[Huangqin Qingre Chubi Capsules alleviate rheumatoid arthritis by inhibiting entry of intestine-derived LPS into bloodstream and blocking M1 macrophage-FLS cell communication].

This study aimed to investigate the therapeutic effect of Huangqin Qingre Chubi Capsules(HQC) on rheumatoid arthritis(RA) and the mechanism of inhibiting RA macrophage polarization by reducing the entry of intestine-derived lipopolysaccharide(LPS) into the bloodstream. ELISA and 16S rRNA analysis were used to assess the inhibitory effect of HQC on LPS in the intestinal contents of mice in vivo. The effect of HQC on macrophage proliferation was detected by CCK-8 assay to determine the appropriate dose of drug-containing serum. RT-qPCR and immunofluorescence assay were used to detect the expression of genes related to macrophage polarization. Transcriptomics was used to predict the biomolecular function of macrophages upon LPS stimulation, and molecular docking was utilized to verify the binding of key HQC components to Wnt family member 7b(Wnt7b). Following co-culture of macrophages with fibroblast-like synoviocytes(FLS), RT-qPCR, Western blot, scratch assay, flow cytometry, and immunofluorescence assay were employed to investigate the regulatory mechanism of HQC on M1 macrophage-FLS communication via the Wnt/β-catenin signaling pathway. The results showed that LPS was highly expressed in the intestinal contents of collagen-induced arthritis(CIA) model mice, and HQC administration exhibited a negative correlation with this expression. M1 macrophages promoted the expression of inflammatory factors such as inducible nitric oxide synthase(iNOS), tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6), and also increased oxidative activity; these effects could be reversed by HQC. Transcriptomic analysis predicted that the Wnt/β-catenin signaling pathway was highly correlated with the effect of HQC on macrophage polarization in RA treatment. HQC-containing serum inhibited FLS migration, promoted apoptosis, and suppressed the expression of key genes in the Wnt signaling pathway, including c-Myc, CCND1, and β-catenin. Molecular docking indicated strong binding affinity between key components of HQC and Wnt7b. Overexpression of Wnt7b in macrophages, followed by co-culture with FLS, significantly interfered with the therapeutic effects of HQC. These findings demonstrated that HQC alleviates RA by inhibiting the entry of intestine-derived LPS into the bloodstream, thereby blocking M1 macrophages-FLS communication.