Protective effects of chronic administration of silymarin on blood glucose and lipids and oxidative stress in diabetic rats

Introduction: In diabetic patients, decreasing of oxidative stress level and serum glucose and lipidsis clinically important. In this study, the effects of chronic administration of silymarin (S) on bloodglucose and lipids and oxidative stress in diabetic rats were investigated.Materials and Methods: In this experimental study, male rats (n =40) were randomly divided into 4groups, i.e. control, S-treated control, diabetic, and S-treated diabetic groups. The treatment groups (indiabetic group, before induction of diabetes by i.p. administration of streptozotocin) were received aninitial dose (200 mg/kg) and then a daily dose (100mg/kg) for 8 weeks. Serum glucose, triglyceride,total cholesterol, LDL- and HDL- cholesterol levels and activities of superoxide desmolase (SOD)enzyme and malondialdehyde (MDA) levels were determined before the study and after 8 weeks.Results: After 8 weeks, serum glucose, total cholesterol, LDL cholesterol, and triglyceride levelswere increased (P=0.03-0.0001) and HDL- cholesterol level was decreased (P=0.03) significantly inthe diabetic group as compared with the control group. S treatment of diabetic rats caused a decreasein serum glucose, total cholesterol, LDL cholesterol, and triglyceride levels (P=0.01-0.0001) and anincrease in HDL- cholesterol level ((P=0.03). On the other hands, serum SOD antioxidant activity wasdecreased and serum MDA levels increased in diabetic rats in compared to the control group. In Streateddiabetic rats, serum SOD activity was increased and serum MDA levels decreased.Conclusion: Treatment of diabetic rats with silymarin not only decreases the level of serum glucosebut also has beneficial effect on serum lipids and oxidative stress level