Effects of a Hwanggi-tang Ethanol Extract on Glucose Uptake and Metabolism in Murine Myotubes

Objectives The aim of this study was to evaluate the effects of Hwanggi-tang on glucose digestion, uptake, and metabolism in murine C2C12 myotubes. Methods Hwanggi-tang was prepared according to the Dong-ui-bo-gam (≪東醫寶鑑≫) prescription by 70% ethanol extraction. The effect on glucose digestion was examined by determining the inhibitory effect of Hwanggi-tang on α-glucosidase activity. We also compared and verified the gene and protein expression of genes related to glucose uptake in C2C12 myotubes treated with Hwanggi-tang or insulin. Glucose metabolism was assessed by the expression levels of associated enzymes. Results Hwanggi-tang caused a dose-dependent inhibition of α-glucosidase activity, induced glucose uptake by activation of the PI3K/Akt/mTOR pathway in the insulin signaling pathway, and promoted glucose oxidation and β-oxidation. Conclusions Hwanggi-tang exerts an anti-diabetic effect on murine myotubes by inhibiting glucose digestion and inducing glucose uptake and consumption. Keywords: carbohydrate metabolism, diabetes mellitus, herbal medicine, skeletal muscle fiber