Hwangryunhaedoktang exerts anti-inflammation on LPS-induced NO production by suppressing MAPK and NF-κB activation in RAW264.7 macrophages

OBJECTIVE： This study aimed to evaluate whether Hwangryunhaedoktang （HHT）, a herbal compound, has an inhibitory effect on lipopolysaccharide （LPS）-induced inflammation in RAW264.7 macrophages. METHODS： The effects of HHT were evaluated by confirming nitric oxide （NO） production and expression of inducible NO synthase （iNOS） and mitogen-activated protein kinases （MAPKs） in LPS-stimulated RAW264.7 macrophages via the Griess assay, Western blotting, and real-time reverse transcription quantitative polymerase chain reaction. Western blot analyses and luciferase assays were used to evaluate whether HHT has an effect on the phosphorylation and translocation of nuclear factor-κB （NF-κB）. The secretion and expression of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） were determined via enzyme-linked immunosorbent assay and Western blot analyses. RESULTS： HHT suppressed LPS-induced NO production and expression of iNOS in a dose-dependent manner. Additionally, MAPKs activation was also attenuated via inhibition of phosphorylation of extracellular signal-regulated kinases 1/2, c-Jun N-terminal kinase and p38 which were related to inflammatory pathway. Furthermore, HHT also effectively attenuated NF-κB activation and its translocation to the nucleus, a process that is closely linked to inflammation. LPS normally induced the expression of inflammatory cytokines such as TNF-α and IL-6, but the secretion and expression of TNF-α and IL-6 were significantly attenuated by pretreating the cells with HHT. CONCLUSION： HHT suppressed LPS-induced NO production by blocking the activation of NF-κB and MAPK signaling pathways in RAW264.7 macrophages. Furthermore, HHT may have an anti-inflammatory effect by suppressing the LPS-induced secretion of TNF-α and IL-6. Therefore, the traditional herbal formula HHT might be a useful potential therapeutic agent for inflammation.