Patchouli alcohol restores gut homeostasis in irritable bowel syndrome with diarrhea through myosin Va-mediated neurotransmitter regulation.

BACKGROUND

Patchouli alcohol (PA), the active ingredient of Pogostemonis Herba, is important in medicine and food, effectively alleviating irritable bowel syndrome with diarrhea (IBS-D) symptoms; however, its mechanism remains unclear. Myosin Va, particularly in the intestinal longitudinal muscle myenteric plexus (LMMP), modulates neurotransmitter release, restoring gastrointestinal motility.

PURPOSE: To investigate the primary targets and potential mechanisms of PA in the treatment of IBS-D.

STUDY

DESIGN

PA treats IBS-D may involve the regulation of neurotransmitter release through the modulation of Myosin Va, and remodels neurons of colon LMMP, ultimately restores enteric nervous system (ENS) homeostasis.

METHODS

The GEO database, UK Biobank (UKB) public database and Mendelian randomization (MR) were utilized to identify differentially expressed genes and risk genes in IBS-D population. Network pharmacology and molecular docking were applied to screen for targets of PA in the treatment of IBS-D and predicted the binding affinity of drug targets. We established a chronic restraint stress-induced IBS-D rat model, after that PA (5 mg/kg and 20 mg/kg) was given to treat disease, and multi-omics methods such as bacterial 16S rRNA sequencing, whole transcriptome sequencing and snRNA-seq were used to observe the therapeutic effect of PA. Then measured the expression levels of LMMP neurotransmitter and Myosin Va via in vivo and in vitro experiments. Additionally, observe the effect of PA on Myosin Va-deficient DBA(Dilute, Brown and Non-Agouti) mice, and the regulation of Myosin Va expression by PA was verified by knockdown and overexpression gene function.

RESULTS

Bioinformatics analysis, Mendelian randomization and Network pharmacology suggested that neurotransmitter are PA targets in IBS-D treatment. Molecular docking predicted a strong binding affinity between PA and these targets. Multiomics indicated aberrant gastrointestinal motility, imbalanced excitatory and inhibitory neurons, and significantly reduced myosin Va expression under chronic restraint stress-induced IBS-D rat. PA treatment significantly improved these symptoms and restored intestinal microbiota homeostasis. Ex vivo experiments, DBA mice verification and gene function experiments suggested that PA treatment of IBS-D involves regulation of neurotransmitter release by modulating myosin Va and remodeling colon LMMP neurons, restoring enteric nervous system homeostasis.

CONCLUSION

Our results provide a theoretical basis for PA application in IBS-D treatment.