Abstract: Abstract: Objective To explore the effect of dihydromyricetin (DMY) on the cholesterol efflux in macrophage derived foam cells and analyze the possible mechanisms. Methods RAW 264.7 macrophages were incubated by oxidized low density lipoprotein (ox-LDL, 50 mg/L) for 48 h to induce foam cells. Subsequently, the foam cells were subdivided into control group (RPMI1640 media) and DMY 1-4 groups (10, 20, 40 and 80 μmol/L) and cultured for 24 h. Cholesterol efflux from foam cells was examined by [ 3 H] labed cholesterol. The high performance liquid chromatography assay was used to test the cellular contents of free cholesterol (FC), cholesteryl ester (CE) and total cholesterol (TC). The expression of ATP-binding cassette transporter A1 (ABCA1) was measured by Western blot assay. Results Compared with control group, cholesterol efflux was significantly increased, the content of FC, TC CE and CE/TC ratio were significantly decreased and expression of ABCA1 was significantly up-regulated in dose dependent manner in DMY (20, 40 and 80 μmol/L) groups (P < 0.05). There were no significant differences in cholesterol efflux, the content of FC, TC and CE, and expression of ABCA1 between control group and DMY (10 μmol/L) group of foam cells (P > 0.05). Conclusion DMY promotes the cholesterol efflux in the macro⁃ phage derived foam cells, which may be related with the increase of ABCA1 induced by DMY.

Key words: atherosclerosis, foam cells, macrophages, cholesterol, disease models, animal, dihydromyricetin, cholesterol efflux, ABCA1