The underlying rationality of Chinese medicine herb pair Coptis chinensis and Dolomiaea souliei: From the perspective of metabolomics and intestinal function

Scientific connotation of the compatibility of traditional Chinese medicine from the perspective of the intestinal flora

Revealing the connotation of the compatibility of Chinese medicines (CM) is a requirement for the modernization of traditional Chinese medicine (TCM). However, no consensus exists on the specific mechanism of traditional Chinese medicine compatibility (TCMC). Many studies have shown that the occurrence and development of diseases and the efficacy of CM are closely related to intestinal flora (IF), which may provide a new perspective to understand the theory of TCM. This study aimed to summarize the relationship between the changes in IF before and after the compatibility of different drugs and the synergistic, toxicity reduction, and incompatibility effects of drug pairs from the perspective of the effects of CM on the IF and the regulation of microbial metabolites. These studies showed that the effect of drug pairs on the composition of the IF is not a simple superposition of two single drugs, and that the drug pairs also play a specific role in regulating the production of intestinal bacterial metabolites; therefore, it has a different pharmacodynamic effect, which may provide a perspective to clarify the compatibility mechanism. However, research on the interpretation of the scientific connotations of TCMC from the perspective of the IF is still in its infancy and has limitations. Therefore, this study aimed to summarize previous research experience and proposed to conduct a deep and systematic study from the perspective of drug pair dismantling, IF, intestinal bacteria metabolite, organism, and disease to provide a reference for scientific research on the compatibility mechanism of CM.

Quercetin serves as the major component of Xiang-lian Pill to ameliorate ulcerative colitis via tipping the balance of STAT1/PPARγ and dictating the alternative activation of macrophage

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese herbal formula, Xiang-lian Pill (XLP), is commonly prescribed for ulcerative colitis (UC) patients to relieve their clinical symptom. Nonetheless, the underlying cellular and molecular mechanisms of XLP's anti-UC effect remain incompletely understood.

AIM OF THE STUDY

To evaluate the therapeutic effect and elucidate the possible working mechanisms of XLP in UC treatment. The major active component of XLP was also characterized.

MATERIALS AND METHODS

Colitis was induced in C57BL/6 mice with 3% dextran sulfate sodium (DSS) dissolved in drinking water for 7 consecutive days. The UC mice were grouped and treated with XLP (3640 mg/kg) or vehicle orally during the procedure of DSS induction. Mouse body weight, disease activity index (DAI) score and colon length were recorded. Histopathological changes and inflammatory cell infiltration were evaluated by pathological staining and flow cytometric analysis (FACS). Network pharmacology, bioinformatic analysis, widely targeted and targeted metabolomics analysis were performed to screen the potential effective ingredients and key targets. Bone marrow derived macrophages (BMDMs), peripheral blood mononuclear cells (PBMCs), RAW264.7 and THP-1 cells were used to dissect the anti-inflammatory effect of XLP.

RESULTS

Oral administration of XLP ameliorated DSS induced mouse colitis, as evidenced by reduced DAI and colonic inflammatory destruction. FACS results demonstrated that XLP treatment effectively restored immune tolerance in colon, inhibited the generation of monocyte derived macrophages and skewed macrophage polarization into M2 phenotype. Network pharmacology analysis suggested that innate effector modules related to macrophage activation comprise the major targets of XLP, and the counter-regulatory STAT1/PPARγ signaling possibly serves as the critical downstream pathway. Subsequent experiments unveiled an imbalance of STAT1/PPARγ signaling in monocytes derived from UC patients, and validated that XLP suppressed LPS/IFN-γ induced macrophage activation (STAT1 mediated) but facilitated IL-4 induced macrophage M2 polarization (PPARγ dependent). Meanwhile, our data showed that quercetin served as the major component of XLP to recapitulate the regulatory effect on macrophages.

CONCLUSION

Our findings revealed that quercetin serves as the major component of XLP that regulates macrophage alternative activation via tipping the balance of STAT1/PPARγ, which provides a mechanistic explanation for the therapeutic effect of XLP in UC treatment.