Protective role of L-carnitine supplementation against exhaustive exercise induced oxidative stress in rats

The objective of this study was to investigate temperature dependent effects of oral l-carnitine supplementation on exhaustive exercise induced oxidative damage in rats. 42 male Spraque Dawley rats were randomly divided into seven experimental groups. These groups were formed as three non-carnitine exercise groups, three carnitine-exercise groups and a sedentary group. l-carnitine was given intraperitoneally to the carnitine-exercise groups 1h before the exercise in 100mg/kg. Blood was collected to measure paraoxonase-1 (PON1) activity, plasma malondialdehyde (MDA), low-density lipoprotein (LDL) and cholesterol concentrations. These biomarkers were measured in venous blood samples collected before and after the rats swam in pools at different water temperatures (18°C, 28°C and 38°C). In the non-carnitine group, exercise caused a significant decrease in PON1 activity and a significant elevation in MDA concentration at 28°C compared to the sedentary group. No significant alterations were evidenced in LDL and cholesterol concentrations upon exercise. The decrease in PON1 activity became higher with increasing temperature whereas the elevation in MDA levels increased at 18°C. In the l-carnitine supplementation group, recovery in PON1 activity was observed significant at 28°C and very significant at 38°C. MDA concentration was almost the same with that of the non-carnitine group at 18 and 38°C, but it significantly decreased at 28°C. Considering the recovery in PON1 and MDA levels at 28°C, which is the temperature of the sedentary group; our results suggest that l-carnitine supplementation has a protective role on exhaustive exercise-induced oxidative stress. Findings of this study also demonstrate influences of thermal stress on these parameters during exhaustive exercise.     

Interaction of hypercaloric diet and physical exercise on lipid profile, oxidative stress and antioxidant defenses.

The present study examined the interaction of hypercaloric diet (HD) and physical exercise on lipid profile and oxidative stress in serum and liver of rats. Male Wistar rats (60-days-old) were fed with a control (C) and hypercaloric diet (H). Each of the two dietary groups (C and H) was divided into three subgroups (n=8), sedentary (CS and HS), exercised 2days a week (CE2 and HE2) and exercised 5days a week (CE5 and HE5). The swimming was selected as a model for exercise performance. After 8-weeks exercised rats showed decreased lactate dehydrogenase serum activities, demonstrating the effectiveness of the swimming as an aerobic-training protocol. Exercise 5-days a week reduced the body weight gain. Triacylglycerol (TG) and very low-density lipoprotein (VLDL-C) were increased in HD-fed rats. HE5 and CE5 rats had decreased TG, VLDL-C and cholesterol. HE2 rats had enhanced high-density lipoprotein (HDL-C) in serum. No alterations were observed in lipid hydroperoxide (LH), while total antioxidant substances (TAS) were increased in serum of exercised rats. HD-fed rats had hepatic TG accumulation. Superoxide dismutase activities were increased and catalase was decreased in liver of exercised rats. The interaction of HD and physical exercise reduced TAS and enhanced LH levels in hepatic tissue. In conclusion, this study confirmed the beneficial effect of physical exercise as a dyslipidemic-lowering component. Interaction of HD and physical exercise had discrepant effects on serum and liver oxidative stress. The interaction of HD and physical exercise reduced the oxidative stress in serum. HD and physical exercise interaction had pro-oxidant effect on hepatic tissue, suggesting that more studies should be done before using physical exercise as an adjunct therapy to reduce the adverse effects of HD.     

Beneficial effects of L-arginine against diabetes-induced oxidative stress in gastrointestinal tissues in rats

Oxidative stress occurs in diabetic patients and experimental models of diabetes. The ability of L-arginine to ameliorate oxidative stress after treatment with alloxan was investigated in rats. Adult male rats were injected intraperitoneally with multiple doses of alloxan to produce experimental oxidative stress characteristic of diabetes mellitus. The rats were maintained in this state for eight weeks. Rats were decapitated and gastrointestinal tissues were isolated. The results were interpreted and the significance was analyzed using unpaired, two-tailed Student’s t tests and two-way repeated measures ANOVA. Hyperglycemia was observed in the plasma after three days of alloxan treatment. This was associated with a depression of glutathione (GSH) concentration as well as superoxide dismutase (SOD) and catalase (CAT) activities in the pylorus and ileum. In addition, the malonyldialdehyde (MDA) levels were significantly elevated, indicating increased lipid peroxidation and oxidative stress in the same tissues. L-arginine supplementation (0.15 mg/ml) through drinking water until eight weeks after alloxan injection significantly ameliorated the oxidative stress, as evidenced by lower MDA levels as well as higher levels of endogenous GSH, SOD, and CAT (p < 0.001). These effects were paralleled by marked protection and prophylaxis against alloxan-induced hyperglycemia. Thus, exogenously administered L-arginine might improve the clinical manifestation of diabetes mellitus and decrease the oxidative stress in the gastrointestinal tract. In addition, the study supports the beneficial effects of L-arginine. These effects might be attributed to its direct, NO-dependent antioxidant capacity and/or NO-independent pathways.     

Protective role of l-carnitine supplementation against exhaustive exercise induced oxidative stress in rats

The objective of this study was to investigate temperature dependent effects of oral l-carnitine supplementation on exhaustive exercise induced oxidative damage in rats. 42 male Spraque Dawley rats were randomly divided into seven experimental groups. These groups were formed as three non-carnitine exercise groups, three carnitine-exercise groups and a sedentary group. l-carnitine was given intraperitoneally to the carnitine-exercise groups 1 h before the exercise in 100 mg/kg. Blood was collected to measure paraoxonase-1 (PON1) activity, plasma malondialdehyde (MDA), low-density lipoprotein (LDL) and cholesterol concentrations. These biomarkers were measured in venous blood samples collected before and after the rats swam in pools at different water temperatures (18 °C, 28 °C and 38 °C). In the non-carnitine group, exercise caused a significant decrease in PON1 activity and a significant elevation in MDA concentration at 28 °C compared to the sedentary group. No significant alterations were evidenced in LDL and cholesterol concentrations upon exercise. The decrease in PON1 activity became higher with increasing temperature whereas the elevation in MDA levels increased at 18 °C. In the l-carnitine supplementation group, recovery in PON1 activity was observed significant at 28 °C and very significant at 38 °C. MDA concentration was almost the same with that of the non-carnitine group at 18 and 38 °C, but it significantly decreased at 28 °C. Considering the recovery in PON1 and MDA levels at 28 °C, which is the temperature of the sedentary group; our results suggest that l-carnitine supplementation has a protective role on exhaustive exercise-induced oxidative stress. Findings of this study also demonstrate influences of thermal stress on these parameters during exhaustive exercise.     

Influence of chronic exercise on reserpine-induced oxidative stress in rats: behavioral and antioxidant evaluations

Several neurological diseases are related to oxidative stress (OS) and neurotoxicity. Considering that physical exercise may exert beneficial effects on antioxidant defenses, our objective was to evaluate the influence of a swimming exercise on an OS animal model (reserpine-induced orofacial dyskinesia). In this model, the increased dopamine metabolism can generate OS and neuronal degeneration, causing involuntary movements. The increase in vacuous chewing movements and facial twitching caused by reserpine (1 mg/kg s.c.) was partially prevented by exercise. An increase in catalase activity and a decrease in GSH levels were observed in the striatum. Physical training did not change the effects of reserpine on catalase, however it partially recovered GSH. Exercise per se caused a significant GSH decrease. There was a positive correlation between catalase and OD (r=0.41; r=0.47, P<0.05) and a negative correlation between GSH and OD (r=0.61; r=0.71, P<0.05). These results reveal the benefit of exercise in attenuating the motor disorder related to OS.     

Protective effects of L-arginine against cisplatin-induced renal oxidative stress and toxicity: role of nitric oxide

Nephrotoxicity is a dose-limiting factor in clinical use of cisplatin. The changes in renal haemodynamics were suggested to play a role in cisplatin-induced nephrotoxicity. The aim of the present study was to investigate the effect of modulation of nitric oxide on the severity of cisplatin-induced nephrotoxicity using an experimental rat model. A nitric oxide precursor, L-arginine and an inhibitor of nitric oxide synthase, L-NAME were used. After six days of cisplatin injection, acute nephrotoxicity was demonstrated by a marked increase in serum creatinine and blood urea nitrogen. Histological examination of the kidneys confirmed the occurrence of renal damage. Moreover, cisplatin induced an increase in the level of lipid peroxides and oxidized glutathione and a depletion of reduced glutathione. The activities of the antioxidant enzymes glutathione peroxidase and superoxide dismutase were also lowered. Besides, there was a reduction in the kidney total nitrate/nitrite levels. L-arginine significantly attenuated the oxidative stress and nephrotoxic effect of cisplatin. On the other hand, L-NAME was found to aggravate cisplatin nephrotoxicity. In conclusion, the decrease in the kidney nitric oxide level contributes, at least in part, in the mechanism underlying the nephrotoxicity of cisplatin. Furthermore, L-arginine shows nephroprotective effects and might be useful in improving the therapeutic index of cisplatin.     

Protective effects of zinc on oxidative stress enzymes in liver of protein-deficient rats

Persons afflicted with protein malnutrition are generally deficient in a variety of essential micronutrients like zinc, copper, iron, and selenium, which in turn affects number of metabolic processes in the body. To evaluate the protective effects of zinc on the enzymes involved in oxidative stress induced in liver of protein-deficient rats, the current study was designed. Zinc sulfate at a dose level of 227 mg/L zinc in drinking water was administered to female Sprague-Dawley normal control as well as protein-deficient rats for a total duration of 8 weeks. The effects of zinc treatment in conditions of protein deficiency were studied on rat liver antioxidant enzymes, which included catalase, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), glutathione reduced (GSH), and glutathione-S-transferase (GST). Protein deficiency in normal rats resulted in a significant increase in hepatic activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase and the levels of lipid peroxidation. A significant inhibition in the levels of reduced glutathione and the enzyme activity of superoxide dismutase has been observed after protein deficiency in normal rats. Interestingly, Zn treatment to protein-deficient animals lowered already raised activity catalase, glutathione peroxidase, and glutathione-S-transferase and levels of lipid peroxidation to significant levels when compared to protein-deficient animals. Also, Zn treatment to the protein-deficient animals resulted in a significant elevation in the levels of GSH and SOD activity as compared to their respective controls, thereby indicating its effectiveness in regulating their levels in adverse conditions. It has also been observed that concentrations of zinc, copper, iron, and selenium were found to be decreased significantly in protein-deficient animals. However, the levels of these elements came back to within normal limits when zinc was administrated to protein-deficient rats. This study concludes that zinc has the potential to regulate the activities of oxidative stress enzymes as well as essential hepatic elements.     

Protective effects of ligustrazine on cisplatin-induced oxidative stress, apoptosis and nephrotoxicity in rats

Cisplatin is an effective agent against various solid tumors. However, its nephrotoxicity been reported to be a dose-limiting factor for treating various types of tumors. The aim of this study was to determine the protective effects of ligustrazine on cisplatin-induced nephrotoxicity through tissue oxidant/antioxidant parameters, light microscopic evaluation, and tubular apoptosis in rats. Ligustrazine was administered in doses of 50 and 100 mg/kg/day intraperitoneally (i.p.), for 7 consecutive days, starting 2 days before a single intraveneous dose of cisplatin (8 mg/kg). Results revealed that treatment with cisplatin alone caused significant changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, blood urea nitrogen, and kidneys histopathological damages. All the aforementioned changes were effectively attenuated by ligustrazine. In addition, cisplatin caused increases in the levels of malondialdehyde, nitric oxide, nitric oxide synthase and decreases in the levels of reduced glutathione, glutathione-S-transferase, superoxide dismutase. These changes were restored to near normal levels by ligustrazine at 100 mg/kg. In conclusion, ligustrazine has dose dependent protective effects against cisplatin-induced renal tubular toxicity.     

Protective effect of lycopene on oxidative stress and antioxidant status in Cyprinus carpio during cypermethrin exposure

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 28:609–616, 2013.     

姜黄素对软骨细胞氧化应激损伤的保护作用

目的：通过建立H2O2诱导软骨细胞损伤模型,观察姜黄素对软骨细胞的保护作用。方法体外培养SD大鼠关节软骨细胞,随机分为对照组、模型组（H2O2）、姜黄素低中高剂量剂量组（20、40、80μmol／L）。姜黄素与软骨细胞培养48 h后,加入H2O2,24 h后收集细胞,MTT和流式细胞仪测定细胞增殖能力,测定细胞超氧化物歧化酶（SOD）、丙二醛（MDA）、过氧化氢酶（CAT）含量,Real－Time PCR和Western blot法检测细胞Nrf2 mRNA及其蛋白表达水平。结果与对照组比较,模型组软骨细胞存活率降低,具有分裂象的S期和G2／M期细胞明显减少;SOD、CAT含量降低,MDA含量增加,Nrf2 mRNA及其蛋白表达水平下调。经姜黄素预先处理,软骨细胞存活率升高,细胞增殖能力恢复,SOD、CAT含量升高,MDA含量降低,Nrf2 mRNA及其蛋白表达水平升高。随浓度升高变化更明显。结论姜黄素对软骨细胞氧化应激损伤有保护作用,可通过增强Nrf2表达实现。     

染料木素对野百合碱诱导的大鼠肺动脉高血压的保护作用

目的 研究染料木素对野百合碱引起的肺动脉高血压（PH）模型大鼠的降压作用及机制。方法 大鼠随机分组后,模型组及染料木素组大鼠sc 50 mg/kg野百合碱制备PH模型,对照组sc生理盐水。野百合碱注射后第3天,染料木素低、中、高剂量组ig染料木素10、50、100 mg/kg,对照组和模型组大鼠ig给予等体积生理盐水,1次/d,连续2周。末次给药后,采用尾套法测量清醒大鼠尾部动脉血压;小动物生理仪检测大鼠平均心室压和收缩压;荧光实时定量PCR（RT-qPCR）检测血清白细胞介素（IL）-6、IL-8、IL-1β、肿瘤坏死因子-α（TNF-α）、转化生长因子-β（TGF-β）水平;试剂盒测定大鼠血清超氧化物歧化酶（SOD）值及丙二醛（MDA）、总抗氧化能力（T-AOC）和活性氧（ROS）水平。结果 与模型组比较,染料木素50、100 mg/kg组动脉血压、右心室收缩压（RVSP）和右心室舒张末期压（RVeDP）均显著下降（P<0.05、0.01）;染料木素10、50、100 mg/kg剂量均可显著降低大鼠血清中IL-6、IL-8、IL-1β、TNF-α、TGF-β的表达（P<0.05、0.01）;染料木素10、50、100 mg/kg剂量组ROS和MDA水平显著降低,而T-AOC和SOD水平显著增加（P<0.05、0.01）。结论 染料木素对野百合碱诱导的PH大鼠具有降低血压的作用,其机制可能与其阻断氧化应激有关。     

芍药苷对大鼠低氧性肺动脉高压的防治作用及其抗氧化机制研究

目的 研究芍药苷对低氧诱导的肺动脉高压大鼠模型的作用并初步探讨其作用机制。方法 60只SD大鼠随机分为6组,每组10只,分别为：对照组（等体积生理盐水,ig）、模型组（等体积生理盐水,ig）、阳性对照组（西地那非25 mg/kg,ig）、芍药苷低、中、高剂量组（20、40、80 mg/kg,ig）。对照组大鼠置于正常环境中饲养,其余各组均于给药0.5 h后置于全自动低压低氧舱内（大气压50 kPa,氧浓度10%）,每天8 h,持续21 d。在实验终点时检测各组大鼠平均肺动脉压（mPAP）、平均颈动脉压（mCAP）、右心室肥厚指数（RVHI）及观察肺动脉病理变化;检测血浆内皮素（ET-1）、血清一氧化氮（NO）水平;检测肺组织匀浆超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）活性、丙二醛（MDA）含量。结果 与对照组比较,模型组大鼠mPAP、RVHI、血浆ET-1水平、肺组织中MDA含量显著升高（P＜0.01）,血清中NO水平、肺组织中SOD、CAT、GSH-Px活性显著降低（P＜0.01）,HE染色显示大鼠肺小动脉管壁明显增厚,管腔狭窄。与模型组比较,芍药苷中、高剂量组大鼠mPAP、RVHI、血浆ET-1水平、肺组织中MDA含量显著降低（P＜0.05或P＜0.01）,血清中NO水平、肺组织中SOD、CAT、GSH-Px活性显著升高（P＜0.05或P＜0.01）;HE染色显示不同剂量芍药苷干预后,大鼠肺小动脉管壁增厚和管腔狭窄均不同程度减轻。结论 芍药苷可降低低氧诱导的大鼠肺动脉高压与右心室肥厚程度,减轻肺小动脉血管重塑,其机制可能与降低大鼠血浆ET-1水平、升高血清NO水平,改善血管内皮舒缩因子失衡,提高大鼠肺组织匀浆中SOD、CAT、GSH-Px活性、降低MDA含量,减轻大鼠肺组织氧化应激损伤有关。     

Protective effects of selenium on methimazole-induced anemia and oxidative stress in adult rats and their offspring

The present study investigates the potential ability of selenium, considered as an antioxidant with pharmacological property to alleviate oxidative stress and hematological parameter disorders induced by methimazole, an antithyroid drug. Pregnant Wistar rats were randomly divided into four groups of six each: group I served as negative control and received a standard diet; group II received 250 mg/L of methimazole in drinking water and a standard diet; group III received both methimazole (250 mg/L, orally) and selenium (0.5 mg/kg of diet) supplemented to the standard diet; group IV served as positive control and received a supplement of selenium in the diet (0.5 mg/kg of diet) as sodium selenite (Na(2)SeO(3)). Treatment was started from the 14th day of pregnancy until day 14 after delivery. Methimazole reduced the number of red blood cells, hemoglobin concentration and hematocrit in mothers and their pups. Besides, plasma iron, vitamins B(9), B(12), C and E levels were reduced. Lipid peroxidation increased, objectified by high malondialdehyde levels and lactate dehydrogenase activity in plasma, while glutathione, glutathione peroxidase, superoxide dismutase and catalase activities showed a significant decline. Co-administration of selenium through diet improved all the parameters cited above. It can be concluded that the administration of selenium alleviates methimazole-induced toxicity, thus demonstrating its antioxidant efficacy.     

Protective effects of quercetin against phenylhydrazine-induced vascular dysfunction and oxidative stress in rats.

Oxidative stress is a major contributor to the development of vascular dysfunction found in various pathological conditions. Quercetin, one of the potent antioxidant bioflavonoid compounds, has been shown to alleviate oxidative injury by modulation of gene expression leading to suppression of production of reactive oxygen and nitrogen species and conferring an antiapoptotic activity. The aim of the present study was to investigate the protective effects of quercetin in a model of phenylhydrazine (PHZ)-induced oxidant stress, vascular dysfunction and hemodynamic disturbance in rats. Male Sprague-Dawley rats were administered quercetin orally (25 or 50mg/kg/day) for 6 days. On day four, all animals except those in the normal control group, were administered PHZ intraperitoneally. The results showed that PHZ induced severe hemolysis. The mean arterial pressure and hindlimb vascular resistance of PHZ-control rats were markedly decreased compared to normal controls. Treatment with quercetin significantly improved arterial blood pressure and peripheral vascular resistance. Vascular responsiveness to bradykinin, acetylcholine, and phenylephrine in PHZ-control rats was dramatically suppressed and quercetin restored these responses in a dose-dependent manner. Quercetin partially protected blood glutathione, suppressed plasma malondialdehyde levels, and largely suppressed nitric oxide metabolites and superoxide anion production. These results provide the first evidence for the role of the flavonoid, quercetin, in the alleviation of vascular dysfunction in an animal model of PHZ-induced oxidant stress.     

Protective effects of Sesbania grandiflora on kidney during alcohol and polyunsaturated fatty acid-induced oxidative stress

Context: Kidney is an organ highly vulnerable to damage caused by reactive oxygen species (ROS), due to abundance of polyunsaturated fatty acids in the composition of renal lipids. Oxidative stress plays an important role in the development of alcohol-induced tissue injury. This leads to membrane damage by lipid peroxidation, alteration of enzyme function and formation of acetaldehyde protein adducts. Many alcoholics along with alcohol consume fried foods that are normally made up of polyunsaturated fatty acid (PUFA). The toxic effects of alcohol are further enhanced by the consumption of PUFA.

Objective: In our study, we analyzed the effect of Sesbania grandiflora (S. grandiflora) on alcohol and PUFA-induced oxidative stress in male albino Wistar rats.

Materials and methods: The levels of lipid peroxidative markers (thiobarbutric acid reactive substances [TBARS] and lipid hydroperoxides [HP]), the levels of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase) and non-enzymatic (reduced glutathione, vitamin E, vitamin C) antioxidants were analyzed in kidney to evaluate the effects of S. grandiflora.

Results: The levels of TBARS and HP were significantly increased in alcohol + ΔPUFA group, which were found to be reduced on treatment with S. grandiflora. The levels of both enzymatic and non-enzymatic antioxidants were decreased in alcohol + ΔPUFA group, which were found to be restored on treatment with S. grandiflora.

Conclusion: From this, we conclude that S. grandiflora protects the kidney against alcohol and PUFA-induced oxidative stress, which can be attributed to the phenolic compounds and anthocyanins present in the plant.     

Protective effect of lycopene on gentamicin-induced oxidative stress and nephrotoxicity in rats

A potential therapeutic approach to protect or reverse gentamicin-induced oxidative stress and nephrotoxicity would have more importance for clinical consequences. Therefore, the present study was designed to investigate the possible protective effects of lycopene against gentamicin-induced renal damage in rats. Male Sprague-Dawley rats were divided into four groups of six rats in each one; first group served as control. The other groups were treated intraperitoneally with gentamicin alone (100 mg kg(-1) per day) for six successive days, gentamicin for 6 days following 10 days of orally lycopene (4 mg kg(-1) per day) pre-treatment and 6-days of simultaneous lycopene and gentamicin. Biochemical and histopathological examinations were utilized for evaluation of the oxidative stress and renal nephrotoxicity. Creatinine, urea, Na(+) and K(+) levels in plasma and malondialdehyde (MDA), reduced glutathione (GSH) levels and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were determined in kidney tissue. Administration of gentamicin to rats induced a marked renal failure, characterized by a significant increase in plasma creatinine and urea concentrations. The animals treated with gentamicin alone showed a significantly higher kidney MDA and lower GSH-Px and CAT activities but unaffected GSH concentrations when compared with the control group. Pre-treatment with lycopene produced amelioration in biochemical indices of nephrotoxicity in plasma. However, little changes were observed in the kidney MDA and GSH levels and GSH-Px and CAT activities when compared with the gentamicin treated group. The histological structures of the renal proximal tubules showed similar patterns. On the other hand, administration of simultaneous lycopene to rats produced amelioration in MDA and GSH levels and GSH-Px and CAT activities when compared with gentamicin group. In addition, simultaneous lycopene was found to reduce the degree of kidney tissue damage in histopathological findings. These results indicate that specially simultaneous treatment of lycopene might have produced amelioration in biochemical indices and oxidative stress parameters against gentamicin-induced nephrotoxicity, but pre-treatments with lycopene had no beneficial effects on these parameters. It was concluded that lycopene as a novel natural antioxidant might have protective effects against gentamicin-induced nephrotoxicity and oxidative stress in rats.     

Protective effect of bezafibrate on streptozotocin-induced oxidative stress and toxicity in rats

The present study was aimed to find out the protective effect of bezafibrate on lipid peroxidation (LPO), activities of both enzymatic and non-enzymatic antioxidants and histopathological examination of pancreas in streptozotocin (STZ)-induced diabetic rats. Experimental diabetes was induced by a single dose of STZ (60mg/kg, i.p.) injection. The oxidative stress was measured by tissue LPO level, reduced glutathione (GSH) content and by enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in liver and pancreas. Biochemical observations were further substantiated with histological examination of pancreas. The increase in blood glucose, LPO level with reduction in GSH content and decreased enzymatic activities were the salient features observed in diabetic control rats. Administration of bezafibrate (30mg/kg day, p.o.) for 15 days caused a significant reduction in blood glucose and LPO level in STZ treated rats (group III) when compared with diabetic control rats (group II). Furthermore, bezafibrate treated diabetic rats (group III) showed significant increase in the activities of both enzymatic and non-enzymatic antioxidants when compared to diabetic control rats (group II). Degenerative changes of pancreatic beta-cells in STZ treated rats were minimized to near normal morphology by administration of bezafibrate as evident by histopathological examination. The results obtained clearly indicate the role of oxidative stress in the induction of diabetes and suggest a protective effect of bezafibrate in this animal model.     

Protective effect of selenium on gentamicin-induced oxidative stress and nephrotoxicity in rats

Gentamicin (GM) is a widely used antibiotic against serious, life-threatening infections, but its usefulness is limited by the development of nephrotoxicity. The present study was designed to determine the protective effect of selenium (Se) in GM-induced nephrotoxicity in rats. Experiments were done on 32 adult Wistar rats divided into four groups of 8 animals each. The GM group received gentamicin (100?mg/kg), whereas the GM+Se group received the same dose of GM and selenium (1?mg/kg) by intraperitoneal (i.p.) injections on a daily basis. Animals in the Se group, serving as a positive control, received only selenium (1?mg/kg) and the control group received saline (1?mL/day), both given i.p. All groups were treated during 8 consecutive days. Quantitative evaluation of GM-induced structural alterations and degree of functional alterations in the kidneys were performed by histopathological and biochemical analyses in order to determine potential beneficial effects of selenium coadministration with GM. GM was observed to cause a severe nephrotoxicity, which was evidenced by an elevation of serum urea and creatinine levels. The significant increases in malondialdehyde levels and protein carbonyl groups indicated that GM-induced tissue injury was mediated through oxidative reactions. On the other hand, simultaneous selenium administration protected kidney tissue against oxidative damage and the nephrotoxic effect caused by GM treatment. Exposure to GM caused necrosis of tubular epithelial cells. Necrosis of tubules was found to be prevented by selenium pretreatment. The results from our study indicate that selenium supplementation attenuates oxidative-stress-associated renal injury by reducing oxygen free radicals and lipid peroxidation in GM-treated rats.