Inhibitory Actions Of Lupinifolin Isolated From Derris Reticulata Stem Against Carbohydrate-Digesting Enzymes

Background: Postprandial hyperglycemia is linked with the development of diabetic complications. Inhibition against the carbohydrate-digesting enzymes, specifically pancreatic alpha-amylase and intestinal alpha-glucosidase, delays carbohydrate digestion and subsides postprandial plasma glucose (PPG) levels. Objectives: This study aimed to examine the effects of lupinifolin, purified from Derris reticulata stem, a medicinal plant traditionally used for the treatment of diabetes mellitus, on in vitro alpha-amylase and alpha-glucosidase enzyme activities and enzyme kinetics. Subjects and Methods: The identification of the isolated phytochemical was performed using nuclear magnetic resonance-mass spectrometry (NMR-MS) spectrometry.In vitro pancreatic alpha-amylase and alpha-glucosidase activities and enzyme kinetics were determined using the enzymatic colorimetric methods. Results: The purified phytochemical was identified as lupinifolin from the NMR-MS spectrometry. The isolated lupinifolin produced a significant alpha-amylase and alpha-glucosidase inhibitory actions with the median inhibitory concentrations of 3.43 +/- 0.77 and 56.29 +/- 11.64 mu g/mL, respectively. The study of enzyme kinetics showed that lupinifolin exhibited the mode of non-competitive and mixed enzyme inhibitions against alpha-amylase and alpha-glucosidase, respectively. Conclusion: The potent alpha-amylase and alpha-glucosidase inhibitory actions of lupinifolin derived from D. reticulata stem evidently suggest its potential use as an alternative for the control of PPG.