Anti-Inflammatory Effects of Taraxasterol on LPS-Stimulated Human Umbilical Vein Endothelial Cells

In the present study, we used the human umbilical vein endothelial cells (HUVECs) to investigate the anti-inflammatory effects and mechanism of taraxasterol on vascular inflammation. HUVECs were pre-treated with taraxasterol 1 h before lipopolysaccharide (LPS) treatment. The concentrations of TNF-α, IL-8, PGE2, and NO were measured. The expression of VCAM-1, ICAM-1, iNOS, COX-2, NF-κB, and LXRα was detected by western blot analysis. The results showed that taraxasterol not only reduced the production of TNF-α, IL-8, PGE2, and NO induced by LPS, but also reduced the expression of iNOS and COX-2. Taraxasterol also suppressed LPS-induced NF-κB activation and VCAM-1 and ICAM-1 expression. Furthermore, taraxasterol concentration-dependently increased the expression of LXRα. The inhibition of taraxasterol on TNF-α, IL-8, PGE2, and NO production can be reversed by geranylgeranyl diphosphate (GGPP, the LXRα inhibitor). Here, we found that taraxasterol inhibited vascular inflammation through activating LXRα.