Nephroprotective effect of silymarin in hyperglycemia-induced oxidative stress in rats.

ABSTRACT

Background: Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia. Hyperglycemia is the etiological factor for oxidative stress-induced microvascular and macrovascular complications. Many animal experimental models and clinical trials have proved the antioxidant defense mechanism of flavonoids in ameliorating the progression of chronic diabetic complications. Hence, the objective of this study was to evaluate the nephroprotective effects of silymarin in alloxan induced Type I diabetes. Methods: Male Wistar rats were divided into five groups of six each. Group I served as control. Group II, III, IV and V were diabetic rats. Group II diabetic rats received the vehicle. Groups III and IV were treated with 200 mg/kg and 400 mg/kg of silymarin, respectively. Group V was treated with glibenclamide (0.5 mg/kg). After 3 weeks, blood samples were collected from all the groups of animals to measure serum glucose, urea and creatinine. Lipid peroxidation study and histopathological study were conducted in the renal tissue to confirm the oxidative damage. Results: The serum glucose, urea and creatinine significantly increased in untreated diabetic rats. In addition, there was a significant rise in lipid peroxidation with a glomerular atrophy and necrotic tubular epithelium in the renal tissue. The rise in serum glucose, urea and creatinine was ameliorated by silymarin. The renal tissue showed increased antioxidant levels, decreased lipid peroxides and only mild changes in glomeruli and tubules. Conclusion: The results of this study indicate silymarin is an effective nutritional supplement to prevent complications of diabetes.