Cimifugin improves intestinal barrier dysfunction by upregulating SIRT1 to regulate the NRF2/HO-1 signaling pathway.

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal dysfunction. Cimifugin is an active component of Radix saposhnikoviae which is effective for maintaining intestinal barrier integrity and intestinal function. This study aimed to investigate the treatment efficacy of Cimifugin on intestinal barrier dysfunction and to unveil the relevant mechanism through network pharmacology and experimental verification as well as molecular docking. Through SuperPred and Pubchem databases, the targets of Cimifugin were obtained. The disease targets were screened using Disgenet and GEO databases. With STRING database and Cytoscape software, the analysis of PPI network was performed. In DAVID database, the hub genes of Cimifugin were analyzed using GO and Pathway enrichment analyses. To validate the binding of Cimifugin with core targets, molecular docking was performed. The in vitro cellular model of intestinal barrier was established via the induction of Caco2 cells with LPS. TEER was used to detect epithelial barrier function and permeability was measured using FITC-dextran (FD4). Western blotting was used to measure the expressions of SIRT1, tight junction proteins, and NRF2/HO-1 signaling pathway-related proteins. The fluorescence intensity of ZO-1, Occludin, and Claudin-1 was detected using immunofluorescence staining. ELISA was used to detect the expression levels of inflammatory cytokines. Through the integration of all targets of IBS and Cimifugin, 94 frequent drug-disease-related targets were identified. These targets were enriched in some signaling pathways, like cellular responses to stress, cellular responses to stimuli, and VEGFA-VEGFR2. Ten hub genes including PTGS2, ANPRP, TGFB1, ACACA, SIRT1, NEF2L2, APEX1, IL6, AKT1, and HSP90AB1 were obtained. Cimifugin showed strong affinity with four key genes, including AKT1, SIRT1, IL6, and NFE2L2 (NRF2), which were obtained through the intersection of hug genes with cellular responses to stimuli. In vitro experiments showed that Cimifugin ameliorated LPS-induced intestinal barrier injury in Caco2 cells via upregulating SIRT1 to modulate NRF2/HO-1 signaling pathway. Cimifugin could alleviate intestinal barrier dysfunction in IBS by upregulating SIRT1 to regulate the NRF2/HO-1 signaling pathway.