Effective Inhibition of Foam Cells Formation by Tanshinone IIA in RAW264.7 Macrophages Induced with LDL Isolated from Hypercholesterolemia Patients: A Proteomic Analysis

Tanshinone IIA is the major active ingredient of Salviae miltiorrhizae extract, and has been widely used in China for the treatment of cardiovascular and cerebrovascular diseases. We have identified proteins modulated by Tanshinone IIA during the formation of macrophage-derived foam cells to uncover its anti-atherosclerotic mechanism. Low density lipoprotein (LDL) isolated from hyperlipidemia patients, designated as HP-LDL. HP-LDL (80 μg/mL for 24 h) can improve the total cholesterol and the proportion of cholesterol ester in the RAW264.7 macrophage and transform it into foam cell, which can be inhibited by Tanshinone IIA (20 μg/mL, 24 h). Two-dimensional electrophoresis and matrixassisted laser desorption ionization time-of-flight mass spectrometry were used to analysis and identify the proteins differentially expressed after Tanshinone IIA treatment of HP-LDL induced RAW264.7 macrophage transformation into foam cell. Fifteen proteins have been identified, which involved the different cellular functions, such as regulation of cytosolic calcium concentration, oxidative stress, inflammation, cell proliferation and differentiation, and lipid metabolism. This provides new insight into the anti-atherosclerotic mechanism of Tanshinone IIA.