Dachengqi decoction alleviates acute lung injury and inhibits inflammatory cytokines production through TLR4/NF‐κB signaling pathway in vivo and in vitro

Sepsis that arises from uncontrolled pulmonary inflammation could induce acute lung injury (ALI), leading to the high death rate. Dachengqi decoction (DCQD) is a common traditional Chinese herbal medicine with strong anti-inflammatory effects. The current study aimed to explore the effect of DCQD on the inflammatory cytokines production, the aquaporin-1 (AQP-1) and AQP-5 protein expression in lipopolysaccharide (LPS)-induced ALI models, and the potential mechanisms underlying its effects.Sprague-Dawley rats and HULEC-5a cells were used as study models in the research. To detect related molecules in the study, the real-time polymerase chain reaction analysis, cell counting kit-8 assay, Western blot analysis, and enzyme-linked immunosorbent assay were performed.DCQD could inhibit the expression of LPS-induced inflammatory cytokines, including interleukin-6 (IL-6), IL-8, and tumor necrosis factor-α (TNF-α), in lung tissues and could reduce pulmonary edema by upregulating the expression of AQP-1 and AQP-5 in rats with LPS-induced ALI. Moreover, the results suggested that the toll-like receptor 4 (TLR4)/NF-κB signaling is indispensable for DCQD to increase the expression of AQP-1 and AQP-5 and inhibits the production of IL-6, IL-8, and TNF-α in LPS-induced HULEC-5a cells.The results of our study suggested that DCQD suppresses the TLR4/NF-κB signaling pathway, increases the protein expression of AQP-1 and AQP-5, and inhibits the production of inflammatory cytokines, by which it may alleviate the inflammatory reactions in ALI and benefit the treatments.