Ethanolic Extract of Propolis Promotes Reverse Cholesterol Transport and the Expression of ATP‐Binding Cassette Transporter A1 and G1 in Mice

Abstract

The ethanolic extract of propolis (EEP) is beneficial in increasing high density lipoprotein (HDL) cholesterol (HDL-C) and diminishing risks of atherosclerosis. In this study, we examined the effects of EEP on reverse cholesterol transport in mice. (3)H -cholesterol laden macrophage was injected intraperitoneally into mice fed by gastric gavage with EEP. Plasma lipid level was determined and (3)H-cholesterol was traced in plasma, liver and feces. The effects of EEP on ATP-binding cassette transporter A1 and G1 (ABCA1 and ABCG1) and scavenger receptor BI (SR-BI) in mice liver and in cultured cells were also investigated. EEP administration led to a significant increase in HDL-C and peritoneal macrophage-original (3)H-cholesterol in plasma, liver and feces. Liver protein expressions of ABCA1 and ABCG1 were increased but SR-B1 was not. In vitro experiments with HepG2 and Raw264.7 cell lines confirmed the above results. The finding of these studies shows that EEP-enhanced reverse cholesterol transport may have resulted from EEP stimulated plasma HDL level and hepatic ABCA1 and ABCG1 expression.