In VitroInhibition ofα‐Amylase andα‐Glucosidase by Extracts fromPsiadia punctulataandMeriandra bengalensis

Background. This research assessed thein vitroantidiabetic activity and phytochemical constituents of the traditionally used medicinal plants,Psiadia punctulata and Meriandra bengalensis.Method. The leaves of both plants were subjected to cold extraction method using 70% ethanol and hot Soxhlet extraction using n‐hexane, chloroform, methanol, and distilled water. The extracts were studied for their effect on glucose transport across yeast cells and inhibition ofα‐amylase andα‐glucosidase enzyme activities. Thin‐layer chromatographic analysis of ethanol extract was also undertaken.Results. The results of yeast glucose uptake assay revealed that extracts from both plants had a maximum increase in glucose uptake at the 25mM glucose concentration with a maximum dose of 2000μg/ml plant extract. The ethanol extract ofP. punctulataand aqueous extract ofM. bengalensisshowed a high activity of 68% and 96%, respectively, at 25mM and 2000μg/ml of glucose and extract concentration.P. punctulataexerted peak inhibition activity ofα‐amylase of 37.5 ± 3% mg/dl (IC50= 0.523 mg/dl) for methanol and distilled water extract at 0.5 mg/dl, respectively.M. bengalensismethanol extract exhibited the highest inhibition activity of 38 ± 8 % mg/dl (IC50 = 0.543 mg/dl) at 0.5 mg/dl. In theα‐glucosidase inhibition assay, the methanolic extract ofP. punctulataexhibited the highest inhibitory activity of 17.29 ± 9% mg/dl (IC50= 0.761 mg/dl) at 0.5mg/dl. The chloroform extract ofM. bengalensishad the highest inhibitory activity of 30 ± 5% mg/dl (IC50= 0.6mg/dl) at 0.5 mg/dL. Phytochemical analysis of the different extracts ofP. punctulataandM. bengalensisrevealed the presence of flavonoids, alkaloids, tannins, saponins, phytosterols, and carbohydrates. Thin‐layer chromatography analysis of ethanolic extract of both plants indicated presence of 15 and 17 spots forP. punctulataandM. bengalensisrespectively.Conclusion.P. punctulataandM. bengalensisextracts have moderate inhibitory activity against pancreaticα‐amylase and relatively low inhibitory activities againstα‐glucosidase. The observed effects may be associated with the presence of flavonoids, saponins, and alkaloids. Additionalin vivoanalysis, toxicological studies, isolation, and structural characterization of the phytomolecules identified in this study and molecular docking studies should be undertaken.