Experimental Colitis Model Research Articles

Anti-inflammatory activity of peiminine in acetic acid-induced ulcerative colitis model.

Ulcerative colitis is a chronic inflammatory disorder of the intestinal mucosa and a prevalent gastrointestinal condition in developed countries. Peiminine, derived from the Fritillaria imperialis plant, exhibits remarkable anti-inflammatory and anti-cancer properties. This study aims to investigate the anti-inflammatory effects of peiminine in an experimental model of ulcerative colitis. Ulcerative colitis was induced intra-rectally in all groups, except the negative control, using 100 μl of 4% acetic acid. Peiminine treatment was initiated after ulcerative colitis induction and symptom manifestation. After the final injection, mice were sacrificed on day 15 for assessment. Various parameters were evaluated, including disease activity index, myeloperoxidase activity, nitric oxide levels, production and expression of IL-1, IL-6, TNF-α cytokines, and expression of IL-1β, IL-6, TNF-α, iNOS, and COX2 genes. Microscopic pathological evaluation was performed on colon tissue. Peiminine treatment resulted in reduced levels of NO, MPO, IL-1β, IL-6, and TNF-α. Furthermore, the expression of IL-1β, IL-6, TNF-α genes, iNOS, and COX2 genes was decreased in response to peiminine treatment in these mice. This study demonstrates the effectiveness of peiminine in alleviating inflammatory manifestations and mitigating intestinal tissue damage in an experimental model of ulcerative colitis, probably by anti-inflammatory procedure. Peiminine holds potential as a therapeutic adjunct for the management of ulcerative colitis.

Intestinal Anti-inflammatory Effects of Linum usitatissimum Alkaloid on Experimental Ulcerative Colitis in BALB/c Mice

Introduction: There is growing interest in alternative therapies for managing inflammatory bowel disorders (IBD) that offer efficacy and a suitable safety profile. The present study aimed to evaluate the intestinal anti-inflammatory effect of the alkaloid extract of Linum usitatissimum (ALU) on the acetic acid (AA) experimental model of colitis. Methods: For in vivo experiments, an 8-day 5% acetic acid administration protocol was used in BALB/c mice to induce colitis. The intestinal anti-inflammatory effect of oral ALU (12.5, 25, and 50mg/kg) was evaluated after 8 days. Colon damage was evaluated macroscopically (colon weight/ colon length), and the histological alterations were also assessed. Results: ALU treatment significantly reduced signs of intestinal inflammation compared to the Acetic acid control mice, confirmed by histological examination. Conclusion: These results suggest that the total alkaloid extract from Linum usitatissimum seeds has potent intestinal anti-inflammatory properties and may be a promising treatment for ulcerative colitis.

Anti-Inflammatory Effects of Synthetic Peptides Based on Glucocorticoid-Induced Leucine Zipper (GILZ) Protein for the Treatment of Inflammatory Bowel Diseases (IBDs).

Glucocorticoids (GCs) are commonly used to treat autoimmune and inflammatory diseases, but their clinical effects and long-term use can lead to serious side effects. New drugs that can replace GCs are needed. Glucocorticoid-induced leucine zipper (GILZ) is induced by GCs and mediates many of their anti-inflammatory effects, such as inhibiting the pro-inflammatory molecule NF-κB. The GILZ C-terminal domain (PER region) is responsible for GILZ/p65NF-κB interaction and consequent inhibition of its transcriptional activity. A set of five short peptides spanning different parts of the PER region of GILZ protein was designed, and their anti-inflammatory activity was tested, both in vitro and in vivo. We tested the biological activity of GILZ peptides in human lymphocytic and monocytic cell lines to evaluate their inhibitory effect on the NF-κB-dependent expression of pro-inflammatory cytokines. Among the tested peptides, the peptide named PEP-1 demonstrated the highest efficacy in inhibiting cell activation in vitro. Subsequently, PEP-1 was further evaluated in two in vivo experimental colitis models (chemically induced by DNBS administration and spontaneous colitis induced in IL-10 knock-out (KO) mice (to assess its effectiveness in counteracting inflammation. Results show that PEP-1 reduced disease severity in both colitis models associated with reduced NF-κB pro-inflammatory activity in colon lamina propria lymphocytes. This study explored GILZ-based 'small peptides' potential efficacy in decreasing lymphocyte activation and inflammation associated with experimental inflammatory bowel diseases (IBDs). Small peptides have several advantages over the entire protein, including higher selectivity, better stability, and bioavailability profile, and are easy to synthesize and cost-effective. Thus, identifying active GILZ peptides could represent a new class of drugs for treating IBD patients.

Nanoencapsulation of Curcuma longa L. extract for the treatment of experimental colitis

Inflammatory bowel diseases (IBDs) are gastrointestinal chronic inflammatory diseases characterized by chronic and recurrent intestinal ulcerations. Curcuminoids are naturally occurring polyphenolic compounds with remarkable bioactivity; however, their low water affinity and bioavailability usually hinder their application. Encapsulation techniques can be coupled with extraction procedures to yield nanoparticles that may have enhanced properties. In this work, curcuminoids were extracted from rhizomes of Curcuma longa L. and simultaneously encapsulated using ultrasound. The characterization of the curcuminoids nanoparticles showed that particles ranging from 124 ± 81 to 252 ± 68 nm were formed, and the main properties of the curcuminoids were maintained after encapsulation. Experimental colitis was induced in rats by 2,4,6-trinitrobenzene sulfonic acid, and they were subsequently treated with 10, 25, or 50 mg kg-1 of nanoencapsulated curcuminoids for 7 days through gavage, during which the disease activity index (DAI) was evaluated. Then the rats were euthanized, and the distal colon was removed for macroscopic analysis and the assessment of the activity of the enzymes myeloperoxidase and N-acetylglucosaminidase. The dose of 25 mg kg-1 of nanoencapsulated curcuminoids reduced the DAI and the activity of inflammatory enzymes compared to the untreated group and was established as the minimum effective dose to be used in the treatment of this model of experimental colitis in rats.

CPW partially attenuates DSS-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Mirabegron alleviates acetic acid-induced colitis in rats: Role of adiponectin and GSTM1/GSH detoxification pathway

The prevalence of the debilitating chronic disease ulcerative colitis (UC) is increasing significantly. Mirabegron is a selective beta-3 adrenergic receptor (β-3 AR) agonist used to treat an overactive bladder. Previous reports have demonstrated the antidiarrheal effect of β-3AR agonists. Therefore, the current study aims to investigate the potential symptomatic effects of mirabegron on an experimental colitis model. The effects of oral administration of mirabegron (10 mg/kg) for seven days on rats receiving intra-rectal acetic acid instillation on the sixth day were examined using adult male Wistar rats. Sulfasalazine was utilized as a reference medication. Gross, microscopic, and biochemical observations of the experimental colitis were performed. The quantity and mucin content of goblet cells were found to have significantly decreased in the colitis group. In the colons of rats administered mirabegron, the number of goblet cells and the optical density of its mucin content increased. Mirabegron’s ability to increase adiponectin in serum and decrease glutathione, GSTM1, and catalase in the colon may account for its protective effects. In addition, mirabegron decreased the expression of the proteins caspase-3 and NF-κB p65. It also prevented the activation of their upstream signaling receptors TLR4 and p-AKT by acetic acid administration. In conclusion, mirabegron prevented acetic acid-induced colitis in rats, possibly due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

Protective effect of the novel calcineurin inhibitor voclosporin in experimental colitis.

Acute severe steroid-refractory ulcerative colitis remains a medically challenging condition with frequent need of surgery. It can be treated with the calcineurin inhibitor cyclosporine A with the need for therapeutic drug monitoring and significant toxicity. Recently, a novel calcineurin inhibitor, voclosporin, has been approved for the treatment of lupus nephritis with no need for therapeutic drug monitoring and an improved long-term safety profile. However, the therapeutic effect of voclosporin in acute severe steroid-refractory ulcerative colitis is still uncertain. We aimed to assess the therapeutic potential of voclosporin to ameliorate inflammation in an experimental model of colitis. We used the dextran sodium sulfate-induced model of colitis in C57BL/6 J wildtype mice treated with either cyclosporine A, voclosporin or solvent control. We employed endoscopy, histochemistry, immunofluorescence, bead-based multiplex immunoassays and flow cytometry to study the therapeutic effect of calcineurin inhibitors in a preventive setting. Acute colitis was induced by dextran sodium sulfate characterized by weight loss, diarrhea, mucosal erosions and rectal bleeding. Both cyclosporine A and voclosporin strongly ameliorated the course of disease and reduced colitis severity in a similar manner. Voclosporin was identified as biologically effective in a preclinical model of colitis and may be a potential therapeutic option in treating acute severe steroid-refractory ulcerative colitis.

Mutant LRRK2 exacerbates immune response and neurodegeneration in a chronic model of experimental colitis

The link between the gut and the brain in Parkinson’s disease (PD) pathogenesis is currently a subject of intense research. Indeed, gastrointestinal dysfunction is known as an early symptom in PD and inflammatory bowel disease (IBD) has recently been recognised as a risk factor for PD. The leucine-rich repeat kinase 2 (LRRK2) is a PD- and IBD-related protein with highest expression in immune cells. In this study, we provide evidence for a central role of LRRK2 in gut inflammation and PD. The presence of the gain-of-function G2019S mutation significantly increases the disease phenotype and inflammatory response in a mouse model of experimental colitis based on chronic dextran sulphate sodium (DSS) administration. Bone marrow transplantation of wild-type cells into G2019S knock-in mice fully rescued this exacerbated response, proving the key role of mutant LRRK2 in immune cells in this experimental colitis model. Furthermore, partial pharmacological inhibition of LRRK2 kinase activity also reduced the colitis phenotype and inflammation. Moreover, chronic experimental colitis also induced neuroinflammation and infiltration of peripheral immune cells into the brain of G2019S knock-in mice. Finally, combination of experimental colitis with overexpression of α-synuclein in the substantia nigra aggravated motor deficits and dopaminergic neurodegeneration in G2019S knock-in mice. Taken together, our results link LRRK2 with the immune response in colitis and provide evidence that gut inflammation can impact brain homeostasis and contribute to neurodegeneration in PD.

Juglone Mediates Inflammatory Bowel Disease Through Inhibition of TLR-4/NF KappaB Pathway in Acetic Acid-induced Colitis in Rats.

Juglone is a phenolic bioactive compound with antimicrobial, antitumour, antioxidant, and anti-inflammatory characteristics. Given its anti-inflammatory and antioxidant effects, it was selected for evaluation in the inflammatory bowel diseases (IBD) model. The current study was performed to evaluate the therapeutic impacts of the juglone in acetic acid-induced colitis in male Wistar rats. Juglone was extracted from Pterocarya fraxinifolia via maceration method. Colitis was induced in 36 male Wistar rats (n = 6), except in the sham group, 1 ml of acetic acid 4% was administered intrarectally. Twenty-four hours after induction of colitis, in 3 groups, juglone was administered orally (gavage) at 3 doses of 50, 100, and 150 mg/kg for 2 successive days (once a day). Other groups included the control group (only treated with acetic acid), sham group (normal saline), and standard group (Dexamethasone). To evaluate the inflammation sites, macroscopic and microscopic markers were assessed. The mRNA expression of interleukin (IL)-1β, and tumor necrosis factor-alpha (TNF)-α were assessed by real-time PCR, while myeloperoxidase (MPO) was measured spectrophotometrically. ELISA assay kits were used to determine the colonic levels of SOD, ROS, NF-κB, and TLR-4. Macroscopic and microscopic assessments revealed that juglone significantly decreased colonic tissue damage and inflammation at 150 mg/kg. Juglone at 100, 150 mg/kg significantly decreased the TNF-α, MPO, and TLR-4 levels, as well as the SOD activity. All juglone-treated groups reduced the NF-κB levels compared to the control group (p < 0.001). The compound decreased the IL-1β, and ROS levels at the concentration of 150 mg/kg. Juglone attenuated colitis symptoms, reduced inflammation cytokines, declined neutrophil infiltration, and suppressed IL- 1β and TNF-α expressions in acetic acid-induced colitis rats. It may be proposed that juglone improved colitis in animal model through suppression of inflammatory parameters and downregulation of the NF-κB-TLR-4 pathway. Juglone exhibited anti-inflammatory and antioxidant effects in the experimental colitis model and could be a therapeutic candidate for IBD. Juglone should be a subject for further animal and clinical trials in IBD models and for safety concerns.

Differential Effects of Ontamalimab Versus Vedolizumab on Immune Cell Trafficking in Intestinal Inflammation and Inflammatory Bowel Disease.

The anti-MAdCAM-1 antibody ontamalimab demonstrated efficacy in a phase II trial in ulcerative colitis and results of early terminated phase III trials are pending, but its precise mechanisms of action are still unclear. Thus, we explored the mechanisms of action of ontamalimab and compared it to the anti-α4β7 antibody vedolizumab. We studied MAdCAM-1 expression with RNA sequencing and immunohistochemistry. The mechanisms of action of ontamalimab were assessed with fluorescence microscopy, dynamic adhesion and rolling assays. We performed in vivo cell trafficking studies in mice and compared ontamalimab and vedolizumab surrogate [-s] antibodies in experimental models of colitis and wound healing. We analysed immune cell infiltration under anti-MAdCAM-1 and anti-α4β7 treatment by single-cell transcriptomics and studied compensatory trafficking pathways. MAdCAM-1 expression was increased in active inflammatory bowel disease. Binding of ontamalimab to MAdCAM-1 induced the internalization of the complex. Functionally, ontamalimab blocked T cell adhesion similar to vedolizumab, but also inhibited L-selectin-dependent rolling of innate and adaptive immune cells. Despite conserved mechanisms in mice, the impact of ontamalimab-s and vedolizumab-s on experimental colitis and wound healing was similar. Single-cell RNA sequencing demonstrated enrichment of ontamalimab-s-treated lamina propria cells in specific clusters, and in vitro experiments indicated that redundant adhesion pathways are active in these cells. Ontamalimab has unique and broader mechanisms of action compared to vedolizumab. However, this seems to be compensated for by redundant cell trafficking circuits and leads to similar preclinical efficacy of anti-α4β7 and anti-MAdCAM-1 treatment. These results will be important for the interpretation of pending phase III data.

Inhibition of NADPH Oxidase (NOX) 2 Mitigates Colitis in Mice with Impaired Macrophage AMPK Function.

Macrophage adenosine monophosphate-activated protein kinase (AMPK) limits the development of experimental colitis. AMPK activation inhibits NADPH oxidase (NOX) 2 expression, reactive oxygen species (ROS) generation, and pro-inflammatory cytokine secretion in macrophages during inflammation, while increased NOX2 expression is reported in experimental models of colitis and inflammatory bowel disease (IBD) patients. Although there are reductions in AMPK activity in IBD, it remains unclear whether targeted inhibition of NOX2 in the presence of defective AMPK can reduce the severity of colitis. Here, we investigate whether the inhibition of NOX2 ameliorates colitis in mice independent of AMPK activation. Our study identified that VAS2870 (a pan-Nox inhibitor) alleviated dextran sodium sulfate (DSS)-induced colitis in macrophage-specific AMPKβ1-deficient (AMPKβ1LysM) mice. Additionally, VAS2870 blocked LPS-induced TLR-4 and NOX2 expression, ROS production, nuclear translocation of NF-κB, and pro-inflammatory cytokine secretion in bone marrow-derived macrophages (BMDMs) from AMPKβ1LysM mice, whereas sodium salicylate (SS; AMPK β1 activator) did not. Both VAS2870 and SS inhibited LPS-induced NOX2 expression, ROS production, and pro-inflammatory cytokine secretions in bone marrow-derived macrophages (BMDMs) from wildtype (AMPKβ1fl/fl) mice but only VAS2870 inhibited these effects of LPSs in AMPKβ1LysM BMDMs. Furthermore, in macrophage cells (RAW 264.7), both SS and VAS2870 inhibited ROS production and the secretion of pro-inflammatory cytokines and reversed the impaired autophagy induced by LPSs. These data suggest that inhibiting NOX2 can reduce inflammation independent of AMPK in colitis.

Lafoensia pacari alleviates intestinal damage by modulating cyclooxygenase-2: In silico and in vivo evaluation in a colitis model.

Inflammatory bowel diseases (IBD) are a worldwide health problem and mainly affect young people, consequently affecting the workforce. Available treatments are often associated with side effects, and new therapeutic options are needed. For centuries, plants have represented important substrates in the field of drug development. Lafoensia pacari (L. pacari) is a plant whose pharmaceutical potential has been described, and may have biological activity relevant to the treatment of IBD symptoms. To investigate the activity of keto-alcoholic extracts of L. pacari with respect to ameliorating the inflammatory and nociceptive symptoms of acute experimental colitis in mice. Keto-alcoholic extracts of L. pacari leaves and bark were administered to male and female Swiss mice weighing 25 g to 30 g (n = 8 male mice and n = 8 female mice). The effect of these extracts was observed in an acetic acid-induced acute experimental model of colitis with regard to antinociception/analgesia and inflammatory tissue damage. Recorded macroscopic indices included the Wallace score and the colon weight obtained using a precision scale. Mechanical hyperalgesia was determined using an electronic analgesimeter. Behavior related to overt pain was determined by quantifying the number of writhing instances within 20 min of administration of acetic acid. Molecular docking was performed using human and murine cyclooxygenase-2 (COX-2) with 3 flavonoids (ellagic acid, kaempferol, and quercetin) on the AutoDock Vina software. Analysis of variance followed by Tukey's posttest was used with P < 0.05 indicating significance. In this murine model of colitis, administration of extracts from L. pacari ameliorated acetic acid-induced writhing and colitis-associated inflammatory pain. These improvements may be attributable to the reduction in edema, inflammation (e.g., ulcers, hyperemia, and bowel wall damage), and the intensity of abdominal hyperalgesia. The keto-alcoholic extracts of L. pacari leaves and bark administered at a dose of either 100 mg/kg or 300 mg/kg significantly reduced the number of writhing events when compared to the negative control (P < 0.05). Additionally, extracts of L. pacari bark also performed better than Dipyrone. Leaf extracts administered at 10 mg/kg, 30 mg/kg, and 100 mg/kg and bark extracts administered at 30 mg/kg significantly reduced or prevented the development of edema in the colon of treated mice, while mesalazine did not. Moreover, using molecular docking, we observed that the flavonoids present in L. pacari extracts bind to COX-2, an event not unique to ellagic acid. The results of this study demonstrate a potential novel application of L. pacari extracts for the reduction of inflammation and promotion of antinociception/analgesia as demonstrated by our findings in a murine model of colitis. These findings were also corroborated by in silico analyses, and suggest that L. pacari extracts may be a promising therapeutic agent in the treatment of IBD.

DJ-X-013 ameliorates inflammation by reducing TNF-α/NF-κB expression and experimental colitis by inducing myeloid-derived suppressor cells

Abstract Inflammation is a body’s defense response for a short duration however if persists for long periods, it causes tissue damage and pathological consequences. Moreover, it paves the way for several diseases including inflammatory bowel disease (IBD). Therefore, there is an urgent need for a natural and safe anti-inflammatory therapeutic compound. To address this issue, we aimed to determine the anti-inflammatory effects of DJ-X-013, using lipopolysaccharide (LPS) activated RAW 264.7 macrophage in vitro and dextran sodium sulfate (DSS) induced experimental model of colitis in vivo. DJ-X-013 drastically reduced tumor necrosis factor-alpha and inducible nitric oxide synthase expression in LPS-activated RAW 264.7 macrophages. Further, DJ-X-013 also impeded the expression of NF-κB and other inflammatory markers and pathways like IL-6, IL-1β, STAT3, ERK, and JNK as compared to LPS-activated cells. Additionally, DJ-X-013 also modulates the migratory activity of RAW 264.7 macrophages during wound healing. Next, using DSS induced colitis model, we observed that the reduction of body weight and colon length were slightly improved in the DJ-X-013 group compared to the control. Intriguingly, myeloid-derived suppressor cells, neutrophils, and CD8 +T cells increased, while Th17 cells frequency decreased in the spleen, mesenteric lymph nodes, and colon lamina propria in DJ-X-013 treated group as compared to DSS. However, natural killer and natural killer T cells were marginally enhanced in the DJ-X-013 group as compared to the DSS alone. Hence, the DJ-X-013 exhibits an immunomodulatory effect and might be a promising drug for IBD and other inflammatory diseases, however, further investigation is required for prudent conclusions. This research is supported by NIH grant R01 AI140405

Network pharmacology-based identification of bioavailable anti-inflammatory agents from Psoralea corylifolia L. in an experimental colitis model

Ethnopharmacological relevanceIn traditional oriental medicine, the dried seeds of Psoralea corylifolia L. (PC) have been used to treat various diseases, including gastrointestinal, urinary, orthopedic, diarrheal, ulcer, and inflammatory disorders. Aim of the studyAlthough its various biological properties are well-known, there is no information on the therapeutic effects and bioavailable components of PC against inflammatory bowel disease. Therefore, we focused on the relationship between hydroethanolic extract of PC (EPC) that ameliorates colitis in mice and bioactive constituents of EPC that suppress pro-inflammatory cytokines in macrophages. Materials and methodsWe investigated the therapeutic effects of EPC in a dextran sulfate sodium-induced colitis mouse model and identified the orally absorbed components of EPC using UPLC-MS/MS analysis. In addition, we evaluated and validated the mechanism of action of the bioavailable constituents of EPC using network pharmacology analysis. The effects on nitric oxide (NO) and inflammatory cytokines were measured by Griess reagent and enzyme linked immunosorbent assay in lipopolysaccharide (LPS)-induced macrophages. ResultsIn experimental colitis, EPC improved body weight loss, colon length shortening, and disease activity index. Moreover, EPC reduced the serum levels of pro-inflammatory cytokines and histopathological damage to the colon. Network pharmacological analysis identified 13 phytochemicals that were bioavailable following oral administration of EPC, as well as their potential anti-inflammatory effects. 11 identified EPC constituents markedly reduced the overproduction of NO, tumor necrosis factor-α, and/or interleukin-6 in macrophages induced by LPS. The LPS-induced expression of the nuclear factor kappa-light-chain-enhancer of activated B cells reporter gene was reduced by the 4 EPC constituents. ConclusionsThe results indicate that the protective activity of EPC against colitis is a result of the additive effects of each constituent on the expression of inflammatory cytokines. Therefore, it suggests that 11 bioavailable phytochemicals of EPC could aid in the management of intestinal inflammation, and also provides useful insights into the clinical application of PC for the treatment of inflammatory bowel diseases.

Role of prebiotics, probiotics, and synbiotics in management of inflammatory bowel disease: Current perspectives.

Experimental evidence supports the fact that changes in the bowel microflora due to environmental or dietary factors have been investigated as implicating factors in the etiopathogenesis of inflammatory bowel disease (IBD). The amassing knowledge that the inhabited microbiome regulates the gut physiology and immune functions in IBD, has led researchers to explore the effectiveness of prebiotics, probiotics, and synbiotics in treating IBD. This therapeutic approach focuses on restoring the dynamic balance between the microflora and host defense mechanisms in the intestinal mucosa to prevent the onset and persistence of intestinal inflammation. Numerous microbial strains and carbohydrate blends, along with their combinations have been examined in experimental colitis models and clinical trials, and the results indicated that it can be an attractive therapeutic strategy for the suppression of inflammation, remission induction, and relapse prevention in IBD with minimal side effects. Several mechanisms of action of probiotics (for e.g., Lactobacillus species, and Bifidobacterium species) have been reported such as suppression of pathogen growth by releasing certain antimicrobial mediators (lactic and hydrogen peroxide, acetic acid, and bacteriocins), immunomodulation and initiation of an immune response, enhancement of barrier activity, and suppression of human T-cell proliferation. Prebiotics such as lactulose, lactosucrose, oligofructose, and inulin have been found to induce the growth of certain types of host microflora, resulting in an enriched enteric function. These non-digestible food dietary components have been reported to exert anti-inflammatory effects by inhibiting the expression of tumor necrosis factor-α-related cytokines while augmenting interleukin-10 levels. Although pro-and prebiotics has established their efficacy in healthy subjects, a better understanding of the luminal ecosystem is required to determine which specific bacterial strain or combination of probiotics and prebiotics would prove to be the ideal treatment for IBD. Clinical trials, however, have given some conflicting results, requiring the necessity to cite the more profound clinical effect of these treatments on IBD remission and prevention. The purpose of this review article is to provide the most comprehensive and updated review on the utility of prebiotics, probiotics, and synbiotics in the management of active Crohn's disease and ulcerative colitis/pouchitis.

Interleukin-35 and Interleukin-37 anti-inflammatory effect on inflammatory bowel disease: Application of non-coding RNAs in IBD therapy.

Inflammatory bowel disease (IBD) is a widespread autoimmune disease that may even be life-threatening. IBD is divided into two major subtypes: ulcerative colitis and Crohn's disease. Interleukin (IL)-35 and IL-37 are anti-inflammatory cytokines that belong to IL-12 and IL-1 families, respectively. Their recruitment relieves inflammation in various autoimmune diseases, including psoriasis, multiple sclerosis, rheumatoid arthritis, and IBD. Regulatory T cells (Tregs) and regulatory B cells (Bregs) are the primary producers of IL-35/IL-37. IL-35 and IL-37 orchestrate the regulation of the immune system through two main strategies: Blocking nuclear transcription factor kappa-B (NF-kB) and mitogen-activated protein kinase (MAPK) signaling pathways or promoting the proliferation of Tregs and Bregs. Moreover, IL-35 and IL-37 can also inhibit inflammation by adjusting the T helper (Th)17/Treg ratio balance. Among the anti-inflammatory cytokines, IL-35 and IL-37 have significant potential to reduce intestinal inflammation. Therefore, administering IL-35/IL-37-based drugs or blocking their inhibitor microRNAs could be a promising approach to alleviate IBD symptoms. Overall, in this review article, we summarized the therapeutic application of IL-35 and IL-37 in both human and experimental models of IBD. Also, it is hoped that this practical information will reach beyond IBD therapy and shed some light on treating all intestinal inflammations.

A Chemically Induced Experimental Colitis Model with a Simple Combination of Acetic Acid and Trinitrobenzene Sulphonic Acid.

It was aimed to induce a new experimental colitis model by using acetic acid and trinitrobenzene sulphonic acid together and to investigate the severity of inflammation biochemically and histopathologically in comparison with other models. Fifty-six Wistar albino male rats were randomly divided into 4 groups as control, acetic acid, trinitrobenzene sulphonic acid, and combined groups, and the animals were sacrificed following the induction of colitis on the third day and on the seventh day. The serum amyloid A and myeloperoxidase were tested in plasma samples, and the tumor necrosis factor-alpha, interleukin 33, and ST2 were assayed in colon tissue samples with enzyme-linked immunosorbent assay in addition to histopathological examination. There were statistically significant differences between the combined and the control groups both on the third day and on the seventh day in all parameters. There was no difference between the acetic acid group on the seventh day and the control groups in biochemical parameters. The acetic acid model forms acute colitis. The combined model is found to be more successful in forming inflammation when compared to other models.

The protective effect of IL-12/23 neutralizing antibody in sarcopenia associated with dextran sulfate sodium-induced experimental colitis.

The improvement of colitis symptoms by treatment with IL-12/23 p40 neutralizing antibody should increase the muscle mass and the function of the sarcopenia phenotype. An experimental colitis model was induced by oral administration of 2% dextran sulfate sodium (DSS) for 7days. During induction of colitis, IL-12/23 p40 neutralizing antibody was injected twice on Days 3 and 5. The total body mass index was measured by dual-energy X-ray absorptiometry. The muscle function was measured by forelimb grip strength and fatigue running distance. The muscle fibre cross-sectional area (CSA) was calculated after the transverse section and haematoxylin and eosin staining, and gene expression was confirmed by RT-qPCR. Differentiated C2C12 cells were used as in vitro models and treated with recombinant IL12/23 proteins to mimic the enhanced cytokines in colitis. The symptoms of colitis were alleviated by injection of IL-12/23 p40 neutralizing antibody compared with phosphate-buffered saline (PBS), and the disease activity index score was significantly lower on Day 8 (0.0±0.00 of cont. vs. 11.3±0.9 of DSS+PBS, P<0.0001; DSS+PBS vs. 7.7±1.25 of DSS+p40Ab, P<0.0001). The CSA of the gastrocnemius and tibialis anterior muscle fibres decreased in mice with DSS-induced colitis (gastrocnemius, 1258.2 μm2 ± 176.45 of cont. vs. 640.1 μm2 ± 59.83 of DSS + PBS, P < 0.0001; tibialis anterior, 1251.8 μm2 ± 331.48 of cont. vs. 678.9 μm2 ± 67.59 of DSS + PBS, P < 0.0001), and the treatment of IL-12/23 p40 neutralizing antibody partially restored CSA of the gastrocnemius (640.1 μm2 ± 59.83 of DSS + PBS vs. 1062.0 μm2 ± 83.41 of DSS + p40Ab, P < 0.0001) and tibialis anterior (678.9 μm2 ± 67.59 of DSS + PBS vs. 1105.3 μm2 ± 143.15 of DSS + p40Ab, P = 0.0003).vs. 640.1μm2 ±59.83 of DSS+PBS, P<0.0001) and tibialis anterior (1251.8μm2 ±331.48 of cont. vs. 678.9μm2 ±67.59 of DSS+PBS, P<0.0001), and the treatment of IL-12/23 p40 neutralizing antibody partially restored CSA of the gastrocnemius (640.1μm2 ±59.83 of DSS+PBS vs. 1062.0μm2 ±83.41 of DSS+p40Ab, P<0.0001) and tibialis anterior (678.9μm2 ±67.59 of DSS+PBS vs. 1105.3μm2 ±143.15 of DSS+p40Ab, P=0.0003). In the evaluation of muscle function, grip strength and fatigue distance decreased by colitis were partially restored (grip strength: 139.9g±5.38 of cont. vs. 83.9g±5.48 of DSS+PBS, P<0.0001; DSS+PBS vs. 118.6g±4.05 of DSS+p40Ab, P<0.0001; fatigue distance: 872.5m±104.01 of cont. vs. 58.2m±107.72 of DSS+PBS, P<0.0001; DSS+PBS vs. 328.0m±109.71 of DSS+p40Ab, P=0.0015) by injection of IL-12/23 p40 neutralizing antibody. Our study demonstrates that Il-12/23 acts directly on muscle to induce atrophy, and the IL-12/23 p40 neutralizing antibody is effective not only in suppressing colitis but also in maintaining muscle mass and improving muscle function in an experimental colitis model.

Therapeutic Mechanism of Baicalin in Experimental Colitis Analyzed Using Network Pharmacology and Metabolomics.

Baicalin is an important active flavonoid isolated from the roots of Scutellaria baicalensis (S. baicalensis), a well-known traditional Chinese herb used in treating inflammatory bowel disease (IBD). The objectives of this study were to assess the potential benefit of baicalin in experimental colitis, as well as to investigate metabolic biomarkers of experimental colitis in conjunction with network pharmacology. Using a widely utilized network pharmacology technique, baicalin's targets and pathways were predicted. Simultaneously, experimental colitis was induced by intrarectal administration of TNBS. Histopathology examinations were performed to confirm pathological changes. Plasma samples were examined by using an untargeted metabolomics technique based on ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) to screen differential metabolites and associated metabolic pathways. Additionally, network pharmacology and integrated analysis of metabolomics were used to identify the primary targets. Through network pharmacology research, tumor necrosis factor (TNF), interleukin 6 (IL6), serine/threonine-protein kinase (AKT1), and other 7 proteins were found to be the main targets of baicalin against IBD. The untargeted metabolomics results showed that 47 metabolites in glycerophospholipids and sphingolipid metabolism were involved as key pathways in the experimental colitis model group. 19 metabolites, including Sphingomyelin (SM d42:2, SM d42:1, SM d34:1), Lysophosphatidic acids (LPA 18:4), 1-Palmitoylglycerophosphocholine, and 17(18)-EpETE were demonstrated as key metabolites for baicalin to exert effects. Moreover, udp-glucose ceramide glucosyltransferase (UGCG), sphingomyelin synthase 1 (SGMS1), and sphingosine kinase (SPHK1) were predicted as sphingolipids-linked targets of baicalin against experimental colitis by integrative analysis. Based on these results, it implies that sphingolipid metabolism and sphingolipid signaling pathway might be acted as therapeutic mechanism for baicalin against experimental colitis.

Anthocyanin extract from black rice attenuates chronic inflammation in DSS-induced colitis mouse model by modulating the gut microbiota

AbstractThere is substantial evidence for the probiotic activity of anthocyanins, but the relationship between anthocyanins involved in the regulation of microbiota and intestinal inflammation has not been fully elucidated. The aim of this study was to investigate the regulatory effects of black rice anthocyanin extract (BRAE) on intestinal microbiota imbalance in mice with dextran sulfate sodium (DSS)-induced chronic colitis. DSS was added into drinking water to induce a mouse model of chronic experimental colitis, and BRAE was given by gavage (200 mg/kg/day) for 4 weeks. Body weight, fecal viscosity, and hematochezia were monitored during administration. After mice were sacrificed, the serum concentrations of TNF-α and IL-6 were detected by enzyme-linked immunosorbent assay, and the composition of intestinal flora was analyzed by 16S rDNA sequencing. The results showed that BRAE significantly suppressed DSS-induced colonic inflammatory phenotypes and maintained colon length in mice. In addition, BRAE reduced intestinal permeability and improved intestinal barrier dysfunction in mice with colitis. Gut microbiota analysis showed that BRAE significantly improved the imbalance of intestinal microecological diversity caused by DSS, inhibited the increase in the relative abundance of inflammatory bacteria, and promoted the abundance of anti-inflammatory probiotics includingAkkermansiaspp.