Antihyperglycemic, antioxidant and hypolipidemic effect of Punica granatum L flower extract in streptozotocin induced diabetic rats

To investigate the antihyperglycemic, hypolipidemic and antioxidant effects of aqueous and ethanolic flower extracts of Punica granatum (P. granatum) in streptozotocin (STZ) induced diabetes mellitus in wistar rats. Antihyperglycemic, hypolipidemic and antioxidant effect of P. granatum aqueous (PGFAet) and ethanolic extracts (PGFEet) at doses of 200 and 400 mg/kg bw was evaluated in streptozotocin induced diabetic rats. Glycosylated hemoglobin, plasma insulin, cholesterol and lipoprotein levels, lipid peroxide levels and the antioxidant enzyme levels were determined. The administration of the extracts markedly reduced blood glucose and glycosylated hemoglobin increased the levels of plasma insulin and liver glycogen. The extract also had a hypolipidemic activity decreasing the levels of total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglycerides. The levels of lipid peroxides in terms of thiobarbituric acid reactive substances (TBARS) were remarkably reduced and the activities of the enzymes SOD, CAT and GPx and GSH were increased. We also saw an increase in the activity of the enzyme glucokinase and decrease in glucose-6-phosphatase. It can be concluded that the flower extracts of P. granatum (PGFAet and PGFEet) has significant restorative effect on the blood glucose, hyperlipidemia and oxidative stress. It can be concluded from the studies that the ethanolic extracts of the flowers of P. granatum at dosage 400 mg/kg/day exhibit significant effect in lowering blood sugar and lipid levels and increasing the antioxidant enzymes when compared to the aqueous extract. Glycosylated hemoglobin levels were reduced and the extract exhibited a stimulatory effect on insulin.