Beneficial role of diosgenin on oxidative stress in aorta of streptozotocin induced diabetic rats

The present study was designed to investigate the beneficial role of diosgenin on oxidative stress markers and histopathological changes in aorta of streptozotocin induced diabetic rats. Diabetes was induced in experimental rats by a single intraperitoneal injection of streptozotocin (55 mg/kg body weight (b.w.)). From the sixth week, experimental rats received diosgenin at different doses (10,20 and 40 mg/kg b.w.) once daily for 4 weeks. At the end of the experimental periods, diabetic rats exhibited significant increase in the levels of plasma glucose, glycosylated hemoglobin with significant decrease in insulin and total hemoglobin. The activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and the levels of reduced glutathione were decreased while increases in the levels of lipid peroxidation markers were observed in aortic tissues of diabetic rats. Oral administration of diosgenin to diabetic rats significantly decreased the plasma glucose and increased the insulin level based on a dose dependent manner. Diosgenin at a dose of 40 mg/kg b.w. was more pronounced effect than the other two doses and used for further studies. All the manifestations observed in diabetic rats were significantly reversed to near normal at a dose of 40 mg/kg b.w. of diosgenin. These findings suggest that diosgenin could have a beneficial role against aortic damage induced by oxidative stress in diabetic state, which was evidenced by the propensity of diosgenin to modulate the antioxidant defense and to decrease the lipid peroxidation in aorta. (C) 2012 Published by Elsevier B.V.