Antioxidative Effects of Tempol on Mitochondrial Dysfunction in Diabetic Nephropathy

Introduction. Oxidative stress has a well-known role in diabetic nephropathy, and mitochondria are the major source of reactive oxygen species production. This study aimed to assess the effect of tempol, a superoxide dismutase mimetic agent, on mitochondrial antioxidant enzymes and cell viability in diabetic nephropathy. Materials and Methods. Adult male Wistar rats were divided into 4 groups of 7 animals. Diabetes mellitus was induced by injection of streptozotocin in 2 groups, the rat in one of which were also treated with tempol for 4 weeks. Another group without diabetes mellitus received tempol, and the last group was the control. At the end of the treatment period, the kidney mitochondria were isolated and their antioxidant enzymes, including superoxide dismutase, glutathione peroxidase, and catalase were assessed. Malondialdehyde, total antioxidant capacity, and kidney cells viability were studied, as well. Results. The diabetic group was significantly different compared with the control group in malondialdehyde, catalase, and glutathione peroxidase activities. Superoxide dismutase and total antioxidative capacity did not show any significant differences among the four groups. Moreover, the diabetic group treated with tempol had significantly different glutathione peroxidase level and kidney cells viability, compared to the other diabetic group (P < .05) Conclusions. Diabetic nephropathy induces changes in mitochondrial antioxidative biomarkers and cells viability, some of which can be modified by tempol administration in rats.