Anti-inflammatory Property of Chicken Feet, Acanthopanax, and Eucommia ulmoides Oliver Mixture Extract in LPS-stimulated RAW 264.7 Macrophage Cells

This study was to investigate the anti-inflammatory effect of chicken-feet, Acathopanax, and Eucommia ulmoides Oliver mixture (CAEM) extract against lipopolysaccharide (LPS) in RAW 264.7 macrophage cells. We examined cytotoxicity of CAEM extract on RAW 264.7 cells, and their anti-inflammatory properties by measuring nitric oxide (NO) and pro-inflammatory cytokine production. In addition, inflammation-related gene expression was analyzed by real time-PCR in LPS-stimulated RAW 264.7 macrophage cells. Treatment of CAEM extract at concentrations of 0.31-2.5 mg/ mL did not have any cytotoxic effect in RAW 264.7 cells. Treatment of LPS significantly increased the NO production, whereas CAEM extract (1.25, 2.5 mg/mL) significantly decreased the levels of NO, compared to only LPS-treated cells. Furthermore, treatment with CAEM extract significantly suppressed the LPS-induced interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) production. In order to confirm whether CAEM extract regulates inflammation-related gene expression, we analyzed the mRNA levels of IL-6, TNF-α, IL-1β, and inducible NO synthase (iNOS) by real time-PCR. Exposure of RAW 264.7 cells on LPS upregulated the mRNA levels of IL-6, TNF-α, IL-1β, and iNOS, compared to control group. However, those of expression were downregulated by treatment with CAEM extract. These findings suggest that CAEM extract may contribute to the prevention and treatment of inflammatory-related diseases.