C-Phycocyanin inhibits hepatic gluconeogenesis and increases glycogen synthesis via activating Akt and AMPK in insulin resistance hepatocytes.

C-Phycocyanin (C-PC), a kind of blue protein isolated from Spirulina platensis, can ameliorate hyperglycemia, but its effects on gluconeogenesis and glycogenesis are unknown. In the present study, we investigated the effects and underlying mechanisms of C-PC on gluconeogenesis and glycogenesis in insulin resistant hepatocytes. Insulin resistance was induced by high glucose (HG) in human hepatocellular carcinoma (HepG2) cells. C-PC ameliorated glucose production and phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) expression in HG-induced insulin resistant HepG2 cells. It also increased glucose uptake, glycogen content and glycogen synthase (GS) activation in HG-induced insulin resistant HepG2 cells. The data revealed the mechanism of C-PC in improving glucose homoeostasis via activating the IRS/PI3 K/Akt and SIRT1/LKB1/AMPK signaling pathway in insulin resistant hepatocytes. C-PC could be a promising leading compound for the development of a hypoglycemic agent.