Oleanolic acid inhibits proliferation of HUVECs, and inhibits migration and tube formation via VEGF pathway

To investigate the effects of oleanolic acid (OA) on the proliferation, migration and the formation of tube-like structure in human vascular endothelial cells (HUVECs).  MTT assay, flat plate scarification, Transwell plates and matrigel-induced tube formation assay were performed to detect the effects of OA on proliferation, migration and tube formation.  MTT assay showed that the inhibition rates of HUVECs treated with 60 and 100 μg·mL⁻¹ of OA for 24 h were 19% and 83% respectively.  Treatment of HUVECs significantly inhibited the cell migration in a dose-dependent manner.  The vascular indexes of HUVECs treated with 40 and 60 μg·mL⁻¹ OA were 33% and 20% respectively.  Western blotting analysis showed that treatment of the cells with OA significantly attenuated the expression and secretion of VEGF.  Additionally, VEGF could in part reverse the effects of OA on migration and tube formation of HUVECs.  In conclusion, OA inhibits the proliferation, and VEGF plays an important role in OA induced decreased migration and tube formation of HUVECs.