Rat Model Of Experimental Colitis Research Articles

Effect of Artemisia vulgaris Hydro-Alcoholic Extract on Oxidative Stress and Inflammatory Damages in a Rat Model of Experimental Colitis

Background: Herbal medicines can be used as a possible therapeutic agent in inflammatory diseases. Objectives: This study aimed to determine the effect of Artemisia vulgaris (AV) hydro-alcoholic extract on oxidative stress and inflammatory damage in an experimental rat model of colitis. Methods: Thirty male Sprague-Dawley rats were randomly divided into 6 groups: Control, colitis, sulfasalazine, AV50, AV100, and AV200. The animals of the AV groups were treated with the hydro-alcoholic extract of A. vulgaris via gavage for 72 h. Body weight was measured at the beginning and end of the experiment. In the end, serum levels of malondialdehyde (MDA) as a lipid peroxidation marker, antioxidants such as glutathione (GSH), superoxide dismutase (SOD) activity, serum tumor necrosis factor-α (TNF-α), and nitric oxide (NO) levels as inflammatory biomarkers were measured. Macroscopic and microscopic damage in the rat's colon was also examined in histological studies. Results: The A. vulgaris extract treatment dose-dependently improved colonic injury (P < 0.001 to P < 0.05) and body weight (P < 0.001) in colitis rats. Moreover, it enhanced SOD activity and GSH levels (P < 0.001) and reduced serum MDA, TNF-α, and NO levels (P < 0.001 to P < 0.01) in the rats with colitis. Conclusions: Treatment with A. vulgaris could mitigate ulcerative colitis (UC) symptoms, which is probably attributed to its antioxidant and anti-inflammatory properties.

Understanding the tonifying and the detoxifying properties of Chinese medicines from their impacts on gut microbiota and host metabolism: a case study with four medicinal herbs in experimental colitis rat model

BackgroundChinese medicines (CMs) have emerged as an alternative therapy for ulcerative colitis through reinforcing the vital qi and/or eliminating the pathogenic factors according to the traditional Chinese medicinal theory. Presystemic interactions of CMs with gut microbiota and the associated metabolic network shift are believed to be essential to achieve their holistic health benefits in traditional oral application.MethodsThis study first employed 16S rDNA-based microbial profiling and mass spectrometry-based urinary metabolomics to simultaneously evaluate four single CMs frequently prescribed as main constituent herbs for alleviating UC, the tonic ginseng and Astragali Radix (AR) and the detoxifying Scutellaria Radix (SR) and Rhubarb, on a dextran sodium sulfate (DSS)-induced colitis rat model, with aims to understanding the tonifying or detoxifying properties of CMs through clinical phenotypes, the common features and herb-specific signatures in gut microbial alterations and the associated host metabolic shifts. Colitis was induced in rats receiving 5% DSS for consecutive 7 days. Control group received water alone. Herbal groups received 5% DSS and respective herbal preparation by gavage once daily. Body weight, stool consistency, and rectal bleeding were recorded daily. Feces and urine were freshly collected at multiple time points. On day 7, blood and colon tissues were collected to determine anti-/pro-inflammatory cytokines levels, colonic myeloperoxidase activity, and histopathologic alterations.ResultsGut microbiome was more prone to herb intervention than metabolome and displayed increasing associations with metabolic dynamics. Although both the tonic and the detoxifying herbs alleviated colitis and caused some similar changes in DSS-induced microbiome and metabolome disturbance, the tonic herbs were more effective and shared more common microbial and metabolic signatures. The detoxifying herbs elicited herb-specific changes. Rhubarb uniquely affected phenylalanine metabolism and established high correlations between Akkermansia muciniphila and Parasutterella and hydroxyphenylacetylglycine and phenylbutyrylglycine, while SR caused significant elevation of steroidal glucuronides dehydropregnenolone glucuronide and estriol glucuronide, both displaying exclusive correlations with genus Acetatifactor.ConclusionBoth tonic and detoxifying herbs tested ameliorated experimental colitis and elicited alternative microbial and host metabolic reprogramming. The findings highlight the importance of presystemic interactions with gut microbiota to host metabolic shifts and promote modern translation of tonic and detoxifying properties of CMs.

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.

MiR-330 alleviates dextran sodium sulfate-induced ulcerative colitis through targeting IRAK1 in rats.

Ulcerative colitis (UC) is a chronic multifactorial inflammatory bowel disease that severely impairs patients' life quality. microRNAs (miRNAs) have been reported to exhibit potential therapeutic effects in the management of UC. With the aim to investigate the regulatory effects of miR-330 on UC-related colon tissue damage and inflammation, a rat model of experimental colitis was established by oral administration of dextran sodium sulfate (DSS). DSS-treated rats showed mucosal damage, colonic inflammation, and elevated myeloperoxidase activity compared with the healthy controls. Dual-luciferase reporter assay confirmed the binding of interleukin-1 receptor-associated kinase 1 (IRAK1) and miR-330. Subsequently, rats were intracolonically injected with miR-330 argomir with/without administration of IRAK1 during DSS treatment. The miR-330 overexpression reduced DSS-induced colonic injury and the production of proinflammatory cytokines. The level of IRAK1 was negatively regulated by the expression of miR-330. IRAK1 overexpression abolished the protective effect of miR-330 on DSS-induced colonic inflammation and mucosal injury in rats. In conclusion, we clarify the role of miR-330 in pathogenesis of UC, suggesting miR-330 alleviated DSS-induced colitis by downregulating IRAK1, shedding lights on miR-330 as a therapeutic candidate for UC treatment.

Anticolitic Effect of Berberine in Rat Experimental Model: Impact of PGE2/p38 MAPK Pathways.

Berberine (BER), a natural isoquinoline alkaloid, has been demonstrated to have appreciable anticolitis effects. Nevertheless, the protective mechanism of BER in ulcerative colitis (UC) is barely understood. The present study was aimed at exploring the therapeutic efficacy of BER on UC in experimental colitis rat model. Rats were orally administered with BER for seven days at low and high doses (25 and 50 mg/kg/day) before AcOH intracolonic instillation. BER significantly retrieved colon inflammation and mucosal damage indicated by inhibition of macroscopic score and lessened the levels of inflammatory biomarkers (IL-1β, IL-6, TNF-α, MPO, and PGE2). Notable downregulation of mRNA expression of p38 MAPK and increased protein expression of TGF-β were achieved by BER treatment. The anti-inflammatory potential of BER was supported by the histopathological screening of colon mucosa. In addition, BER restored colonic antioxidant capacity through elevation of GSH level and antioxidant enzymatic activities (SOD, CAT, GPx, and GR) together with reductions of both MDA and NO levels. Marked downregulation of Nos2 mRNA expression is accompanied by increased Nrf2 and Hmox-1 expressions in colon specimens treated by BER. Furthermore, BER exhibited noticeable antiapoptotic activities through decreasing proapoptotic proteins (Bax and caspase-3) and lessening antiapoptotic Bcl-2 protein in the colon mucosa. Based on these findings, BER may improve colitis markedly which may be mediated by its striking antioxidant, anti-inflammatory, and antiapoptotic properties.

Effects of erythropoietin on bacterial translocation in a rat model of experimental colitis.

In this experimental study, it was aimed to assess the effects of erythropoietin (EPO) on bacterial translocation in a rat model of colitis. The rats were randomly assigned into control, colitis and EPO-treated groups (n= 8 in each group). Saline solution (NS) was administered to control rats via rectal route. A trinitrobenzene sulfonic acid and ethanol mixture (TNBS-E) was used to induce colitis in the experiment groups. No treatment was administered to colitis group after induction. Starting at one day after induction of colitis with TNBS-E, EPO (1000 IU/kg) was administered subcutaneously for three days to the rats in the EPO-treated group. Colonic inflammation was assessed by gross and microscopic examination on day five. Blood samples were obtained to evaluate bacterial translocation while hepatic, mesenteric tissue samples and mesenteric lymph node (MLN) samples were collected for tissue culture. Tissue myeloperoxidase (MPO) levels, and tumor necrosis factor alpha (TNF- α) and endotoxin levels in the sera were studied. Significant gross and microscopic differences were found in the comparison between colitis and EPO-treated groups (p <0.05). MPO level was significantly lower when compared to the colitis group (p <0.05). Serum TNF-α and plasma endotoxin levels were significantly lower in the EPO-treated group than the colitis group (p <0.05). Bacterial translocation was lower in the liver, spleen, MLNs and systemic blood in the EPO-treated group when compared to the colitis group (p <0.05). In TNBS-E-induced rat model of colitis, EPO significantly decreased inflammation and bacterial translocation based on histopathological, biochemical and microbiological parameters.

Elevated Expression of AXL May Contribute to the Epithelial-to-Mesenchymal Transition in Inflammatory Bowel Disease Patients.

Understanding the molecular mechanisms inducing and regulating epithelial-to-mesenchymal transition (EMT) upon chronic intestinal inflammation is critical for understanding the exact pathomechanism of inflammatory bowel disease (IBD). The aim of this study was to determine the expression profile of TAM family receptors in an inflamed colon. For this, we used a rat model of experimental colitis and also collected samples from colons of IBD patients. Samples were taken from both inflamed and uninflamed regions of the same colon; the total RNA was isolated, and the mRNA and microRNA expressions were monitored. We have determined that AXL is highly induced in active-inflamed colon, which is accompanied with reduced expression of AXL-regulating microRNAs. In addition, the expression of genes responsible for inducing or maintaining mesenchymal phenotype, such as SNAI1, ZEB2, VIM, MMP9, and HIF1α, were all significantly induced in the active-inflamed colon of IBD patients while the epithelial marker E-cadherin (CDH1) was downregulated. We also show that, in vitro, monocytic and colonic epithelial cells increase the expression of AXL in response to LPS or TNFα stimuli, respectively. In summary, we identified several interacting genes and microRNAs with mutually exclusive expression pattern in active-inflamed colon of IBD patients. Our results shed light onto a possible AXL- and microRNA-mediated regulation influencing epithelial-to-mesenchymal transition in IBD.

Effects of quercitrin on bacterial translocation in a rat model of experimental colitis

BackgroundThis study aimed to analyze the effects of quercitrin, which has anti-inflammatory properties, on bacterial translocation in inflammatory bowel diseases by using an experimental colitis model. MethodsForty male Wistar-Albino rats were used in the study. Rats were divided into 4 groups (control, colitis, treatment 1 and 2 groups). The rats in the control group were given normal drinking water. In the colitis group, colitis was induced by 5% DSS in drinking water. The control and colitis groups underwent operation on Day 7. In the 2 treatment groups, 5% DSS was added to drinking water for the first 7 days and the groups were treated with quercitrin at the doses of 1 and 5 mg/kg/day for the following 10 days. Treatment groups operated on Day 18. Blood samples were taken for blood culture and left colectomy was performed. The inflammation in the colon was macroscopically and microscopically evaluated and graded. Tissue samples were taken (liver, spleen and mesenteric lymph nodes (MLN)) for tissue culturing in order to assess bacterial translocation. Tissue myeloperoxidase (MPO), serum tumor necrosis factor-alpha (TNF-α) and plasma endotoxin levels were measured. ResultsWhen the control and colitis groups were compared, observed that colitis was induced by DSS (p < 0.05). When the colitis and treatment groups were compared, it was found that quercitrin had a significant therapeutic effect (p < 0.05). ConclusionIn the experimental colitis model established by using DSS, treatment with quercitrin resulted in a histopathological improvement and reduction in biochemical parameters, inflammation and in bacterial translocation (p < 0.05).

Specific Gene- and MicroRNA-Expression Pattern Contributes to the Epithelial to Mesenchymal Transition in a Rat Model of Experimental Colitis.

The aim of this study was to determine the gene- and microRNA-expression profile contributing to epithelial to mesenchymal transition in a rat model of experimental colitis. For this, inflammation was induced by injecting 2,4,6-trinitrobenzene sulphonic acid to the colon of male Wistar rats. Samples were taken from both inflamed and uninflamed regions of the same colon, total RNA was isolated, and the mRNA and microRNA expressions were monitored. We have determined that the expression of genes responsible for inducing mesenchymal phenotype, such as Egr1, Fgf2, Fgf7, Jak2, Notch2, Hif1α, Zeb2, Mmp9, Lox, and Vim, was all significantly induced in the inflamed regions of the affected colons while the epithelial marker E-cadherin (Cdh1) was downregulated. In contrast, the expression of microRNAs miR-192, miR-143, miR-375, miR-30a, miR-107, and miR-200b responsible for the regulation of the above mentioned genes was significantly downregulated in inflamed colon. Importantly, we detected moderate induction in the expression of five out of six tested microRNAs in the uninflamed regions. In summary, we identified numerous interacting genes and microRNAs with mutually exclusive expression pattern in inflamed regions of colitis-induced rats. These findings suggest that—among others—an important step in the epithelial to mesenchymal transition in experimental colitis is the dysregulated microRNA expression.

Effect of aqueous and particulate silk fibroin in a rat model of experimental colitis

Silk fibroin (SF) has anti-inflammatory properties and promotes wound healing. Moreover, SF particles act as carriers of active drugs against intestinal inflammation due to their capacity to deliver the compound to the damaged colonic tissue. The present work assesses the effect of SF in the trinitrobenzenesulfonic acid model of rat colitis that resembles human intestinal inflammation. SF (8mg/kg) was administered in aqueous solution orally and in two particulate formats by intrarectal route, following two technologies: spray drying to make microparticles and desolvation in organic solvent to produce nanoparticles. SF treatments ameliorated the colonic damage, reduced neutrophil infiltration and improved the compromised oxidative status of the colon. They also reduced the gene expression of pro-inflammatory cytokines like IL-1β and the anti-inflammatory cytokine IL-10. Moreover, they improved the intestinal wall integrity by increasing the gene expression of some of its markers (villin, trefoil factor-3 and mucins), thus accelerating the healing. The immunomodulatory properties of SF particles were also tested in vitro in macrophages: they activated the immune response in basal conditions without increasing it after a pro-inflammatory insult. In conclusion, SF particles could be useful as carriers to deliver active drugs to the damaged intestinal colon with additional anti-inflammatory and healing properties.

Modulation in Natriuretic Peptides System in Experimental Colitis in Rats.

Renin-angiotensin system is involved in the pathophysiology of colonic inflammation. However, there are a few reports about modulation of natriuretic peptide system. This study investigates whether a local atrial natriuretic peptide (ANP) system exists in rat colon and whether ANP plays a role in the regulation of colonic motility in experimental colitis rat model. Experimental colitis was induced by an intake of 5 % dextran sulfate sodium (DSS) dissolved in tap water for 7 days. After rats were killed, plasma hormone concentrations and mRNAs for natriuretic peptide system were measured. Functional analysis of colonic motility in response to ANP was performed using taenia coli. DSS-treated colon showed an increased necrosis with massive infiltration of inflammatory cells. The colonic natriuretic peptide receptor-A mRNA level and particulate guanylyl cyclase activity in response to ANP from colonic tissue membranes were higher, and the mRNA levels of ANP and natriuretic peptide receptor-B were lower in DSS-treated rats than in control rats. ANP decreased the frequency of basal motility in a dose-dependent manner but did not change the amplitude. The inhibitory responses of frequency of basal motility to ANP and 8-bromo-cGMP were enhanced in DSS-treated rat colon. In conclusion, augmentation of inhibitory effect on basal motility by ANP in experimental colitis may be due an increased expression of colonic natriuretic peptide receptor-A mRNA. These data suggest that local natriuretic peptide system is partly involved in the pathophysiology of experimental colitis.

Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis.

BackgroundThe aim of the study was to investigate preventive effects of glutamine (Gln), omega-3 fatty acids (FA) on erythrocyte deformability (EDEF) in rat model of indomethacin-induced enterocolitis.MethodsNineteen Wistar albino male rats were divided into three groups: control group, colitis induced by indomethacin and were fed with a standard laboratory diet (group 1), and colitis induced by indomethacin and were also fed with Gln, omega-3 FA (group 2). An investigation was performed in a rat model of experimental colitis induced by subcutaneous injections of 2 mL intdomethacine solution applied at 24 and 48 hours intervals to male Wistar rats for 14 days. Gln and omega-3 FA were added to the daily standard diets of the animals during 14 days of injections. During the study, changes in body weight were evaluated. The intestines were examined, and colitis was macroscopic and histologically scored. The circulating tumor necrosis factor alpha (TNF-α) and interleukine-1β (IL-1β), erythrocyte transit time (ETT) and thiobarbituric acid reactive substances (TBARS) levels were determined in addition to calculation of EDEF indices in all groups.ResultsNo significant differences in body weight changes could be determined between the standard diet and special diet groups at the end of the experiment. After macroscopic and microscopic scoring, in all of the groups that colitis was found induced, the lowest microscopic score was observed in the group 2. But Gln and omega-3 FA supplemented diet did not change the mean macroscopic and histological scores in all rats. The proliferating cell nuclear antigen (PCNA) levels were significantly higher in group 1 and group 2 compared to the control group. Effects of the diet on circulating TNF-α and IL-1β levels were found correlated with inflammation but statistically significant differences were not found in the group 1 and group 2 (P < 0.05). The ETT and TBARS levels in standard and special diet groups were significantly increased (P < 0.05). However, EDEF indices which are an important parameter of the study were decreased in indomethacin-induced enterocolitis groups that fed with standard and special diet.ConclusionsIncreases in ETT and TBARS levels did not return to normal by addition of Gln and omega-3 FA to diet. Our results suggest that determination of effective optimal doses and route of administration for these nutrients may play an important role in reducing EDEF and microvascular changes.

Effect of Astragalus polysaccharides on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis

AimAstragalus membranaceus is a Chinese medicinal herb and has been shown to improve hapten-induced experimental colitis. One of its major components is polysaccharides. We investigated the effect of Astragalus polysaccharides (APS) on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis. MethodsThe experimental colitis model was induced by TNBS. Forty five rats were divided into five groups (n=9): Normal control group, receiving ethanol vehicle with no TNBS during induction and IP saline injection during treatment; TNBS colitis model group (TNBS+IP saline), receiving only IP saline vehicle treatment; APS low dose group (TNBS+L-APS), receiving APS 100mg/kg; APS high dose group (TNBS+H-APS), receiving APS 200mg/kg; and positive control group (TNBS+Dexm), receiving dexamethasone 0.3mg/kg. The clinical features, macroscopic and microscopic scores were assessed. The expressions of TNF-α, IL-1β and NFATc4 were measured by real-time PCR and ELISA assays. ResultsCompared to normal control rats, TNBS+IP saline had significant weight loss, increased macroscopic and microscopic scores, higher disease activity index (DAI) up-regulation of TNF-α, IL-1β and NFATc4 mRNA expression and up-regulation of TNF-α and IL-1β protein expression. Compared to TNBS+IP saline, treatment with APS or dexamethasone significantly reduced DAI, partially but significantly prevented TNBS colitis-induced weight loss and improved both macroscopic and microscopic scores; high dose APS or dexamethasone significantly down-regulated TNF-α and IL-1β expressions (both mRNA and protein) and up-regulated NFATc4 mRNA and protein expression. The effect of high dose APS and dexamethasone is comparable. ConclusionsAPS significantly improved experimental TNBS-induced colitis in rats through regulation of TNF-α, IL-1β and NFATc4 expression.

PD9-01 THERAPEUTIC EFFECT OF ANTISENSE OLOGONUCLEOTIDE (OND) TARGETING NERVE GROWTH FACTOR (NGF) ON BLADDER HYPESENSITIVITY IN RAT WITH EXPERIMENTAL COLITIS

You have accessJournal of UrologyInfections/Inflammation of the Genitourinary Tract: Interstitial Cystitis1 Apr 2014PD9-01 THERAPEUTIC EFFECT OF ANTISENSE OLOGONUCLEOTIDE (OND) TARGETING NERVE GROWTH FACTOR (NGF) ON BLADDER HYPESENSITIVITY IN RAT WITH EXPERIMENTAL COLITIS Naoki Kawamorita, Satoru Yoshikawa, Yoichi Arai, Pradeep Tyagi, Michael Chancellor, and Naoki Yoshimura Naoki KawamoritaNaoki Kawamorita More articles by this author , Satoru YoshikawaSatoru Yoshikawa More articles by this author , Yoichi AraiYoichi Arai More articles by this author , Pradeep TyagiPradeep Tyagi More articles by this author , Michael ChancellorMichael Chancellor More articles by this author , and Naoki YoshimuraNaoki Yoshimura More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.783AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Pelvic organ “cross sensitization” seems to contribute to overlapping symptoms in patients with chronic pelvic pain syndrome (CPPS) including bladder pain syndrome/interstitial cystitis (BPS/IC). However, it is not known whether NGF overexpression in the bladder is involved in this cross sensitization mechanism. Therefore, we investigated whether local instillation of liposome-OND conjugates (L-OND) targeting NGF overexpression in the bladder can suppress bladder hypersensitivity in a rat model of experimental colitis. METHODS Five groups of female SD rats were used; (a) control (no treatment), (b) colitis-OND (intracolonic 2,4,6,trinitrobenzen sulfonic acid [TNBS] enema & intravesical L-OND), (c) colitis-saline (TNBS & intravesical saline), (d) sham-OND (L-OND was given without colitis) and (e) sham-saline (saline was given without colitis). A day before evoking TNBS colitis, either L-OND or saline was instilled to the bladder. (1) Behavior testing: Resiniferatoxin (0.3µM, 0.3 ml) was administered into the bladder for 1 min to evaluate nociceptive behaviors such as licking (lower abdominal licking) and freezing (motionless head-turning) for 15 min. (2) Cystometry: Saline followed by 0.1% acetic acid (AA) were continuously infused to evaluate changes in intracontraction intervals (ICIs) in conscious rats. (3) Molecular analysis: Harvested bladders were divided to mucosal and detrusor layers to measure the mRNA and protein expression of NGF by qPCR and ELISA, respectively. RESULTS (1) In the colitis-saline group, the score of freezing behavior, which represents bladder pain sensation, was significantly higher than that of other groups including the colitis-OND group. (2) The reduction rate of ICI after AA instillation in the colitis-saline group was approximately 40% in contrast to 10% in the colitis-OND group. (3) The mRNA and protein expression of NGF in the mucosa was significantly higher in the colitis-saline group compared to the colitis-OND group. CONCLUSIONS These results indicate that intravesical treatment of NGF antisense with liposome, which suppressed mucosal NGF overexpression, reduced colitis-induced bladder hypersensitivity evidenced by increased bladder pain behavior (freezing) and AA-induced bladder overactivity. Thus, the intravesical NGF antisense treatment could be effective for hypersensitive bladder symptoms in CPPS including BPS/IC, in which the cross-sensitization mechanism contributes to overlapping symptoms from different pelvic organs. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e211 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Naoki Kawamorita More articles by this author Satoru Yoshikawa More articles by this author Yoichi Arai More articles by this author Pradeep Tyagi More articles by this author Michael Chancellor More articles by this author Naoki Yoshimura More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Protective and worsening peripheral nociceptin/orphanin FQ receptor-mediated effect in a rat model of experimental colitis

Nociceptin/orphanin FQ (N/OFQ) and nociceptin orphanin peptide (NOP) receptors represent an endogenous system modulating gastrointestinal functions and inflammation. We investigated the peripheral effect of N/OFQ and of UFP-101, the NOP antagonist, in a model of colitis induced by TNBS (2,4,6 trinitrobenzenesulphonic acid; 60mg/kg). Male rats received two intraperitoneal injections per day of N/OFQ, UFP-101 or saline for 3 days after colitis induction. Four days after TNBS, animals were sacrificed and colonic histological damage, myeloperoxidase (MPO) activity and cytokine (IL-1β and IL-10) levels were evaluated. N/OFQ plasmatic levels were assessed by radioimmunoassay.TNBS increased all the inflammatory variables considered. In colitic rats, N/OFQ (0.02 and 0.2nmol/kg) improved microscopic damage, MPO activity and decreased IL-1β levels in comparison with TNBS group, whereas at the highest dose (20nmol/kg) the peptide worsened colitis. UFP-101 at the dose of 1nmol/kg, without pharmacological activity, antagonised the protective effect of N/OFQ (0.2nmol/kg) on colitis, but at a dose level of 3 and 10nmol/kg worsened inflammation, revealing the endogenous N/OFQergic system protective role. N/OFQ plasmatic levels were not modified in TNBS-treated rats compared with controls, whereas they were reduced in rats treated with the doses of UFP-101 aggravating colitis.In conclusion, peripheral low doses of N/OFQ have a beneficial effect on colonic inflammation in rats. In contrast, N/OFQ at a dose 100–1000-fold higher than those that protect worsens colitis, probably through different mechanisms. The peripheral N/OFQergic system can represent a new field of investigation in some intestinal inflammatory conditions.

Dietary Phosphatidylcholine Supplementation Attenuates Inflammatory Mucosal Damage in a Rat Model of Experimental Colitis

This study was designed to follow the time course of inflammatory activation in a rodent model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. We hypothesized that oral phosphatidylcholine (PC) pretreatment regimens may influence leukocyte-mediated microcirculatory reactions in this condition. In series I, Wistar rats were monitored 1 day after colitis induction (n = 24), and in series II (n = 24) on day 6 following a TNBS enema. The PC-pretreated animals received a 2% PC-enriched diet for 6 days before the TNBS enema (series I), or for 3 days before and 3 days after TNBS treatment (series II). The macrohemodynamics, serosal microcirculation (visualized by intravital videomicroscopy), colonic xanthine oxidoreductase, myeloperoxidase and nitric oxide end products, and changes in proinflammatory cytokine levels in plasma were measured. The mucosal structural injury was monitored in vivo by means of confocal laser scanning endomicroscopy. The TNBS enema induced a systemic hyperdynamic circulatory reaction with increased serosal capillary blood flow and significantly elevated colonic inflammatory enzyme activities, levels of nitric oxide production, and cytokine concentrations. Acute colitis caused disruption of the capillary network, whereas the morphologic damage was less severe in series II. The PC pretreatment protocols led to significant decreases in the serosal hyperemic reaction, the cytokine levels, and the inflammatory enzyme activities. The objective signs of tissue damage were reduced in both series, and the number of mucus-producing goblet cells in the resolving phase of colitis was increased. Dietary PC efficiently decreases the cytokine-mediated progression of inflammatory events and preserves the microvascular structure in the large intestine.

Mo1104 Protective Role of Peripheral N/OFQergic System in a Rat Model of Experimental Colitis

Mo1104 Protective Role of Peripheral N/OFQergic System in a Rat Model of Experimental Colitis

The effect of methylsulfonylmethane on the experimental colitis in the rat

Methylsulfonylmethane (MSM), naturally occurring in green plants, fruits and vegetables, has been shown to exert anti-inflammatory and antioxidant effects. MSM is an organosulfur compound and a normal oxidative metabolite of dimethyl sulfoxide. This study was carried out to investigate the effect of MSM in a rat model of experimental colitis. Colitis was induced by intracolonic instillation of 1ml of 5% of acetic acid. Rats were treated with MSM (400mg/kg/day, orally) for 4days. Animals were euthanized and distal colon evaluated histologically and biochemically. Tissue samples were used to measurement of malondialdehyde (MDA), myeloperoxidase (MPO), catalase (CAT), glutathione (GSH) and proinflammatory cytokine (TNF-α and IL-1β) levels. Results showed that MSM decreased macroscopic and microscopic colonic damage scores caused by administration of acetic acid. MSM treatment also significantly reduced colonic levels of MDA, MPO and IL-1β, while increased the levels of GSH and CAT compared with acetic acid-induced colitis group. It seems that MSM as a natural product may have a protective effect in an experimental ulcerative colitis.

The Effect of Exopolysaccharide-Producing Probiotic Strains on Gut Oxidative Damage in Experimental Colitis

Oxidative stress plays a role in disease initiation and progression in inflammatory bowel disease (IBD) and manipulation of this pathway may attenuate disease progress. In this study, the effect of exopolysaccharide (EPS)-producing probiotic bacteria on gut oxidative damage was evaluated in a rat model of experimental colitis. Colitis was induced by intracolonic administration of acetic acid. Rats were treated daily with two probiotic strains, L. delbrueckii subsp. bulgaricus B3 strain (EPS of 211 mg/l; high-EPS group) or L. delbrueckii subsp. bulgaricus A13 strain (EPS of 27 mg/l; low-EPS group), which were given directly into the stomach. Non-colitis-fed control and preventative groups were only treated with the high-EPS producing strain. Antioxidant enzyme activities (superoxide dismutase, catalase, total glutathione, reduced glutathione, glutathione disulfide) and lipid peroxidation were measured in colonic tissue samples after a treatment period of 7 days. Significant oxidative damage was associated with a higher level of malondialdehyde (MDA) activity and reduced antioxidant enzyme activities in the colitis model group. All antioxidant enzyme activities were higher in both probiotic-treated groups compared with those of the colitis model group (P < 0.001). Lipid peroxidation was significantly ameliorated in both probiotic groups. The improvement of oxidative stress parameters was significantly more in the high-EPS group than in the low-EPS group (P < 0.001). EPS-producing probiotic bacteria significantly attenuate oxidative stress in experimental colitis. Increased EPS production gives rise to a better probiotic function. These results suggest that EPS molecules could revaluate probiotic strains and exert their beneficial effects on the host and this may have a therapeutic potential.

Glutamine Prevents Fibrosis Development in Rats with Colitis Induced by 2,4,6-Trinitrobenzene Sulfonic Acid

We investigated the effects of glutamine on the development of colonic fibrosis and on the expression of the major fibrogenic factors in a rat model of experimental colitis. Colitis was induced in one-half of the male Wistar rats by intracolonic administration of 30 mg of 2,4,6-trinitrobenzene sulfonic acid (TNBS). L-Glutamine (25 mg/kg) was administered rectally to one-half of the controls and one-half of the colitic rats. The control, control+glutamine, TNBS, and TNBS+glutamine groups were studied at d 2 and 7 after colitis induction. Glutamine induced a significant decrease in the area of colon fibrosis and in the staining of α-smooth muscle actin positive cells within areas of extracellular matrix deposits in the submucosa. Collagen synthesis was stimulated following TNBS administration, with a significant increase in procollagen IV, collagen III, and collagen Iα2 mRNA levels in the colon by d 2 after TNBS instillation. Tissue inhibitor of metalloproteinase, connective tissue growth factor, transforming growth factor-β, platelet-derived growth factor, and phosphorylated Smad3 were overexpressed in the colon of TNBS-treated rats. These effects were significantly abrogated in the colitic rats treated with glutamine. Our findings suggest that glutamine treatment not only attenuates the outcome of TNBS-induced colitis by reducing the inflammatory response but also by downregulating the increased expression of several gene pathways that contribute to the accumulation of matrix proteins. This molecule may be an interesting candidate for reducing the risk of fibrosis and stricture formation in inflammatory bowel disease.