KHAYA SENEGALENSIS HAS INHIBITORY ACTIVITY AGAINST α-GLUCOSIDASE

Abstract

Abstract

Inhibition of α-glucosidase, an enzyme responsible for the hydrolysis of oligosaccharides to simple absorbable sugars, is implicated in the management of postprandial hyperglycaemia. The current study evaluates α-glucosidase inhibitory potentials of Khaya senegalensis stem bark. The result of an in vitro analysis using α-glucosidase from Saccharomyces cerevisiae and p-nitrophenylα-D-glucopyranoside as substrate showed that the stem bark extract of K. senegalensis (IC₅₀ = 7.7 ± 0.02 μg /ml), had significant α-glucosidase inhibitory effect in a concentration dependant manner. From the study of the enzyme kinetics, the stem bark extract of K. senegalensis exhibited a non-competitive inhibition with a Ki of0.33μg/ml. In an in vivostudy, using Wister albino rats, the extract significantly attenuated postprandial hyperglycaemiaof Area Under Glucose Curve (AUC_Glucose) following maltose administration. Two hithertounknown bioactive compounds with α-glucosidase inhibitory activity were obtained from themethanol partition of the aqueous extract. The study therefore concludes that blood glucose lowering effect of K. senegalensis is mediated partly by the inhibition of the α-glucosidase activity in the intestine.