Abstract: Objective: To investigate the hypoglycemic effect of theasaponin on a type 2 diabetic rat model. Methods: The rat model was established by feeding of a high-fat diet combined with intraperitoneal injection of streptozotocin (STZ). Fasting blood glucose, glucose tolerance, and blood lipids were measured after 40 days of continuous administration of theasaponin. Liver function and other related indicators were observed. Results: Theasaponin could effectively regulate hyperglycemia and dyslipidemia in type 2 diabetic rats, and significantly improve serum total cholestrol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels (P < 0.01). Furthermore, it could significantly decrease the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum (P < 0.01) and repair the morphology of islet and liver tissue in diabetic rats. Conclusion: Theasaponin at a certain dose (50–150 mg/(kg mb·d)) has obvious hypoglycemic effects on the STZ-induced type 2 diabetic rat model.

Key words: tea tree; theasaponin; type 2 diabetes mellitus; hypoglycemic effect