Increase In Colon Weight Research Articles

Mechanism of Sishen-Pill-Regulated Special Memory T and mTfh Cell via Involving JAK/STAT5 Pathway in Colitis Mice.

It is known that memory T cells (mT cell) and memory T follicular cells (mTfh) play vital roles in the IBD pathogenesis. Sishen Pill (SSP) is a classic prescription used to treat chronic ulcerative colitis (UC). However, it is still unclear whether SSP can regulate immune homeostasis induced by mT cell and mTfh to treat IBD. In this study, we measured mT cell and mTfh level to explore the conceivable mechanism of SSP-treated IBD. The mice colitis were induced by dextran sulfate sodium (DSS) and were treated by SSP for 7 days. The therapeutic effect of SSP was evaluated by macroscopic and microscopic observation; the mT cell, mTfh, and their subsets were analyzed by flow cytometry. Activation of the JAK/STAT signaling pathway was analyzed by using a Western blot. In the present study, SSP significantly reversed weight loss and colonic injury (colon weight increase and colonic length shortening) caused by 3% DSS in physiological saline solution. Flow cytometry showed that the percentages of CD4+ and CD8+ expressions on central memory T cells were enhanced after SSP treatment, while the CD4+ T cm, CD4+ mTfh (memory T follicular helper) cells and their subpopulations were also significantly increased. Moreover, SSP inhibited the expression of JAK/STAT signaling pathway proteins JAK1, PIAS3, STAT5, p-STAT5, BIM, BAX, caspase-3, and β-casein and promoted the expression of JAK3, PISA1, Bcl-2, and caveolin-1. In summary, SSP can regulate immune homeostasis induced by mT cell and mTfh in DSS-induced colitis, which is potentially correlated with JAK/STAT signaling pathway activation.

A novel role of pirfenidone in attenuation acetic acid induced ulcerative colitis by modulation of TGF-β1 / JNK1 pathway

Colon diseases are a major health burden, particularly ulcerative colitis, in both men and women worldwide. Environmental and genetic factors in various colonic pathologies influence the onset and outcome of diseases. As the evidence from recent research is considered, the importance of inflammation in the onset, progression, and outcome is gaining more traction. The goal of this study was to see if pirfenidone could treat ulcerative colitis (UC) and if so, what mechanisms were involved. By intracolonic instillation [2 ml, 3 percent v/v acetic acid (AA)], ulcerative colitis was induced. Pirfenidone was administered to rats in different experimental groups (125 or 250 and 500 mg/kg, orally) for two weeks. Compared to normal group, the AA group showed an increase in colon weight, length, body weight, clinical evaluation, and macroscopic scoring of UC, serum lactate dehydrogenase, C-reactive protein, malondialdehyde, while decreasing serum total antioxidant capacity. Significant increases in colon Jun N terminal kinase1 (JNK1), transforming growth factor-beta (TGF-β1), interleukin 1 beta (IL1β), and Caspase-3 content. Furthermore, immunohistochemical staining revealed increased nuclear factor kappa B (NF-κB) expression along with histopathological changes. Pirfenidone inhibited inflammatory biomarkers release and restored oxidants/antioxidants hemostasis. In a dose-dependent manner, pirfenidone treatment showed a significantly decrease in all of these parameters. In addition, pirfenidone has significantly preserved the histopathological architecture of tissues. Current data demonstrate that Pirfenidone protects against AA-induced UC by modulating the TGF-β1/JNK1 and Caspase-3 pathways. Pirfenidone's antioxidant, anti-inflammatory, and anti-apoptotic properties are thought to be responsible for its therapeutic benefit.

Lycium barbarum Polysaccharides and Capsaicin Alleviate Dextran Sulfate Sodium‐Induced Ulcerative Colitis in Rats via Anti‐Inflammatory Effect

Ulcerative colitis (UC), a chronic remittent inflammatory condition, leads to inflammation and ulcer in the colon and rectum. This study investigated the protective effects of Lycium barbarum polysaccharides (LBP, 51.25% polysaccharides) from wolfberry extract and capsaicin (CAP, 85% capsaicin) from cayenne pepper extract on UC induced by dextran sulfate sodium (DSS) in rats. Sprague-Dawley rats were divided in to 5 groups: control, UC, UC treated with 100 mg/kg bw LBP (LBP), UC treated with 12 mg/kg bw CAP (CAP), and UC treated with a combination of 50 mg/kg bw LBP and 6 mg/kg bw CAP (MIX) groups. Treatment with LBP and/or CAP was orally administered by gavage from week 1 to week 4, and 5% DSS was given in drinking water for 6 days during week 3 to induce UC. After 4-week treatment, rats were sacrificed, and colon length, colon weight, disease activity index (DAI), and colonic levels of interferon-γ (IFN-γ), interleukin (IL)-17A, and IL-22 were measured. The DSS group induced UC symptoms, elevated DAI score, shortened colon length, and increased colon weight to length ratio compared with the control group. The LBP, CAP, and MIX groups significantly decreased DAI scores on days 5 and 6 during the DSS-induced period, and significantly reversed a decrease in colon length and an increase in colon weight to length ratio caused by DSS. The DSS group significantly increased proinflammatory cytokines IFN-γ, IL-17A, and IL-22 levels in the colon. The LBP and CAP groups significantly decreased colonic IFN-γ, IL-17A, and IL-22 levels compared with the DSS group, however, the MIX group only significantly decreased colonic IL-22 levels. Our results suggested that administration of LBP and/or CAP attenuates DSS-induced UC symptoms and improves colon length through suppression of colon inflammation.

Abstract 3228: Immune checkpoint blockade and autoimmune diseases: Development of a mouse model of colitis induced by anti-CTLA-4

Abstract Immunotherapies prime or activate patient’s immune system to fight disease and has recently been a source of registered and promising new cancer treatments with major beneficial clinical outcomes in several cancers. However, by increasing the activity of the immune system, therapies as such targeting the immune checkpoint blockade can have profound inflammatory side effects, termed immune-related adverse events, with particular organs affected such as gastrointestinal tract, endocrine glands, skin and liver. In patients treated with the anti-CTLA-4 antibody, Ipilimumab, the overall incidence of diarrhea and colitis has been reported as 32.8%. This side effect is also observed in patients treated with anti-PD-1 therapy. The reproduction of such aspects of immune checkpoint inhibitors side effects in preclinical animal models would serve to dig into deciphering mechanisms involved, but also to evaluate combination therapies and modalities to reduce and manage such incidence with potential beneficial translation in clinical practice. We thus first ought to establish a checkpoint blockade-related autoimmune mouse model of colitis, using female C57BL/6 mice which were tested to determine their response to orally administered dextran sulfate sodium (DSS) combined to multiple injections of anti-CTLA-4 antibody or an isotype control antibody. After administration of DSS in drinking water for 7 days, mice that received an anti-CTLA-4 antibody showed no difference in body weight loss and Disease Activity Index (composite of body weight loss, stool consistency and presence of blood in stools), when compared to mice that received DSS plus the isotype control antibody. Histological sections analysis from the colons of mice culled at Day 10 confirmed that the combined treatment did not change the colitis score.However, when looking at later time points corresponding to the usual recovery phase of colitis, the effect of anti-CTLA4 treatment was clearly revealed by a sustained body weight loss and the persistence of a high Disease Activity Index, while the isotype control-treated animals slowly returned to baseline values similar to untreated animals. At sacrifice on Day 19, these in life findings were confirmed by a decrease in colon length (- 0.94 cm), an increase in colon weight (+ 231 mg) and a high mucus colon production in the anti-CTLA4-treated group versus the isotype control-treated group. Histological analysis of colons, and a more in depth characterization of the immune infiltrates will be presented. Citation Format: Edwige Nicodeme, Florence Blandel, Valerie Boullay, Yannick Saintillan, Gael Krysa, Anne-Benedicte Boullay, Jean-Jacques Tousaint, Robin Artus, Laure Levenez, Jeremy Odillard, Ingrid Jacquet, Olivier Duchamp, Fabrice Viviani. Immune checkpoint blockade and autoimmune diseases: Development of a mouse model of colitis induced by anti-CTLA-4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3228.

Gallic acid improved inflammation via NF-κB pathway in TNBS-induced ulcerative colitis

Gallic acid (GA), as an active component, has been found in many fruits and plants, and it exhibits potential protective effects, such as anti-inflammatory, antioxidant, antiviral and anticancer. However, the effects of GA on ulcerative colitis (UC) remain unknown. The purpose of this study was to investigate the effects of GA on IL-1β-induced HIEC-6 cells and TNBS-induced UC in mice. Various biochemical analyses including proliferation and apoptosis were assessed in HIEC-6 cells. In addition, body weight of mice, the level of cytokines and histological changes were utilized to analyze the GA protecting mice with UC.Our results showed that administration of GA significantly increased the expressions of IL-4, and IL-10, while down-regulated IL-1, IL-6, IL-12, IL-17, IL-23, TGF-β and TNF-α expressions compared with a model control group in vitro and in vivo. Moreover, flow cytometry and TUNEL analysis revealed that administration of GA significantly inhibited the apoptosis of HIEC-6 cells and mics in UC. Furthermore, pretreatment with GA obviously reversed the decrease in body weight, increase in colon weight, and attenuated the histological changes derived from UC. In addition, western blot analysis demonstrated that GA efficiently suppressed NF-κB signaling pathway in TNBS-induced UC. In conclusion, the findings of this study demonstrated that GA plays an anti-inflammatory role in UC via inhibiting NF-κB pathway.

Investigation of the relationship between the Th17/IL-23 pathway and innate-adaptive immune system in TNBS-induced colitis in rats.

Objective(s):This study was aimed at investigating immune activations of the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model in colonic mucosa by immunohistochemical and Western blot methods.Materials and Methods:For this purpose, 16 female Wistar albino rats were divided into two random groups of control (n=8) and colitis (n=8). The experimental colitis model was induced by intracolonic administration of TNBS (25 mg/rat). Control animals received only rectal saline for the same time. The animals were sacrificed on the 15th day after TNBS administration, and colon tissue was removed and examined morphologically. Colon samples were stained immunohistochemically with anti-CD3, anti-CD4, anti-CD5, anti-CD8, anti-CD11b, anti-CD45, anti-TNF-α, anti-IL-17, anti-IL-22 and anti-IL-23 antibodies. Additionally, the colonic tissue IL-17 and IL-22 expressions were examined by the Western blot method.Results:In the experimental results, it was determined that there was a significant decrease in body weight and an increase in colon weight in the colitis group when comparing initial experiments. The colon tissue ulcerations, inflammation, crypt loss and Goblet cell loss were observed in the colitis group in microscopic examinations. The immunohistochemical positive cell numbers significantly increased in the colitis group. The immunoreactive lymphocytes in the propria, intracryptal and submucosal layers were found to be increased in the colitis group of rats. In addition, IL-17 and IL-23 expressions were increased in colitis colon mucosa found by Western blot analysis.Conclusion:The Th17/IL-23 pathway and IL-22 serve important roles in the pathogenesis of ulcerative colitis, and will be further examined by study.

UNC5B receptor deletion exacerbates DSS‐induced colitis in mice by increasing epithelial cell apoptosis

The netrin-1 administration or overexpression is known to protect colon from acute colitis. However, the receptor that mediates netrin-1 protective activities in the colon during colitis remains unknown. We tested the hypothesis that UNC5B receptor is a critical mediator of protective function of netrin-1 in dextran sodium sulfate (DSS)-induced colitis using mice with partial deletion of UNC5B receptor. DSS colitis was performed in mice with partial genetic UNC5B deficiency (UNC5B+/− mice) or wild-type mice to examine the role of endogenous UNC5B. These studies were supported by in vitro models of DSS-induced apoptosis in human colon epithelial cells. WT mice developed colitis in response to DSS feeding as indicated by reduction in bw, reduction in colon length and increase in colon weight. These changes were exacerbated in heterozygous UNC5B knockout mice treated with DSS. Periodic Acid-Schiff stained section shows damages in colon epithelium and mononuclear cell infiltration in WT mice, which was further increased in UNC5B heterozygous knockout mice. This was associated with large increase in inflammatory mediators such as cytokine and chemokine expression and extensive apoptosis of epithelial cells in heterozygous knockout mice as compared to WT mice. Overexpression of UNC5B human colon epithelial cells suppressed DSS-induced apoptosis and caspase-3 activity. Moreover, DSS induced large amount of netrin-1 and shRNA mediated knockdown of netrin-1 induction exacerbated DSS-induced epithelial cell apoptosis. Our results suggest that UNC5B is a critical mediator of cell survival in response to stress in colon.

English

Ulcerative colitis and Crohn’s disease are chronic recurrent inflammatory bowel disease (IBD) of unknown origin. Oxidative stress is believed to be a key factor in the pathogenesis of the mucosal damage in IBD. The aqueous extract of Hyphaena thebaica fruits showed an antioxidant activity; this is due to the substantial amount of their water-soluble phenolic contents. This study was undertaken to study the effect of H. thebaica in experimentally induced IBD. Sprague Dawley rats were pretreated orally for 5 days with distilled water in control, H. thebaica 500 mg/kg in acetic acid + H. thebaica group and 5-aminosalisylic acid (5-ASA) 100 mg/kg in acetic acid + 5ASA groups. Colitis was induced by transrectal administration of 4% acetic acid on 5th day. All the animals were sacrificed with ether overdose 48 h after colitis induction, and 10 cm colon segment was resected from distal end. Colon was weighed (for disease activity index) and scored macroscopically and microscopically after histological staining. Biochemical assessments included myeloperoxidase (MPO) and tissue catalase (CAT), glutathione (GSH) and superoxide dismutase (SOD) measurements. H. thebaica showed significant prevention of increase in colon weight and disease activity index along with decrease in macroscopic and microscopic lesion score as compared to control group. Significant improvement was observed in the levels of MPO, CAT and SOD, except GSH. However, the effect of H. thebaica was significantly less than 5-ASA. H. thebaica at 500 mg/kg showed significant amelioration of experimentally induced IBD, which may be attributed to its antioxidant and anti-inflammatory properties.   Key words: Colitis, antioxidant, Hyphaena thebaica, myeloperoxidase, catalase, superoxide.

Oral treatment with a novel small molecule alpha 4 integrin antagonist, AJM300, prevents the development of experimental colitis in mice

Background and aimsInhibition of lymphocyte trafficking by treatment with an anti-α4 integrin antibody has been clinically validated as a therapeutic approach for inflammatory bowel disease (IBD), and the orally effective ‘anti-α4 integrin therapy’ may be more convenient in clinical practice. The aim of this study was to investigate the pharmacological profile and anti-inflammatory effect of a novel, orally active small molecule α4 integrin antagonist, AJM300. MethodsThe binding specificity/potency of HCA2969 (the active metabolite of AJM300) were investigated in vitro. The pharmacodynamics for α4 integrin antagonism of AJM300 was investigated in mice. The anti-inflammatory effect of AJM300 fed in a diet and the anti-α4 integrin monoclonal antibody was evaluated in a mouse colitis model induced by transfer of IL-10 deficient T cells. ResultsHCA2969 selectively inhibited the in vitro binding of α4 integrin (α4β7/α4β1) to the cell adhesion molecules. Oral treatment with AJM300 dose-dependently inhibited lymphocyte homing to Peyer's patches and increased the peripheral lymphocyte count in the same dose range. AJM300 dose-dependently prevented the development of experimental colitis in mice. A significant inhibition of colon weight increase was accompanied by inhibition of T-cell infiltration into the lamina propria of colon. The maximum efficacy of AJM300 (1% diet) was comparable to that achieved by the saturated α4 integrin blockade with antibody. ConclusionsOral treatment with the selective small molecule α4 integrin antagonist (AJM300) prevented the development of colitis and its efficacy was comparable to that of the anti-α4 integrin antibody.

Protective effect of ethanolic extract of seeds of Coriandrum sativum l. in acetic acid-induced ulcerative colitis in male wistar rats

Objective: To evaluate the protective effect of ethanolic extract of dried seeds of Coriandrum sativum L. (C.sativum) in acetic acid-induced ulcerative colitis in rats.Methods: Male Wistar rats were divided into various treatment groups (n=5). The animals were administered with 2ml of acetic acid (4% v/v) via intrarectal route to induce colitis. Prednisolone (2mg/kg) was used as a standard drug and C.sativum was administered at a dose of 100 and 300 mg/kg p.o. Macroscopic scoring, colon weight to length ratio, colonic superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), lipid peroxidation (LPO), myeloperoxidase (MPO) levels and histopathological changes were recorded after the treatment regimen of 11 days.Results: Intrarectal instillation of acetic acid caused significant (P<0.05) increase in colon weight to length ratio, LPO, and MPO levels; and significant (P<0.05) decrease in the levels of SOD, CAT and GSH levels. Pretreatment with C.sativum (100, 300 mg/kg, p.o.) exhibited significant (P<0.05) reversal of all the above biochemical parameters and significantly reversed the histopathological changes induced by acetic acid treatment.Conclusion: The present investigation demonstrates the potent therapeutic value of C.sativum (100, 300 mg/kg, p.o.) in the amelioration of experimental colitis in rats. The beneficial effect of C.sativum could be attributed to its antioxidant effect.

A Novel, Orally Active Alpha 4 Integrin Antagonist, AJM300 Prevents the Development of Experimental Colitis Induced by Adoptive Transfer of IL-10 Deficient CD4+ T Cells in Mice.

Abstract Inhibition of lymphocyte trafficking by treatment with an antibody to α4 integrin has been clinically validated as a therapeutic approach for inflammatory bowel disease (IBD). The aim of this study was to investigate the pharmacological profile of AJM300, a novel small molecule α4 integrin antagonist. The active metabolite of AJM300 (HCA2969) selectively inhibited the in vitro binding of α4β7 integrin and α4β1 integrin to MAdCAM-1 and VCAM-1, respectively. Oral administration of AJM300 dose-dependently inhibited lymphocyte homing to Peyer's patches in normal mice. In addition, an increase in the peripheral lymphocyte count was observed in the same dose range that inhibited lymphocyte homing and was associated with the pharmacokinetics of HCA2969 in mice. AJM300 in the diet (AJM300M1) dose-dependently prevented the development of colitis in mice induced by adoptive transfer of IL-10 deficient CD4(+) T cells. In mice fed 1% AJM300M1 the concentration of HCA2969 in plasma was maintained over the EC(90) value for lymphocyte homing for 24 h. A significant inhibition of colon weight increase was observed at a 1% dose of AJM300M1 and was accompanied by inhibition (> 95%) of T-cell infiltration into the colon. This was comparable to the efficacy achieved by a full blockade of α4 integrin by antibody treatment. Furthermore, a histological improvement of epithelial cell hyperplasia, a reduction of inflammatory cell infiltration and a maintenance of mucus production were observed with AJM300M1. These results suggest that AJM300 might be a promising oral drug for the treatment of IBD.

Response to Comment on “Tissue Factor-Dependent Chemokine Production Aggravates Experimental Colitis”

In our recent work we utilized genetically modified mice to investigate the role of tissue factor (TF) in experimental colitis. We present evidence suggesting TF plays a detrimental role in this disease via signal transduction dependent KC production in colon epithelial cells, which provokes granulocyte influx leading to subsequent inflammation and organ damage. We agree with Gambone et al. that experiments using genetically modified mice should ideally be performed with littermate controls. Unfortunately, intercrosses of 50% TF mice are problematic and employing this strategy resulted in insufficient TFlow (1%) mice within a similar age category as littermate wildtype controls. Consequently, we opted for an experimental set-up in which littermate 1% and 50% TF mice were compared with non-littermate C57Bl/6 wildtypes. The 1 and 50% TF mice had been backcrossed for 6 generations with C57BL/6 mice and are thus largely on a C57Bl/6 genetic background (1). However, we performed a control experiment to exclude potential strain differences biasing our results. To this end, wildtype mice obtained from an intercross of 50% TF mice were compared with non-littermate wildtype C57Bl/6 mice in the DSS-induced experimental colitis model as described in our paper (2). In this particular experiment we did not observe differences between the groups with respect to body weight loss, increase in colon weight, reduction in colon length and disease severity score. Unfortunately however, disease symptoms were rather mild and somewhat variable (perhaps resulting from a new batch of DSS). After careful consideration we decided not to include these data in the published manuscript. Despite the limitations of this control experiment, we are confident the differences reported in our paper are indeed due to changes in TF levels and not due to strain differences

The effect of pentoxifylline and its metabolite-1 on inflammation and fibrosis in the TNBS model of colitis

TNBS-induced colitis has characteristics resembling human Crohn's disease including transmural inflammation, ulceration, and fibrosis. Current treatments target acute symptoms but do not necessarily prevent fibrotic complications of the disease. The aim of this study was to determine the effect of pentoxifylline and its primary metabolite (M-1) on fibrosis in the TNBS-induced colitis model. Myeloperoxidase activity and interleukin-18 are indicators of inflammation and were elevated in the TNBS model. The morphology damage score assesses colon damage and was also elevated in the TNBS model. Collagen as the indicator of fibrosis was quantified and visualized by the Sirius Red/Fast Green staining technique and collagen type I was assessed by Western analysis. Collagen was elevated in the TNBS-induced model. Pentoxifylline and M-1 treatment significantly attenuated colon damage and inflammation in TNBS-colitis (P<0.05). M-1 treatment significantly reduced the TNBS-induced increase in colon weight, colon thickness and total collagen content (P<0.05). Results suggest that pentoxifylline and M-1 inhibit intestinal fibrosis in this experimental model and may prove beneficial in the treatment of intestinal fibrosis associated with human Crohn's disease with the added benefit of inhibiting inflammation and ulceration. This is the first study to examine the effects of racemic M-1 in vivo and one of the few studies to examine the effect of drugs on both inflammation and fibrosis in an experimental model of colitis.

Effect of fruit extract of Fragaria vesca L. on experimentally induced inflammatory bowel disease in albino rats

Aim:Ulcerative colitis and Crohn’s disease are chronic recurrent inflammatory bowel disease (IBD) of unknown origin. Oxidative stress is believed to be a key factor in the pathogenesis and perpetuation of the mucosal damage in IBD.Materials and Methods:Ethanolic extract of Fragaria vesca (EFFV) fruits was prepared by percolation method and subjected to oral toxicity testing using OECD guidelines. Albino rats were pretreated orally for 5 days with 3% gum acacia in control, EFFV 500 mg/kg in test and 5-aminosalisylic acid (5-ASA) 100 mg/kg in standard groups. Colitis was induced by transrectal administration of 4% acetic acid on 5th day. All the animals were sacrificed with ether overdose 48 hours after colitis induction, and 10 cm colon segment was resected from proximal end. Colon was weighed (for disease activity index) and scored macroscopically and microscopically after histological staining. Biochemical assessments included myeloperoxidase (MPO) and tissue catalase (CAT), glutathione (GSH) and superoxide dismutase (SOD) measurements. Statistical analysis was done using one-way analysis of variance (ANOVA) followed by Dunnett’s “t” test.Results:EFFV showed significant (P < 0.05) prevention of increase in colon weight and disease activity index along with decrease in macroscopic and microscopic lesion score as compared to control group. Significant improvement was observed in the levels of MPO, CAT and SOD, except GSH (P < 0.05). However, the effect of EFFV was significantly less than 5-ASA (P < 0.05).Conclusions:EFFV at 500 mg/kg showed significant amelioration of experimentally induced IBD, which may be attributed to its antioxidant and anti-inflammatory properties.

Thromboxane-prostanoid receptor expression and antagonism in dextran-sodium sulfate-induced colitis

In the current study of murine colitis, the potential roles of thromboxane and the thromboxane-prostanoid (TP) receptor were investigated, in as much as thromboxane signaling has been implicated in human inflammatory bowel disease. Colitis was induced in C57BL/6 mice via ingestion of dextran sodium sulfate (DSS), with or without co-administration of the thromboxane synthase inhibitor ozagrel (25 mg/kg/day) or the TP receptor antagonist vapiprost (2.5 mg/kg/day). Immunohistochemistry of colonic tissue demonstrated a DSS-induced increase in TP receptor expression, but not of thromboxane synthase. Moreover, tissue levels of the metabolite thromboxane B(2) were unchanged by DSS. Vapiprost, but not ozagrel, partially attenuated histologic signs of inflammation induced by DSS, with vapiprost allowing a smaller increase in colon weight per unit length than ozagrel. Vapiprost also tended to attenuate DSS-induced alterations in intestinal transit. In summary, TP receptor antagonism was more effective than thromboxane synthase inhibition in alleviating DSS-induced colitis in mice.

The possible mechanisms of Fructus Mume pill in the treatment of colitis induced by 2,4,6-trinitrobenzene sulfonic acid in rats

Ethnopharmacological relevance Fructus Mume pill (FMP) has been used as a folk remedy for gastrointestinal diseases in China over thousands of years. FMP was approved for the treatment of gastrointestinal diseases in 2001 by the State Food and Drug Administration (SFDA) of China. Although FMP had significant efficacy for treatment of the patients with inflammatory bowel disease (IBD) in the clinic, the mechanism of action is still unclear. Aim of the study In the present study, the effects and possible mechanism of FMP on colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) were investigated. Materials and methods Fifty-four SD rats were divided into six groups. Nine rats for each group from three independent experiments were investigated for the effects of FMP. Results FMP protected against diarrhea, colon weight increase, colonic accretion, ulceration and myeloperoxidase (MPO) activity elevation. The effects of FMP on recovery of colonic damage and restoration of the normal structures of colorectums were superior to dexamethasone (DEX). FMP promoted the restoration of abnormal cytokine secretion after TNBS treatment. FMP was effective in restoring the balance of intestinal bacteria population from the imbalance of G +/G − in rats with colitis. Conclusions The results indicated that FMP is effective in treatment of colitis in an experimental rat model. The possible mechanisms may be through down-regulation of Th1-polarized immune response and opsonic effect of intestinal commensal bacteria in this model system.

Vincristine delays gastric emptying and gastrointestinal transit of liquid in awake rats

We evaluated the effects of vincristine on the gastrointestinal (GI) motility of awake rats and correlated them with the course of vincristine-induced peripheral neuropathy. Vincristine or saline was injected into the tail vein of male Wistar rats (180-250 g) on alternate days: 50 microg/kg (5 doses, N = 10), 100 microg/kg (2, 3, 4 and 5 doses, N = 49) or 150 microg/kg (1, 2, or 5 doses, N = 37). Weight and stool output were measured daily for each animal. One day after completing the vincristine treatment, the animals were fasted for 24 h, gavage-fed with a test meal and sacrificed 10 min later to measure gastric emptying (GE), GI transit and colon weight. Sensory peripheral neuropathy was evaluated by hot plate testing. Chronic vincristine treatments with total cumulative doses of at least 250 microg/kg significantly decreased GE by 31-59% and GI transit by 55-93%. The effect of 5 doses of vincristine (150 microg/kg) on GE did not persist for more than 1 week. Colon weight increased after 2 and 5 doses of vincristine (150 microg/kg). Fecal output decreased up to 48 h after the fifth dose of vincristine (150 microg/kg). Vincristine decreased the heat pain threshold 1 day after 5 doses of 50-100 microg/kg or after 3-5 doses of 150 microg/kg. This effect lasted for at least 2 weeks after the fifth dose. Chronic intravenous vincristine treatment delayed GE and GI transit of liquid. This effect correlated with the peak increase in colon weight but not with the pain threshold changes.

The beneficial effect of Rheum tanguticum polysaccharide on protecting against diarrhea, colonic inflammation and ulceration in rats with TNBS-induced colitis: The role of macrophage mannose receptor in inflammation and immune response

Rhubarb has been used as a folk remedy for gastrointestinal disease in China for over two thousand years. In the present study, we evaluated the effect of Rheum tanguticum polysaccharide (RTP), a water soluble fraction extracted from rhubarb, on protection from inflammation and colonic damage in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. RTP protected against diarrhea, colon weight increase, and ulceration induced by TNBS. It was at least as effective as dexamethasone (DEX). RTP significantly decreased myeloperoxidase (MPO) activity in the colonic mucosa. Oral administration of RTP was as effective as intraperitoneal (i.p.) injection on toxicity protection and MPO activity. To further investigate the possible underlying mechanism, we studied the role of mannose receptor (MR) in cytokine secretion, ligand binding and endocytosis of macrophages. The secretion of IFN-γ was dramatically increased while IL-4 decreased in colitis compared to the control (normal rats), and RTP restored the condition similar to the control in vivo. The secretion of IFN-γ by macrophages was induced by RTP and lipoarabinomannan (LAM) but not mannose in vitro. Mannose completely inhibited the effect of RTP, while RTP and LAM affected each other on IFN-γ secretion. The MR-mediated ligand binding and endocytosis of macrophages were markedly decreased in colitis and RTP restored their function to near normal condition. The results indicated that RTP targeted MR and down-regulation of Th1-polarized immune response may be the possible mechanism for its attenuation of intestinal inflammation and damage. RTP may be useful for treatment of patients with inflammatory bowel disease.

Efficacy of Intracolonic Administration of Low-Molecular-Weight Heparin CB-01-05, Compared to Other Low-Molecular-Weight Heparins and Unfractionated Heparin, in Experimentally Induced Colitis in Rat

Parenteral administration of low-molecular-weight heparins (LMWHs) and unfractionated heparin (UFH) resulted effective in improving the symptoms of experimental colitis in rat. Today, there is little information about their activity by intracolonic instillation. The scope of this study was to evaluate the ability of CB-01-05 (a LMWH with a mean molecular weight of about 5,700), compared to a series of other LMWHs and to UFH, directly instilled into the distal colon of the rat, to ameliorate dinitrobenzene (DNB)-induced experimental colitis. Adult male Wistar rats underwent colitis induction by intracolonic instillation of DNB. Starting 24 h after colitis induction, CB-01-05 (0.005-0.9 mg), other LMWHs (0.3-0.6 mg), and UFH (0.6 mg) were instilled, by rectal route, into the distal colon once a day for three consecutive days. On the day following the last administration, the animals were sacrificed and the distal colon was isolated, weighed, macroscopically examined, and processed for histology. Additional experiments in rat splenocytes, performed in order to elucidate the anti-inflammatory mechanisms of CB-01-05, were performed. Among the tested items, only CB-01-05 at doses ranging from 0.2 to 0.9 mg was significantly effective in reducing colon weight increase and in improving both the mucosal damaged area and the histological score. The other LMWHs resulted far less effective, showing decreasing activity closely related with the decrease of their molecular weight, thus demonstrating their biological nonequivalence. CB-01-05 resulted also more active than UFH. CB-01-05 was shown to interfere with cytokines production by rat splenocytes, mainly inhibiting interferon (IFN)-gamma expression. CB-01-05 instilled into the colon is well tolerated, has strong anti-inflammatory effect on DNB-induced colitis in rat, and is the most effective agent among other LMWHs and UFH. These results suggest that the anti-inflammatory activity of CB-01-05, together with its topical administration, could represent a new approach in the management of ulcerative colitis.

Proglumide attenuates experimental colitis in rats

Ulcerative colitis is associated with altered contractile activity and transit time of colon. On the other hand, cholecystokinin (CCK) has been shown to play an important role in regulation of gastrointestinal motor function including colonic contraction and transit. In the present study, an attempt was made to study the effect of proglumide, a CCK receptor antagonist on experimental colitis in rats. Experimental colitis was induced in male Sprague–Dawley rats by instilling 1 ml of 4% acetic acid followed by flushing with 0.5 ml air. The rats were kept in a head-down position for 30 s. Finally, each rat received 1.5 ml colonic wash with 1.5 ml saline. Four groups of rats received proglumide orally (0, 250, 500 and 1000 mg/kg). The first dose of proglumide was given 1 h before acetic acid challenge, whereas the second dose of proglumide was given 25 h after the first dose. Sham control rats received an equal volume of saline instead of acetic acid. Forty-eight hours after the acetic acid challenge, the colon was removed, weighed and split longitudinally and scored for injury. Part of the colon was used for histopathological study as well as analysis of myeloperoxidase (MPO) activity (as a marker of neutrophil activity). Acetic acid produced severe diarrhea and exfoliation of the colonic epithelium accompanied by extensive destruction of the mucosal interstitium. Proglumide dose dependently protected rats against acetic acid-induced increase in colon weight, diarrhea, MPO activity and colonic injury. Inhibition of CCK exerts a beneficial effect in experimental colitis. Further studies are warranted to determine the mechanism of protection and the therapeutic potential of CCK inhibitors.