Background Parthenolide has been tested for anti-tumor activities,such as anti-proliferation and pro-apoptosis in recent studies.However,little is known about its role in the process of tumor angiogenesis.This study aims to investigate the effects and potential mechanisms of parthenolide on the proliferation,migration and lumen formation capacity of human umbilical vein endothelial cells.Methods Different concentrations of parthenolide were applied to the human breast cancer cell line MDA-MB-231 cells.After 24-hour incubation,the culture supematants were harvested and used to treat human umbilical vein endothelial cells for 24 hours.Then an inverted fluorescence phase contrast microscope was used to evaluate the human umbilical vein endothelial cells.The secretion of vascular endothelial growth factor (VEGF),interleukin (IL)-8 and matrix metalloproteinases (MMP)-9 in the culture supernatant of the MDA-MB-231 cells was then measured with enzyme-linked immunosorbent assay (ELISA) assays.Results Suppression of proliferation,migration,and the lumen formation capacity of human umbilical vein endothelial cells was observed in the presence of the culture supernatants from the breast cancer cell line treated with different concentrations of parthenolide.Parthenolide decreased the levels of the angiogenic factors MMP-9,VEGF,and IL-8secreted by the MDA-MB-231 cells.Conclusions Parthenolide may suppress angiogenesis through decreasing angiogenic factors secreted by breast cancer cells to interfere with the proliferation,migration and lumen-like structure formation of endothelial cells,thereby inhibiting tumor growth.It is a promising potential anti-angiogenic drug.