Exploring the mechanism of Panax Notoginseng in the treatment of skin wound based on network pharmacology and experimental verification

BackgroundWhen the skin wound defect is too large, it is difficult for the body to heal itself, and medical treatment is often needed. How to shorten the healing cycle and reduce the incidence of infection is a difficult problem faced by clinicians. Panax notoginseng(PN), a traditional Chinese medicine, can promote the absorption of inflammatory exudates, granulation tissue formation and epidermal proliferation, effectively inhibit the inflammatory reaction of wounds and promote the healing of skin wounds, but its molecular mechanism has not been fully clarified so far. Based on network pharmacology and animal experiments, this study explored the target and molecular mechanism of PN in the treatment of skin wound. MethodsThe active components and potential targets of PN were obtained from the Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP) and UniProt database, and the skin wound-related targets were obtained from the GeneCards database. The intersecting targets were filtered using Venny 2.1.0. The intersecting targets were imported into the STRING database to construct a protein-protein interaction (PPI) network. Cluster analysis was performed using the MCODE and CytoHubba plugins in Cytoscape 3.8.2 to obtain core functional network modules and the top 10 key target genes. The intersecting targets were subjected to KEGG and GO enrichment analysis using the DAVID 6.8 database (https://david.ncifcrf.gov/). The component-target-pathway network of PN in the treatment of skin wounds was constructed using Cytoscape 3.8.2 software. In the experimental verification phase, 48 Sprague-Dawley (SD) rats were randomly divided into a control group and a PN group, with 24 rats in each group. A full-thickness skin excision was performed to establish a wound model. The PN group received intraperitoneal injections of the drug, while the control group received an equivalent amount of saline. Wound area measurements were taken on days 1, 4, and 7 after model establishment. Histopathological changes in the injured area and the expression and localization of TNF-, IL-6, and IL-10 were observed through hematoxylin and eosin (HE) staining and immunohistochemical staining. Relative expression levels of the three factors were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). ResultsThis study identified 8 major active components, 156 targets, and 115 signaling pathways involved in the treatment of skin wounds in rats using PN. The top 10 core target genes included TNF, IL-6, and IL-10, primarily enriched in signaling pathways such as NF-{kappa}B, MAPK, and JAK-STAT. Animal experiments revealed that at 4 and 7 days post-injury, the wound area in the PN group was significantly smaller than that in the control group (P<0.05). HE staining showed reduced infiltration of neutrophils and inflammatory cells in the injury area at 7 days in the PN group, accompanied by more pronounced fibroblast proliferation and collagen secretion. Molecular detection indicated that TNF-, IL-6, and IL-10 positive reactants were mainly distributed in the cytoplasm and matrix of epidermal cells, inflammatory cells, and fibroblasts in the skin. qRT-PCR and ELISA results showed that TNF- expression in the PN group was significantly lower than that in the control group at 4 and 7 days (P<0.01). IL-6 expression was lower than that in the control group at all time points, peaking at 4 days and then decreasing (P<0.01). IL-10 expression was significantly lower than that in the control group at 1 and 7 days (P<0.01). ConclusionPN exhibits characteristics such as multi-component, multi-target, multi-pathway synergy, and multiple regulatory pathways in the treatment of skin wounds. It can reshape the dynamic balance of cytokine networks, including TNF-, IL-6, and IL-10, optimize the temporal progression of "inflammation initiation - repair transition - tissue remodeling", and provide a therapeutic effect of "efficient debridement - orderly repair - low scar risk" for skin wounds. It is one of the ideal natural drugs for regulating skin wound healing.