Carnosic acid reduces cytokine-induced adhesion molecules expression and monocyte adhesion to endothelial cells

Expression of cell adhesion molecules on the endothelium and the attachment of monocytes to endothelium may play a major role in the early atherogenic process. We investigated the effects of carnosic acid on the adhesion of U937 cells to IL-1 beta-treated human umbilical vein endothelial cells (HUVECs), as well as on the expression of adhesion molecules. Our data showed that pretreatment with 10 and 20 A mu mol/l carnosic acid significantly reduced the number of U937 cells adhering to IL-1 beta-treated HUVECs. In addition, we found that 20 A mu mol/l carnosic was more effective than 10 A mu mol/l carnosic acid at inhibiting expression of cell adhesion molecules (ICAM-1, VCAM-1, and E-selectin), the nuclear translocation of NF-kappa B subunits p65 and p50, and the production of ROS in IL-1 beta-stimulated HUVECs. We conclude that carnosic acid inhibits IL-1 beta-induced ICAM-1, VCAM-1 and E-selectin expression in HUVECs through a mechanism that involves NF kappa B. We propose that the reduction in binding of human monocytic cell line U937 to IL-1 beta-treated HUVECs is due to the anti-inflammatory properties of carnosic acid.