alpha-Glucosidase Inhibitor Activity of Terminalia Species

摘要

Terminalia arjuna, Terminalia ballerica, Terminalia chebula, Terminalia catappa, Terminalia kaerbachii and Terminalia microcarpa leaves were tested for their alpha-glucosidase inhibitory activity in vitro. The alpha-glucosidase activity was determined by measuring the p-nitrophenol release from pNPG at 400 nm. Terminalia kaerbachii has the highest alpha-glucosidase inhibitor activity with IC_50 value of 0.27+-0.17 mug mL~-1 and is a promising antidiabetic herbal medicine candidate. However, most of the Terminalia species are also potential as antidiabetic medicine candidates as the IC_50 values are approximately 5 mug mlT~-1, which is near the IC_50 value of 1-deoxynojirimycin, the reference compound, except for Terminalia microcarpa, which has IC_50 value of 25.15+-0.04 mug mlT~-1 (above 21 mugmL~-1). From the phytochemical screening, Terminalia kaerbacchi contains alkaloids, flavonoids and cathechic tannins, but does not contain saponin, quinon, steroid/terpenoids and gallic tannins.