In Vitro Studies on α-Amylase And α-Glucosidase Inhibitory Activity Of Antigonon leptopus (Hook Et. Arn) Leaf Extract and its Fractions

Abstract

Antigonon leptopus leaves and their methanolic extracts and fractions were tested for their ability to inhibit α-amylase and α-glucosidase activity in vitro. Fractions of Antigonon leptopus leaves were obtained by dispersing evenly in distilled water and subjected to solvent fractionation with toluene, ethyl acetate and butan-2- one under decreased pressure and concentrated. These extracts were tested in vitro for their inhibitory effects on αamylase and α-glucosidase inhibitory activities, as well as for several antioxidant characteristics.. A dose-dependent inhibition of α-amylase and α-glucosidase enzymes was found in the methanolic extract and fractions thereof. It was shown that the ethyl acetate fraction of Antigonon leptopus had the greatest enzyme inhibitory activity (IC50 values of 3.95 mg/ml for α-amylase, and of 3.4 mg/ml for α-glucosidase) and that its potency compared well to that of the standard medication Acarbose. Research on this plant's chemistry showed that it is rich in a wide range of chemicals including alkaloids, flavonoids, carbohydrates, tannins and saponin. Total phenolic and total flavonoid contents were also calculated. Antigonon leptopus has been used in traditional medicine to treat diabetes by lowering postprandial blood sugar levels. Antigonon leptopus ethyl acetate fraction has strong α-amylase and α-glucosidase enzyme inhibitory capabilities. The glucose absorption may be regulated by high TPC and TFC levels, which may be the cause of enzyme inhibition.