Kechuangping Mixture Inhibits LPS‑induced Macrophage Immune Response Through Suppressing the TLR4/MyD88/NF-κB Signal Pathway

Background: Kechuangping mixture (KCPM) based on Maxingshigan decoction has a significant clinical effect in the treatment of pediatric pneumonia, especially for asthmatic pneumonia. This study explored the effects of KCPM on lipopolysaccharide (LPS)-induced macrophage immune response and the molecular mechanism involved. Methods: : CCK-8 assays was used to detect the effect of KCPM on cell viability. The RAW 264.7 macrophages were divided into four groups: blank, LPS, KCPM, LPS+KCPM. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to examine the secretion of inflammatory factors and the expression of TLR4/MyD88/NF-κB signal pathways with or without KCPM stimulation. Results: : KCPM inhibited the differentiation of RAW264.7 macrophages induced by LPS. The secretion of pro-inflammatory cytokines IL-6 and TNF-α induced by LPS was decreased by pre-treatment with KCPM. While, treatment with KCPM advanced, the anti-inflammatory cytokines IL-10 and TGF-β increased significantly. Additionally, KCPM exhibited a potent inhibitory effect on the expression of iNOS and a promotive effect on the expression of Arg-1. Moreover, KCPM clearly suppressed the transcription level of TLR4, MyD88 and NF-κB signal pathways. Conclusion: KCPM promoted the macrophages polarization toward to M2 phenotype, as a result, limited the macrophage immune response. TLR4/MyD88/NF-κB signal pathways may play an important role in this process.