Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins alleviate insulin-resistance via activating PI3K/AKT pathway in HepG2 cells

Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins (BLPs) were natural bioactive com-pounds 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-GSK38 and GYS2 expres-sion, 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 he-patic 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.

Automated summary

Chinese bayberry leaves proanthocyanidins (BLPs) have significant effects on hepatic glucose metabolism, promoting glycogen synthesis and reducing gluconeogenesis. These effects may be achieved through the activation of the PI3K/AKT signaling pathway. Additionally, BLPs can also regulate the expression of specific miRNAs, further influencing hepatic glucose metabolism.