Effects of Total Flavonoids from Mulberry Leaves on β-cells Oxidative Injury of Type2 Diabetic Rats

Objective To investigate the effect and mechanism of total flavonoid(MFTF) from mulberry leaves on β-cells oxidative injury in type-2 diabetic(T2DM) rats.Methods Diabetes was induced by a intraperitoneal injection of streptozotocin(30 mg·kg-1 body weight).Animals were randomly divided into five groups:the model,MFTF(50,100,150 mg·kg-1) and rosiglitazone(1.8 mg·kg-1)groups,with other 10 normal rats as a control group.Fasting blood glucose(FBG),insulin(FINS) level in serum,malondialadehyde(MDA) content,the activity of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in the rats'pancreatic tissue were measured after being orally treated once daily for five consecutive weeks.Bcl-2 and Bax expression in islet tissues were detected by using immunohistochemistry and the rate of pancreatic islet β cell apoptosis was tested by both TUNEL and immunohistochemistry.Results MFTF significantly decreased the level of MDA and FBG(P0.05),increased the activity of SOD,GSH-Px and FINS content in pancreatic tissue(P0.05 or P0.01),markedly up-regulated the expression of Bcl-2 and down-regulated Bax(P0.05 or P0.01)at the dose of 150 mg·kg-1.Conclusion MFTF shows strong anti-oxidation and alleviates β cell apoptosis in T2DM rats.