Effect of cinnamon water extract on monocyte-to-macrophage differentiation and scavenger receptor activity

Kang, Hee; Park, Sung-Hyun; Yun, Jeong-Moon; Nam, Tae-Gyu; Kim, Young-Eun; Kim, Dae-Ok; Kim, Youn Jung

Since macrophages respond to modified LDL, fatty acids, and other lipid metabolites, persistent low grade inflammation is observed in metabolic disorders such as obesity, type II diabetes and atherosclerosis [24, 25] . LDL oxidation in the vascular wall triggers the activation of resident macrophages, recruitment and differentiation of blood monocytes, and the formation of lipid-laden foam cells [13] . LDL could be oxidized by various stimuli but any chronic inflammatory environment further promotes LDL oxidation. Thus traditional herbal medicines that have been proved to be anti-inflammatory can be a good resource to prevent or ameliorate atherosclerosis. Since treatment of THP-1 cells with PMA induces differentiation into macrophages, this cell line is widely used for atherosclerotic research [15] . CD11b is induced not only in PMA-stimulated THP-1 cells but also in oxidized LDL-stimulated mouse monocytes in vivo [18] . It forms a noncovalently linked heterodimer with the common βsubunit CD18 and binds to various adhesion molecules in the endothelial cells and extracellular matrix, therefore mediating the migration and adhesion of cells during monocyte differentiation [11, 26] . Our result indicates that CWE can reduce CD11b dependent monocyte recruitment in the atherogenic lesion.