Dynamic Role of Macrophage Sub Types on Development of Atherosclerosis and Potential Use of Herbal Immunomodulators as Imminent Therapeutic Strategy

Atherosclerosis, a major contributor to cardiovascular disease, is a global alarm causing mortality worldwide. Being a progressive disease in the arteries, it mainly causes the recruitment of monocytes to the inflammatory sites and subsides pathological conditions. Monocyte-derived macrophage mainly acts in foam cell formation by engorging the LDL molecules, oxidizes it into Ox-LDL and leads to plaque deposit development. Macrophages in general differentiate, proliferate and undergo apoptosis at the inflammatory site. Frequently two subtypes of macrophages M1 and M2 have to act crucially in balancing the micro-environmental conditions of endothelial cells in arteries. The productions of pro-inflammatory mediators like IL-1, IL-6, TNF-α by M1 macrophage have atherogenic properties majorly produced during the early progression of atherosclerotic plaques. To counteract cytokine productions and M1-M2 balance, secondary metabolites (phytochemicals) from plants act as a therapeutic agent in alleviating atherosclerosis progression. This review summarizes the fundamental role of the macrophage in atherosclerotic lesion formation along with its plasticity characteristic as well as recent therapeutic strategies using herbal components and anti-inflammatory cytokines as potential immunomodulators.