Stewartiakoreana extract stimulates proliferation and migration of human endothelial cells and induces neovasculization in vivo

Angiogenesis, the growth of new blood vessels from preexisting vasculature, plays an important role in physiological and pathological processes such as embryonic development and wound healing. This study investigated the effects of methanol extracts of Stewartia koreana leaves (SKE) on angiogenesis. Stewartia koreana significantly promoted the proliferation and migration of human umbilical vein endothelial cells in a dose-dependent manner. The SKE induced endothelial cell proliferation in the range of 50 microg/mL without cytotoxicity. Treatment of HUVECs resulted in the activation of the mitogen-activated protein kinases that was correlated with endothelial cell proliferation and migration. SKE also stimulated angiogenesis in a chick chorioallantoic membrane assay, demonstrating promotion of new blood vessel formation in vivo. Local administration of SKE onto skin punched wounds resulted in increased von Willebrand Factor antigen, indicating that it stimulated neovasculization in the wound region. The results suggest that Stewartia koreana extracts may potentially be useful for the development of agents to accelerate vascular wound healing or to promote the growth of collateral blood vessels in ischemic tissues.