α-Glucosidase inhibitory activity of selected Philippine plants

Ethnopharmacological relevance: Antidesma bunius Spreng. (Phyllantaceae), Averrhoa bilimbi L (Oxalidaceae), Biophytum sensitivum (L.) DC. (Oxalidaceae), Ceriops tagal (Perr.) C.B. Rob. (Rhizophoraceae), Kyllinga monocephala Rottb. (Cyperaceae), and Rhizophora mucronata Lam. (Rhizophoraceae) are used as remedies to control diabetes. In the present study, these plants were screened for their potential alpha-glucosidase inhibitory activity. Materials and methods: The 80% aqueous ethanolic extracts were screened for their alpha-glucosidase enzyme inhibitory activity using yeast alpha glucosidase enzyme. Results: Except for A. bilimbi with IC50 at 519.86 +/- 3.07, all manifested a significant enzyme inhibitory activity. R. mucronata manifested the highest activity with IC50 at 0.08 +/- 1.82 mu g mL(-1) followed by C. tagal with IC50 at 0.85 +/- 1.46 mu g mL(-1) and B. sensitivum with IC50 at 2.24 +/- 1.58 mu g mL(-1). Conclusion: This is the first report on the alpha-glucosidase inhibitory effect of the six Philippine plants; thus, partly defining the mechanism on why these medicinal plants possess antidiabetic properties. (C) 2012 Elsevier Ireland Ltd. All rights reserved.