Crotalaria ferruginea extract attenuates lipopolysaccharide-induced acute lung injury in mice by inhibiting MAPK/NF-κB signaling pathways

Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to study the antiinflammatory activity of CFE in vivo.The LPS-induced shock model was used to analyze the effect of CFE on survival.LPS-stimulated RAW264.7 cell model was used to investigate the anti-inflammatory activity of CFE in vitro and the effects on mitogen-activated protein kinase(MAPK)or nuclear factor-κB(NF-κB)signaling pathways.Results:CFE administration decreased the number of inflammatory cells,reduced the levels of tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interferon-γ,and diminished protein content in the bronchoalveolar lavage fluid of mice.CFE also reduced lung wet-to-dry weight ratio,myeloperoxidase,and lung tissue pathological injury.CFE preadministration improved the survival rate of mice challenged with a lethal dose of LPS.CFE reduced LPS-activated RAW264.7 cells to produce nitric oxide,TNF-α,MCP-1,and IL-6.Furthermore,CFE inhibited nuclear translocation and phosphorylation of NF-κB P65,extracellular signal-regulated kinase,c-Jun N-terminal kinases,and P38 MAPKs.Conclusions:CFE exhibits potent anti-inflammatory activity in LPS-induced ALI mice,LPS-shock mice,and RAW264.7 cells,and its mechanism may be associated with the inhibition of NF-κB and MAPK signaling pathways.Crotalaria ferruginea may be a useful therapeutic drug for the treatment of ALI and other respiratory inflammations.