No abstract

Diabetes mellitus is highly prevalent worldwide. High-fat-diet (HFD) consumption can lead to liver fat accumulation, impair hepatic glycometabolism, and cause insulin resistance and the development of diabetes. Resveratrol has been shown to improve the blood glucose concentration of diabetic mice, but its effect on the abnormal hepatic glycometabolism induced by HFD-feeding and the mechanism involved are unknown. In this study, we determined the effects of resveratrol on the insulin resistance of high-fat-diet-fed mice and a hepatocyte model by measuring serum biochemical indexes, key indicators of glycometabolism, glucose uptake, and glycogen synthesis in hepatocytes. We found that resveratrol treatment significantly ameliorated the HFD-induced abnormalities in glucose metabolism in mice, increased glucose absorption and glycogen synthesis, downregulated protein phosphatase 2A (PP2A) and activated Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ), and increased the phosphorylation of AMP-activated protein kinase (AMPK). In insulin-resistant HepG2 cells, the administration of a PP2A activator or CaMKKβ inhibitor attenuated the effects of resveratrol, but the administration of an AMPK inhibitor abolished the effects of resveratrol. Resveratrol significantly ameliorates abnormalities in glycometabolism induced by HFD-feeding and increases glucose uptake and glycogen synthesis in hepatocytes. These effects are mediated through the activation of AMPK by PP2A and CaMKKβ.