Total Panax notoginseng Saponins Repair the Epidermal Barrier by Regulating a Multi-Pathway Network: Insights from an Integrative RHE Model and Multi-Omics Study

The abnormal barrier function of the stratum corneum is a significant characteristic of surface-active agent-induced inflammatory skin diseases, and its cause is closely related to the abnormal lipid components of the stratum corneum. Total saponins of <i>Panax notoginseng</i> (TSPN) have significant potential in improving inflammatory skin barrier function. This study aims to investigate the barrier repair efficacy of TSPN using the EpiKutis^® skin model and to explore the potential mechanisms through multi-omics analysis based on transcriptomics, proteomics, and lipid metabolomics. We found that TSPN could ameliorate Sodium dodecyl sulfate (SDS)-induced barrier impairment in the EpiKutis^® model, alleviating stratum corneum thickening and upregulating the expression of barrier-related proteins, e.g., Filaggrin, Involucrin, and Loricrin. Through an integrated multi-omics network, we identified seven key target proteins and screened six lipid metabolites, which are involved in lipid metabolism and exert barrier-repairing effects through five pathways. The result indicated that TSPN might repair the epidermal barrier by regulating the phosphatidylinositol 3 kinase (PI3K)-protein kinase B (AKT)-mediated proliferation pathway, Mitogen-activated protein kinase (MAPK)-mediated apoptotic pathways, sphingolipid synthesis, Calcium/calmodulin-dependent protein kinase II beta (CAMK2B)-mediated actin cytoskeleton regulation, and Inositol-trisphosphate 3-kinase B (ITPKB)-mediated phosphatidylinositol signaling system. Further study is needed to explore the mechanism of the molecular link between lipid abnormalities and skin barrier function.