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

Scavenger receptors consist of eight classes; among them, SRA, belonging to class A, is expressed mostly in macrophages [12, 27] . CD36, one of the class B scavenger receptors, is distributed in a variety of cells including platelets, cells with hematopoietic origin, adipocytes, and endothelial cells [28] . The expression of SRA and CD36 can be differentially controlled. Peroxisome-proliferatoractivated γ, a transcription factor that is involved in lipid metabolism and monocyte differentiation, influences the expression of CD36, but not of SRA [29] . The different response of SRA and CD36 genes to CWE treatment indicate that CWE may separately affect PMA-activated signaling pathways that express these genes. It should be noted here that inhibition of acetyl LDL uptake in THP-1 cells by CWE was more marked than that of SRA and CD36 expression. A similar effect was observed in peritoneal macrophages of which scavenger receptors had already occupied before CWE treatment. We postulate that since CWE is likely to have high molecular weight polysaccharides, it may have some activity that competitively binds with scavenger receptors, as does fucoidan.