In vitro antihyperglycaemic effects of some Malaysian plants

Uncontrolled postprandial hyperglycaemia increases the risk of vascular diabetic complications. One of the therapeutic approaches to control postprandial hyperglycaemia is by inhibiting ?-amylase and ?-glucosidase enzyme activities. In this study, 47 extracts from 22 Malaysian tropical plants were assayed for ?-amylase and ?-glucosidase inhibitory activities. Four plant species demonstrated potent ?-amylase inhibition. The plants were Burkillantus malaccensis (stem), Horsfieldia polyspherula (leaf and stem), Labisia pumila (leaf and root) and Phyllanthus pulcher (stem). The IC50 values of the extracts ranged from 1.2 to 2.8 ?g ml-1. Four plant species could be classified as strong ?-glucosidase inhibitors with IC50 values ranging from 2.4 to 6.1 ?g ml-1. The plants were Gironniera parvifolia (stem), H. polyspherula (leaf and stem), P. pulcher (leaf and stem) and Rothmannia schoemanii (stem). Extracts of P. pulcher (stem) and H. polyspherula (leaf and stem) showed potent inhibitory activity against both enzymes. The plant extracts are potentially useful in the development of new antidiabetic remedies