INHIBITORY EFFECTS OF ALPHA (?)-AMYLASE AND ?-GLUCOSIDASE BY ROOTS AND BARKS OF ULMUS DAVIDIANA VAR. JAPONICA

Man Kyu Huh*

ABSTRACT

Ulmus davidiana var. japonica was used for medicinal purposes in oriental medicine. This study was to evaluate and compare the α-amylase and α-glucosidase inhibitory activity of extracts from U. davidiana var. japonica. α-glucosidase inhibition of water extract for roots ranged from 24.9% at 0.25 mg/ml to 43.7% at 1.0 mg/ml. α-glucosidase inhibition of water extract for barks was ranged from 31.4% at 0.25 mg/ml to 51.6% at 1.0 mg/ml. Although the α-amylase inhibitory activity of the bark was higher than root, there was not significant difference between two groups (p>0.05). The IC50 for water extracts of root and bark were 22.89 and 17.96 ug/ml, respectively. α-glucosidase inhibition of water extract for roots ranged from 24.9% at 0.25 mg/ml to 43.7% at 1.0 mg/ml. α-glucosidase inhibition of water extract for barks was ranged from 31.4% at 0.25 mg/ml to 51.6% at 1.0 mg/ml. The mode of inhibition of U. davidiana var. japonica extracts against both α-amylase and α-glucosidase was confirmed by Lineweaver–Burk plots. Crude water and ethanol extracts of U. davidiana var. japonica mixed non-competitively inhibited α-amylase and α-glucosidase.

Keywords: ?-amylase, ?-glucosidase, Inhibitory activity, Lineweaver–Burk plots, Ulmus davidiana var. japonica.