Pomegranate (Punica granatum Linn.) leaves attenuate disturbed glucose homeostasis and hyperglycemia mediated hyperlipidemia and oxidative stress in streptozotocin induced diabetic rats

IntroductionPunica granatum Linn. (Punicaceae) commonly known as pomegranate, has traditionally in Unani and Ayurvedic medicine been widely used to treat diabetes and its complications. In order to scientifically appraise its traditional use, the present study was carried to evaluate its antihyperglycemic activity employing relevant animal models and in vitro methods.MethodsDiabetes was induced in rats by single intraperitonial injection of streptozotocin (65 mg/kg) in ice cold citrate buffer (pH 4.3). Ethyl acetate fraction of P. granatum leaves (EAPG) was administered by oral gavage to STZ diabetic rats at doses of 50 mg/kg, 100 mg/kg and 200 mg/kg for 28 days. Glibenclamide (5 mg/kg) was used as standard drug. On the 29th day, overnight fasted rats were sacrificed and blood was collected for various biochemical estimations including blood glucose, glycosylated haemoglobin, serum insulin, lipid profile and total protein. Glycogen content of liver and skeletal muscle was estimated. Histopathology of the pancreas was also carried out.ResultsDiabetic rats treated with EAPG showed a dose dependent reduction of fasting blood glucose and normalized the lipid profile and liver antioxidant status in comparison to diabetic control group. EAPG treatment significantly increased the liver and skeletal muscle glycogen content while it reduced the glycosylated haemoglobin as compared to untreated diabetic control rats. Although there was marked reduction in blood glucose, serum insulin was not increased to a significant level in EAPG treated STZ diabetic rats suggesting an extra-pancreatic mechanism of action.ConclusionEAPG appears to possesses antihyperglycemic activity along with antihyperlipidemic and antioxidant potential which may prove beneficial for the management of diabetes and associated complications.