Studies on Activity Guided Fractionation of Pomegranate Peel Extracts and Its Effect on Antidiabetic and Cardiovascular Protection Properties

Abstract

Pomegranate peel (PP) was sequentially extracted with hexane, ethyl acetate, methanol, methanol/water and water (C1–C5, respectively) and the extracts were assessed for its antioxidant and antidiabetic potential. Extracts, C2 and C3, which exhibited maximum free radical scavenging and α-glucosidase inhibitory activity, were further fractionated using hexane, ethyl acetate and methanol (C2–F1, F2, F3; C3–F4, F5, F6). Fractions, F1 and F5, of methanol extract showed highest 2,2-diphenyl picrylhydrazyl scavenging activity (IC50 – 3.69 and 4.39 µg/mL, respectively); F5 exhibited significantly high 2,2′-azinobis 3-ethylbenzothiazoline 6-sulfonic acid, superoxide and hydroxyl radical scavenging activity (IC50 – 3.6, 20.89 and 10.7 µg/mL) and α-glucosidase inhibition (IC50 – 0.0453 µg/mL). F5 demonstrated promising inhibition against LDL oxidation (IC50 – 16.2 µg/mL) and ACE inhibition properties (IC50 – 0.77 µg/mL). These findings suggest the ability of PP extracts to manage type 2 diabetes and associated complications. Practical Applications Natural antioxidants have been recommended as an aid for prevention and management of diabetes and associated complications. Pomegranate peel (PP) is reported to be a rich source of dietary antioxidants. We evaluated the effect of activity guided fractionation of PP on antioxidant and antidiabetic potential of extracts prepared by sequential extraction followed by its fractionation. The results indicated that on fractionation of crude extracts, the antioxidant and antidiabetic activity of some of fractions were significantly improved. The antidiabetic effect of PP active fraction may be related to α-glucosidase inhibition and enhanced glucose uptake. The active fraction was found to be effective in reducing cardiac problems associated with diabetes by inhibiting LDL oxidation and ACE. The study points out the potential of PP as nutraceuticals for the prevention and management of type 2 diabetes and associated complications.