Abstract
Brevilin A (BA), a sesquiterpene lactone isolated from Centipeda minima herb, has been identified to exhibit potent anticancer activity. However, the potential pharmacological effect and mechanism of BA in regulating endothelial cell (EC) angiogenesis, a key event in tumor growth, is poorly understood. In this study, BA was shown to significantly prevent vascular endothelial growth factor (VEGF) induced EC angiogenic capacities in vitro, ex vivo, and in vivo. Subsequent functional assays revealed that BA dose dependently inhibited VEGF-stimulated survival, proliferation, migration, and triggered apoptosis activity in human umbilical vein endothelial cells (HUVECs), as well as suppressed the expression of antiapoptotic protein Bcl-2, increased the expression of proapoptotic protein caspase-3 and Bax, and suppressed PI3K/AKT pathway. Meanwhile, BA was also able to depolarize mitochondrial membranal permeability (MMP), accelerate mitochondrial superoxide accumulation, induce intracellular reactive oxygen species (ROS) production, and decreased intracellular glutathione (GSH) in HUVECs. Furthermore, both mitochondria-specific superoxide scavenger Mito-TEMPOL and broad-spectrum antioxidant N-acetyl-cysteine (NAC) dramatically abolished BA-induced mitochondrial dysfunction and mitochondrial ROS production, causing the reversion of PI3K/AKT pathway and repression of apoptosis, eventually correcting the impaired endothelial behavior in survival, growth, migration, and angiogenesis. Collectively, our data for the first time identified a new mechanism for antiangiogenic effect of BA in vascular EC, one that is based on the regulation of mitochondrial-dependent ROS overproduction.