Exploration of the Active Components and Mechanism of Jiegeng (Platycodonis Radix) in the Treatment of Influenza Virus Pneumonia Through Network Pharmacology Analysis and Experimental Verification

This study aimed to explore the pathogenesis of platycodin D and luteolin, which are both active components in Jiegeng (Platycodonis Radix), in the treatment of influenza virus pneumonia through network pharmacology analysis combined with experimental verification. The bioactive components of Jiegeng (Platycodonis Radix) were screened by TCMSP and literature mining, and the results were standardized via the UniProt database. The action targets for the disease were identified from databases including OMIM, GeneCards, TTD, DisGeNET, and PharmGKB. Then, the visualized key target regulatory network and protein-protein interaction (PPI) network for the active components were established using Cytoscape3.7.1 software. The findings were illustrated through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The intervention concentrations of platycodin D and luteolin were screened by the CCK8 method, and the important signaling pathways of platycodin D and luteolin for treating influenza virus pneumonia were verified by RT-qPCR and Western blot tests. From data mining, 89 common drug-disease targets were screened out, and five major active components of Jiegeng (Platycodonis Radix), including platycodin D and luteolin, were obtained. Besides, 11 therapeutic targets including IL-17, IL-6, TNF-α, JUN, and MAKP1 were identified by PPI network analysis. GO and KEGG enrichment analyses showed that the pathways most related to the mechanisms of Jiegeng (Platycodonis Radix) against influenza virus pneumonia included the TNF and IL-17 signaling pathways and apoptosis. In vitro experiments demonstrated that the model group exhibited a notable elevation in mRNA levels of IL-6, IL-17, TNF-α, JUN, MAPK1, and the IL-17/-acting protein ratio, as compared to the control group (p < 0.05). In contrast to the model group, the IL-6, IL-17, TNF-α, JUN, MAPK1 mRNA expression levels, and the IL-17 protein ratio in both the platycodin D group and luteolin group were considerably decreased (p < 0.05). Combined with network pharmacology and experimental verification, this study revealed that platycodin D and luteolin in Jiegeng (Platycodonis Radix) may treat influenza virus pneumonia by regulating inflammation through the IL-17 signaling pathway.