Integration of Network Pharmacology and Untargeted Metabolomics Reveals Changpu San's Antidepressant Mechanisms via Tryptophan Metabolism.

Ethnopharmacological Relevance: Changpu San (CPS) is a traditional Chinese medicine (TCM) formula historically used to treat symptoms resembling depression. However, its antidepressant effects and underlying mechanisms remain unclear.

Aim Of The Study: This study aims to evaluate CPS's antidepressant effects and elucidate its mechanisms by combining network pharmacology with untargeted metabolomics.

Materials And Methods: A chronic unpredictable mild stress (CUMS) mouse model was used to assess CPS's antidepressant effects via behavioral tests and body weight monitoring. By integrating network pharmacology and untargeted metabolomics, both based on UPLC-Q-Exactive-Orbitrap-MS for CPS chemical profiling and serum metabolite analysis, a key pathway was identified. This pathway was validated through UPLC-QQQ-MS/MS and ELISA by measuring relevant biomarkers, while its association with colonic microbiota was further investigated using 16S rDNA sequencing.

Results: CPS alleviated depression-like behaviors in CUMS mice. A total of 140 compounds were identified in CPS, revealing 140 core targets related to depression. Metabolomics analysis identified 42 serum metabolites significantly altered in CUMS mice, with tryptophan metabolism emerging as a shared pathway across both approaches. Experimental validation showed CPS partially reversed tryptophan metabolism dysregulation, significantly increasing tryptophan levels and reducing kynurenine levels in the brain. Moreover, CPS modulated the colonic microbiota, with key genera such as Prevotella and Bacillus showing correlations with tryptophan metabolism and inflammation.

Conclusion: CPS shows promise as an effective antidepressant, potentially through modulating tryptophan metabolism and reshaping colonic microbiota. This study provides valuable insights into its mechanisms and offers a methodological reference for researching other TCM formulas.