Abstract: OBJECTIVE To study the protective effect and mechanism of buddleoside on human aortic endothelial cells. METHODS MTT assay was used to detect the viability of EA.hy926 in TNF-α and buddleoside. EA.hy926 cells were treated with TNF-α(50 ng·mL^-1) for inflammatory injury model. After being pretreated with different concentrations(5, 15, 25 mmol·L^-1) of buddleoside for 24 h, DAPI staining was used to evaluate the effect of buddleoside on adhesion of EA.hy926 and THP-1. The protein expression of TLR4, IκBα, NF-κB, ICAM-1 and VCAM-1 were tested by Western blot method respectively. The mRNA expression of ICAM-1 and VCAM-1 were tested by RT-PCR method respectively. ELISA method was used to measure the levels of IL-1, IL-6 and IL-8. RESULTS Buddleoside could inhibit the adhesion of TNF-α stimulated EA.hy926 cell and THP-1 cell. ELISA results showed that buddleoside reduced IL-1, IL-6 and IL-8 production in TNF-α-stimulated EA.hy926. Buddleoside significantly decreased TLR4, NF-κB, ICAM-1 and VCAM-1 protein expression in TNF-α-stimulated EA.hy926 cell. In addition, buddleoside increased IκBα protein expression. RT-PCR result showed buddleoside decreased ICAM-1 and VCAM-1 mRNA expression in TNF-α-stimulated EA.hy926 cell. CONCLUSION Buddleoside can alleviate the inflammatory injury of vascular endothelial cells, and its mechanism may be mainly through the inhibition of TLR4/IκBα/NF-κB signaling pathway.