Linderae Radix extract attenuates ulcerative colitis by inhibiting the JAK/STAT signaling pathway.

BACKGROUND: Linderae Radix (LR), the dried root of Lindera aggregata (Sims) Kosterm., is a traditional Chinese herbal medicine that has been used for thousands of years for promoting Qi circulation, soothing the liver, and treating diarrhea and dysentery. Previous studies have found that ethanol extract of LR plays an anti-ulcerative colitis (UC) role by regulating Th17/ Treg balance. Water extract is the classic clinical application form of LR, but the effect of water extract of LR (LRWE) on UC and its underlying mechanism is still unclear. PURPOSE: Purpose: UC is a gastrointestinal disease characterized by intestinal inflammation, mucosal injury, and fibrosis, and it is one of the high-risk factors for colon cancer. However, there is still a lack of remedies with satisfactory effects. This study aimed to investigate the efficacy and the potential mechanism of LRWE against UC. METHODS: LRWE samples were prepared using a reflux extraction method. Colitis in mice was induced by administering 2.5 % DSS water solution to evaluate the therapeutic effect of LRWE by assessing disease activity score, colon length, and fecal morphology. H&E staining, TEM, Masson staining, and AB-PAS staining were applied to observe histopathological changes in the colon tissues. Differentially expressed genes in colon tissues were analyzed by transcriptomics. Cell apoptosis was detected by TUNEL staining. The expression of inflammatory factors such as IL-6 and IL-1ß, as well as the expression of p-STAT1, p-JAK2, p-STAT3, Bax, and Bcl-2, were detected by immunofluorescence and immunohistochemistry. The expression of occludin, Bcl-2, Bax, and JAK/STAT signaling pathway-related vital proteins were quantified by Western blot (WB). RESULTS: LRWE alleviated body weight loss, colon shortening, DAI scores, pathological changes, and ultrastructural features of colon tissue in mice with colitis. It also inhibited the increase of pro-inflammatory cytokines (such as TNF-α, IL-6, and IL-1ß) and increased IL-10 levels. Additionally, it protected the intestinal barrier by upregulating the expression of Occludin and Mucin-2. Mechanistically, LRWE could inhibit the activation of JAK-STAT signaling pathway by reducing the protein expression of p-JAK2, p-STAT3, p-STAT1, Bcl2, and Bax, thus reducing the inflammatory responses and inhibiting cell apoptosis. CONCLUSION: LRWE has a protective effect on DSS-induced UC. This effect is related to the inhibition of the JAK-STAT signaling pathway, the improvement of intestinal inflammation, and the reduction of intestinal epithelial cell apoptosis.

DIREN mitigates DSS-induced colitis in mice and attenuates collagen deposition via inhibiting the Wnt/ß-catenin and focal adhesion pathways.

BACKGROUND: DIREN is a SHE ethnic medicine with stasis-resolving, hemostasis, clearing heat, and removing toxin effects. It is clinically used in the treatment of gastrointestinal bleeding, such as ulcerative colitis (UC). AIM OF THE STUDY: Fibrosis is one of the pathological changes in the progression of UC, which can make it challenging to respond to a treatment. We aimed to illuminate the role of DIREN in DSS-induced UC and tried to unveil its related mechanisms from two perspectives: intestinal inflammation and collagen deposition. MATERIALS AND METHODS: A 2.5 % dextran sulfate sodium (DSS) water solution was used to induce colitis in mice. The therapeutic effect of DIREN was assessed using the disease activity index, histopathological score, and colon length. Masson and Sirius Red staining was used to observe the fibrosis in the colon. Apoptosis of colonic epithelial cells was observed by TUNEL immunofluorescence staining. RNA-seq observed differential genes and enrichment pathways. Immunohistochemistry and RT-qPCR were used to detect the expression of molecules related to fibrosis and focal adhesion signaling in colon tissue. RESULTS: The administration of DIREN resulted in a reduction of disease activity index (DAI) in mice with UC while simultaneously promoting an increase in colon length. DIREN mitigated the loss of goblet cells in the colon of UC mice and maintained the integrity of the intestinal mucosa barrier. Masson staining revealed a reduction in colonic fibrosis with DIREN treatment, while Sirius red staining demonstrated a decrease in collagen Ⅰ deposition. DIREN reduced apoptosis of colonic epithelial cells and the expression of genes, such as CDH2, ITGA1, and TGF-ß2. Additionally, the results of GSEA analysis of colon tissue transcriptome showed that the differentially expressed genes were enriched in the focal adhesion pathway. DIREN was found to downregulate the protein expression of BAX, N-cadherin, ß-catenin, Integrin A1, and Vinculin while upregulating the protein expression of BCL2. Additionally, it led to the co-expression of N-cadherin and α-SMA. CONCLUSION: DIREN exerts a protective effect against DSS-induced UC by ameliorating colonic fibrosis via regulation of focal adhesion and the WNT/ß-catenin signaling pathway, thereby inhibiting fibroblast migration and reducing collagen secretion.