[Network pharmacological analysis and experimental study of Pulsatilla chinensis against inflammatory injury caused by pneumonia in mice infected with influenza virus FM_1].

Network pharmacology and the mouse model of viral pneumonia caused by influenza virus FM_1 were employed to explore the main active components and the mechanism of Pulsatilla chinensis against the inflammatory injury of influenza virus-induced pneumonia. The components and targets of P. chinensis were searched from TCMSP, and the targets associated with influenza virus-induced pneumonia were searched from GeneCards. The common targets between P. chinensis and influenza virus-induced pneumonia were identified with Venn diagram established in Venny 2.1. The herb-component-disease-target(H-C-D-T) network was constructed by Cytoscape 3.7.2. The above data were imported into STRING for PPI network analysis. Gene Ontology(GO) enrichment and KEGG pathway enrichment were performed with DAVID. BALB/cAnN mice were infected with the influenza virus FM_1 by nasal drip to gene-rate the mouse model of pneumonia. Immunohistochemistry was adopted to the expression profiling of inflammatory cytokines in the lung tissues of mice in the blank group, model group, and P. chinensis group 1, 3, 5, and 7 days after infection. The pathological changes of lung and trachea of mice in blank group, model group, and P. chinensis group were observed with light microscope and scanning electron microscope at all the time points. The network pharmacological analysis indicated that 9 compounds of P. chinensis were screened out, with a total of 57 targets, 22 of which were overlapped with those of influenza virus-induced pneumonia. A total of 112 GO terms(P<0.05) were enriched, including 81 terms of biological processes, 11 terms of cell components, and 20 terms of molecular functions. A total of 53 KEGG signaling pathways(P<0.05) were enriched, including TNF signaling pathway, influenza A signaling pathway, NF-κB signaling pathway, MAPK signaling pathway and other signaling pathways related to influenza/inflammation. In the P. chinensis group, the expression of TNF-α and IL-1 in the lung tissue was down-regulated on the 3 rd day after infection, and that of IL-6 in the lung tissue was down-regulated on the 5 th day after infection. Light microscopy and scanning electron microscopy showed that P. chinensis significantly alleviated the pathological damage of lung and trachea compared with the model group. This study reflects the multi-components, multi-targets, and multi-pathways of P. chinensis against influenza virus-induced pneumonia. P. chinensis may reduce the production of proinflammatory cytokines and mediators and block the pro-inflammatory signaling pathways to alleviate viral pneumonia, which provides reference for future research.