Studies on the anti-angiogenic effect of Marsdenia tenacissima extract in vitro and in vivo

Marsdenia tenacissima, which is widely used as an anticancer herb in traditional Chinese medicine, has been shown to possess anticancer activities. However, the underlying molecular mechanism(s) involved in the anticancer effect of this herb are poorly understood. Angiogenesis is important in the development of cancer. The main features of angiogenesis are increased vasculature and overexpression of vascular endothelial growth factor (VEGF). In the present study, the effects of M. tenacissima extract (MTE) on human umbilical vein endothelial cell (HUVEC) proliferation, migration and capillary-like tube formation were investigated in vitro and using the chick embryo chorioallantoic membrane (CAM) assay in vivo. It was observed that MTE inhibited the proliferation of HUVECs by blocking the cell cycle progression from G1 to S. In addition, MTE inhibited the migration and tube formation of HUVECs. MTE treatment decreased the VEGF-A expression in human hepatoma cells (HepG2), as well as the expression of VEGF-A and VEGF receptor (VEGFR)-2 in HUVECs. MTE exposure in the CAM was able to reduce the formation of blood vessels in chick embryos. Overall, the present data suggest that extracts of M. tenacissima may serve as potential anti-angiogenesis agents.