Rat Model Of Colitis Research Articles

Anti-ulcer effect of megosin in a model of acute experimental colitis in RATS

Megosin is the original derivative of gossypol. Previously, the drug was obtained by condensation of gossypol with β-aminoethylsulfate sodium and used as an immunosuppressive agent, which was a low-toxic substance and contributed to a longer engraftment of skin flaps in mice, kidneys and lungs in dogs. Further, it was used as an antiherpetic agent, in the form of a 3% ointment. At present, the Institute of Bioorganic Chemistry, on the basis of existing dosage forms, has developed megosin enteric capsules for the treatment of ulcerative colitis and conducted histological studies, which proved the ulcer-healing effect of the new dosage form of megosin.

Histological study of the effect of quercetin on experimentally induced ulcerative colitis in adult male albino rats

Background Ulcerative colitis is a huge health problem, and its occurrence is increasing around the world. It is manifested with abdominal pain, diarrhea, bloody stool, and body weight loss. Aim This work aimed to evaluate the possible effects of quercetin on a rat model of ulcerative colitis that was induced by acetic acid. Materials and methods A total of 40 adult male albino rats were used in this study. Rats were divided into controls, that is, group I, which included 10 rats that received intrarectal injection of a single dose of 2 ml of physiological saline, and experimental cases, that is, group II. The experimental group contained 30 rats and were divided into three equal subgroups. Subgroup IIA received 50 mg/kg/day of quercetin orally for three consecutive days, subgroup IIB received intrarectal injection of a single dose of 2 ml of 4% acetic acid solution for ulcerative colitis induction, and subgroup IIC received 50 mg/kg/day of quercetin orally for 3 consecutive days before induction of ulcerative colitis by a single dose of acetic acid that was received by intrarectal injection on the fourth day. Colonic specimens were subjected to histological and immunohistochemical examinations. The data were analyzed statistically. Results The current study of subgroup IIB showed disturbed normal histological architecture of colonic structure, but in subgroup IIC, quercetin resulted in preservation of normal histological architecture of the colon. Conclusion There is a correlation between quercetin and reduction of the severity of acute attacks of ulcerative colitis induced by acetic acid in adult male albino rats. Quercetin leads to protection of colon.

Budesonide-Loaded Hyaluronic Acid Nanoparticles for Targeted Delivery to the Inflamed Intestinal Mucosa in a Rodent Model of Colitis.

The aim of the present study was to investigate the therapeutic potential of budesonide- (BDS-) loaded hyaluronic acid nanoparticles (HANPs) for treatment of inflammatory bowel disease (IBD) using an acute model of colitis in rats. The therapeutic efficacy of BDS-loaded HANPs in comparison with an aqueous suspension of the drug with the same dose (30 μg/kg) was investigated 48 h following induction of colitis by intrarectal administration of acetic acid 4% in rats. Microscopic and histopathologic examinations were conducted in inflamed colonic tissue. Tissue concentration of tumor necrosis factor (TNF)-α was assessed by ELISA assay kit, while the activity of myeloperoxidase (MPO) was measured spectrophotometrically. Results from in vivo evaluations demonstrated that administrations of BDS-HANPs ameliorated the general endoscopic appearance, quite close to the healthy animals with no signs of inflammation and reduced the cellular infiltration, as well as the TNF-α level, and the MPO activity. It was found that delivery by BDS-loaded HANPSs alleviated the induced colitis significantly better than the same dose of the free drug. These data further suggest the potential of HANPs as a targeted drug delivery system to the inflamed colon mucosa.

The effect of montelukast, a leukotriene receptor antagonist, on the acetic acid-induced model of colitis in rats: Involvement of NO-cGMP-KATP channels pathway.

Inflammatory bowel disease is a chronic autoimmune disorder that may involve entire gastrointestinal tract. The leukotrienes have a role as mediators in the pathophysiology of colitis. Here, we investigated the effect of a leukotriene receptor antagonist, montelukast, and also the role of the NO-cGMP-KATP channel pathway in acetic acid-induced colitis. Rectal administration of acetic acid (4%) was used for induction of colitis in rats. To investigate our hypothesis, the rats were intraperitoneally pre-treated with L-NAME (NOS inhibitor), L-arginine, sildenafil, methylene blue, glibenclamide, or diazoxide 15 min before treatment with montelukast (5–20 mg/kg, i. p.), for three consecutive days. Then, microscopic, macroscopic, and inflammatory parameters were evaluated. Montelukast reduced the microscopic and macroscopic damage induced by acetic acid. Montelukast also reduced the level of IL-1β and TNF-α. We also showed that the effects of montelukast were significantly attenuated by L-NAME, methylene blue (guanylate cyclase inhibitor), and an ATP-sensitive potassium channel blocker (glibenclamide). Also, the administration of L-arginine, sildenafil, and diazoxide before montelukast produced protective effect. In conclusion, the pathway of the NO-cGMP-KATP channel is involved in the protective effect of montelukast in acetic acid-induced colonic tissue damage.

Global alteration of colonic microRNAome landscape associated with inflammatory bowel disease.

Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract that associates with, among others, increased risk of colorectal cancer. There is a growing evidence that miRNAs have important roles in pathological processes, such as inflammation or carcinogenesis. Understanding the molecular mechanisms such as alterations in microRNAome upon chronic intestinal inflammation is critical for understanding the exact pathomechanism of IBD. Hence, we conducted a genome wide microRNAome analysis by applying miRNA-Seq in a rat model of experimental colitis, validated the data by QPCR, examined the expression of a selection of precursor and mature miRNAs, performed in depth biological interpretation using Ingenuity Pathway Analysis and tested the obtained results on samples derived from human patients. We identified specific, interdependent expression pattern of activator/repressor transcription factors, miRNAs and their direct targets in the inflamed colon samples. Particularly, decreased expression of the miR-200 family members (miR-200a/b/c,-141, and -429) and miR-27b correlates with the reduced level of their enhancers (HNF1B, E2F1), elevated expression of their repressors (ZEB2, NFKB1) and increased expression of their target genes (ZEB2, RUNX1). Moreover, the marked upregulation of six miR-27b target genes (IFI16, GCA, CYP1B1, RUNX1, MEF2C and MMP13) in the inflamed colon tissues is a possible direct consequence of the lack of repression due to the downregulated miRNA-27b expression. Our data indicate that changes in microRNAome are associated with the pathophysiology of IBD, consequently, microRNAs offer potential targets for the diagnosis, prognosis and treatment of IBD.

Influence of laboratory-controlled ethanolic wheatgrass extract on acetic acid-induced changes in biochemical and antioxidant indices in the colitis of Wistar rats

Introduction and Aim: Triticum aestivum (wheatgrass) is a good source of mineral nutrients and antioxidant enzymes. It also acts as a detoxifying agent and helps to revive healthy cells. The present study aimed to assess the effects of acetic acid on biochemical and antioxidant indices in the colitis of Wistar rats using an ethanolic extract derived from the dried shoots of wheatgrass maintained under specified growth conditions.
 
 Materials and Methods: Aqueous and ethanolic extract of wheatgrass was subjected to preliminary phytochemical screening and in-vitro antioxidant activity. Effects of the ethanolic wheatgrass extract were investigated in the acetic acid-induced rat colitis model. Sulphasalazine was used as the standard anti-inflammatory drug. Malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidant capacity (TAC), catalase (CAT), and reduced glutathione (GSH) levels were estimated in the rat blood. Colitis was quantified with a clinical score and colon length/weight index was measured. Histopathological analyses were also performed on the colon tissue of rats.
 
 Results: The presence of phytochemical elements such as saponins, tannins, alkaloids, and terpenes in aqueous and ethanolic wheatgrass extract was discovered. These compounds have the potential to boost antioxidant and anti-inflammatory effects. The ethanolic extract significantly reduced MDA, MPO, and antioxidant levels (TAC, CAT, and GSH) in colon tissue and blood. Biochemical measurements corroborated the conclusions of histopathological investigation.
 
 Conclusion: According to macroscopic, microscopic, histological, and other biochemical studies, ethanolic wheatgrass extract significantly inhibits experimental colitis in rats.

Therapeutic efficacy of human adipose mesenchymal stem cells in Crohn’s colon fibrosis is improved by IFN-γ and kynurenic acid priming through indoleamine 2,3-dioxygenase-1 signaling

BackgroundInflammatory bowel diseases (IBD) are chronic relapsing–remitting inflammatory diseases of the gastrointestinal tract that are typically categorized into two subtypes: Crohn's disease (CD) and ulcerative colitis (UC). Although MSCs therapy has achieved encouraging outcomes in IBD therapy, objective responses are limited in colon fibrosis stenosis owing to the complicated microenvironment of CD and MSCs heterogeneity of quality. Here, we chose IFN-γ and kynurenic acid (KYNA) to overcome the low response and heterogeneity of human adipose-derived MSCs (hADSCs) to treat IBD and expand the therapeutic effects based on the excellent ability of IFN-γ and KYNA to promote indoleamine 2,3-dioxygenase-1 (IDO-1) signaling, providing a potential protocol to treat IBD and fibrosis disease.MethodshADSCs were isolated, cultured, and identified from human abdominal adipose tissue. The CD pathology-like acute colitis and chronic colon fibrosis rat model was induced by 2,4,6-trinitrobenzen sulfonic acid (TNBS). hADSCs were pretreated in vitro with IFN-γ and KYNA and then were transplanted intravenously at day 1 and 3 of TNBS administration in colitis along with at day 1, 15, and 29 of TNBS administration in chronic colonic fibrosis. Therapeutic efficacy was evaluated by body weights, disease activity index, pathological staining, real-time PCR, Western blot, and flow cytometry. For knockout of IDO-1, hADSCs were transfected with IDO-1-targeting small gRNA carried on a CRISPR-Cas9-lentivirus vector.ResultshADSCs treated with IFN-γ and KYNA significantly upregulated the expression and secretion of IDO-1, which has effectively ameliorated CD pathology-like colitis injury and fibrosis. Notably, the ability of hADSCs with IDO-1 knockout to treat colitis was significantly impaired and diminished the protective effects of the primed hADSCs with IFN-γ and KYNA.ConclusionInflammatory cytokines IFN-γ- and KYNA-treated hADSCs more effectively alleviate TNBS-induced colitis and colonic fibrosis through an IDO-1-dependent manner. Primed hADSCs are a promising new strategy to improve the therapeutic efficacy of MSCs and worth further research.

Upregulation of P2X3 receptors in primary afferent pathways involves in colon-to-bladder cross-sensitization in rats.

Background: Clinical investigation indicates a high level of co-morbidity between bladder overactivity and irritable bowel syndrome. The cross-sensitization of afferent pathways has been demonstrated to be the main reason for the cross-organ sensitization, but the underlying mechanism is unclear. Methods: A single dose of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) was applied to induce the colitis rat models by intracolonic administration. All rats were randomly divided into three groups: control, TNBS-3-day, and TNBS-7-day groups. Western blot and immunofluorescent staining were performed to detect the expression of the P2X3 receptor. The spontaneous contractions of the detrusor strip were measured to evaluate the detrusor contractility function. The micturition function was measured by a cystometry experiment. The intercontractile interval (ICI) and maximum bladder pressure (BP) were recorded. Results: The distal colon from colitis showed serious tissue damage or chronic inflammation after TNBS instillation (p < 0.01). However, there were no detectable histological changes in bladder among groups (p > 0.05). TNBS-induced colitis significantly increased P2X3 receptor expression on the myenteric and submucosal plexus of the distal colon and urothelium of the bladder, especially at day 3 post-TNBS (p < 0.05). Meanwhile, the expression of the P2X3 receptor on DRG neurons was increased in TNBS-induced colitis (p < 0.01). The detrusor strip of rats exhibited detrusor overactivity after days 3 and 7 of TNBS administration (p < 0.01), but inhibition of the P2X3 receptor had no effect (p > 0.05). Moreover, the rats with colitis exhibited the micturition pattern of bladder overactivity, manifested by decreased ICI and increased maximum BP (p < 0.05). Interestingly, inhibition of the P2X3 receptor by intrathecal injection of A-317491 alleviated bladder overactivity evoked by TNBS-induced colitis (p < 0.05). Conclusion: The upregulation of the P2X3 receptor in an afferent pathway involved in bladder overactivity evoked by TNBS-induced colonic inflammation, suggesting that the P2X3 receptor antagonist may be an available and novel strategy for the control of bladder overactivity.

Diacetylrhein, an anthraquinone antiarthritic agent, suppresses dextran sodium sulfate-induced inflammation in rats: A possible mechanism for a protective effect against ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory life-threatening and premalignant disorder with no cure that even might end up with surgical removal of a large section or even all of the colon. It is characterized by relapsing-remitting courses of intestinal inflammation and mucosal damage in which oxidative stress and exaggerated inflammatory response play a significant role. Most of the current medications to maintain remission are symptomatic and have many adverse reactions. Therefore, the potential for improved management of patients with UC continues to increase. Yet, the benefits of using the antiarthritic agent diacetylrhein to counteract inflammation in UC are still obscure. Hence, our study was designed to explore its potential role in UC using a model of dextran sodium sulfate-induced acute colitis in rats. Our results revealed that diacetylrhein targeted the NLRP3 and inhibited the inflammasome assembly. Consequently, caspase-1 activity and the inflammatory cytokines IL-1β and IL-18 were inhibited leading to a curbed pyroptosis process. Additionally, diacetylrhein revealed a significant antiapoptotic potential as revealed by the levels of pro-apoptotic and anti-apoptotic proteins. Concomitant to these effects, diacetylrhein also interrupted NFκB signals leading to improved microscopic features of inflamed colon and decreased colon weight to length ratio, indices of disease activity, and macroscopic damage. Additionally, a reduction in the myeloperoxidase activity, IL-6, and TGF-β alongside an increase in the gene expression of Ocln and ZO-1 were detected. To conclude diacetylrhein showed a significant antioxidant and anti-inflammatory potential and therefore might represent a promising agent in the management of acute UC.

The Therapeutic Potential of Urolithin A for Cancer Treatment and Prevention.

Urolithin A is the metabolite of natural polyphenol ellagic acid and ellagitannins generated by gut microbiota. Urolithin A is better absorbed in the gastrointestinal tract than its parent substances. Thus, the variable effects of ellagitannin-reach food (like pomegranate fruit, walnuts, tea, and others) on people's health might be linked with the differences in individual microbiota content. Urolithin A possesses various anti-inflammatory and anti-cancer effects, as shown by in vivo and in vitro studies. In the current review, we consider anti-inflammatory and direct anti-cancer urolithin A effects as well as their molecular mechanisms, which might be the basement of clinical trials, estimating urolithin A anti-cancer effects. Urolithin A attenuated the pro-inflammatory factors production (IL-6, IL-1β, NOS2 and others) in vitro studies. Oral urolithin A treatment caused prominent anti-cancer and anti-inflammatory action in various in vivo studies, including colitis rat model, carrageenan-induced paw edema mice model, models of pancreatic cancer, and models of obesity. The main molecular mechanisms of these effects might be the modulation of aryl hydrocarbon receptors, which antagonism may lead to decreasing of chronic inflammation. Other primary targets of urolithin A might be the processes of protein phosphorylation (for instance, it decreases the phosphorylation of protein kinase B) and p53 stabilization. Anti-inflammatory effects of urolithin A can be reached in physiologically relevant concentrations. This might be of vital importance for preventing immune suppression associated with chronic inflammation in cancer. Considering the favorable urolithin A safety profile, it is a promising compound for cancer treatment and prevention.

Involvement of nitrergic neurons in colonic motility in a rat model of ulcerative colitis.

BACKGROUNDThe mechanisms underlying gastrointestinal (GI) dysmotility with ulcerative colitis (UC) have not been fully elucidated. The enteric nervous system (ENS) plays an essential role in the GI motility. As a vital neurotransmitter in the ENS, the gas neurotransmitter nitric oxide (NO) may impact the colonic motility. In this study, dextran sulfate sodium (DSS)-induced UC rat model was used for investigating the effects of NO by examining the effects of rate-limiting enzyme nitric oxide synthase (NOS) changes on the colonic motility as well as the role of the ENS in the colonic motility during UC.AIMTo reveal the relationship between the effects of NOS expression changes in NOS-containing nitrergic neurons and the colonic motility in a rat UC model. METHODSMale rats (n = 8/each group) were randomly divided into a control (CG), a UC group (EG1), a UC + thrombin derived polypeptide 508 trifluoroacetic acid (TP508TFA; an NOS agonist) group (EG2), and a UC + NG-monomethyl-L-arginine monoacetate (L-NMMA; an NOS inhibitor) group (EG3). UC was induced by administering 5.5% DSS in drinking water without any other treatment (EG1), while the EG2 and EG3 were gavaged with TP508 TFA and L-NMMA, respectively. The disease activity index (DAI) and histological assessment were recorded for each group, whereas the changes in the proportion of colonic nitrergic neurons were counted using immunofluorescence histochemical staining, Western blot, and enzyme linked immunosorbent assay, respectively. In addition, the contractile tension changes in the circular and longitudinal muscles of the rat colon were investigated in vitro using an organ bath system. RESULTSThe proportion of NOS-positive neurons within the colonic myenteric plexus (MP), the relative expression of NOS, and the NOS concentration in serum and colonic tissues were significantly elevated in EG1, EG2, and EG3 compared with CG rats. In UC rats, stimulation with agonists and inhibitors led to variable degrees of increase or decrease for each indicator in the EG2 and EG3. When the rats in EGs developed UC, the mean contraction tension of the colonic smooth muscle detected in vitro was higher in the EG1, EG2, and EG3 than in the CG group. Compared with the EG1, the contraction amplitude and mean contraction tension of the circular and longitudinal muscles of the colon in the EG2 and EG3 were enhanced and attenuated, respectively. Thus, during UC, regulation of the expression of NOS within the MP improved the intestinal motility, thereby favoring the recovery of intestinal functions.CONCLUSIONIn UC rats, an increased number of nitrergic neurons in the colonic MP leads to the attenuation of colonic motor function. To intervene NOS activity might modulate the function of nitrergic neurons in the colonic MP and prevent colonic motor dysfunction. These results might provide clues for a novel approach to alleviate diarrhea symptoms of UC patients.

The Immune Change of the Lung and Bowel in an Ulcerative Colitis Rat Model and the Protective Effect of Sodium Houttuyfonate Combined With Matrine.

ObjectiveTo explore the immune change of lung injury of Ulcerative colitis (UC) by observing the changes of inherent immunity and adaptive immunity of the lung and bowel in UC rat models after the treatment of Sodium Houttuyfonate combined with Matrine. MethodUC rat models were established with the mucous membrane of colon allergize combined with TNBS-alcohol enteroclysis for 1 week and 5 weeks. 1-week experimental rats were divided into normal group and model group, 5/each group. 5-weeks experimental rats were divided into normal group, model group, Sodium Houttuyfonate (2.9mg/ml) combined with Matrine (1.47mg/ml), and positive control sulfasalazine (10mg/ml), 5/each group. All rats were administered by gavage for 5 weeks. The histopathological and fibrotic changes in the lung and bowel were observed, and the expressions of Tumor Necrosis Factor (TNF)- α, interleukin (IL)-8 in the lung, bowel, and serum were detected by radio-immunity and immunohistochemistry, and the mRNA expressions of Toll-like receptor (TLR)-4, nuclear factor kappa (NF-κB), Macrophage migration inhibitory factor (MIF), Mucosal addressing cell adhesion molecule-1 (MadCAM1) and Pulmonary surfactant protein-A (SP-A) in the lung and bowel were detected by Real time-PCR.ResultCompared with the normal group, the model rats had significant histopathological and fibrotic changes both in the lung and bowel, and all treatment groups were improved. After treatment, TLR4, IL-8, MIF, and TNF-α in the lung decreased (P<0.05); NF-KB, IL-8, and MIF in the bowel increased (P<0.05); MadCAM1 both in lung and bowel decreased (P<0.05); SP-A decreased in bowel and increased in the lung (P<0.05).ConclusionThe cause of lung injury in this model was found to be related to inherent immunity and adaptive immunity, while the cause of bowel injury in this model was found to be mainly related to adaptive immunity. Sodium Houttuyfonate combined with Matrine could improve bowel and lung injury.

Understanding the Habitual Pattern of Concomitant Consumption of Herbs to Alleviate the Symptoms of Ulcerative Colitis by Comparative Proteome Analysis

Anchang decoction is an empirical prescription for the treatment of ulcerative colitis in China. In order to better understand its therapeutic function, large efforts have been made to identify its chemical constituents and to unravel the efficacy of its principal constituents. However, the molecular mechanism of its combinations is still unclear. Proteomics application has yielded some positive results in drug development and the identification of potential drug targets, suggesting the potential of this analytical approach to explore the action of molecular mechanisms of herbal formula by robustly addressing dynamic proteome changes. Label-free quantification and parallel reaction monitoring were used to identify differentially expressed proteins in the colon tissue of ulcerative colitis rats, fed with Anchang decoction and mesalazine, respectively. In this study, a total of 1,182 proteins were identified. From GO and KEGG analyses, the proteins of cytoskeleton and cytochrome P450 changed significantly with the occurrence of ulcerative colitis. In the meantime, antigen binding proteins and antioxidant-related proteins turned out to have drastic fluctuations with mesalazine and Anchang decoction. It has also been confirmed that KRT8, MYH11, FLNA, and LMNA are all related to the formation of ulcerative colitis based on parallel reaction monitoring analysis. The increase in FGG in the ulcerative colitis rat model is due to mesalazine, whereas that in KRT8 is due to Anchang decoction. The results from this study provide insights for the mechanism of action of Anchang decoction, which turns out to be an efficient technical pipeline for understanding worldwide medicinal herbs.

The Effect of Serine Protease Inhibitors on Visceral Pain in Different Rodent Models With an Intestinal Insult.

Background: Serine proteases are believed to play a key role in the origin of abdominal pain in IBD and IBS. We previously demonstrated a reduction of visceral pain in a post-inflammatory IBS rat model after a single intraperitoneal or intracolonic administration of a serine protease inhibitor. The aim of this study was to investigate the efficacy of serine protease inhibition on visceral pain in two different animal models involving a colonic insult based either on acute inflammation or on neonatal irritation. Moreover, protease profiling was explored in the acute colitis model. Methods: An acute 2,4,6-trinitrobenzenesulphonic acid (TNBS) colitis rat model and a chronic neonatal acetic acid mouse model were used in this study. Visceral sensitivity was quantified by visceromotor responses (VMRs) to colorectal distension, 30 min after intraperitoneal administration of the serine protease inhibitors nafamostat, UAMC-00050 or their vehicles. Colonic samples from acute colitis rats were used to quantify the mRNA expression of a panel of serine proteases and mast cell tryptase by immunohistochemistry. Finally, proteolytic activities in colonic and fecal samples were characterized using fluorogenic substrates. Key Results: We showed a significant and pressure-dependent increase in visceral hypersensitivity in acute colitis and neonatal acetic acid models. UAMC-00050 and nafamostat significantly reduced VMRs in both animal models. In acute colitis rats, the administration of a serine protease inhibitor did not affect the inflammatory parameters. Protease profiling of these acute colitis animals revealed an increased tryptase immunoreactivity and a downregulation of matriptase at the mRNA level after inflammation. The administration of UAMC-00050 resulted in a decreased elastase-like activity in the colon associated with a significantly increased elastase-like activity in fecal samples of acute colitis animals. Conclusion: In conclusion, our results suggest that serine proteases play an important role in visceral hypersensitivity in an acute TNBS colitis model in rats and a neonatal acetic acid model in mice. Moreover, we hypothesize a potential mechanism of action of UAMC-00050 via the alteration of elastase-like proteolytic activity in acute inflammation. Taken together, we provided fundamental evidence for serine protease inhibitors as a promising new therapeutic strategy for abdominal pain in gastrointestinal diseases.

Inflammatory-Dependent Bidirectional Effect of Bile Acids on NLRP3 Inflammasome and Its Role in Ameliorating CPT-11-Induced Colitis.

Irinotecan (CPT-11) in combination with 5-fluorouracil and leucovorin is a first-line chemotherapy regimen for the treatment of colorectal cancer; however, its clinical application is limited by the dose-limiting gastrointestinal toxicity of colitis. In our previous studies, several bile acids (BAs) were found significantly elevated in the colon of the CPT-11-induced rat colitis model. On the other hand, NLRP3 inflammasome has been reported to play important roles in mediating colitis. Interestingly, BA was stated to activate the NLRP3 inflammasome in some studies, while in some other reports, it showed an inhibitory effect. We assumed that the inflammatory status in different circumstances might have contributed to the controversial findings. In this study, we first discovered, under non-inflammatory conditions, that supplementing BA could activate the NLRP3 inflammasome in THP-1-differentiated macrophages and promote inflammation. In lipopolysaccharide (LPS)-induced inflammatory macrophages, however, BA inhibited the NLRP3 inflammasome and reduced inflammation. Further experiments demonstrated that Takeda G protein-coupled receptor 5 (TGR5) is essential in mediating the inhibitory effect of BA, while phospho-SP1 (p-SP1) is key to the activation. Furthermore, we applied the above findings to ameliorate CPT-11-caused colitis in rats by inhibiting SP1 with mithramycin A (MitA) or activating TGR5 using oleanolic acid (OA). Our findings may shed light on the discovery of effective interventions for reducing dose-limiting chemotherapy-induced colitis.

Multi-Strain-Probiotic-Loaded Nanoparticles Reduced Colon Inflammation and Orchestrated the Expressions of Tight Junction, NLRP3 Inflammasome and Caspase-1 Genes in DSS-Induced Colitis Model.

Gut modulation by multi-strain probiotics (MSPs) is considered an effective strategy for treating inflammatory bowel disease (IBD). The combination of nanomaterial-based MSPs can improve their viability and resistance and can allow their targeted release in the gastrointestinal tract to be achieved. Thus, our aim is to investigate the prospective role of MSP integration into nanomaterials (MSPNPs) and the underlying molecular mechanisms supporting their application as an alternative therapy for IBD using a colitis rat model. To induce the colitis model, rats received 5% DSS, and the efficacy of disease progression after oral administration of MSPNPs was assessed by evaluating the severity of clinical signs, inflammatory response, expressions of tight-junction-related genes and NLRP3 inflammasome and caspase-1 genes, microbial composition and histopathological examination of colonic tissues. The oral administration of MSPNPs successfully alleviated the colonic damage induced by DSS as proved by the reduced severity of clinical signs and fecal calprotectin levels. Compared with the untreated DSS-induced control group, the high activities of colonic NO and MPO and serum CRP levels were prominently reduced in rats treated with MSPNPs. Of note, colonic inflammation in the group treated with MSPNPs was ameliorated by downstreaming NLRP3 inflammasome, caspase-1, IL-18 and IL-1β expressions. After colitis onset, treatment with MSPNPs was more effective than that with free MSPs in restoring the expressions of tight-junction-related genes (upregulation of occludin, ZO-1, JAM, MUC and FABP-2) and beneficial gut microbiota. Interestingly, treatment with MSPNPs accelerated the healing of intestinal epithelium as detected in histopathological findings. In conclusion, the incorporation of MPSs into nanomaterials is recommended as a perspective strategy to overcome the challenges they face and augment their therapeutic role for treating of colitis.

Protective effect of fermented okara on the regulation of inflammation, the gut microbiota, and SCFAs production in rats with TNBS-induced colitis

Dysbiosis of gut microbiota is intimately related to ulcerative colitis. The literature has revealed the gut microbiota metabolism of dietary fiber, which is a key resource for short-chain fatty acids (SCFAs) production and subsequently leads to anti-inflammatory effects. It is known that okara (a soybean byproduct) is rich in dietary fiber, but the effect of fermented okara on relieving colitis remains unclear. The object of this study was to investigate the effects of Aspergillus oryzae-fermented okara (FO) on colitis prevention through gut microbiota manipulation in a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rat model. The results showed that administration of FO elevated the relative abundance of SCFAs-producing bacteria (Lachnospiraceae and Bifidobacteriaceae) and SCFAs production, which engaged with GPR43 (SCFAs receptor) consequently decreased the production of proinflammatory cytokines (IL-6, IL-1β, and TNF-α), inflammatory mediators (COX-2, iNOS, PGE2, and NO), and MCP-1 chemokine and increased anti-inflammatory cytokine (IL-10 and IL-4) production through inhibition of HDAC3/MAPK-related proteins and the NF-κB inflammatory pathway in TNBS-induced colitis in rats. Moreover, increased activity of antioxidants, such as SOD, CAT, GSH, and GPx, and decreased MDA and MPO production were also observed after FO administration in TNBS-induced colitis in rats. This study demonstrated the novel potential of soybean byproducts for alleviating TNBS-induced intestinal inflammation and enhancing antioxidant capacity for colitis improvement. This new finding may enhance the value of okara for functional food development.

Dextran Sulphate Sodium Acute Colitis Rat Model: A Suitable Tool for Advancing Our Understanding of Immune and Microbial Mechanisms in the Pathogenesis of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a group of disorders causing inflammation in the digestive tract. Recent data suggest that dysbiosis may play a pivotal role in the IBD pathogenesis. As microbiome-based therapeutics that modulate the gut ecology have been proposed as a novel strategy for preventing IBD, the aim of presenting study was to evaluate the dextran sulphate sodium (DSS) rat model mainly in terms of microbial shifts to confirm its suitability for dysbiosis study in IBD. Acute colitis was induced using 5% DSS solution for seven days and rats were euthanized five days after DSS removal. The faecal/caecal microbiota was analyzed by next generation sequencing. Disease activity index (DAI) score was evaluated daily. Blood and colon tissue immunophenotyping was assessed by flow cytometry and histological, haematological, and biochemical parameters were also evaluated. The colitis induction was reflected in a significantly higher DAI score and changes in all parameters measured. This study demonstrated significant shifts in the colitis-related microbial species after colitis induction. The characteristic inflammation-associated microbiota could be detected even after a five day-recovery period. Moreover, the DSS-model might contribute to an understanding of the effect of different treatments on extraintestinal organ impairments. The observation that certain bacterial species in the gut microbiota are associated with colitis raises the question of whether these organisms are contributors to, or a consequence of the disease. Despite some limitations, we confirmed the suitability of DSS-induced colitis model to monitor microbial changes during acute colitis, in order to test attractive new microbiome-based therapies.

Mechanism of Fructus Mume Pills Underlying Their Protective Effects in Rats with Acetic Acid-Inducedulcerative Colitis via the Regulation of Inflammatory Cytokines and the VEGF-PI3K/Akt-eNOS Signaling Pathway.

Background Fructus mume pills (FMPs) have been clinically proven to be effective for treating ulcerative colitis (UC). However, the therapeutic and protective mechanisms have not been fully studied. Aim We aimed to explore the mechanism of FMPs in an acetic acid (AA)-induced ulcerative colitis rat model. Methods The targets, GO terms, and KEGG pathways for the FMPs and UC were screened and constructed using network pharmacology. A possible mechanism was verified in a 4% AA-induced colitis rat model. Colitis activity and state were evaluated using the disease activity index, and colon ulceration and intestinal mucosal damage were determined by histopathological observation through HE, AB-PAS, and Masson pathological staining. The concentrations of TNF-α, IL-6, IL-8, IL-10, MPO, MMP9, CXCR1, eNOS, and VEGF were measured to evaluate vascular permeability effects. Results The network pharmacology results showed 108 active compounds, and 139 FMP-related targets were identified. Twenty-nine targets were identified for FMPs against UC, which included MMP9, MMP3, ESR1, PTGS1, PPARA, MPO, and NOS2. A total of 1,536 GO terms and 41 pathways were associated with FMP treatment of UC. The pharmacological evaluation showed that FMPs attenuated inflammation in AA-induced colitis by reducing the serum concentrations of TNF-α, IL-6, IL-8, and IL-10 and the colonic concentrations of MPO, MMP9, and CXCR1. FMPs ameliorated hyperpermeability by reducing the colonic VEGF and eNOS concentrations. FMPs also significantly decreased the VEGFA, VEGFR2, Src, and eNOS protein expressions in colon tissue through the VEGF-PI3K/Akt-eNOS signaling pathway. Conclusion These results suggest that FMPs control UC inflammation by regulating inflammatory cytokine concentrations. FMPs alleviate AA-induced UC by regulating microvascular permeability through the VEGF-PI3K/Akt-eNOS signaling pathway.

Sex‐specific colonic mitochondrial dysfunction in the indomethacin‐induced inflammatory bowel disease model in rats

Inflammatory bowel disease (IBD) characterized by inflammation of the gastrointestinal tract. It includes Crohn’s disease and ulcerative colitis. In 2015, 3 million U.S. adults have been diagnosed with IBD and many people go undiagnosed due to mild symptoms. Women appear to have more severe and recurring symptoms of IBD compared to men, most likely due to hormonal fluctuations. Several studies show mitochondrial alterations in IBD patients. Our hypothesis is mitochondrial dysfunction in IBD could have a sex‐specific effect. Male and female rats received two doses of indomethacin (7.5 mg/kg) 24 hour apart to induce IBD. Colon tissues were collected for mitochondrial isolation two days after injections. Mitochondrial respiration and reactive oxygen species (mtROS) production were measured simultaneously by an Oroboros Fluorespirometer using glutamate/malate, succinate, oleate (long‐chain fatty acid; LCFA), or octanoate (medium chain fatty acid; MCFA). Complex IV activity, a marker of oxidative phosphorylation capacity, was measured. Data were normalized to mitochondrial content using citrate synthase (CS) activity, which confirms that the observed changes are not due to loss of mitochondrial content. CS activity showed no change in females but a significant decrease in male IBD rats compared to controls (2425 ± 200.2 vs. 3586 ± 214.4 nmol citrate/min/g tissue, p&lt;0.05). When respiration was normalized to CS activity, males showed no significant difference compared to controls with complex I and complex II‐driven respiration. However, IBD females showed a significant decrease in Complex I‐driven respiration (0.4258 ± 0.02903 vs 0.5437 ± 0.03939 nmol e‐/nmol citrate, p&lt;0.5) and Complex II ‐driven respiration (0.7489 ± 0.035118 vs. 0.9029 ± 0.04664 nmol e‐/nmol citrate, p&lt;0.05). For LCFA oxidation, males (0.6912 ± 0.07261 vs. 0.2554 ± 0.01185 nmol e‐/nmol citrate, p&lt;0.05) and females (0.3984 ± 0.03192 vs. 0.2389 ± 0.02243 nmol e‐/nmol citrate, p&lt;0.05) showed a significant increase in activity compared to controls. Both males and females showed no significant decrease in LCFA or MCFA oxidation. Males and females both showed a significant increase in mtROS with all substrates. Complex IV activity was not different than controls in males but female activity was significantly decreased (1.099 ± 0.09693 vs. 1.379 ± 0.05922 nmol e‐/nmol citrate, p&lt;0.05). Alterations to mitochondrial function and mitochondrial content observed in the indomethacin‐induced IBD rat model suggests a link between mitochondrial dysfunction and IBD. There are differences in male and female rats suggesting a potential mechanism for the observed differences in male and female patients. Our study provides a better understanding of the role mitochondria in the development of IBD. It also opens an avenue for the development of strategies to re‐establish normal mitochondrial function that could provide more options for preventive and therapeutic interventions for IBD.