Biochemical evaluation of antihyperglycemic and antioxidant nature of Psidium guajava leaves extract in streptozotocin-induced experimental diabetes in rats

摘要

The present study was designed to evaluate the antidiabetic and antioxidant potential of Psidium guajava Linn. (Myrtaceae) leaves, an important ingredient in many Ayurvedic preparations, in streptozotocin-induced diabetes in rats. Oral administration of P. guajava leaf extract (300 mg/kg body weight/day) for 30 days to streptozotocin-induced diabetes rats significantly decreased the levels of blood glucose, glycosylated hemoglobin and improved the levels of plasma insulin and hemoglobin.The levels of protein, urea, creatinine, non-enzymatic antioxidants, and the activities of enzymatic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase were markedly altered in liver of STZ-induced diabetic rats. Oral administration of P. guajava for 30 days restored all these biochemical parameters to near control levels. The present study reveals the efficacy of P. guajava leaf extract in the amelioration of diabetes, which may be attributed to its hypoglycemic nature along with its antioxidant potential. The antidiabetic and antioxidant effects of P. guajava leaf were also compared with glyclazide, a standard hypoglycemic drug.