Abstract: Objective: To explore the effect of β-casomorphin-7 (β-CM-7) on blood glucose and oxidative stress in diabetic rats induced by streptozotocin (STZ). Methods: Forty male SD rats were divided into 4 groups: normal group, diabetic control group, insulin treatment group (administered with humulin at 3.7 × 10-8 mol/(day animal)) and β-CM-7 (7.5 × 10-8 mol/(day animal)) treatment group. After administration for 30 consecutive days, all rats were sacrificed and measured for serum glucose level, MDA level, SOD activity and the contents of insulin and glucagons as well as leg muscle glycogen and liver glycogen contents. Results: The β-CM-7 treatment and insulin treatment groups revealed a significant decrease in blood glucose level, a reduction in MAD level, and an increase in SOD activity when compared with the diabetic control group (P＜0.05). The β-CM-7 treatment group displayed an increase in insulin content when compared with the diabetic control group and a significant increase (P＜0.05) in liver glycogen content when compared with the blank control group. Conclusion: β-CM-7 can reduce free radical-mediated oxidative stress and blood glucose level, promote the secretion of insulin and increase the content of muscular glycogen in diabetic rats thus having hypoglycemic effect.

Key words: β-casomorphin-7, rat, blood glucose, lipid peroxidation