Effects of caffeic acid and cinnamic acid on glucose uptake in insulin-resistant mouse hepatocytes.

Tumor necrosis factor-alpha was used to induce insulin resistance of mouse liver FL83B cells. Two phenolic acids, caffeic acid and cinnamic acid, were then added separately to investigate their effects on glucose uptake of the insulin-resistant cells. The results suggest that these two phenolic acids may promote insulin receptor tyrosyl phosphorylation, up-regulate the expression of insulin signal associated proteins, including insulin receptor, phosphatidylinositol-3 kinase, glycogen synthase, and glucose transporter-2, increase the uptake of glucose, and alleviate insulin resistance in cells as a consequence.