Patchouli alcohol modulates PXR-Wnt signaling in Helicobacter pylori-associated gastric cancer models

BackgroundHelicobacter pylori (HP) infection is a principal risk factor for gastric cancer, driving tumorigenesis through chronic inflammation, disruption of the epithelial barrier, and genomic instability. Patchouli alcohol (PA), the major bioactive constituent of Pogostemon cablin, exhibits anti-inflammatory, antioxidant, and antitumor properties; however, its role and underlying mechanisms in HP-associated gastric cancer remain poorly understood.PurposeWe hypothesized that HP infection suppresses the activity of the pregnane X receptor (PXR), thereby relieving its inhibitory effect on Wnt/β-catenin signaling and epithelial–mesenchymal transition (EMT), promoting gastric cancer invasiveness. PA was proposed as a PXR agonist capable of counteracting HP-induced malignant phenotypes via modulation of the PXR–Wnt/EMT axis.MethodsA multi-level integrative approach was employed: (1) single-cell transcriptomic analysis to characterize expression and regulatory features of the PXR–Wnt–EMT axis in HP-positive versus HP-negative gastric cancer epithelial cells; (2) virtual knockout and TCGA-STAD cohort analyses to assess the causal relationship between PXR and Wnt/EMT signaling; (3) molecular docking and 100 ns molecular dynamics simulations to evaluate PA binding to the PXR ligand-binding domain (LBD) and complex stability; (4) metabolomic and proteomic analyses in HP-associated gastric cancer models to validate PA-mediated modulation of metabolic networks and Wnt/EMT signaling.ResultsSingle-cell analysis revealed that HP-positive epithelial cells exhibited reduced PXR activity alongside upregulation of Wnt/β-catenin signaling and EMT transcription factors. Virtual PXR knockout recapitulated Wnt/EMT transcriptional activation, and TCGA-STAD analysis confirmed a significant negative correlation between PXR activity and Wnt/EMT signaling. Molecular docking and MD simulations demonstrated stable binding of PA to the PXR LBD. Metabolomic profiling revealed disrupted bile acid and lipid metabolism in HP model mice, partially restored by PA treatment. Proteomic and immunofluorescence analyses showed that PA downregulated Wnt pathway proteins (Dvl3, Tcf7l2) and mesenchymal EMT markers (N-cadherin, MMP9) while upregulating the Wnt inhibitor APC and epithelial marker E-cadherin, collectively reversing HP-induced Wnt/EMT hyperactivation.ConclusionPA activates PXR through both direct and indirect mechanisms, thereby suppressing Wnt/β-catenin signaling and EMT, and ultimately inhibiting the initiation and progression of H. pylori–associated gastric cancer. This study elucidates the molecular link between HP-induced PXR downregulation and aberrant Wnt/EMT activation, highlighting PA as a potential therapeutic and preventive candidate for HP-related gastric cancer.