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

Background: 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.

Objective: We investigated the effects of carnosic acid on the adhesion of U937 cells to IL-1beta-treated human umbilical vein endothelial cells (HUVECs), as well as on the expression of adhesion molecules.

Results: Our data showed that pretreatment with 10 and 20 micromol/l carnosic acid significantly reduced the number of U937 cells adhering to IL-1beta-treated HUVECs. In addition, we found that 20 micromol/l carnosic was more effective than 10 micromol/l carnosic acid at inhibiting expression of cell adhesion molecules (ICAM-1, VCAM-1, and E-selectin), the nuclear translocation of NF-kappaB subunits p65 and p50, and the production of ROS in IL-1beta-stimulated HUVECs.

Conclusions: We conclude that carnosic acid inhibits IL-1beta-induced ICAM-1, VCAM-1 and E-selectin expression in HUVECs through a mechanism that involves NFkappaB. We propose that the reduction in binding of human monocytic cell line U937 to IL-1beta-treated HUVECs is due to the anti-inflammatory properties of carnosic acid.