L-Norvaline and Alpha-tocopherol Treatment Protect Against Diabetes-Induced Oxidative Stress in Testes of Male Rats

Abstract

The present study aimed to evaluate the effect of L-Norvaline and alpha-tocopherol in protection and combating the oxidative stress of testes in hyperglycemic male rats. In our study single dose of streptozotocin was used for induction of diabetes and fasting serum glucose level was checked and those animals showing FSG above 250 mg/dL were selected. The diabetic animals were randomly divided into seven groups comprising six animals in each group and one group of normal non diabetic animals received the vehicle 0.1 M citrate buffer pH 4.5. L-Norvaline was administered at higher (10 mg/kg) and lower (8 mg/kg) dose intraperitoneally to the different groups of diabetic animals along with alpha-tocopherol (900 mg/kg) orally for a period of 30 days. Sildenafil at an oral dose of 5 mg/kg was used as reference drug. After that period, testis was isolated and homogenized. The homogenized tissue was centrifuged, separating the supernatant and preserved it for assessing the oxidative stress parameters. The level of various antioxidant enzymes were assessed such as superoxide dismutase, reduced glutathione, glutathione peroxidase and glutathione reductase. Assessment of lipid peroxidation was also done in treated groups. The statistical analyses were carried out using Graph Pad Prism 5.0 software. All values were presented as Mean ± S.E.M. The level of superoxide dismutase, reduced glutathione, glutathione peroxidase and glutathione reductase were highly diminished in the diabetic rats compared with normal group. L-Norvaline alone showed no significant improvement in those enzymes parameters except in reduced glutathione (P<0.05). L-Norvaline both at higher dose and lower dose along with alpha-tocopherol showed significant improvement in the level of antioxidant enzymes as compared with diabetic group (P<0.05, P<0.01, P<0.001). Treated groups also showed a significant decrease in the level of malondialdehyde as compared to diabetic group (P<0.01, P<0.001). Standard drug, Sildenafil showed no improvement in any parameters after 30 days. The present can be concluded by establishing the fact that LNorvaline and Alpha-tocopherol could be a good combination in scavenging free radicals in testes due to streptozotocin induced hyperglycemia in male Wistar rats.