Endocrine Abstracts

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 (5–50 mg/ml), the extract also produced 8–74% (P<0.001) decrease in starch digestion in vitro. E. officinalis (1–50 mg/ml) inhibited protein glycation 44–87% (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.