Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins alleviate insulin-resistance via activating PI3K/AKT pathway in HepG2 cells
Mengting Wang, Haiguang Mao, Jianchu Chen, Qiang Li, Wei Ma, Nan Zhu, Lili Qi, Jinbo Wang
Abstract
Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins (BLPs) were natural bioactive compounds in the treatment of obesity and diabetes with a unique structural characteristic. This study aimed to investigate the effect of BLPs on hepatic glucose metabolism in insulin-resistant HepG2 cells and elucidate the underlying mechanism. With the supplementation of BLPs, the glucose consumption and glucose uptake in IR-HepG2 cells were increased. BLPs promoted glycogen synthesis via up-regulating p-GSK3β and GYS2 expression, and attenuated gluconeogenesis by down-regulating PEPCK and G6Pase expression. It was attributed to the activation of PI3K/AKT signal pathway by BLPs, which was confirmed using the PI3K inhibitor LY294002. Moreover, BLPs remarkably reduced the expression of miR-29a, miR-423 and miR-122, which involved in hepatic glucose metabolism. Our results provide an insight of the hypoglycemic potential of BLPs on the hepatic glucose metabolism, suggesting that BLPs can be further used as a novel ingredient in functional food.