Aqueous Extract ofAnnona macroprophyllata: A Potentialα-Glucosidase Inhibitor

Abstract

Annona genus contains plants used in folk medicine for the treatment of diabetes. In the present study, an aqueous extract prepared fromAnnona macroprophyllata(Annonaceae, also known asA. diversifolia) leaves was evaluated on both the activity of yeastα-glucosidase (anin vitroassay) and sucrose tolerance in Wistar rats. The results have shown that the aqueous extract fromA. macroprophyllatainhibits the yeastα-glucosidase with an IC50 = 1.18 mg/mL, in a competitive manner with aKi= 0.97 mg/mL, a similar value to that of acarbose (Ki= 0.79 mg/mL). The inhibitory activity ofA. macroprophyllatawas reinforced by its antihyperglycemic effect, at doses of 100, 300, and 500 mg/kg in rats. Chromatographic analysis identified the flavonoids rutin and isoquercitrin in the most polar fractions ofA. macroprophyllatacrude extract, suggesting that these flavonoids are part of the active constituents in the plant. Our results support the use ofA. macroprophyllatain Mexican folk medicine to control postprandial glycemia in people with diabetes mellitus, involving active constituents of flavonoid nature.