Fig. 9.

Benzil or paraoxon treatments cause significant retention of cholesteryl esters in cholesterol-loaded macrophages. Results are shown for cholesteryl esters (A), total cholesterol (B), and free cholesterol (C). THP-1 monocytes were cultured in growth medium containing 100 nM PMA for 7 days to induce differentiation into macrophages. Adherent cells were then loaded with cholesterol by incubating with 50 μg/ml of human acetylated LDL for 48 h. Cholesterol efflux from the lipid-laden macrophages was accomplished by culturing cells in growth medium containing 10% FBS, which serves as the cholesterol acceptor. Either 50 μM benzil (benzil) or 10 μM paraoxon (PO) was added to the culture media during the cholesterol efflux period to determine their effect on cholesteryl ester retention. Control refers to vehicle-treated cells. Cholesteryl ester, total, and free cholesterol levels are expressed as nmol/mg protein (mean ± SD, n = 4). *, p≤0.05 compared to control (Student’s t-test, n = 4).