Antiangiogenic effects of p-coumaric acid in human endothelial cells.

p-Coumaric acid, a hydroxy derivative of cinnamic acid, has been known to possess antioxidant and anticancer activities. Despite its potential contribution to chemopreventive effects, the mechanism by which p-coumaric acid exerts its antiangiogenic actions remains elusive. In this study, we revealed that p-coumaric acid inhibited the sprouting of endothelial cells in rat aortic rings and inhibited the tube formation and migration of endothelial cells. We observed that p-coumaric acid could downregulate mRNA expression levels of the key angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor. Also, we demonstrated that p-coumaric acid inhibited both the AKT and ERK signaling pathways, which are known to be crucial for angiogenesis. Using a mouse model, we also showed that p-coumaric acid effectively suppressed tumor growth in vivo by lowering hemoglobin contents. Collectively, these findings indicate that p-coumaric acid possesses potent anticancer properties due to the inhibition of angiogenesis in vivo.