Metabolomic profiling reveals effects of marein on energy metabolism in HepG2 cells

Previous studies have suggested that Coreopsis tinctoria improves insulin resistance in rats fed with high-fat diet. But little is known about the antidiabetic effects of marein which is the main component of C. tinctoria. This study investigated the effects of ethyl acetate extract of C. tinctoria (AC) on insulin resistance (IR) in rats fed a high-fat diet. High glucose and fat conditions cause a significant increase in blood glucose, insulin, serum TC, TG and LDL-C, leading to an abnormal IR in rats. However, treatment with AC protects against HFD-induced IR by improving fasting serum glucose and lipid homeostasis. High glucose conditions cause a significant decrease in glycogen synthesis and increases PEPCK and G6Pase protein levels and Krebs-cycle-related enzymes levels, leading to an abnormal metabolic state in HepG2 Cells. However, treatment with Marein improves IR by increasing glucose uptake and glycogen synthesis and by downregulating PEPCK and G6Pase protein levels. The statistical analysis of HPLC/MS data demonstrates that Marein restores the normal metabolic state. The results show that AC ameliorates IR in rats and Marein has the potential effect in improving IR by ameliorating glucose metabolic disorders.