Background: The purpose of this study was to evaluate α-amylase inhibitory effects of hydroethanolic extracts of bark from Daniella oliveri, Sclerocarya birrea, Maranthes polyandra, and Pteleopsis suberosa to fight type-II diabetes. Methods: Compound extractions were performed by hydroethanol maceration followed by liquid-liquid fractionation with solvents. TLC profiling was carried out with different fractions. The inhibitory effects of plant extracts on α-amylase activity were determined using rice starch as a substrate. Results: TLC profiling of different fractions showed different phytochemical compounds. The hydroethanolic plant extracts exhibited dose-dependent inhibition of α-amylase. D. oliveri displayed competitive inhibition, M. polyandra and S. birrea showed uncompetitive inhibition and Pteleopsis suberosa exerted mixed-inhibition. M. polyandra extract exerted the highest inhibitory effect (IC50 = 0.5 mg/mL). Conclusions: The barks of M. polyandra exhibit a remarkable α-amylase inhibitory effect which can be a novel source of antidiabetic molecules.

phenolic compounds; α-amylase inhibition; Sclerocarya birrea; Maranthes polyandra; Daniella oliveri; Pteleopsis suberosa