Efficacy of drugs used in the treatment of IBD and combinations thereof in acute DSS-induced colitis in mice

Expression of MAF bZIP transcription factor B protects against ulcerative colitis through the inhibition of the NF-κB pathway

PURPOSE

The aim of this study was to explore whether MAF bZIP transcription factor B (MAFB) might alleviate ulcerative colitis (UC) in dextran sulfate sodium (DSS)-induced mice and LPS-induced IEC-6 cells.

METHODS

UC in vivo and in vitro model was established by using DSS and LPS, respectively. The mice body weight and disease activity index (DAI) score were recorded daily, and colon length was measured. Moreover, the permeability was evaluated utilizing a fluorescein isothiocyanate dextran (FITC-Dextran) probe. Histopathological changes of DSS-induced colitis mice was assessed utilizing H&E staining. Next, qRT-PCR was performed to detect IL-1β, IL-6, TNF-α, and IL-10 level in in vivo and in vitro. Furthermore, the level of MDA, SOD, CAT, and GSH were evaluated in colon tissues. Besides, the expressions of tight junction proteins and NF-κB pathway relative proteins were examined in colitis mice and IEC-6 cells using western blot, immunohistochemistry and immunofluorescence.

RESULTS

MAFB level was downregulated in DSS-induced colitis mice. Moreover, the upregulation of MAFB protected mice from DSS-induced colitis by suppressing DSS-induced inflammation, oxidative stress, and intestinal barrier impairment. We also demonstrated that the upregulation of MAFB inactivated NF-κB pathway in DSS-caused colitis mice. Subsequently, we observed that MAFB upregulation could inhibit LPS-caused epithelial barrier impairment and inflammation in IEC-6 cells. Additionally, MAFB overexpression could suppress the activation of NF-κB pathway in IEC-6 cells.

CONCLUSION

The upregulation of MAFB could protect against UC via the suppression of inflammation and the intestinal barrier impairment through inhibiting the NF-κB pathway.

PIM1-HDAC2 axis modulates intestinal homeostasis through epigenetic modification

The mucosal barrier is crucial for intestinal homeostasis, and goblet cells are essential for maintaining the mucosal barrier integrity. The proviral integration site for Moloney murine leukemia virus-1 (PIM1) kinase regulates multiple cellular functions, but its role in intestinal homeostasis during colitis is unknown. Here, we demonstrate that PIM1 is prominently elevated in the colonic epithelia of both ulcerative colitis patients and murine models, in the presence of intestinal microbiota. Epithelial PIM1 leads to decreased goblet cells, thus impairing resistance to colitis and colitis-associated colorectal cancer (CAC) in mice. Mechanistically, PIM1 modulates goblet cell differentiation through the Wnt and Notch signaling pathways. Interestingly, PIM1 interacts with histone deacetylase 2 (HDAC2) and downregulates its level via phosphorylation, thereby altering the epigenetic profiles of Wnt signaling pathway genes. Collectively, these findings investigate the unknown function of the PIM1-HDAC2 axis in goblet cell differentiation and ulcerative colitis/CAC pathogenesis, which points to the potential for PIM1-targeted therapies of ulcerative colitis and CAC.

Baitouweng decoction alleviates ulcerative colitis by regulating tryptophan metabolism through DOPA decarboxylase promotion

Background

Baitouweng decoction (BTW) is a classic botanical drugs formula that has been widely used clinically for the treatment of gut-related disorders in China. However, its role in ameliorating ulcerative colitis (UC) remains to be explored.

Purpose

The study aimed to determine the therapeutic efficacy and potential mechanism of action of BTW on dextran sodium sulfate (DSS)-induced colitis mice.

Methods

In vivo: 3.5% DSS-induced experimental colitis mice were treated with BTW (Pulsatilla chinensis (Bunge) Regel, Phellodendron chinense C. K. Schneid, Coptis chinensis Franch and Fraxinus chinensis Roxb), kynurenine or DOPA decarboxylase (DDC) inhibitor (carbidopa). In vitro: Caco-2 cells were stimulated with TNF-α to activate inflammation and later treated with various concentrations of BTW and carbidopa. Model evaluation included body weight, disease activity index (DAI) score, colon length and histopathology. Cytokine levels were measured by flow cytometry. Protein levels were analyzed by proteomics and functionally annotated. The levels of tryptophan metabolites in mouse serum and colon were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Alcian Blue/Phosphate Acid Schiff (AB/PAS) staining, immunohistochemistry and western blot were used to assess the intestinal barrier function and detect the protein expression levels.

Results

BTW significantly reduced the DAI, ameliorated colonic injury and regulated inflammatory cytokines in DSS-induced colitis mice. The botanical drugs formula also promoted intestinal epithelial barrier repair by enhancing the expression of the tight junction (TJ) proteins. Tryptophan metabolic signaling pathway was significantly enriched in DSS-induced UC mice, and BTW decreased the level of kynurenine, increased indole metabolites. The therapeutic effect of BTW was evidently reduced when kynurenine was given to mice. Also, BTW promoted DDC protein expression and activated the aryl hydrocarbon receptor (AHR)/IL-22 signaling pathway.

Conclusion

BTW improves ulcerative colitis by promoting DDC expression, regulating the conversion of tryptophan metabolism from the kynurenine pathway to the indole metabolism pathway, thereby modulating tryptophan metabolism to increase indole metabolites, and activating AHR receptors to restore intestinal barrier function.

Suppression of MyD88 disturbs gut microbiota and activates the NLR pathway and hence fails to ameliorate DSS-induced colitis

Background

Myeloid differentiation factor 88 (MyD88) is the core adaptor for Toll-like receptors defending against microbial invasion and initiating a downstream immune response during microbiota-host interaction. However, the role of MyD88 in the pathogenesis of inflammatory bowel disease is controversial. This study aims to investigate the impact of MyD88 on intestinal inflammation and the underlying mechanism.

Methods

MyD88 knockout (MyD88-/-) mice and the MyD88 inhibitor (TJ-M2010-5) were used to investigate the impact of MyD88 on acute dextran sodium sulfate (DSS)-induced colitis. Disease activity index, colon length, histological score, and inflammatory cytokines were examined to evaluate the severity of colitis. RNA transcriptome analysis and 16S rDNA sequencing were used to detect the potential mechanism.

Results

In an acute DSS-colitis model, the severity of colitis was not alleviated in MyD88-/- mice and TJ-M2010-5-treated mice, despite significantly lower levels of NF-κB activation being exhibited compared to control mice. Meanwhile, 16S rDNA sequencing and RNA transcriptome analysis revealed a higher abundance of intestinal Proteobacteria and an up-regulation of the nucleotide oligomerization domain-like receptors (NLRs) signaling pathway in colitis mice following MyD88 suppression. Further blockade of the NLRs signaling pathway or elimination of gut microbiota with broad-spectrum antibiotics in DSS-induced colitis mice treated with TJ-M2010-5 ameliorated the disease severity, which was not improved solely by MyD88 inhibition. After treatment with broad-spectrum antibiotics, downregulation of the NLR signaling pathway was observed.

Conclusion

Our study suggests that the suppression of MyD88 might be associated with unfavorable changes in the composition of gut microbiota, leading to NLR-mediated immune activation and intestinal inflammation.

Transcriptomic and metabolomic analysis unveils nanoplastic-induced gut barrier dysfunction via STAT1/6 and ERK pathways

The widespread prevalence of micro and nanoplastics in the environment raises concerns about their potential impact on human health. Recent evidence demonstrates the presence of nanoplastics in human blood and tissues following ingestion and inhalation, yet the specific risks and mechanisms of nanoplastic toxicity remain inadequately understood. In this study, we aimed to explore the molecular mechanisms underlying the toxicity of nanoplastics at both systemic and molecular levels by analyzing the transcriptomic/metabolomic responses and signaling pathways in the intestines of mice after oral administration of nanoplastics. Transcriptome analysis in nanoplastic-administered mice revealed a notable upregulation of genes involved in pro-inflammatory immune responses. In addition, nanoplastics substantially reduced the expression of tight junction proteins, including occludin, zonula occluden-1, and tricellulin, which are crucial for maintaining gut barrier integrity and function. Importantly, nanoplastic administration increased gut permeability and exacerbated dextran sulfate sodium-induced colitis. Further investigation into the underlying molecular mechanisms highlighted significant activation of signaling transsducer and activator of transcription (STAT)1 and STAT6 by nanoplastic administration, which was in line with the elevation of interferon and JAK-STAT pathway signatures identified through transcriptome enrichment analysis. Additionally, the consumption of nanoplastics specifically induced nuclear factor kappa-B (NF-κB) and extracellular signal-regulated kinase (ERK)1/2 signaling pathways in the intestines. Collectively, this study identifies molecular mechanisms contributing to adverse effects mediated by nanoplastics in the intestine, providing novel insights into the pathophysiological consequences of nanoplastic exposure.

Quercetin ameliorates ulcerative colitis by restoring the balance of M2/M1 and repairing the intestinal barrier via downregulating cGAS‒STING pathway

Macrophage polarization is closely associated with the pathogenesis of ulcerative colitis (UC). Quercetin, a flavonoid, has shown promise as a treatment for inflammatory diseases, but its specific mechanism of action remains unclear. This study investigates whether quercetin can regulate intestinal macrophage polarization and promote intestinal tissue repair via the cGAS-STING pathway for the treatment of UC. In vivo, mice with 3% DSS-induced UC were intraperitoneally injected with quercetin and RU.521 for 7 days, following which their general conditions and corresponding therapeutic effects were assessed. The impact of interferon-stimulated DNA (ISD) and quercetin on macrophage polarization and the cGAS-STING pathway was investigated using RAW264.7 cells and bone marrow-derived macrophages (BMDMs) in vitro. The results demonstrated that ISD induced M1 macrophage polarization and activated the cGAS-STING pathway in vitro, while quercetin reversed ISD's inflammatory effects. In vivo, quercetin suppressed the cGAS-STING pathway in the intestinal macrophages of DSS-induced UC mice, which reduced M1 macrophage polarization, increased M2 polarization, and facilitated intestinal barrier repair in UC. Taken together, these findings provide new insights into the mechanisms via which quercetin could be used to treat UC.

Selection of Fermentation Supernatant from Probiotic Strains Exhibiting Intestinal Epithelial Barrier Protective Ability and Evaluation of Their Effects on Colitis Mouse and Weaned Piglet Models

The intestinal epithelial barrier can prevent the invasion of pathogenic microorganisms and food antigens to maintain a consistent intestinal homeostasis. However, an imbalance in this barrier can result in various diseases, such as inflammatory bowel disease, malnutrition, and metabolic disease. Thus, the aim of this study was to select probiotic strains with epithelial barrier-enhancing ability in cell-based model and further investigate them for their improving effects on colitis mouse and weaned piglet models. The results showed that selected specific cell-free fermentation supernatants (CFSs) from Ligilactobacillus salivarius P1, Lactobacillus gasseri P12, and Limosilactobacillus reuteri G7 promoted intestinal epithelial cell growth and proliferation, strengthening the intestinal barrier in an intestinal epithelial cell line Caco-2 model. Further, the administration of CFSs of L. salivarius P1, L. gasseri P12, and L. reuteri G7 were found to ameliorate DSS-induced colitis in mice. Additionally, spray-dried powders of CFS from the three strains were examined in a weaned piglet model, only CFS powder of L. reuteri G7 could ameliorate the feed/gain ratio and serum levels of D-lactate and endotoxin. In conclusion, a new potential probiotic strain, L. reuteri G7, was selected and showed ameliorating effects in both colitis mouse and weaned piglet models.

Compound sophora decoction alleviates ulcerative colitis by regulating macrophage polarization through cGAS inhibition: network pharmacology and experimental validation

INTRODUCTION

Ulcerative colitis (UC) is a refractory disease with complex pathogenesis, and its pathogenesis is not clear. The present study aimed to investigate the potential target and related mechanism of Compound Sophora Decoction (CSD) in treating UC.

METHODS

A network pharmacology approach predicted the components and targets of CSD to treat UC, and cell and animal experiments confirmed the findings of the approach and a new target for CSD treatment of UC.

RESULTS

A total of 155 potential targets were identified for CSD treatment of UC, with some related to macrophage polarization, such as nitric oxide synthase (NOS2), also known as inducible nitric oxide synthase (iNOS). GO and KEGG enrichment analysis indicated that oxidative stress response and multiple inflammatory signaling pathways such as TNF-α may play a significant role. In vitro experiments revealed that Interferon-stimulated DNA (ISD) interference can cause polarization imbalances in Raw 264.7 and bone marrow-derived macrophages (BMDMs). Flow cytometry demonstrated that polarization of macrophages in the intestine, spleen, and lymph nodes in vivo was also unbalanced after dextran sulfate sodium (DSS) modeling with pathological intestinal injury. Both in vitro and in vivo studies indicated that after inducing inflammation, the levels of macrophage polarization-related markers (iNOS and Arg1) and inflammation-related factors (CCL17, IL10, TNF-α, and CXCL10) changed, accompanied by increased expression of cGAS. However, CSD treatment based on inflammation can inhibit the expression of cGAS protein and mRNA, lower the level of inflammatory factors, promote the expression of anti-inflammatory factors, and regulate macrophage polarization.

CONCLUSION

We concluded that CSD alleviated DSS-induced UC by inhibiting cGAS, thus regulating macrophage polarization.

An olsalazine nanoneedle-embedded inulin hydrogel reshapes intestinal homeostasis in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and refractory condition characterized by disrupted epithelial barrier, dysregulated immune balance, and altered gut microbiota. Nano-enabled interventions for restoring gut homeostasis have the potential to alleviate inflammation in IBD. Herein, we developed a combination of olsalazine (Olsa)-based nanoneedles and microbiota-regulating inulin gel to reshape intestinal homeostasis and relieve inflammation. The Olsa-derived nanoneedles exhibited reactive oxygen species scavenging ability and anti-inflammatory effects in lipopolysaccharide-simulated macrophages. The composite of nanoneedles and inulin gel (Cu2(Olsa)/Gel) displayed a macroporous structure, improved bio-adhesion, and enhanced colon retention after oral administration. Mechanistically, the composite effectively downregulated pro-inflammatory cytokine levels and promoted epithelial barrier repair through anti-inflammatory and antioxidant therapies, resulting in significant alleviation of colitis in three animal models of IBD. Furthermore, analysis of gut microbiota revealed that Cu2(Olsa)/Gel treatment increased the diversity of intestinal microflora and decreased the relative abundance of pathogenic bacteria such as Proteobacteria. Overall, this study provides a self-delivering nanodrug and dietary fiber hydrogel composite for IBD therapy, offering an efficient approach to restore intestinal homeostasis.

A tailored series of engineered yeasts for the cell-dependent treatment of inflammatory bowel disease by rational butyrate supplementation

Intestinal microbiota dysbiosis and metabolic disruption are considered essential characteristics in inflammatory bowel disorders (IBD). Reasonable butyrate supplementation can help patients regulate intestinal flora structure and promote mucosal repair. Here, to restore microbiota homeostasis and butyrate levels in the patient's intestines, we modified the genome of Saccharomyces cerevisiae to produce butyrate. We precisely regulated the relevant metabolic pathways to enable the yeast to produce sufficient butyrate in the intestine with uneven oxygen distribution. A series of engineered strains with different butyrate synthesis abilities was constructed to meet the needs of different patients, and the strongest can reach 1.8 g/L title of butyrate. Next, this series of strains was used to co-cultivate with gut microbiota collected from patients with mild-to-moderate ulcerative colitis. After receiving treatment with engineered strains, the gut microbiota and the butyrate content have been regulated to varying degrees depending on the synthetic ability of the strain. The abundance of probiotics such as Bifidobacterium and Lactobacillus increased, while the abundance of harmful bacteria like Candidatus Bacilloplasma decreased. Meanwhile, the series of butyrate-producing yeast significantly improved trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice by restoring butyrate content. Among the series of engineered yeasts, the strain with the second-highest butyrate synthesis ability showed the most significant regulatory and the best therapeutic effect on the gut microbiota from IBD patients and the colitis mouse model. This study confirmed the existence of a therapeutic window for IBD treatment by supplementing butyrate, and it is necessary to restore butyrate levels according to the actual situation of patients to restore intestinal flora.

Identifying Key Genes to the Early Diagnosis of Inflammatory Bowel Disease by Integrating Analysis at the Blood and Tissue Levels

Background

Inflammatory bowel disease (IBD) encompasses Crohn's disease (CD) and ulcerative colitis (UC), is challenging to diagnose, and frequently relapses, significantly affecting patients' quality of life. Despite extensive efforts, the pathogenesis of IBD remains unclear.

Methods

In this study, we integrated bioinformatics analysis and animal disease model to investigate IBD from two dimensions to identify potential diagnostic biomarkers and explore the pathogenesis of distinct conditions at tissue-specific levels.

Results

Firstly, we identified dysferlin (DYSF) and C-X-C motif chemokine ligand 2 (CXCL2) as crucial biomarkers for IBD, with 11 and 13 putative biomarkers for CD and UC, respectively, identified by peripheral blood testing only. CXCL8 and S100 calcium-binding protein A8 (S100A8) were determined to be critical hub genes and validated by real-time polymerase chain reaction (RT-PCR). Secondly, in CD, the differentially expressed genes (DEGs) were mainly associated with immunity based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, while the metabolism of multiple substances and substance transport activity were dominant in UC. Thirdly, essential genes in the pathological progression of CD and UC were identified through protein-protein interaction networks and molecular complex detection (MCODE) analysis. Finally, pathological examination and quantitative analysis of IBD models confirmed the above results.

Conclusions

Our findings could contribute to understanding the molecular mechanism of IBD, hold clinical significance for early diagnosis and prevention, and provide effective targets for treating IBD.

TNF-α Mediated the Disruption of Hepatic Tight Junction Expression in Blood-Biliary Barrier of Colitis via Downregulating PI3K/AKT Signaling Pathway

Hepatocyte tight junctions (TJ) constituted blood-biliary barrier is the most important hepatic barrier for separating bile from the bloodstream, disruption or dysfunction of TJ barrier is involved in hepatobiliary manifestations of colitis, but the underlying mechanism is still not clear. This study aims to investigate the effect and underlying mechanism of tumor necrosis factor alpha (TNF-α) on hepatic TJ protein expression in blood-biliary barrier and identify its role in the pathogenesis of acute colitis-related cholestasis. Acute colitis rat model was induced by trinitrobenzene sulfonic acid (TNBS) intra-colonic administration. TJs expression of blood-biliary barrier was tested in colitis rats, the serum TNF-α level was also determined in order to elucidate the correlation of TNF-α and TJs. HepaRG cells were used to investigate the effect of TNF-α on TJs, and the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway were also evaluated in rats and TNF-α treated HepaRG cells. Acute colitis was induced in rats at 5 d post TNBS, which is accompanied with cholestasis-like alteration. Serum TNF-α level was increased in colitis rats and positively correlated with the alteration of total bile acids and bilirubin, marked decrease in TJs was found in TNF-α treated HepaRG cells and the rats, down-regulated PI3K/AKT signaling pathway were also identified in TNF-α treated HepaRG cells and the rats. The study concluded that serum TNF-α mediated the down-regulation of PI3K/AKT signaling pathway, which contributed to the reduction of TJ protein expression in acute colitis-related intrahepatic cholestasis. These findings suggest that TNF-α plays an important role in the pathogenesis of intrahepatic cholestasis of colitis.

The Anti-Inflammatory Effects of Adipose Tissue Mesenchymal Stem Cell Exosomes in a Mouse Model of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a group of chronic, relapsing inflammatory disorders that affect the gastrointestinal tract, with the primary subtypes being ulcerative colitis (UC) and Crohn's disease (CD). We aimed to evaluate the therapeutic potential of extracellular vesicles released by adipose-tissue-derived mesenchymal stem cells, which we, in this manuscript, call "exosomes" (ASC-EXOs), in a mouse model of IBD. We specifically aimed to determine the effectiveness of different treatment protocols and compare the effects with that of anti-IL-12 p40 monoclonal antibody. The addition of dextran sulfate sodium (DSS) to drinking water induced multiple signs of IBD, including weight loss, soft stool, and bloody feces. ASC-EXOs given by either intraperitoneal (IP) or intravenous (IV) routes resulted in moderate improvement in these signs of IBD. IV ASC-EXOs resulted in significantly reduced body weight loss, improved histopathological scoring, and suppressed the disease activity index (DAI) compared to the IBD control group. Also, a reduction in PCR for pro-inflammatory cytokines was observed. IV ASC treatment resulted in dose-related reduction in IBD signs, including weight loss. An increasing number of injections with ASC-EXOs reduced histopathological scores as well as DAI. Co-administration of ASC-EXOs with anti-IL-12 p40 significantly decreased DAI scores in the ASC-EXO + anti-IL-12 p40 group. In conclusion, ASC-EXOs have potential as a therapeutic agent for IBD, but the route of administration, number of injections, and dosage need to be considered to optimize the effects of ASC-EXO treatment. This study also highlights the potential benefits of combination therapies of ASC-EXOs and anti-IL-12. Our findings pave the way for further studies to unravel the underlying therapeutic mechanisms of ASC-EXOs in IBD treatment.

Bacterial indole-3-lactic acid affects epithelium-macrophage crosstalk to regulate intestinal homeostasis

Tryptophan and its derivatives perform a variety of biological functions; however, the role and specific mechanism of many tryptophan derivatives in intestinal inflammation remain largely unclear. Here, we identified that an Escherichia coli strain (Ec-TMU) isolated from the feces of tinidazole-treated individuals, and indole-3-lactic acid (ILA) in its supernatant, decreased the susceptibility of mice to dextran sulfate sodium-induced colitis. Ec-TMU and ILA contribute to the relief of colitis by inhibiting the production of epithelial CCL2/7, thereby reducing the accumulation of inflammatory macrophages in vitro and in vivo. Mechanistically, ILA downregulates glycolysis, NF-κB, and HIF signaling pathways via the aryl hydrocarbon receptor, resulting in decreased CCL2/7 production in epithelial cells. Clinical evidence suggests that the fecal ILA level is negatively correlated with the progression indicator of inflammatory bowel diseases. These results demonstrate that ILA has the potential to regulate intestinal homeostasis by modulating epithelium-macrophage interactions.

Therapeutic Effects of Valeriana jatamansi on Ulcerative Colitis: Insights into Mechanisms of Action through Metabolomics and Microbiome Analysis

Ulcerative colitis (UC), belonging to inflammatory bowel disease (IBD), is a chronic and relapsing inflammatory disorder of the gastrointestinal tract, which has not been completely cured in patients so far. Valeriana jatamansi is a Chinese medicine used clinically to treat "diarrhea," which is closely related to UC. This study was to elucidate the therapeutic effects of V. jatamansi extract (VJE) on dextran sodium sulfate (DSS)-induced UC in mice and its underlying mechanism. In this work, VJE effectively ameliorates the symptoms and histopathological scores and reduces the production of inflammatory factors in UC mice. The colon untargeted metabolomics analysis and 16S rDNA sequencing showed remarkable differences in colon metabolite profiles and intestinal microbiome composition between the control and DSS groups, and VJE intervention can reduce these differences. Thirty-two biomarkers were found and modulated the primary pathways including pyrimidine metabolism, arginine biosynthesis, and glutathione metabolism. Meanwhile, twelve significant taxa of gut microbiota were found. Moreover, there is a close relationship between endogenous metabolites and intestinal flora. These findings suggested that VJE ameliorates UC by inhibiting inflammatory factors, recovering intestinal maladjustment, and regulating the interaction between intestinal microbiota and host metabolites. Therefore, the intervention of V. jatamansi is a potential therapeutic treatment for UC.

An Activation-Specific Anti-Mac-1 Designed-Ankyrin-Repeat-Protein Attenuates Colitis in Mice

(1) Background: Inflammatory bowel diseases are complex and multifactorial disorders of unknown etiology. The extravasation of activated leukocytes is a critical step in the pathogenesis of these diseases. Leukocyte integrin Mac-1 (α_Mβ₂; CD11b/CD18) is crucial for the extravasation of myeloid cells, and a novel activation-specific anti-Mac-1 Designed Ankyrin Repeat protein (DARPin F7) is a promising therapeutic agent for inflammatory diseases. In its activated conformation, Mac-1 expresses the high-affinity binding site I-domain, which the DARPin F7 selectively targets. In our study, we aimed to explore the therapeutic potential of anti-Mac-1 DARPin F7 in murine dextrane sodium sulfate (DSS)-induced colitis. (2) Methods: C57BL/6J mice received 3% DSS drinking water for five days, followed by normal drinking water for one week. The mice were treated with DARPin F7 or a control substance daily via intraperitoneal injections. Disease activity index (DAI), colon length, myeloperoxidase (MPO) activity measurements, H&E staining, and qRT-PCR were conducted after euthanizing the mice on day 12. (3) Results: Treatment with DARPin F7 resulted in less pronounced colon shortening and significantly lower histological scores. The DARPin F7-treated animals experienced substantially less disease and myeloperoxidase (MPO) activity. Animals that received DARPin F7 treatment suffered less weight loss and recovered from the weight loss more efficiently. Treatment with DARPin F7 also led to significantly reduced mRNA expression of inflammatory cytokines. (4) Conclusion: Anti-Mac-1 treatment markedly reduced disease activity and inflammatory reaction accompanying DSS-induced colitis in mice.

Serum amyloid A and metabolic disease: evidence for a critical role in chronic inflammatory conditions

Serum amyloid A (SAA) subtypes 1-3 are well-described acute phase reactants that are elevated in acute inflammatory conditions such as infection, tissue injury, and trauma, while SAA4 is constitutively expressed. SAA subtypes also have been implicated as playing roles in chronic metabolic diseases including obesity, diabetes, and cardiovascular disease, and possibly in autoimmune diseases such as systemic lupus erythematosis, rheumatoid arthritis, and inflammatory bowel disease. Distinctions between the expression kinetics of SAA in acute inflammatory responses and chronic disease states suggest the potential for differentiating SAA functions. Although circulating SAA levels can rise up to 1,000-fold during an acute inflammatory event, elevations are more modest (∼5-fold) in chronic metabolic conditions. The majority of acute-phase SAA derives from the liver, while in chronic inflammatory conditions SAA also derives from adipose tissue, the intestine, and elsewhere. In this review, roles for SAA subtypes in chronic metabolic disease states are contrasted to current knowledge about acute phase SAA. Investigations show distinct differences between SAA expression and function in human and animal models of metabolic disease, as well as sexual dimorphism of SAA subtype responses.

Network Pharmacology Study of Bioactive Components and Molecular Mechanisms of the Glycoside Fraction from Picrorhiza scrophulariiflora Against Experimental Colitis

Purpose

To explore the potential mechanism of glycosidic fraction of Picrorhiza scrophulariiflora Pennell (GPS) extract for the treatment of colitis using UPLC-QTOF-MS analysis, network pharmacology and experimental research.

Methods

The active components of GPS extract were identified by UPLC-QTOF-MS analysis and extracted their targets from the databases, which was used for network pharmacology analysis. Kyoto Encyclopedia of genes and genomes (KEGG) pathway analysis was performed to discover potential therapeutic mechanisms, and the network pharmacology results were then validated by in vivo and in vitro experiments.

Results

The results showed that GPS extract significantly alleviated the clinical signs of colitis, including body weight, disease activity index, colon shortening, and colon tissue damage, and inhibited the transcription and production of colonic IL-1β and IL-6 in DSS-induced colitis mice. In vitro, GPS extract also significantly suppressed nitric oxide (NO) production, iNOS expression, IL-1β and IL-6 transcription of LPS-activated RAW 264.7 cells. Network pharmacology integrated with experimental validation identified that GPS extract significantly suppressed Akt, p38, ERK, and JNK phosphorylation in vivo and in vitro, and luteolin, apocynin, caffeic acid, caffeic acid methyl ester, luteoloside, picroside II, aucubin, cinnamic acid, vanillic acid, and sweroside were the main components responsible for the anti-inflammatory effect of GPS. These findings demonstrate that the potential anti-inflammatory effect of GPS extract against colitis is achieved through suppressing PI3K/Akt and MAPK pathways, and that the abovementioned active components mainly exerted its anti-inflammatory effect.

Conclusion

The therapeutic effect of GPS extract on colitis is related to PI3K/Akt and MAPK pathways, which is a promising remedy for colitis therapy.

Angelica sinensis aboveground part polysaccharide and its metabolite 5-MT ameliorate colitis via modulating gut microbiota and TLR4/MyD88/NF-κB pathway

The roots of Angelica sinensis have been used in Traditional Chinese Medicine for thousands of years. However, tons of aerial parts of this herb (aboveground part) are commonly discarded during the process of root preparations. A polysaccharide (ASP-Ag-AP) in the aboveground parts of A. sinensis was isolated and preliminarily characterized as typical plant pectin. ASP-Ag-AP exhibited noticeable protective effects against dextran sodium sulfate (DSS)-induced colitis, including reduction of colonic inflammation, modulation of barrier function, and alteration of gut microbiota and serum metabolite profile. Anti-inflammatory effects of ASP-Ag-AP were observed by inhibiting TLR4/MyD88/NF-κB signaling pathway in vitro and in vivo. Additionally, the level of serum metabolite 5-methyl-dl-tryptophan (5-MT) was reduced by DSS and restored by ASP-Ag-AP, which also negatively correlated with Bacteroides, Alistipes, Staphylococcus and pro-inflammatory factors. The protection from inflammatory stress on intestinal porcine enterocytes cells (IPEC-J2) of 5-MT was observed through the inhibition of TLR4/MyD88/NF-κB pathway. Besides, 5-MT also exhibited robust anti-inflammatory effect in colitis mice with improving colitis symptoms, barrier function and gut microbiota, which was the same as presented by ASP-Ag-AP. Therefore, ASP-Ag-AP could be a promising agent for colitis prevention and 5-MT could be the signal metabolite of ASP-Ag-AP on defending against intestinal inflammatory stress.

Total flavone of flowers of Abelmoschus manihot (L.) Medic inhibits the expression of adhesion molecules in primary mesenteric arterial endothelial cells and ameliorates dextran sodium sulphate-induced ulcerative colitis in mice

BACKGROUND

Flowers of Abelmoschus manihot (L.) medic (AM) is a traditional Chinese medicine used to treat chronic nephritis, nephrotic syndrome, diabetic nephropathy, and colonic inflammation.

PURPOSE

This study aimed to explore the influence of the total flavone of AM flowers (TFA) on acute ulcerative colitis (UC) and the potential underlying mechanism.

METHODS

Efficacy of TFA (30, 60, 120 mg/kg) on UC was evaluated in a dextran sodium sulphate (DSS)-induced colonic inflammatory mouse model by analyzing disease activity index (DAI), histopathological score, colon length, and cytokine expression. Expression levels of critical adhesion molecules and nuclear factor kappa B (NF-κB) were examined by qRT-PCR, Western blotting, or immunofluorescence labeling. Myeloperoxidase activity was examined using ELISA. In vitro THP-1 adhesion assay was used to evaluate monocyte adhesion.

RESULTS

TFA significantly reduced DAI score, prevented colon shortening, and ameliorated histological injuries of colons in DSS-treated mice. TFA inhibited the expression of cytokines (IL-1β and TNF-α) and adhesion molecules (ICAM-1, VCAM-1, and MAdCAM-1) in colon tissues of DSS mice. In vitro studies on mesenteric arterial endothelial cells (MAECs) showed that TFA attenuated TNF-α-induced upregulation of ICAM-1, VCAM-1, and MAdCAM-1, as well as THP-1 cell adhesion to MAECs. TFA also suppressed the phosphorylation and nuclear translocation of NF-κB in MAECs.

CONCLUSION

TFA efficaciously ameliorates UC possibly by inhibiting monocyte adhesion through blocking TNF-α-induced NF-κB activation, which in turn suppresses the upregulation of adhesive molecules in colon endothelial cells. Inhibiting the expression of adhesion molecule in MAECs may represent a useful strategy for therapeutic development to treat UC, with TFA being a safe and efficacious therapeutic agent.

A mouse model to test the anti-inflammatory effect of facultative anaerobes on dextran sulfate sodium-induced colitis

The role of facultative anaerobic bacteria in colitis remains to be elucidated. We have adapted a mouse model to explore the effect of individual facultative anaerobic bacteria on colitis, focusing on adapting a cocktail of antibiotics and multiple instillations by gavage. Weight, disease activity index, colon length, and histological score are used to assess the severity of colitis. We also describe anaerobic processing protocols of preparing facultative anaerobes. For complete details on the use and execution of this protocol, please refer to Li et al. (2022).1.

Metabolomics integrated network pharmacology reveals the mechanism of Ma-Mu-Ran Antidiarrheal Capsules on acute enteritis mice

Acute enteritis (AE) is a type of digestive disease caused by biochemical factors that irritate the intestinal tract or pathogenic bacteria that infect it. In China, Ma-Mu-Ran Antidiarrheal Capsules (MMRAC) have been applied against diarrhea caused by AE and bacillary dysentery for many years, but the underlying mechanisms of their beneficial effects are not known. In the present study, network pharmacology and metabolomics were performed to clarify the active ingredients of MMRAC and explore the specific mechanism of MMRAC on AE mice. A total of 43 active components of MMRAC with 87 anti-AE target genes were identified, and these target genes were enriched in IL-17 and HIF-1 signaling pathways. Integration analysis revealed that purine metabolism was the critical metabolic pathway by which MMRAC exerted its therapeutic effect against AE. Specifically, MAPK14, MMP9, PTGS2, HIF1A, EGLN1, NOS2 were the pivotal targets of MMRAC for the treatment of AE, and Western blot analysis revealed MMRAC to decrease protein levels of these pro-inflammatory signaling molecules. According to molecular docking, these key targets have a strong affinity with the MMRAC compounds. Collectively, MMRAC relieved the colon inflammation of AE mice via regulating inflammatory signaling pathways to reduce hypoxia and improved energy metabolism.

Identification of cuproptosis hub genes contributing to the immune microenvironment in ulcerative colitis using bioinformatic analysis and experimental verification

Instruction

Ulcerative colitis (UC) can cause a variety of immune-mediated intestinal dysfunctions and is a significant model of inflammatory bowel disease (IBD). Colorectal cancer (CRC) mostly occurs in patients with ulcerative colitis. Cuproptosis is a type of procedural death that is associated with different types of diseases to various degrees.

Methods

We used a combination of bioinformatic prediction and experimental verification to study the correlation between copper poisoning and UC. We used the Gene Expression Omnibus database to obtain disease gene expression data and then identified relevant genes involved in various expression levels in normal and UC samples. The Kyoto Encyclopedia of Genes and Genomes pathway analysis was performed to cluster the genes that are highly responsible and find the central interaction in gene crosstalk. Notably, DLD, DLAT, and PDHA1 were present in high-scoring PPI networks. In addition, hub gene expression information in UC tissues was integrated to estimate the relationship between UC copper poisoning and the immune environment.

Results

In our study, the expression of DLD, DLAT, and PDHA1 in UC tissues was lower than that in normal tissues. The key genes associated with cuproptosis have therapeutic effects on immune infiltration. We verified the expression of DLD, DLAT, and PDHA1 using real-time quantitative polymerase chain reaction in mouse models of UC induced by DSS.

Discussion

Notably, this study clearly indicates that bioinformatic analysis performed to verify the experimental methods provides evidence that cuproptosis is associated with UC. This finding suggests that immune cell infiltration in UC patients is associated with cuproptosis. The key genes associated with cuproptosis can be helpful for discovering the molecular mechanism of UC, thus facilitating the improvement of UC treatment and preventing the associated CRC.

Synthetic Lignin-Derived Therapeutic Nano Reagent as Intestinal pH-Sensitive Drug Carriers Capable of Bypassing the Gastric Acid Environment for Colitis Treatment

Oral drug delivery is a common route for management of inflammatory bowel disease (IBD) but suffers from low bioavailability and systemic side effects during passage through the alimentary canal. Here, we present a therapeutic nano reagent of a ferulic acid-derived lignin nanoparticle (FALNP). We showed that FALNP with favorable antioxidant activity can regulate IBD. More importantly, the intestinal pH-responsive degradability of FALNP allows it to withstand the harsh gastric acid environment, bypass physiological barriers, and target the intestine for gastrointestinal delivery. In vivo experiments showed that oral administration of FALNP markedly relieved pathological symptoms in a mouse model of acute colitis by reducing oxidative stress and regulating the gut microbiome. By integrating anti-inflammatory medicine, FALNP also can be used as a bioactive carrier to exert a potent synergistic therapeutic effect. In addition to colitis, FALNP can be readily adaptable for use as a carrier platform for therapy of many other intestinal diseases.

Curcumin alleviates experimental colitis via a potential mechanism involving memory B cells and Bcl-6-Syk-BLNK signaling

BACKGROUND

Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease (IBD), which is mainly related to lymphocytes (T or B cells, incl-uding memory B cells), mast cells, activated neutrophils, and macrophages. As the precursor of B cells, the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells, whose dysfunction can easily lead to autoimmune diseases, including IBD.

AIM

To investigate whether or not curcumin (Cur) can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling.

METHODS

Colitis was induced in mice with a dextran sulphate sodium (DSS) solution in drinking water. Colitis mice were given Cur (100 mg/kg/d) orally for 14 con-secutive days. The colonic weight, colonic length, intestinal weight index, occult blood scores, and histological scores of mice were examined to evaluate the curative effect. The levels of memory B cells in peripheral blood of mice were measured by flow cytometry, and IL-1β, IL-6, IL-10, IL-7A, and TNF-α expression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay. Western blot was used to measure the expression of Bcl-6, BLNK, Syk, and other signaling pathway related proteins.

RESULTS

After Cur treatment for 14 d, the body weight, colonic weight, colonic length, colonic weight index, and colonic pathological injury of mice with colitis were ameliorated. The secretion of IL-1β, IL-6, TNF-α, and IL-7A was statistically decreased, while the IL-35 and IL-10 levels were considerably increased. Activation of memory B cell subsets in colitis mice was confirmed by a remarkable reduction in the expression of IgM, IgG, IgA, FCRL5, CD103, FasL, PD-1, CD38, and CXCR3 on the surface of CD19⁺ CD27⁺ B cells, while the number of CD19⁺ CD27⁺ IL-10⁺ and CD19⁺ CD27⁺ Tim-3⁺ B cells increased significantly. In addition, Cur significantly inhibited the protein levels of Syk, p-Syk, Bcl-6, and CIN85, and increased BLNK and p-BLNK expression in colitis mice.

CONCLUSION

Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.

Oral administration of human carbonic anhydrase I suppresses colitis in a murine inflammatory bowel disease model

The incidence of inflammatory bowel disease (IBD) is increasing; hence, effective treatments are warranted. The therapeutic effect of human carbonic anhydrase I (hCA I) in IBD remains unknown. Therefore, we investigated whether oral tolerization to hCA I would induce antigen-specific protection from intestinal inflammation in vivo. Severe combined immunodeficient mice received hCA I, keyhole limpet hemocyanin (KLH), or phosphate-buffered saline (PBS) orally for 7 days. Colons and mesenteric lymph nodes (MLNs) were collected 4 weeks after cell transfer. Additionally, the mechanisms underlying the therapeutic effects were investigated. The comparison between the effects of well-established drugs and hCA I oral administration was investigated. Oral administration of hCA I ameliorated colitis remarkably. hCA I reached the cecum and ameliorated colitis more effectively than mesalazine and similarly to prednisolone. Compared with PBS treatment, hCA I treatment reduced interleukin (IL)-17a, IL-6, and retinoic acid-related orphan receptor gamma t (RORγt) expression in the colon or MLNs; moreover, hCA I markedly reduced IL-6, IL-17, and interferon-gamma (IFN-γ) levels in the MLN. Oral administration of hCA I induced immune tolerance and suppressed colitis in vivo. Thus, hCA I administration could be proposed as a new treatment option for IBD.

Preclinical evidence for quercetin against inflammatory bowel disease: a meta-analysis and systematic review

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, potentially cancerous disease with limited treatment options. Quercetin may be a novel treatment for IBD. However, its efficacy and safety are unknown. Our goal was to conduct a systematic evaluation to summarize the preclinical effects of quercetin, which may help guide future studies.

METHODS

The literature was drawn from three English databases (PubMed, Embase, and Web of Science), and the quality of the included literature was assessed using the SYRCLE list (10 items). The meta-analysis was performed using STATA 15.1 software.

RESULTS

A total of 11 animal studies with 199 animals were involved. The current meta-analysis showed that quercetin could reduce histological score (HS), Disease Activity Index (DAI), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), nitric oxide(NO), malondialdehyde (MDA), myeloperoxidase (MPO) activity and increase colon length (CL), weight change degree (WCD), interleukin-10 (IL-10), glutathione (GSH), superoxide dismutase (SOD) activity and catalase (CAT) activity, which may involve anti-inflammatory, anti-oxidative stress, cytoprotective, barrier protection, flora regulation.

CONCLUSIONS

In conclusion, preclinical evidence suggests that quercetin is an ideal agent for IBD treatment. However, the validity of the findings may be compromised by the low methodological quality and the small number of studies included. There may be some discrepancies between the results of the current analysis and the real situation. More rigorous experimental designs and more comprehensive studies are needed to test the protection of quercetin against IBD.

Ectopically Localized Epithelial Cell Clumps in Ulcers Are Derived from Reserved Crypt Stem Cells in a Mouse Model of Ulcerative Colitis

BACKGROUND

We previously reported that clumps of a few epithelial cells were scattered in ulcer regions in a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC).

AIMS

To determine the ectopically localized epithelial clumps might be derived from stem cells or their daughter progenitor cells.

METHODS

Female BALB/c mice were administered DSS in drinking water for 6 days, followed by withdrawal of DSS for 6 days. Histological and immunohistochemical examinations were conducted in the distal region and proximal region of the colorectum to determine expression of stem cell markers in the epithelial clumps.

RESULTS

Similar to the characteristics of UC, the ulcers were more severe in the distal region close to the anus than in the proximal region of the colorectum. Quantitative analyses revealed that the epithelial clumps appeared in relation to the severity of the ulcer, and they expressed the cell adhesion molecules E-cadherin and β-catenin. Among stem cell markers, the epithelial clumps primarily expressed +5 cell marker Dll1 as reserved intestinal stem cells, followed by +4 cell marker Bmi1 and crypt stem cell marker Lgr5 in that order. Nuclear expression of Sox9, but not nuclear β-catenin, was identified in the clumps.

CONCLUSION

The present results suggest that most epithelial clumps comprised crypt-derived, reserved stem cells, which might have potential for mucosal healing.

RhoB affects colitis through modulating cell signaling and intestinal microbiome

BACKGROUND

The pathogenesis of inflammatory bowel diseases (IBD) is multifactorial, and diagnostic and treatment strategies for IBD remain to be developed. RhoB regulates multiple cell functions; however, its role in colitis is unexplored.

RESULTS

Here, we found RhoB was dramatically increased in colon tissues of ulcerative colitis (UC) patients and mice with DSS-induced colitis. Compared with wild type mice, RhoB^+/- and RhoB^-/- mice developed milder DSS-induced colitis and increased goblet cell numbers and IEC proliferation. Decreased RhoB promoted goblet cell differentiation and epithelial regeneration through inhibiting Wnt signaling pathway and activating p38 MAPK signaling pathway. Moreover, increased SCFA-producing bacteria and SCFA concentrations were detected in intestinal microbiome of both RhoB^+/- and RhoB^-/- mice and upregulated SCFA receptor expression was also observed.

CONCLUSIONS

Taken together, a higher level of RhoB is associated with UC, which also contributes to UC development through modulating cell signaling and altering intestinal bacterial composition and metabolites. These observations suggest that RhoB has potential as a biomarker and a treatment target for UC. Video Abstract.

Cysteine protease of Clonorchis sinensis alleviates DSS-induced colitis in mice

Background

Currently, inflammatory bowel disease (IBD) has become a global chronic idiopathic disease with ever-rising morbidity and prevalence. Accumulating evidence supports the IBD-hygiene hypothesis that helminths and their derivatives have potential therapeutic value for IBD. Clonorchis sinensis (C. sinensis) mainly elicit Th2/Treg-dominated immune responses to maintain long-term parasitism in the host. This study aimed to evaluate the therapeutic effects of cysteine protease (CsCP) and adult crude antigen (CsCA) of C. sinensis, and C. sinensis (Cs) infection on DSS-induced colitis mice.

Methods

BALB/c mice were given 5% DSS daily for 7 days to induce colitis. During this period, mice were treated with rCsCP, CsCA or dexamethasone (DXM) every day, or Cs infection which was established in advance. Changes in body weight, disease activity index (DAI), colon lengths, macroscopic scores, histopathological findings, myeloperoxidase (MPO) activity levels, regulatory T cell (Treg) subset levels, colon gene expression levels, serum cytokine levels, and biochemical indexes were measured.

Results

Compared with Cs infection, rCsCP and CsCA alleviated the disease activity of acute colitis more significant without causing abnormal blood biochemical indexes. In comparison, rCsCP was superior to CsCA in attenuating colonic pathological symptoms, enhancing the proportion of Treg cells in spleens and mesenteric lymph nodes, and improving the secretion of inflammatory-related cytokines (e.g., IL-2, IL-4, IL-10 and IL-13) in serum. Combined with RNA-seq data, it was revealed that CsCA might up-regulate the genes related to C-type lectin receptor and intestinal mucosal repair related signal pathways (e.g., Cd209d, F13a1 and Cckbr) to reduce colon inflammation and benefit intestinal mucosal repair. Dissimilarly, rCsCP ameliorated colitis mainly through stimulating innate immunity, such as Toll like receptor (TLR) signaling pathway, down-regulating the expression of inflammatory cytokines (e.g., IL-12b, IL-23r and IL-7), thereby restraining the differentiation of Th1/Th17 cells.

Conclusions

Both rCsCP and CsCA showed good therapeutic effects on the treatment of acute colitis, but rCsCP is a better choice. rCsCP is a safe, effective, readily available and promising therapeutic agent against IBD mainly by activating innate immunity and regulating the IL-12/IL-23r axis.

Enterobacter ludwigii protects DSS-induced colitis through choline-mediated immune tolerance

Commensal intestinal bacteria play key roles in regulating host immune tolerance; however, bacterial strains and related metabolites directly involved in this regulation are largely unknown. Here, using a mouse model of dextran sulfate sodium (DSS)-induced colitis combined with different antibiotic treatment, Enterobacter ludwigii, abundant in microbiota of mice treated with metronidazole, is screened out to have prophylactic and therapeutic effects on DSS-induced colitis with or without the presence of complex intestinal bacteria. E. ludwigii is found to induce CD103⁺DC and regulatory T (Treg)-mediated immune tolerance for colitis remission using in vitro and in vivo experiments. Moreover, choline, one metabolite of E. ludwigii, is identified to increase dendritic cells' (DCs) immune tolerance to promote Treg differentiation. E. ludwigii is found to induce DCs' immune tolerance ability for Treg differentiation through choline and α7nAChR-mediated retinoic acid (RA) and transforming growth factor beta (TGF-β) upregulation, resulting in protecting mice against DSS-induced colitis. This study suggests potential therapeutic approaches for inflammatory bowel diseases (IBDs).

Wumei pills attenuates 5-fluorouracil-induced intestinal mucositis through Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway and microbiota regulation

BACKGROUND

Radiotherapy and chemotherapy can kill tumor cells and improve the survival rate of cancer patients. However, they can also damage normal cells and cause serious intestinal toxicity, leading to gastrointestinal mucositis[1]. Traditional Chinese medicine is effective in improving the side effects of chemotherapy. Wumei pills (WMP) was originally documented in the Treatise on Exogenous Febrile Diseases. It has a significant effect on chronic diarrhea and other gastrointestinal diseases, but it is not clear whether it affects chemotherapy-induced intestinal mucositis (CIM).

AIM

To explore the potential mechanism of WMP in the treatment of CIM through experimental research.

METHODS

We used an intraperitoneal injection of 5-fluorouracil (5-Fu) to establish a CIM mouse model and an oral gavage of WMP decoction (11325 and 22650 mg/kg) to evaluate the efficacy of WMP in CIM. We evaluated the effect of WMP on CIM by observing the general conditions of the mice (body weight, food intake, spleen weight, diarrhea score, and hematoxylin and eosin stained tissues). The expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and myeloperoxidase (MPO), as well as the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB (TLR4/MyD88/NF-κB) signaling pathway proteins and tight junction proteins (zonula occludens-1, claudin-1, E-cadherin, and mucin-2) was determined. Furthermore, intestinal permeability, intestinal flora, and the levels of short-chain fatty acids (SCFA) were also assessed.

RESULTS

WMP effectively improved the body weight, spleen weight, food intake, diarrhea score, and inflammatory status of the mice with intestinal mucositis, which preliminarily confirmed the efficacy of WMP in CIM. Further experiments showed that in addition to reducing the levels of TNF-α, IL-1β, IL-6, and MPO and inhibiting the expression of the TLR4/MyD88/NF-κB pathway proteins, WMP also repaired the integrity of the mucosal barrier of mice, regulated the intestinal flora, and increased the levels of SCFA (such as butyric acid).

CONCLUSION

WMP can play a therapeutic role in CIM by alleviating inflammation, restoring the mucosal barrier, and regulating gut microbiota.

Aronia melanocarpa (Michx.) Elliott. attenuates dextran sulfate sodium-induced Inflammatory Bowel Disease via regulation of inflammation-related signaling pathways and modulation of the gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Aronia melanocarpa (Michx.) Elliott. Is one of the most functional berries usually used in the preparation of juice and jams, but it has revealed its ethnopharmacological properties due to their richness in biologically active molecules with pharmaceutical and physiological effects.

AIMS OF THE STUDY

The aim of this study was to assess the antioxidant and anti-inflammatory effects of Aronia melanocarpa ethanol-extract as well as the possible mechanisms of action involved and the modulation of gut microbiota in Dextran Sulfate Sodium (DSS)-induced Inflammatory bowel disease in mice.

MATERIALS AND METHODS

Inflammatory bowel disease (IBD) were induced by DSS in drinking water for 7 days to evaluate the properties of A. melanocarpa ethanol-extract (AME) on the intestinal microflora. AME was administered orally to DSS-induced IBD mice for 21 days. Clinical, inflammatory, histopathological parameters, and different mRNA and proteins involved in its possible mechanism of action were determined as well as gut microbiota analysis via 16S high throughput sequencing.

RESULTS

AME improved clinical symptoms and regulated histopathological parameters, pro- and anti-inflammatory cytokines and oxidative stress factors as well as mRNA and protein expressions of transcription factors involved in maintaining the intestinal barrier integrity. In addition, AME also reversed the DSS-induced intestinal dysbiosis effects promoting the production of cecal short chain fatty acids linked to signaling pathways inhibiting IBD.

CONCLUSION

AME improved intestinal lesions induced by DSS suggesting that A. melanocarpa berries could have significant therapeutic potential against IBD due to their antioxidant and anti-inflammatory capacities as well as their ability to restore the gut microbiota balance.

Analysis of the Therapeutic Effect of Changyanning on Intestinal Flora in Inflammatory Bowel Disease

Research Purposes. Inflammatory bowel disease (IBD) is an autoimmune disease coinduced by genes, environment, and immune response, mainly including ulcerative colitis (UC) and Crohn's disease (CD). There are a large number and variety of intestinal bacteria in the human intestinal tract. These bacteria maintain a balance with the human environment and participate in the normal physiological processes of the human body. They play a unique role in defending against pathogen invasion, maintaining the homeostasis of the human immune system and metabolizing substances. Intestinal flora imbalance may be one of the pathogenic factors of IBD, and restoring the disturbed intestinal flora has become a research hotspot in the prevention and treatment of IBD. Changyanning is mainly composed of Dijincao grass, yellow hairy ear grass, camphor tree roots, maple leaves, and so on. Clinical studies have shown that Changyanning alone or in combination has a significant effect on ulcerative colitis, but the treatment mechanism is not yet clear. In this study, we established an IBD animal model to explore the therapeutic mechanism of Changyanning on inflammatory bowel disease and its effect on intestinal flora. Research Methods. Male C57BL/6 SPF mice were given free access to 4% dextran sulfate sodium (DSS) solution for 7 days to establish an ulcerative colitis model. After the model was established, different doses of Changyanning tablets, Changyanning granules, and sulfasalazine were given by gavage for 7 days. The relieving effects of the above drugs on the symptoms of inflammatory bowel disease were evaluated by evaluating the mouse/rat body weight, survival rate, disease activity index, colon length, pathological tissue score, and other indicators. Results. The DSS-induced IBD mouse model showed significant increases in weight loss, DAI score, and pathological score. Both Changyanning tablets and granules can relieve the weight loss of mice, restore the colon length, and protect the colon tissue structure of mice. In reducing DAI and pathological scores in mice, Changyanning granules had a better effect. In conclusion, Changyanning can significantly improve the quality of life of IBD model animals, relieve intestinal inflammatory response, and relieve colonic edema, ulceration, and necrosis. The results show that Changyanning has a certain therapeutic effect on IBD. This study also provides experimental evidence for the application of Changyanning in the treatment of IBD, which is of great significance to its clinical application. The trail is registered in ChiCTR with number (TRN) ChiCTR2000028830.

Targeting the endo-lysosomal autophagy pathway to treat inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a serious public health problem in Western society with a continuing increase in incidence worldwide. Safe, targeted medicines for IBD are not yet available. Autophagy, a vital process implicated in normal cell homeostasis, provides a potential point of entry for the treatment of IBDs, as several autophagy-related genes are associated with IBD risk. We conducted a series of experiments in three distinct mouse models of colitis to test the effectiveness of therapeutic P140, a phosphopeptide that corrects autophagy dysfunctions in other autoimmune and inflammatory diseases. Colitis was experimentally induced in mice by administering dextran sodium sulfate and 2,4,6 trinitrobenzene sulfonic acid. Transgenic mice lacking both il-10 and iRhom2 - involved in tumor necrosis factor α secretion - were also used. In the three models investigated, P140 treatment attenuated the clinical and histological severity of colitis. Post-treatment, altered expression of several macroautophagy and chaperone-mediated autophagy markers, and of pro-inflammatory mediators was corrected. Our results demonstrate that therapeutic intervention with an autophagy modulator improves colitis in animal models. These findings highlight the potential of therapeutic peptide P140 for use in the treatment of IBD.

Polysaccharide from Scutellaria barbata D. Don attenuates inflammatory response and microbial dysbiosis in ulcerative colitis mice

This study aimed to evaluate the effect of polysaccharides from Scutellaria barbata D. Don (PSB) on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in C57BL/6 mice. PSB was isolated, and its chemical composition was preliminarily identified. The average molecular weight of PSB was 1.25 × 10⁴ Da and it was mainly comprised of arabinose, galacturonic acid, galactose, glucose, and glucuronic acid in molar ratios of 1.00:2.09:4.52:4.73:4.90. PSB (25 and 50 mg/kg) and sulfasalazine (200 mg/kg) significantly relieved weight loss and symptoms and alleviated colonic pathological injury in mice with UC. In addition, PSB decreased the levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, and IL-18 in the colon and suppressed DSS-induced activation of the nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways. The improvement in the abundance of several bacterial genera, such as the Lachnospiraceae_NK4A136_group, Ruminococcus, Bacteroides, Parasutterella, and Eisenbergiella might be closely related to the reduction in the intestinal inflammatory response after PSB treatment. These results revealed that PSB could potentially be utilized to treat UC and other diseases associated with an imbalance in the intestinal flora.

Resolvin D1 ameliorates hepatic steatosis by remodeling the gut microbiota and restoring the intestinal barrier integrity in DSS-induced chronic colitis

BACKGROUND AND PURPOSE

The maintenance of intestinalmucosalbarrier function plays an important role in hepatic steatosis. Increasing evidence has shown that resolvin D1 (RVD1) exerts a potential effect on hepatic steatosis. The aims of this study were to explore the mechanisms of RVD1 on hepatic steatosis based on the gut-liver axis and intestinal barrier function.

EXPERIMENTAL APPROACH

We established a DSS-induced chronic colitis model to evaluate hepatic steatosis. RVD1 was administered i.p. during the last 4 weeks. The colon and liver samples were stained with hematoxylin and eosin for histopathological analysis. The expression levels of intestinal tight junction genes and inflammatory genes were determined by quantitative PCR. The serum levels of glucose, cholesterol, triglycerides and LPS were measured, and the gut microbiota was analyzed by 16S rRNA gene sequencing.

KEY RESULTS

RVD1 prevented weight loss, histopathological changes, and elevated levels of inflammatory cytokines. Moreover, RVD1 administration attenuated DSS-induced hepatic steatosis and inflammatory responses in mice. In addition, RVD1 improved intestinal barrier function by increasing levels of tight junction molecules and decreasing the plasma LPS levels. The RVD1-treated mice also showed a different gut microbiota composition compared with found in the mice belonging to the DSS group but similar to that in normal chow diet-fed mice.

CONCLUSIONS AND IMPLICATIONS

RVD1 treatment ameliorates DSS-induced hepatic steatosis by ameliorating gut inflammation, improving intestinal barrier function and modulating intestinal dysbiosis.

Facilitation of colonic T cell immune responses is associated with an exacerbation of dextran sodium sulfate-induced colitis in mice lacking microsomal prostaglandin E synthase-1

Background

Microsomal prostaglandin E synthase-1 (mPGES-1) is a key enzyme that acts downstream of cyclooxygenase and plays a major role in inflammation by converting prostaglandin (PG) H₂ to PGE₂. The present study investigated the effect of genetic deletion of mPGES-1 on the development of immunologic responses to experimental colitis induced by dextran sodium sulfate (DSS), a well-established model of inflammatory bowel disease (IBD).

Methods

Colitis was induced in mice lacking mPGES-1 (mPGES-1^−/− mice) and wild-type (WT) mice by administering DSS for 7 days. Colitis was assessed by body weight loss, diarrhea, fecal bleeding, and histological features. The colonic expression of mPGES-1 was determined by real-time PCR, western blotting, and immunohistochemistry. The impact of mPGES-1 deficiency on T cell immunity was determined by flow cytometry and T cell depletion in vivo.

Results

After administration of DSS, mPGES-1^−/− mice exhibited more severe weight loss, diarrhea, and fecal bleeding than WT mice. Histological analysis further showed significant exacerbation of colonic inflammation in mPGES-1^−/− mice. In WT mice, the colonic expression of mPGES-1 was highly induced on both mRNA and protein levels and colonic PGE₂ increased significantly after DSS administration. Additionally, mPGES-1 protein was localized in the colonic mucosal epithelium and infiltrated inflammatory cells in underlying connective tissues and the lamina propria. The abnormalities consistent with colitis in mPGES-1^−/− mice were associated with higher expression of colonic T-helper (Th)17 and Th1 cytokines, including interleukin 17A and interferon-γ. Furthermore, lack of mPGES-1 increased the numbers of Th17 and Th1 cells in the lamina propria mononuclear cells within the colon, even though the number of suppressive regulatory T cells also increased. CD4⁺ T cell depletion effectively reduced symptoms of colitis as well as colonic expression of Th17 and Th1 cytokines in mPGES-1^−/− mice, suggesting the requirement of CD4⁺ T cells in the exacerbation of DSS-induced colitis under mPGES-1 deficiency.

Conclusions

These results demonstrate that mPGES-1 is the main enzyme responsible for colonic PGE₂ production and deficiency of mPGES-1 facilitates the development of colitis by affecting the development of colonic T cell–mediated immunity. mPGES-1 might therefore impact both the intestinal inflammation and T cell–mediated immunity associated with IBD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41232-021-00188-1.

Effect of Extracellular Vesicles Derived From Lactobacillus plantarum Q7 on Gut Microbiota and Ulcerative Colitis in Mice

Probiotics plays an important role in regulating gut microbiota and maintaining intestinal homeostasis. Extracellular vesicles (EVs) derived from probiotics have emerged as potential mediators of host immune response and anti-inflammatory effect. However, the anti-inflammatory effect and mechanism of probiotics derived EVs on inflammatory bowel disease (IBD) remains unclear. In this study, the effect of Lactobacillus plantarum Q7-derived extracellular vesicles (Q7-EVs) on gut microbiota and intestinal inflammation was investigated in C57BL/6J mice. The results showed that Q7-EVs alleviated DSS-induced colitis symptoms, including colon shortening, bleeding, and body weight loss. Consumption of Q7-EVs reduced the degree of histological damage. DSS-upregulated proinflammatory cytokine levels including IL-6, IL-1β, IL-2 and TNF-α were reduced significantly by Q7-EVs (p < 0.05). 16S rRNA sequencing results showed that Q7-EVs improved the dysregulation of gut microbiota and promoted the diversity of gut microbiota. It was observed that the pro-inflammatory bacteria (Proteobacteria) were reduced and the anti-inflammatory bacteria (Bifidobacteria and Muribaculaceae) were increased. These findings indicated that Q7-EVs might alleviate DSS-induced ulcerative colitis by regulating the gut microbiota.

MTDH Promotes Intestinal Inflammation by Positively Regulating TLR Signalling

Macrophages in the intestinal mucosa can rapidly engage Toll-like receptor [TLR]-mediated inflammatory responses to protect against pathogen invasion, but these same innate immune responses can also drive the induction of colitis. Our previous research revealed that metadherin [MTDH] is overexpressed in multiple cancers and plays vital roles in tumour progression. However, the role of MTDH in intestinal inflammation is largely unknown. In this study, we found the MTDH expression in colonic lamina propria [CLP] macrophages was positively correlated with inflammatory colitis severity. MTDH-/- mice were protected against the symptoms of dextran sodium sulphate [DSS]-induced colitis; however, adoptive transfer of MTDH wild-type [WT] monocytes partially restored the susceptibility of MTDH-/- mice to DSS-induced colitis. TLR stimulation was sufficient to induce the expression of MTDH, whereas the absence of MTDH was sufficient to suppress TLR-induced production of inflammatory cytokines by macrophages. From a mechanistic perspective, MTDH recruited TRAF6 to TAK1, leading to TRAF6-mediated TAK1 K63 ubiquitination and phosphorylation, ultimately facilitating TLR-induced NF-κB and MAPK signalling. Taken together, our results indicate that MTDH contributes to colitis development by promoting TLR-induced pro-inflammatory cytokine production in CLP macrophages and might represent a potential therapeutic approach for intestine inflammation intervention.

Weilan gum oligosaccharide ameliorates dextran sulfate sodium‑induced experimental ulcerative colitis

Ulcerative colitis (UC) is a global disease, characterized by periods of relapse that seriously affects the quality of life of patients. Oligosaccharides are considered to be a prospective strategy to alleviate the symptoms of UC. The present study aimed to evaluate the effect of weilan gum oligosaccharide (WLGO) on a mouse UC model induced by dextran sulfate sodium (DSS). WLGO structural physical properties were characterized by electrospray mass spectrometry and fourier tansform infrared spectroscopy. MTT assays were performed to evaluate the non‑toxic concentration of WLGO. RT‑qPCR and ELISAs were conducted to determine the levels of inflammatory factors. The clinical symptoms and mucosal integrity of the DSS‑induced UC model were assessed by DAI and histological assessment. LPS‑induced Caco‑2 cells and DSS‑induced UC mice were used to explore the effects of WLGO on UC. Treatment of the mice with 4.48 g/kg/day WLGO via gavage for 7 days significantly relieved the symptoms of DSS‑induced UC model mice, whereas significant effects were not observed for all symptoms of DSS‑induced UC in the WLGO‑low group. The disease activity index score was decreased and the loss of body weight was reduced in DSS‑induced UC model mice treated with WLGO. Moreover, colonic damage and abnormally short colon length shortenings were relieved following WLGO treatment. WLGO treatment also reduced the concentration and mRNA expression levels of proinflammatory cytokines, including interleukin‑1β, interleukin‑6 and tumor necrosis factor α, in DSS‑induced UC model mice and lipopolysaccharide‑treated Caco‑2 cells. These results indicated that WLGO may be an effective strategy for UC treatment.

Long noncoding RNA KIF9-AS1 promotes cell apoptosis by targeting the microRNA-148a-3p/suppressor of cytokine signaling axis in inflammatory bowel disease

OBJECTIVE

Inflammatory bowel disease (IBD) is a chronic intestinal disease. This study was attempted to investigate the effects of long noncoding RNA KIF9-AS1 (KIF9-AS1) on the development of IBD and its underlying mechanism of action.

METHODS

Quantitative real time PCR (qRT-PCR) was implemented to examine the expression of KIF9-AS1 and microRNA-148a-3p (miR-148a-3p). The IBD mouse model was induced by dextran sulfate sodium (DSS). The body weight, disease activity index (DAI) score, colon length and histological injury were used to evaluate the colon injury. The levels of proinflammatory cytokines were measured by ELISA. In vitro, IBD was simulated by DSS treatment in colonic cells. Then the apoptosis of colonic cells was detected by flow cytometry assay. Furthermore, a dual-luciferase reporter assay was used to demonstrate the interactions among KIF9-AS1, miR-148a-3p and suppressor of cytokine signaling (SOCS3).

RESULTS

KIF9-AS1 expression was upregulated in IBD patients, DSS-induced IBD mice and DSS-induced colonic cells, whereas miR-148a-3p expression was downregulated. KIF9-AS1 silencing attenuated the apoptosis of DSS-induced colonic cells in vitro and alleviated colon injury and inflammation in DSS-induced IBD mice in vivo. Additionally, the mechanical experiment confirmed that KIF9-AS1 and SOCS3 were both targeted by miR-148a-3p with the complementary binding sites at 3'UTR. Moreover, miR-148a-3p inhibition or SOCS3 overexpression reversed the suppressive effect of KIF9-AS1 silencing on the apoptosis of DSS-induced colonic cells.

CONCLUSION

KIF9-AS1 silencing hampered the colon injury and inflammation in DSS-induced IBD mice in vivo, and restrained the apoptosis of DSS-induced colonic cells by regulating the miR-148a-3p/SOCS3 axis in vitro, providing a new therapeutic target for IBD.

Akkermansia muciniphila Protects Against Psychological Disorder-Induced Gut Microbiota-Mediated Colonic Mucosal Barrier Damage and Aggravation of Colitis

Psychological disorders are associated with increased risk of severe inflammatory bowel disease (IBD) by causing gut microbiota dysbiosis and colonic mucosal barrier damage. However, the interaction between chronic restraint stress (CRS), gut microbiota composition, and colonic mucus remains unclear. We demonstrated that mice under CRS conditions exhibited alterations in microbiota composition, disruption of colonic mucus, and aggravation of colitis. In addition, the abundance of Akkermansia muciniphila was significantly decreased in mice under CRS and UC patients with depression, and positively associated with the expression of MUC2. After antibiotic treatment, the recipient mice colonized with CRS microbiota showed barrier defects and severe colitis. Administration of Akkermansia muciniphila was found to restore colonic mucus and modify the gut microbiota. We confirm that CRS-mediated gut microbiota dysbiosis results in colonic mucosal barrier damage and aggravation of colitis. Our results suggest that A. muciniphila is expected to be a potential probiotic to protect and treat colonic mucus that is involved in IBD with psychological disorders.

Anneslea fragrans Wall. ameliorates ulcerative colitis via inhibiting NF-κB and MAPK activation and mediating intestinal barrier integrity

ETHNOPHARMACOLOGICAL RELEVANCE

Anneslea fragrans Wall. is traditionally used as a folk medicine in treating indigestion, fever, dysentery, diarrhea, and liver inflammation in China, Vietnam and Cambodia. However, its anti-inflammatory activity and mechanism under a safety therapeutic dose as well as the main chemical components have not yet been fully investigated.

AIM OF THE STUDY

This study aimed to explore the therapeutic effect and possible molecular mechanisms of aqueous-methanol extract (AFE) of A. fragrans leaves on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mice and illustrate its potent anti-inflammatory chemical compounds.

MATERIALS AND METHODS

The AFE was obtained and then analyzed by high performance liquid chromatography (HPLC). Phytochemical investigation on the AFE was carried out to isolate and characterize its major components. The acute toxicity test was performed to provide the safety information of AFE. Subsequently, the protective effect of AFE on DSS-induced UC was evaluated by physiological changes, histopathological and immunohistochemical analysis, and the expressions of antioxidant enzyme, pro-inflammatory cytokines and anti-inflammatory cytokines. The expressions of target proteins in nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) were determined by western blot analysis. The tight junction (TJ) proteins in colon tissue were performed by immunohistochemical technique for evaluating the intestinal barrier integrity.

RESULTS

HPLC guided isolation of AFE resulted into two dihydrochalcones, which were elucidated as vacciniifolin (1) and confusoside (2). Acute toxicity evaluation revealed that median lethal dose (LD₅₀) of AFE was greater than 5000 mg/kg. Furthermore, AFE significantly attenuated ulcerative colitis symptoms, suppressed myeloperoxidase activity, and increased the expression of superoxide dismutase and glutathione. AFE treatment could also reduce the levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 and increase the levels of interleukin-4 and interleukin-10 in colon tissues and serum of DSS-induced UC mice. In addition, AFE significantly increased the expression of zonula occludens-1, occludin and claudin-1, and inhibited the phosphorylation of target protein of the NF-κB and MAPK signaling pathways in colon tissue.

CONCLUSION

Dihydrochalcone glycosides are the major chemical constituents in AFE. AFE ameliorated DSS-induced UC in mice by inhibiting the inflammatory response via modulation of NF-κB and MAPK pathways and maintaining the intestinal barrier function, indicating that the plant A. fragrans could be used as a therapeutic candidate for ulcerative colitis.

Butyrate functions in concert with myeloid-derived suppressor cells recruited by CCR9 to alleviate DSS-induced murine colitis

Ulcerative colitis (UC) is a precancerous disease caused mainly by a combination of genetic susceptibility, environmental factors and microbiota dysbiosis. As a kind of short-chain fatty acid (SCFA), butyrate has been shown to be closely related to the progression of colitis. However, the exact regulatory mechanism of butyrate in colitis needs to be further elucidated. In our current research, the effects of butyrate were examined in a dextran sulfate sodium (DSS)-induced murine colitis model, which simulates human UC. The administration of butyrate significantly reversed the signs of colitis and alleviated colonic histological damage in DSS‑induced colitis. The transcription levels of the main proinflammatory mediators, including tumor necrosis factor-α, interleukin-6 and interleukin-12, were also reduced, as determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). This indicates that butyrate could alleviate DSS-induced colitis by inhibiting proinflammatory mediators. In addition, we found that myeloid-derived suppressor cells (MDSCs), which have an inflammation-relieving effect, did not effectively alleviate DSS‑induced colitis but showed a compensatory increase in the DSS group. However, the compensatory increase in MDSCs in the DSS group significantly decreased after butyrate treatment. Moreover, the chemokine receptor CCR9, which mediates the homing of intestinal immune cells, also showed consistent changes similar to MDSCs. Butyrate alone did not have the aforementioned effects on mice. Thus, butyrate may effectively relieve DSS‑induced colitis by synergistic regulatory effects with MDSCs, which migrate and gather through CCR9 recruitment.

Astragaloside IV Alleviates the Experimental DSS-Induced Colitis by Remodeling Macrophage Polarization Through STAT Signaling

Inflammatory bowel disease (IBD) is characterized by chronic and relapsing intestinal inflammation, which currently lacks safe and effective medicine. Some previous studies indicated that Astragaloside IV (AS-IV), a natural saponin extracted from the traditional Chinese medicine herb Ligusticum chuanxiong, alleviates the experimental colitis symptoms in vitro and in vivo. However, the mechanism of AS-IV on IBD remains unclear. Accumulating evidence suggests that M2-polarized intestinal macrophages play a pivotal role in IBD progression. Here, we found that AS-IV attenuated clinical activity of DSS-induced colitis that mimics human IBD and resulted in the phenotypic transition of macrophages from immature pro-inflammatory macrophages to mature pro-resolving macrophages. In vitro, the phenotype changes of macrophages were observed by qRT-PCR after bone marrow-derived macrophages (BMDMs) were induced to M1/M2 and incubated with AS-IV, respectively. In addition, AS-IV was effective in inhibiting pro-inflammatory macrophages and promoting the pro-resolving macrophages to ameliorate experimental colitis via the regulation of the STAT signaling pathway. Hence, we propose that AS-IV can ameliorate experimental colitis partially by modulating macrophage phenotype by remodeling the STAT signaling, which seems to have an essential function in the ability of AS-IV to alleviate the pathological progress of IBD.