C-treated group (MD + Vit). MD and MD + Vit groups were treated orally with a single dose of 8 mg/kg MD body weight at 0 hour. Vitamins E and C were injected at doses of 150 mg/kg body weight, i.m. and 200 mg/kg body weight, i.p., respectively, 30 min after the treatment of MD in the MD + Vit group. Blood samples were taken 24 hours after the MD administration. The level of malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were studied in the erythrocytes. MDA level increased significantly in the MD group compared to the control group (P < 0.05) and decreased significantly in the MD + Vit group compared to the MD group (P < 0.05). The activities of SOD, GSH-Px, and CAT decreased in the MD group compared to the control group (P < 0.05). Only GSH-Px activity increased in the MD + Vit group compared with the MD group. These results suggest that treating rats with MD increases LPO and decreases anti-oxidant enzyme activities in erythrocytes. Furthermore, single-dose treatment with a combination of vitamins E and C 30 min after the administration of MD can reduce LPO caused by MD.