Emblica officinalis stimulates the secretion and action of insulin and inhibits starch digestion and protein glycation
Violet Kasabri1, Peter Flatt2 & Yasser AbdelWahab2
Traditional plant treatments have been used throughout the world for the therapy of diabetes mellitus. The aim of this study was to investigate the efficacy and mode of action of Emblica officinalis Gaertn (Euphorbiaceae) used traditionally for treatment of diabetes in India. E. officinalis aqueous extract stimulated basal insulin output and potentiated glucose-stimulated insulin secretion concentration-dependently in the clonal pancreatic beta cell line, BRIN-BD11 (P<0.001). The insulin secretory activity of plant extract was abolished in the absence of extracellular Ca2+ and by inhibitors of cellular Ca2+ uptake, diazoxide (P<0.001, n=8). Furthermore, the extract increased insulin secretion in depolarised cells and further augmented insulin secretion triggered by IBMX and tolbutamide. Emblica officinalis aqueous extract (1 mg/ml) displayed insulin mimetic activity (230%, P<0.001), furthermore, it enhanced insulin-stimulated glucose transport in 3T3 L1 adipocytes by 460% (P<0.001). Emblica officinalis augmented also synergistically (P<0.001) insulin action, when co-incubated with insulin sensitizers; metformin (2.4-fold), vanadate (4.9-fold), tungstate (4.8-fold) and molybdate (sixfold). At higher concentrations (550 mg/ml), the extract also produced 874% (P<0.001) decrease in starch digestion in vitro. E. officinalis (150 mg/ml) inhibited protein glycation 4487% (P<0.001). This study has revealed that bioactive principles in E. officinalis extract stimulate insulin secretion, enhance insulin action and inhibit both protein glycation and starch digestion. The former actions are dependent on the bioeffective component(s) in the plant being absorbed intact. Future work assessing the use of Emblica officinalis as adjunctive therapeutic nutraceutical or as a source of bioactive antidiabetic principles may provide new opportunities for the integrated management/prevention/reversal of diabetes.