Colorectal tumorigenesis generally progresses from adenoma to adenocarcinoma, accompanied by dynamic changes in the tumor microenvironment (TME). A randomized controlled trial has confirmed the efficacy and safety of Shen-Bai-Jie-Du decoction (SBJDD) in preventing colorectal tumorigenesis. However, the mechanism remains unclear. In this study, we employed single-cell RNA sequencing (scRNA-seq) to investigate the dynamic evolution of the TME and validated cell infiltration with multiplex immunohistochemistry and flow cytometry. Bulk RNA sequencing was utilized to assess the underlying mechanisms. Our results constructed the mutually verifiable single-cell transcriptomic atlases in Apc ^Min/+ mice and clinical patients. There was a marked accumulation of CCL22⁺ dendritic cells (DCs) and an enhanced immunosuppressive action, which SBJDD and berberine reversed. Combined treatment with cholesterol and lipopolysaccharide induced characteristic gene expression of CCL22⁺ DCs, which may represent "exhausted DCs". Intraperitoneal injection of these DCs after SBJDD treatment eliminated its therapeutic effects. TMEM131 derived CCL22⁺ DCs generation by TNF signaling pathway and may be a potential target of berberine in retarding colorectal tumorigenesis. These findings emphasize the role of exhausted DCs and the regulatory mechanisms of SBJDD and berberine in colorectal cancer (CRC), suggesting that the multi-component properties of SBJDD may help restore TME homeostasis and offer novel cancer therapy.

Objective To explore the effects and mechanism of Baitouweng Decoction in intestinal mucosal healing in mice with ulcerative colitis(UC)based on RIPK1/RIPK3/MLKL signaling pathway.Methods Totally 30 C57BL/6 male mice were randomly divided into control group,model group,Baitouweng Decoction group,infliximab group and combination group(Baitouweng Decoction+infliximab),with 6 mice in each group.A mouse model of UC was established by free administration of 3.5%sodium gluconate sulfate solution for 7 days.After modeling,Baitouweng Decoction group was given 8 g/kg Baitouweng Decoction solution by gavage daily,while the infliximab group was given 5 mg/kg infliximab intraperitoneal injection,the combination group was given synchronous gastric and intraperitoneal injection,while the control group and model group were given equal volume of normal saline by gavage for 7 consecutive days.The body mass of mice was recorded daily,fecal characteristics were observed,and disease activity index(DAI)score was performed,colon length was measured after intervention,ELISA was used to detect the contents of serum interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α),RT-qPCR was used to detect mRNA expressions of RIPK1,RIPK3 and MLKL in colon tissue,Western blot and immunofluorescence staining were used to detect the expressions of RIPK1,RIPK3 and MLKL protein in colon tissue.Results Compared with the control group,the model group mice showed a decrease in body mass(P<0.01),an increase in DAI score(P<0.01),a shortened colon length(P<0.01),and an increase in serum IL-6 and TNF-α content(P<0.01);colonic mucosal was destructed,with disappearance of crypts and glandular structures,extensive infiltration of inflammatory cells,and increased pathological score of colon tissue(P<0.01);the mRNA and protein expressions of RIPK1,RIPK3 and MLKL in colon tissue increased(P<0.01,P<0.05).Compared with the model group,the body mass of mice in each treatment group increased(P<0.01),and the DAI score decreased(P<0.01),colon length increased(P<0.01),and the contents of serum IL-6 and TNF-α decreased(P<0.05,P<0.01);the destruction of the colonic mucosal barrier was reduced,the pathological score of colon tissue was reduced(P<0.05);the expressions of RIPK1,RIPK3 and MLKL mRNA and protein in colon tissue decreased(P<0.05,P<0.01).Conclusion Baitouweng Decoction can alleviate intestinal mucosal damage and inflammation in UC mice,and its mechanism may be related to the inhibition of the RIPK1/RIPK3/MLKL signaling pathway.