Terminalia belliricastimulates the secretion and action of insulin and inhibits starch digestion and protein glycationin vitro

Abstract

Traditional plant treatments have been used throughout the world for the therapy of diabetes mellitus. The aim of the present study was to investigate the efficacy and mode of action ofTerminalia belliricaused traditionally for the treatment of diabetes in India.T. belliricaaqueous extract stimulated basal insulin output and potentiated glucose-stimulated insulin secretion concentration-dependently in the clonal pancreatic β-cell line, BRIN-BD11 (P < 0·001). The insulin-secretory activity of the plant extract was abolished in the absence of extracellular Ca2+and by inhibitors of cellular Ca2+uptake, diazoxide and verapamil (P < 0·001;n8). Furthermore, the extract did not increase insulin secretion in depolarised cells and did not further augment insulin secretion triggered by tolbutamide or glibenclamide.T. belliricaextract also displayed insulin-mimetic activity and enhanced insulin-stimulated glucose uptake in 3T3-L1 adipocytes by 300 %. At higher concentrations, the extract also produced a 10–50 % (P < 0·001) decrease in starch digestionin vitroand inhibited protein glycation (P < 0·001). The present study has revealed that components inT. belliricaextract stimulate insulin secretion, enhance insulin action and inhibit both protein glycation and starch digestion. The former actions are dependent on the active principle(s) in the plant being absorbed intact. Future work assessing the use ofT. belliricaas a dietary adjunct or as a source of active anti-diabetic agents may provide new opportunities for the treatment of diabetes.