Abstract: Objective To test the effect of berberine (BBR) on polarization of RAW264.7 mouse macrophages. Methods RAW264.7 cells were divided into control group, high lipid- and inflammatory-model group (stimulated with 100μg/L lipopolysaccharide and aggregated LDL), BBR 5 μmol/L group, BBR 10 μmol/L group and BBR 20 μmol/L group. ELISA and flow cytometry were used to assess specific cell markers (TNF-α, MCP-1, CD86, IL-4, IL-13, TGF-β1 and CD206) to define M1 and M2 polarization. Protein expression of apolipoprotein E (apoE) and very-low-density lipoprotein receptor (VLDL-R) or mRNA expression of apoE receptor-2 (apoER2) were detected by Western blot and RT-qPCR,respetively. Results BBR decreased M1 macrophage-specific cell markers TNF-α and MCP-1 levels (P<0.05)and downregulated the expressions of CD86. In contrast, M2 macrophage-specific cell markers IL-4, TGF-β1 and CD206were upregulated by BBR. BBR could promote the protein expression of apoE and the mRNA expression of VLDL (P<0.001). Conclusions BBR treatment may shift RAW264.7 mouse macrophage to antiinflammatory M2 phenotype by promoting the binding of apoE to VLDLR.

Key words: Key words Berberine, macrophage phenotype, inflammation, apolipoprotein