Objective To investigate the molecular mechanism of Shema Zhichuan Liquid in the treatment of neutrophilic asthma(NA)based on network pharmacology and in vivo experiments.Methods(1)The TCMSP,literature search and Swiss ADME and Swiss Target Prediction databases were used to search and screen the active components and their targets of Shema Zhichuan Liquid.OMIM,GeneCards,DisGeNET and DrugBank databases were used to search and screen NA disease-related targets.The intersection of the active components and NA disease-related targets of Shema Zhichuan Liquid was obtained through the microbiology platform to obtain the potential targets of Shema Zhichuan Liquid for the treatment of NA(common targets).Cytoscape 3.8 software was used to construct the network of"Chinese medicinals-active components-potential targets".The PPI network of potential targets was established by STRING database,and the core targets were obtained by analysing the built-in Mcode plug-in.The Metascape platform was used to enrich the gene ontology(GO),Kyoto Encyclopaedia of Genes and Genomes(KEGG)pathways for the potential targets.(2)BALB/C mice were acclimatised and fed for 1 week and randomly divided into a blank group,NA model group,low-dose group(2.5 g·kg-1)and high-dose group of Shema Zhichuan Liquid(10 g·kg-1),and control group of Dexamethasone(1 mg·kg-1);the NA mouse model was replicated by intraperitoneal injection of sensitizer(OVA+CFA)and nebulized inhalation excitation.OVA/CFA(20 μg OVA+75 μg CFA,0.3 mL)was injected intraperitoneally to sensitize on days 0,7 and 14 respectively,and 5%OVA suspension was nebulized on days 21-30(8 mL each time,40 minutes each time,once a day);1 hour before nebulisation,each group was administered by gastric gavage,and the Dexamethasone control group was administered by intraperitoneal injection once a day.The pathological changes of mouse lung tissue were observed by HE staining;IL-8 content in alveolar lavage fluid was detected by ELISA;mRNA expression levels of NLRP3 and CXCR2 were detected by RT-qPCR;and p-mTOR protein expression levels was detected by immunohistochemistry.Results(1)A total of 826 active component targets and 154 NA disease-related targets were obtained,and 51 potential targets(common targets)for the treatment of NA were obtained from the intersection of the active component and the NA disease-related targets of Shema Zhichuan Liquid.Through the network analysis of"Chinese medicinals-active components-potential targets",quercetin,lignocerotoxin,kaempferol,stigmasterol,naringenin and other key active components were obtained.The PPI network analysis of potential targets yielded 29 core targets,including AKT1,IL6,TNF,EGFR,NLRP3,RELA,MIF,CXCR2,VEGFA,etc..The GO functional enrichment analysis yielded 882 biological process entries,33 cellular component entries,and 61 molecular function entries;KEGG analysis yielded 142 signaling pathways,mainly involving TNF signaling pathway,influenza A signaling pathway,Toll-like receptor pathway,MAPK signaling pathway,mTOR signaling pathway and so on.(2)Results of animal experiments:compared with the blank group,mice in the NA model group showed obvious damage to the airway mucosa,structural disorders,a large number of inflammatory cells infiltration,mucosal congestion,oedema,obvious thickening of the alveolar wall,and narrowing of the alveolar lumen;the level of the inflammatory factor IL-8 in the alveolar lavage fluid was significantly elevated(P＜0.05);the mRNA expressions of NLRP3 and CXCR2 in the lung tissues of the mice were significantly up-regulated(P＜0.01),and the protein expression of p-mTOR was significantly increased.Compared with the NA model group,the structural arrangement of bronchial epithelial cells in the mice in the low-and high-dose groups of Shema Zhichuan Liquid was slightly disordered,with a small amount of inflammatory cell infiltration around the airways and blood vessels,and the congestion and edema of the bronchial mucosa were significantly reduced;the mRNA expression of CXCR2 in the lung tissues of the mice was significantly down-regulated(P＜0.01),and the level of expression of p-mTOR protein was significantly reduced.The IL-8 level in the vesicular lavage fluid of mice in the high-dose group was significantly reduced(P＜0.05);the mRNA expression of NLRP3 in the lung tissue of mice in the low-dose group was significantly down-regulated(P＜0.05).Conclusion The therapeutic effect of Shema Zhichuan Liquid on NA may be achieved through the key active components,such as quercetin,lignocerol and kaempferol,acting on the core targets,such as NLRP3 and CXCR2,and regulating the key signaling pathways,such as the TNF signaling pathway,the MAPK signaling pathway,the Toll-like signaling pathway,and the mTOR pathway.