Acanthoic acid inhibits LPS-induced inflammatory response by activating LXRα in human umbilical vein endothelial cells

Acanthoic acid, a pimaradiene diterpene isolated from Acanthopanax koreanum, has been reported to have anti-inflammatory activities. However, the effect of acanthoic acid on vascular inflammation has not been investigated. The aim of this study was to investigate the anti-inflammatory effects of acanthoic acid on lipopolysaccharide (LPS)-induced inflammatory response in human umbilical vein endothelial cells (HUVECs). The production of cytokines TNF-α and IL-8 was detected by ELISA. The expression of VCAM-1, ICAM-1, E-selectin, NF-κB and LXRα were detected by Western blotting. Adhesion of monocytes to HUVECs was detected by monocytic cell adhesion assay. The results showed that acanthoic acid dose-dependently inhibited LPS-induced TNF-α and IL-8 production. Acanthoic acid also inhibited TNF-α-induced IL-8 and IL-6 production. LPS-induced endothelial cell adhesion molecules, VCAM-1 and ICAM-1 were also inhibited by acanthoic acid. Acanthoic acid inhibited LPS-induced NF-κB activation. Furthermore, acanthoic acid dose-dependently up-regulated the expression of LXRα. In addition, our results showed that the anti-inflammatory effect of acanthoic acid was attenuated by transfection with LXRα siRNA. In conclusion, the anti-inflammatory effect of acanthoic acid is due to its ability to activate LXRα. Acanthoic acid may be a therapeutic agent for inflammatory cardiovascular disease.