Hypoglycemic activity of Pyrus biossieriana Buhse leaf extract and arbutin: Inhibitory effects on alpha amylase and alpha glucosidase

Abstract Background: The mechanism of hypoglycemic and hypolipidemic activities of Pyrus biossieriana Buhse leaf extract (PbBLE) and its phytochemical component arbutin, have not been well determined. The present study was performed to understand the hypoglycemic activity mechanisms of pbBLE and arbutin more clearly. Methods: In vitro enzymatic carbohydrate digestion with PbBLE and arbutin was assessed using ?-amylase and ?-glucosidase powders. The enzyme solutions were premixed with PbBLE and arbutin at different concentrations (0.1, 1, 10 and 100 mg/ml). Substrate solutions and colorimetric reagents were added to the reaction. The release of glucose was determined by spectrophotometric method. Acarbose was used as the positive control. Results: The extract (10, 100 mg/ ml) completely inhibit ?- amylase and ?- glucosidase activities. The extract produced higher reduction of ?-amylase and ?-glucosidase activity than arbutin. Inhibition at various concentrations (0.1, 1, 10, 100 mg/ml) were significantly different (p < 0.05). Conclusion: Our results exhibited that both the extract and arbutin were able to suppress the enzymes strongly.