Chlorogenic Acid Inhibits Ceramide Accumulation to Restrain Hepatic Glucagon Response

Chlorogenic acid (CGA), a dietary natural phenolic acid, has been widely reported to regulate glucose and lipid metabolism. However, the protective effects and the underlying mechanisms of CGA on glucagon-induced hepatic glucose production remain largely uncharacterized. Herein, we investigated the efficacy of CGA on hepatic gluconeogenesis both in vivo and in vitro. The elevated levels of endogenous glucose production induced by infusion of glucagon or pyruvate were lowered in mice administered with CGA. Furthermore, chronic CGA treatment ameliorated the accumulation of glucose and ceramide in high-fat diet (HFD)-fed mice. CGA also attenuated HFD-fed-induced inflammation response. The protective effect of CGA on glucose production was further confirmed in primary mouse hepatocytes by inhibiting accumulation of ceramide and expression of p38 MAPK. Moreover, CGA administration in HFD-fed mice preserved the decreased phosphorylation of Akt in the liver, resulting in the inhibition of FoxO1 activation and, ultimately, hepatic gluconeogenesis. However, these protective effects were significantly attenuated by the addition of C2 ceramide. These results suggest that CGA inhibits ceramide accumulation to restrain hepatic glucagon response.