Tetrandrine attenuates intestinal epithelial barrier defects caused by colitis through promoting the expression of Occludin via the AhR-miR-429 pathway

Estrogen receptor β activation alleviates inflammatory bowel disease by suppressing NLRP3-dependent IL-1β production in macrophages via downregulation of intracellular calcium level

INTRODUCTION

Although several estrogen receptor β (ERβ) agonists have been reported to alleviate IBD, the pivotal mechanism remains obscure.

OBJECTIVES

To examine the effects and mechanisms of ERβ activation on cytokine/chemokine networks in colitis mice.

METHODS

Dextran sulfate sodium salt (DSS) and trinitro-benzene-sulfonic acid (TNBS) were used to induce mouse colitis model. Multiple molecular biological methods were employed to evaluate the severity of mouse colitis and the level of cytokine and/or chemokine.

RESULTS

Bioinformatics analysis, ELISA and immunofluorescence results showed that the targeted cytokines and/or chemokines associated with ERβ expression and activation is IL-1β, and the anti-colitis effect of ERβ activation was significantly attenuated by the overexpression of AAV9-IL-1β. Immunofluorescence analysis indicated that ERβ activation led to most evident downregulation of IL-1β expression in colonic macrophages as compared to monocytes and neutrophils. Given the pivotal roles of NLRP3, NLRC4, and AIM2 inflammasome activation in the production of IL-1β, we examined the influence of ERβ activation on inflammasome activity. ELISA and WB results showed that ERβ activation selectively blocked the NLRP3 inflammasome assembly-mediated IL-1β secretion. The calcium-sensing receptor (CaSR) and calcium signaling play crucial roles in the assembly of the NLRP3 inflammasome. WB and immunofluorescence results showed that ERβ activation reduced intracellular CaSR expression and calcium signaling in colonic macrophages. Combination with CaSR overexpression plasmid reversed the suppressive effect of ERβ activation on NLRP3 inflammasome assembly, and counteracting the downregulation of IL-1β secretion.

CONCLUSION

Our research uncovers that the anti-colitis effect of ERβ activation is accomplished through the reduction of IL-1β levels in colonic tissue, achieved by specifically decreasing CaSR expression in macrophages to lower intracellular calcium levels and inhibit NLRP3 inflammasome assembly-mediated IL-1β production.

Therapeutic effects of tetrandrine in inflammatory diseases: a comprehensive review

Inflammation can be triggered by any factor. The primary pathological manifestations can be summarized as the deterioration, exudation, and proliferation of local tissues, which can cause systemic damage in severe cases. Inflammatory lesions are primarily localized but may interact with body systems to cause provocative storms, parenchymal organ lesions, vascular and central nervous system necrosis, and other pathologic responses. Tetrandrine (TET) is a bisbenzylquinoline alkaloid extracted from the traditional Chinese herbal medicine Stephania tetrandra, which has been shown to have significant efficacy in inflammatory conditions such as rheumatoid arthritis, hepatitis, nephritis, etc., through NF-κB, MAPK, ERK, and STAT3 signaling pathways. TET can regulate the body's imbalanced metabolic pathways, reverse the inflammatory process, reduce other pathological damage caused by inflammation, and prevent the vicious cycle. More importantly, TET does not disrupt body's normal immune function while clearing the body's inflammatory state. Therefore, it is necessary to pay attention to its dosage and duration during treatment to avoid unexpected side effects caused by a long half-life. In summary, TET has a promising future in treating inflammatory diseases. The author reviews current therapeutic studies of TET in inflammatory conditions to provide some ideas for subsequent anti-inflammatory studies of TET.

Recent advances in anti-inflammatory active components and action mechanisms of natural medicines

Inflammation is a series of reactions caused by the body's resistance to external biological stimuli. Inflammation affects the occurrence and development of many diseases. Anti-inflammatory drugs have been used widely to treat inflammatory diseases, but long-term use can cause toxic side-effects and affect human functions. As immunomodulators with long-term conditioning effects and no drug residues, natural products are being investigated increasingly for the treatment of inflammatory diseases. In this review, we focus on the inflammatory process and cellular mechanisms in the development of diseases such as inflammatory bowel disease, atherosclerosis, and coronavirus disease-2019. Also, we focus on three signaling pathways (Nuclear factor-kappa B, p38 mitogen-activated protein kinase, Janus kinase/signal transducer and activator of transcription-3) to explain the anti-inflammatory effect of natural products. In addition, we also classified common natural products based on secondary metabolites and explained the association between current bidirectional prediction progress of natural product targets and inflammatory diseases.

Research progress on pharmacological effects and mechanisms of cepharanthine and its derivatives

Cepharanthine (CEP) is a bisbenzylisoquinoline alkaloid compound found in plants of the Stephania genus, which has biological functions such as regulating autophagy, inhibiting inflammation, oxidative stress, and apoptosis. It is often used for the treatment of inflammatory diseases, viral infections, cancer, and immune disorders and has great clinical translational value. However, there is no detailed research on its specific mechanism and dosage and administration methods, especially clinical research is limited. In recent years, CEP has shown significant effects in the prevention and treatment of COVID-19, suggesting its potential medicinal value waiting to be discovered. In this article, we comprehensively introduce the molecular structure of CEP and its derivatives, describe in detail the pharmacological mechanisms of CEP in various diseases, and discuss how to chemically modify and design CEP to improve its bioavailability. In summary, this work will provide a reference for further research and clinical application of CEP.

Mume Fructus (Prunus mume Sieb. et Zucc.) extract accelerates colonic mucosal healing of mice with colitis induced by dextran sulfate sodium through potentiation of cPLA2-mediated lysophosphatidylcholine synthesis

BACKGROUND

Mume Fructus (MF) is the fruit of Prunus mume Sieb. et Zucc, a plant of Rosaceae family. Previous studies demonstrated that MF was capable of ameliorating ulcerative colitis (UC) in mice, its action mechanism needs to be clarified.

PURPOSE

This study deciphered whether and how MF extract accelerates colonic mucosal healing, the therapeutic endpoint of UC.

METHODS

Biochemical, histopathological and qRT-PCR analyses were utilized to define the therapeutic efficacy of MF on dextran sulfate sodium (DSS)-induced colitis in mice. UHPLC-QTOF-MS/MS-based metabolomics technique was adopted to explore the changes of endogenous metabolites associated with UC and responses to MF intervention. qRT-PCR analysis was performed to confirm the molecular pathway in vivo. The effects of MF and lysophosphatidylcholine (LPC) on cell viability, wound healing, proliferation, and migration were examined through a series of in vitro experiments. Moreover, the effects of different subtypes of phospholipase A2 (PLA2) inhibitors on MF-treated colonic epithelial cells were detected by wound healing test and transwell assay.

RESULTS

Orally administered MF could alleviate colitis in mice mainly by accelerating the healing of colonic mucosa. Guided by an unbiased metabolomics screen, we identified LPC synthesis as a major modifying pathway in colitis mice after MF treatment. Notably, MF facilitated the synthesis of LPC by enhancing the expression of PLA2 in colitis mice. Mechanistically, MF and LPC accelerated wound closure by promoting cell migration. Moreover, the promotion of MF on wound healing and migration of colonic epithelial cells was blunted by a cytosolic phospholipase A2 (cPLA2) inhibitor.

CONCLUSION

MF can facilitate colonic mucosal healing of mice with colitis through cPLA2-mediated intestinal LPC synthesis, which may become a novel therapeutic agent of UC.

Ramelteon improves blood-brain barrier of focal cerebral ischemia rats to prevent post-stroke depression via upregulating occludin

Post-stroke depression (PSD) negatively affects the prognosis of post-stroke animals. Ramelteon has neuroprotection for chronic ischemia animals, but the effect and the biological mechanism of it on PSD is still unclear. This study explored the effects of ramelteon with prophylactic administration on blood-brain barrier in rats with middle cerebral artery occlusion (MCAO) and the oxygen-glucose deprivation/reperfusion (OGD/R) bEnd.3 cells and found that ramelteon pretreatment improved the depressive-like behaviors and decreased infarct area in MCAO rats. Also, this study found ramelteon pretreatment improved viability and inhibited permeability in OGD/R cells. In addition, this study found that MCP-1, TNF-α, and IL-1 levels were raised in the MCAO rats and that occludin protein and mRNA levels were decreased in the MCAO and the OGD/R models, while the Egr-1 level was up-regulated. All of these were antagonized by ramelteon pretreatment. In addition, overexpression of Egr-1 could reverse the effect of 100nM ramelteon pretreatment on FITC and occludin levels in OGD/R cells. In short, this study has demonstrated that the protective effect on PSD of ramelteon pretreatment on MCAO rats is related to the development of BBB permeability and that ramelteon regulates occludin to protect the BBB by inhibiting Egr-1.

Autophagy Reduces the Degradation and Promotes Membrane Localization of Occludin to Enhance the Intestinal Epithelial Tight Junction Barrier against Paracellular Macromolecule Flux

BACKGROUND AND AIMS

Functional loss of the gut epithelium's paracellular tight junction [TJ] barrier and defective autophagy are factors potentiating inflammatory bowel disease [IBD]. Previously, we showed the role of autophagy in enhancing the intestinal TJ barrier via pore-forming claudin-2 degradation. How autophagy regulates the TJ barrier-forming proteins remains unknown. Here, we investigated the role of autophagy in the regulation of occludin, a principal TJ component involved in TJ barrier enhancement.

RESULTS

Autophagy induction using pharmacological activators and nutrient starvation increased total occludin levels in intestinal epithelial cells, mouse colonocytes and human colonoids. Autophagy induction enriched membrane occludin levels and reduced paracellular permeability of macromolecules. Autophagy-mediated TJ barrier enhancement was contingent on the presence of occludin as OCLN-/- nullified its TJ barrier-enhancing effect against macromolecular flux. Autophagy inhibited the constitutive degradation of occludin by preventing its caveolar endocytosis from the membrane and protected against inflammation-induced TJ barrier loss. Autophagy enhanced the phosphorylation of ERK-1/2 and inhibition of these kinases in Caco-2 cells and human colonic mucosa prevented the macromolecular barrier-enhancing effects of autophagy. In vivo, autophagy induction by rapamycin enhanced occludin levels in wild-type mouse intestines and protected against lipopolysaccharide- and tumour necrosis factor-α-induced TJ barrier loss. Disruption of autophagy with acute Atg7 knockout in adult mice decreased intestinal occludin levels, increasing baseline colonic TJ permeability and exacerbating the effect of experimental colitis.

CONCLUSION

Our data suggest a novel role of autophagy in promoting the intestinal TJ barrier by increasing occludin levels in an ERK1/2 mitogen-activated protein kinase-dependent mechanism.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

Plant-derived bisbenzylisoquinoline alkaloid tetrandrine prevents human podocyte injury by regulating the miR-150-5p/NPHS1 axis

Podocytes have become a crucial target for kidney disease. Tetrandrine (TET), the main active component of a Chinese medicine formula Fangji Huangqi Tang, has shown a positive effect on various renal diseases. We aimed to investigate the effect and mechanism of TET on podocytes. The targeting relationship between microRNA (miR)-150-5p and nephrosis 1 (NPHS1) was determined by a dual-luciferase reporter gene assay. Cell proliferation, migration, and apoptosis were detected by cell counting kit-8, Transwell, and flow cytometry assays, respectively. The expression of miR-150-5p and NPHS1 was detected by RT-qPCR. The levels of Nephrin, Caspase-3, Bcl-2, Bax, E-cadherin, and α-smooth muscle actin were detected by Western blot. TET prompted cell viability and inhibited migration and apoptosis of puromycin aminonucleoside-induced human podocytes (HPC) in a dose-dependent manner. miR-150-5p directly targeted NPHS1 and was upregulated in damaged HPC. TET decreased the miR-150-5p expression and increased the level of NPHS1 and Nephrin. Overexpressed miR-150-5p inhibited the expression of NPHS1 and Nephrin, and reversed the protective effects of TET on injured HPC. TET protects the biological function of HPC by suppressing the miR-150-5p/NPHS1 axis. It reveals that TET may be a potential drug and miR150-5p is a potential therapeutic target for the treatment of podocyte injury.

Dietary supplementation of squalene increases the growth performance of early-weaned piglets by improving gut microbiota, intestinal barrier, and blood antioxidant capacity

This study aimed to investigate the effects of dietary squalene (SQ) supplementation on the growth performance of early-weaned piglets. Twenty early-weaned piglets were randomly divided into two groups, the squalene group (SQ) and the control group (CON). The CON group was fed a basal diet, and the SQ group was fed a basal diet with 250 mg/kg squalene. The feeding period lasted 21 days. The results showed that SQ significantly increased the final body weight (FWB, P < 0.05), average daily gain (ADG, P < 0.05), and average daily feed intake (ADFI, P < 0.05) and significantly decreased the F/G ratio (feed intake/gain, P < 0.05) and diarrhea index (DI, P < 0.05). In terms of blood biochemical indicators, SQ significantly increased anti-inflammatory factors such as transforming growth factor-β (TGF-β, P < 0.001), interleukin-10 (IL-10, P < 0.001), and interferon-γ (IFN-γ, P < 0.01), and decreased pro-inflammatory factors such as tumor necrosis factor-α (TFN-α, P < 0.001) and interleukin-6 (IL-6, P < 0.001). Furthermore, SQ significantly increased blood antioxidant indexes (P < 0.001) such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) and significantly decreased the level of malondialdehyde (MDA) (P < 0.001). The villus height (P < 0.001) and V/C ratio (villus height/crypt depth, P < 0.001) of the jejunum were significantly increased in the SQ group, while the crypt depth (P < 0.01) was decreased compared to the CON group. The intestinal permeability indexes, namely diamine oxidase (DAO), D-lactic acid (D-Lac), regenerative insulin-derived protein 3 (REG-3), and FITC-Dextran 4 (FD₄), significantly decreased the concentrations in the treatment group (P < 0.001), and the antioxidant indexes of the jejunum, such as SOD, GSH-Px, CAT, and MDA, were improved by adding SQ. The qPCR results showed that adding SQ could significantly increase the mRNA expression of jejunal tight-junction proteins, such as zonula occludens-1 (ZO-1, P < 0.001), Occludin (P < 0.001), Claudin (P < 0.001), glucagon-like peptide-2 (GLP-2, P < 0.001), and insulin-like growth factor-1 (IGF-1, P < 0.001). Then, we used Western blotting experiments to further confirm the qPCR results. In addition, it was found that adding SQ increased the abundance of beneficial bacteria such as Gemmiger (P < 0.01) and decreased the abundance of harmful bacteria such as Alloprevotella (P < 0.05), Desulfovibrio (P < 0.05), and Barnesiella (P < 0.05). It was interesting that there was a very close correlation among the fecal microbes, growth performance parameters, intestinal barrier, and blood biochemical indicators. In conclusion, the data suggest that SQ supplementation could effectively improve the growth performance of early-weaned piglets by improving the gut microbiota, intestinal barrier, and antioxidant capacity of the blood and jejunal mucosa.

Tilapia skin peptides, a by-product of fish processing, ameliorate DSS-induced colitis by regulating inflammation and inhibiting apoptosis

Intestinal bowel disease (IBD) has always been tough to treat, therefore researchers are struggle to look for treatments that are safe, low cost, and effective. Food-derived peptides are thought to have anti-inflammatory and antioxidant properties, but they have not been studied in depth in the treatment of IBD. Based on this, we explored the effect of tilapia skin peptides (TSPs) on the remission of colitis in the present study. Colonic epithelial cell lines CT-26 and HT-29 were co-treated with lipopolysaccharide (LPS) and TSPs for 12 h. Cell viability was assessed by CCK8 assay. Dextran sulfate sodium (DSS)-induced colitis model was established and 100 mg/kg TSPs were oral administered at the same time as DSS intervention. Colonic mucosal barrier function was assessed by western blotting. The inflammatory responses were evaluated by quantitative real-time PCR along with ELISA, respectively. Apoptosis was investigated by TUNEL and flow cytometry. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to characterize peptides composition of TSPs. It was found that TSPs significantly inhibit LPS-induced inflammation and apoptosis in vitro without affecting cell viability. Moreover, the upregulation and activation of Caspase-3 and Caspase-8 were also reversed by TSPs. Subsequently, in vivo experiments demonstrated that TSPs can attenuate DSS induced colitis, manifested by a decrease in weight loss and colon shortening. The expression of ZO-1 and occluding were significantly increased, and the pro-inflammatory cytokines were down-regulated. Meanwhile, TSPs alleviated DSS-induced apoptosis and reduced the expressions of Caspase-3 and Caspase-8. Finally, we found that TSPs were composed of 51 short peptides, and 12 of them were predicted to have significant biological activity. Collectively, this study suggested that TSPs can alleviate colon damage caused by foreign stimuli via inhibiting inflammation and apoptosis which indicated that it has great potential value for the treatment of IBD.

Glycerol monolaurate ameliorates DSS-induced acute colitis by inhibiting infiltration of Th17, neutrophils, macrophages and altering the gut microbiota

Background and aims

Inflammatory bowel disease (IBD) places a heavy medical burden on countries and families due to repeated and prolonged attacks, and the incidence and prevalence of IBD are increasing worldwide. Therefore, finding an effective treatment is a matter of great urgency. Glycerol monolaurate (GML), which has a twelve-carbon chain, is a compound naturally found in human breast milk. Some studies have shown that GML has antibacterial and anti-inflammatory effects. However, the specific mechanism of action remains unclear.

Methods

Acute colitis was established in mice using 3% DSS, and glycerol monolaurate (500 mg·kg-¹) was administered for two weeks. QPCR and western blotting were performed to examine the inflammatory status. Mice described were subjected to flow cytometry analysis for immune cell activation.

Results

GML treated alleviated macroscopic symptoms such as shortened colons, increased spleen weight, and caused weight loss in mice with DSS-induced colitis. In addition, GML decreased the expression of pro-inflammatory factors (NF-α, IL-1β and IL-1α) and increased the expression of anti-inflammatory factors (IL-10 and TGF-β). GML inhibited the activation of the MAPK and NF-κB signalling pathways, improved tissue damage, and increased the expression of intestinal tight junction proteins. In addition, LPMCs extracted from intestinal tissue via flow cytometry showed that GML treatment led to a decrease of Th17 cells, Neutrophils and Macrophages. 16S rDNA sequencing showed that GML increased the abundance of commensal bacterium such as Akkermansia and Lactobacillus murinus.

Conclusions

We showed that oral administration of GML ameliorated DSS-induced colitis by inhibiting infiltration of Th17 cells, Neutrophils, and Macrophages, protecting the intestinal mucosal barrier and altered the abundance of commensal bacterium. This study provides new insights into the biological function and therapeutic potential of GML in the treatment of IBD.

Impact of the Exposome on the Epigenome in Inflammatory Bowel Disease Patients and Animal Models

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders of the gastrointestinal tract that encompass two main phenotypes, namely Crohn's disease and ulcerative colitis. These conditions occur in genetically predisposed individuals in response to environmental factors. Epigenetics, acting by DNA methylation, post-translational histones modifications or by non-coding RNAs, could explain how the exposome (or all environmental influences over the life course, from conception to death) could influence the gene expression to contribute to intestinal inflammation. We performed a scoping search using Medline to identify all the elements of the exposome that may play a role in intestinal inflammation through epigenetic modifications, as well as the underlying mechanisms. The environmental factors epigenetically influencing the occurrence of intestinal inflammation are the maternal lifestyle (mainly diet, the occurrence of infection during pregnancy and smoking); breastfeeding; microbiota; diet (including a low-fiber diet, high-fat diet and deficiency in micronutrients); smoking habits, vitamin D and drugs (e.g., IBD treatments, antibiotics and probiotics). Influenced by both microbiota and diet, short-chain fatty acids are gut microbiota-derived metabolites resulting from the anaerobic fermentation of non-digestible dietary fibers, playing an epigenetically mediated role in the integrity of the epithelial barrier and in the defense against invading microorganisms. Although the impact of some environmental factors has been identified, the exposome-induced epimutations in IBD remain a largely underexplored field. How these environmental exposures induce epigenetic modifications (in terms of duration, frequency and the timing at which they occur) and how other environmental factors associated with IBD modulate epigenetics deserve to be further investigated.

Current Therapeutic Landscape and Safety Roadmap for Targeting the Aryl Hydrocarbon Receptor in Inflammatory Gastrointestinal Indications

Target modulation of the AhR for inflammatory gastrointestinal (GI) conditions holds great promise but also the potential for safety liabilities both within and beyond the GI tract. The ubiquitous expression of the AhR across mammalian tissues coupled with its role in diverse signaling pathways makes development of a “clean” AhR therapeutically challenging. Ligand promiscuity and diversity in context-specific AhR activation further complicates targeting the AhR for drug development due to limitations surrounding clinical translatability. Despite these concerns, several approaches to target the AhR have been explored such as small molecules, microbials, PROTACs, and oligonucleotide-based approaches. These various chemical modalities are not without safety liabilities and require unique de-risking strategies to parse out toxicities. Collectively, these programs can benefit from in silico and in vitro methodologies that investigate specific AhR pathway activation and have the potential to implement thresholding parameters to categorize AhR ligands as “high” or “low” risk for sustained AhR activation. Exploration into transcriptomic signatures for AhR safety assessment, incorporation of physiologically-relevant in vitro model systems, and investigation into chronic activation of the AhR by structurally diverse ligands will help address gaps in our understanding regarding AhR-dependent toxicities. Here, we review the role of the AhR within the GI tract, novel therapeutic modality approaches to target the AhR, key AhR-dependent safety liabilities, and relevant strategies that can be implemented to address drug safety concerns. Together, this review discusses the emerging therapeutic landscape of modalities targeting the AhR for inflammatory GI indications and offers a safety roadmap for AhR drug development.

Treatment-refractory ulcerative colitis responsive to indigo naturalis

Background

Indigo naturalis (IN) is an herbal medicine that has been used for ulcerative colitis with an unclear mechanism of action. Indigo and indirubin, its main constituents, are ligands of the aryl hydrocarbon receptor (AhR). We assessed the safety, efficacy, and colon AhR activity of IN given orally to patients with treatment-refractory ulcerative colitis. The role of AhR in IN benefit was further evaluated with an AhR antagonist in a murine colitis model.

Methods

This open-label, dose-escalation study sequentially treated 11 patients with ulcerative colitis with either IN 500 mg/day or 1.5 g/day for 8 weeks, followed by a 4-week non-treatment period. The primary efficacy endpoint was clinical response at week 8, assessed by total Mayo score. Secondary endpoints included clinical remission, Ulcerative Colitis Endoscopic Index of Severity, quality of life, and colon AhR activity measured by cytochrome P450 1A1 (CYP1A1) RNA expression.

Results

Ten of 11 (91%) patients, including 8/9 (89%) with moderate-to-severe disease, achieved a clinical response. Among these 10 patients, all had failed treatment with 5-aminosalicylic acid, 8 patients with a tumour necrosis factor (TNF)-alpha inhibitor, and 6 patients with TNF-alpha inhibitor and vedolizumab. Five patients were corticosteroid dependent. Clinical response was observed in all five patients who had been recommended for colectomy. Three patients achieved clinical remission. All patients experienced improved endoscopic severity and quality of life. Four weeks after treatment completion, six patients had worsened partial Mayo scores. Four patients progressed to colectomy after study completion. Colon CYP1A1 RNA expression increased 12 557-fold at week 8 among six patients evaluated. No patient discontinued IN due to an adverse event. Concomitant administration of 3-methoxy-4-nitroflavone, an AhR antagonist, in a murine colitis model abrogated the benefit of IN.

Conclusion

IN is a potentially effective therapy for patients with treatment-refractory ulcerative colitis. This benefit is likely through AhR activation.

Trial registration number

NCT02442960.