RESUMO
<p><b>OBJECTIVE</b>To observe the effect of rosiglitazone on the content of cholesterol and expressions of Acy-coenzyme A: cholesterol acyltransferase 1 (ACAT-1) and scavenger receptor class B type I (SR-BI) in RAW264.7 macrophage-derived foam cells and explore the anti-atherosclerotic mechanism of rosiglitazone.</p><p><b>METHODS</b>RAW264.7 macrophages were incubated with oxidized low-density lipoproteins (ox-LDL) or with both ox-LDL and rosiglitazone (5, 10, or 20 µmol/L). Oil red O staining was used to observe the formation of foam cells, and cholesterol oxidase was used to determine the content of cellular cholesterol contents. Western blotting was used observe the expressions of ACAT-1 and SR-BI in RAW264.7 foam cells.</p><p><b>RESULTS</b>Compared with the control cells, RAW264.7 macrophage-derived foam cells showed significantly increased contents of total cholesterol and free cholesterol (P<0.01) and ACAT-1 expressions (P<0.05) with mildly increased SR-BI expression (P>0.05). Rosiglitazone treatments significantly lowered the contents of total cholesterol and free cholesterol (P<0.05), decreased the expression of ACAT-1 (P<0.05), and increased SR-BI expression (P<0.05) in the foam cells in a dose-dependent manner.</p><p><b>CONCLUSION</b>Rosiglitazone can decrease the contents of total and free cholesterol, down-regulate ACAT-1 expression and up-regulate SR-BI expression in the foam cells produce the anti-atherosclerotic effect.</p>