Tiaochang Xiaoliu Decoction Inhibits CXCR2-Mediated Neutrophil Recruitment and Reshapes Gut Microbiota Metabolic Microenvironment to Intervene in Intestinal Tumor Development

OBJECTIVE To investigate the therapeutic efficacy of Tiaochang Xiaoliu Decoction (TXD) in colorectal adenomas and to elucidate its underlying mechanisms.

METHODS The chemical constituents of TXD were characterized using liquid chromatography-mass spectrometry (LC-MS), and potential therapeutic targets were identified through network pharmacology analysis. The Apc^Min/+ mice were treated with low- or high-dose TXD, with regorafenib serving as a positive control. Tumor burden was quantified, and epithelial proliferation was assessed by histopathological staining. Neutrophil infiltration, including the CXCR2⁺ neutrophil subset, was evaluated by immunofluorescence and flow cytometry. Transcriptomic profiling (RNA-seq) was performed to determine gene expression changes induced by TXD. Intestinal barrier integrity, gut microbiota composition (16S rRNA sequencing), and fecal metabolomic profiles (untargeted metabolomics) were comprehensively analyzed.

RESULTS LC-MS analysis revealed the complex chemical composition of TXD under both positive and negative ion modes. Network pharmacology identified multiple active components targeting key molecules implicated in colorectal adenoma progression, including CXCR2, IL-6, TNF, and MMP9, as well as inflammation- and cancer-related signaling pathways. TXD treatment significantly reduced tumor burden and suppressed epithelial proliferation in Apc^Min/+ mice. Immunofluorescence analysis demonstrated a marked decrease in Ly6G⁺MPO⁺ neutrophil infiltration in colonic and tumor tissues (P < 0.001). Flow cytometry further showed that TXD significantly reduced the proportions of CD45⁺Ly6G⁺CD11b⁺ neutrophils and CXCR2⁺ neutrophil subsets (P < 0.001, P < 0.01), accompanied by decreased levels of CXCL1/2/5 and IL-6 (all P < 0.01). Transcriptomic analysis revealed that TXD downregulated genes associated with neutrophil chemotaxis and activation, including CXCR2, Ly6G, and MPO. In addition, TXD significantly restored intestinal epithelial barrier integrity and reshaped gut microbiota composition, along with lipid and bile acid metabolic profiles.

CONCLUSION TXD suppresses colorectal adenoma development in Apc^Min/+ mice by inhibiting CXCR2-mediated neutrophil recruitment and activation, while concurrently remodeling the gut microbiota-metabolite microenvironment.