Controlling Effect of Ethyl-acetate and n-Butanol Fractions from Punica granatum L. Peel on Postprandial Hyperglycemia In Vivo, and Its Potent α-Amylase Inhibitory

Abstract

Postprandial hyperglycemia plays an important role in the development of type 2 diabetes and has been proposed as an independent risk factor for cardiovascular diseases. Herbal medicine has been used for many years by different cultures around the world for the treatment of diabetes. Punica granatum is one of the traditional remedies used for that reason. In this study, we investigated the effects of organic extracts (ethyl acetate and n-butanol) from Punica granatum peel on postprandial hyperglycemia in vivo caused by glucose, sucrose, maltose, or starch loading. Oral administration of Punica granatum peel extracts (400 mg/kg b.w.) markedly lowered plasma glucose levels in fasted normal rats. We examined in vitro whether the organic fractions of Punica granatum peel have an antidiabetic effect through α-amylase inhibitory action. Ethyl acetate and n-butanol fractions of aqueous/acetone crude extracts displayed a potent inhibitory effect on α-amylase activity (IC50 = 0.85 and 2.13 g/l, respectively). These results suggest that inhibitory activity of Punica granatum peel extracts may contribute to delay in carbohydrate digestion and glucose absorption and improves postprandial hyperglycemia in type 2 diabetes by inhibiting intestinal αamylase and disaccharidases activity.