Determination of alpha-glucosidase inhibitory activity from selected Fabaceae plants

Nineteen plants from Fabaceae family, which were used in Thai traditional medicine for treatment of diabetes, were determined of alpha-glucosidase inhibitory activity via enzymatic reaction. In this reaction, alpha-glucosidase was used as enzyme, which, reacted with the substrate, Rho-nitrophenol-D-glucopyranoside [pNPG]. After that the product, p-nitro phenol [pNP] will be occurred and observed the yellow colour at 405 nm. In this study, acarbose was used as positive standard which, inhibited this enzyme with IC[50] as 331 +/- 4.73 microg/ml. Caesalpiniapulcherrima leaves showed the highest activity with IC[50] as 436.97 +/- 9.44 microg/ml. Furthermore, Bauhinia malabarica leaves presented moderately activity with IC[50] as 745.08 +/- 11.15 microg/ml. However, the other plants showed mild to none activity of alpha-glucosidase inhibition. Accordingly, this study can support anti-diabetes of these plants in traditional medicine and it will be the database of the biological activity of Fabaceae plant