Palbinone and triterpenes from Moutan Cortex (Paeonia suffruticosa,Paeoniaceae) stimulate glucose uptake and glycogen synthesis via activation of AMPK in insulin-resistant human HepG2 Cells

Moutan Cortex is a well-known herb in traditional Korean, Chinese, and Japanese anti-diabetic formulae. In the current study, we investigated the metabolic effects of isolated triterpenes (1–7) in HepG2 cells under high glucose conditions. These compounds remakably stimulated AMP-activated protein kinase (AMPK), GSK-3β, and ACC phosphorylation. The compounds also increased glucose uptake and enhanced glycogen synthesis. Among these, compound 1 displayed the greatest potential anti-diabetic activity though the AMPK activation pathway. Compound 1 significantly increased the levels of phospho-AMPK, phospho-ACC, and phospho-GSK-3β and stimulated glucose uptake and glycogen synthesis in a dose-dependent manner. In conclusion, our results suggest that these compounds, especially compound 1, may have beneficial roles in glucose metabolism via the AMPK pathway.