Pyripyropene A, an Acyl-Coenzyme A: Cholesterol Acyltransferase 2-Selective Inhibitor, Attenuates Hypercholesterolemia and Atherosclerosis in Murine Models of Hyperlipidemia

Objective-Pyripyropene A (PPPA) of fungal origin is the first compound that has been found to strongly and selectively inhibit acyl-coenzyme A: cholesterol acyltransferase 2 (ACAT2) isozyme activity in vitro. The purpose of the present study was to investigate in vivo efficacy of the ACAT2-selective inhibitor in atherosclerosis. Methods and Results-PPPA treatment (10 to 100 mg/kg) caused 30.5 +/- 4.7% to 55.8 +/- 3.3% inhibition of the cholesterol absorption from the mouse intestine. When PPPA (10 to 50 mg/kg per day) was orally administered to apolipoprotein E-knockout mice for 12 weeks, the levels of plasma cholesterol, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) and hepatic cholesterol content were lowered. Furthermore, the ratio of cholesteryl oleate (exclusively synthesized in hepatic ACAT2) to cholesteryl linoleate in VLDL-and LDL-derived cholesteryl ester decreased, indicating that hepatic ACAT2 activity was inhibited by PPPA. PPPA-treated mice had reduced atherogenic lesion areas that were lowered by 26.2 +/- 3.7% to 46 +/- 3.8% in the aortae and by 18.9 +/- 3.6% to 37.6 +/- 6.0% in the hearts. Conclusion-Our findings indicate that ACAT2-selective inhibition in the intestine and the liver can be effective against atherosclerosis and that PPPA appears to be a potential antiatherogenic lead compound. This study is the first demonstration of the in vivo efficacy of PPPA, an ACAT2-selective inhibitor, in atherosclerosis. PPPA-treated atherogenic mice showed a decrease in intestinal cholesterol absorption and cholesterol and cholesteryl oleate levels in both LDL and VLDL, resulting in protection of atherosclerosis development. (Arterioscler Thromb Vasc Biol. 2011;31:1108-1115.)