Abstract

Atherosclerosis is a chronic inflammatory process. The adhesion of leukocytes to the vascular endothelium, mediated by endothelial cell adhesion molecules including vascular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin, is the pivotal early event in atherogenesis. Inflammatory cytokines could activate redox-sensitive transcription factors and induce endothelial expression of adhesion molecules, which could be inhibited to various degrees by different antioxidants suggesting the potential role of endogenous reactive oxygen species (ROS) in atherogenesis. Many clinical drugs that against cardiovascular diseases have exhibited antioxidant effects; these drugs simultaneously inhibit endothelial adhesion molecule expression, such as aspirin, probucol, HMG-CoA reductase inhibitors, angiotensin receptor blockers, angiotensin converting enzyme inhibitors, peroxisome proliferator-activated receptor alpha and gamma ligands, calcium channel blockers, beta-adrenergic blockers, etc. In addition, we have previously demonstrated that Ginkgo biloba extract, a Chinese herb with antioxidant activity, could significantly suppress inflammatory cytokine-stimulated endothelial adhesiveness to human monocytic cells by attenuating intracellular ROS formation, redox-senstive transcription factor activation, and VCAM-1 as well as ICAM-1 expression in human aortic endothelial cells. The similar anti-atherosclerosis effects have been also shown in other Chinese herbs or dietary supplements with antioxidant activity such as magnolol and salvianolic acid B either in vitro or in vivo. Thus, oxidative stress is critical to endothelial adhesiveness in atherogenesis. The inhibition of endothelial adhesion molecule expression by drugs/agents with antioxidant activity may serve as a potential therapeutic strategy for clinical atherosclerosis.