Inflammation is a major pathophysiological mechanism in atherosclerosis . Histopathologically, atherosclerosis is characterized by a thickening of the vascular wall due to lipid accumulation and infiltration of macrophages and lymphocytes [2, 3]. Many evidences have indicated the presence of many cell adhesion molecules and growth factors in atherosclerosis. Other reports have stressed that there are interactions between the adhesion molecules and growth factors in inflammatory responses. Researches have shown that the development of atherosclerosis is caused by a complex interaction between reactive oxygen species, lipids, endothelium, circulation and tissue inflammatory cells, platelets and vascular smooth muscle cells and was not simply due to the accumulation of lipids [4, 5].
Hypercholesterolemia is one of the most important risk factors for atherosclerosis and related occlusive vascular disease . Recent observations suggest that the endothelium's dysfunction and inflammation cause not only the initial stage of the atherosclerotic process but also atherosclerotic plaque development.
Vascular cell adhesion molecule VCAM-1 and intercellular adhesion molecule ICAM-1 are endothelial adhesion molecules of the Ig gene superfamily that may participate in atherogenesis by promoting monocyte accumulation in the arterial intima . Elevated levels of inflammatory markers, especially CRP, are associated with an increased risk of cardiovascular disease [1, 8, 9]. Serum CRP stimulates endothelial cell expression of (ICAM-1) and (VCAM-1) . The ICAM-1 and VCAM-1 are important factors in the development of atherosclerosis and may play an important role in promoting the local inflammation within the atherosclerotic plaque . Cellular adhesion molecules like ICAM-1 and VCAM-1 are involved in the rolling, adhesion and extravasation of monocytes and T-lymphocytes [12–14]. This migration is one of the earliest events in the atherosclerotic process in addition to its later contribution to the chronic inflammatory process. Pathological studies of human atherosclerosis have shown increased expression of CAMs located in endothelial cells. Increased levels of soluble (s) forms of CAMs in circulating blood have been found in a number of conditions with an inflammatory component [15, 16]. Various studies have showed there are many inflammatory markers that can predict cardiovascular events, including cell adhesion molecules, cytokines, chemokines, acute phase reactants such as fibrinogen, serum amyloid A and CRP. Additionally, CRP which has recently emerged as one of the most important inflammatory mediators can directly participate in the pathogenesis of atherosclerosis by activating endothelial cells and promoting the inflammatory component of atherosclerosis [2, 3]. CRP plays a crucial role in the pathogenesis of the vascular inflammatory process which is abrogated by simvastatin therapy. In this study we focus on the effect of natural antioxidant on inflammatory markers, ICAM-1, VCAM-1 and CRP. The results of the present study may help in the prevention and treatment of atherosclerosis. Research in herbal medicine can provide an alternative solution to health problems.
Piper sarmentosum belongs to the family Piperaceae. In different parts of the world, P.s has been used traditionally to cure many diseases . Phytochemically, the plant contains constituents like alkaloids (amide, flavonoids, pyrones)  and it has also been reported to possess pharmacological properties like antituberculosis  anti-cancer , anti-angiogenic , anti-diabetic , antimalarial , antioxidant , neuromuscular blocker  and antiamoebic . Previous study has indicated that aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs  and our previous study indicated that Ps can be reduce atherosclerosis lesion . Piper sarmentosum has flavonoids compounds which are widely distributed in plants which have been reported to have antioxidant, free radical scavenging abilities and anti-inflammatory effect . The active extract of P. sarmentosum contains natural antioxidants like Naringenin (75.7%), Hesperitin (91.7%), Taxifolin/Dihydroquercitin (90.9%) and Quercetin (98.1%) which have high superoxide scavenging action .. The antioxidant activities of phynolic compounds like flavonoid which have anti-inflammatory action by inhibiting IL6 and TNF and inhibits the aggregation and adhesion of platelets in the blood . It has been also shown that flavonoids reduce LDL oxidation, which is an important step in atherogenesis .