Amelioration of colitis in mice by Leuconostoc lactis EJ-1 by M1 to M2 macrophage polarization

Dysregulation of immune responses to environmental antigens by the intestine leads to the chronic inflammatory disease, inflammatory bowel disease (IBD). Recent studies have thus sought to identify a dietary component that can inhibit lipopolysaccharide (LPS)-induced nuclear factor-kappa beta (NF-κB) signaling to ameliorate IBD. This study assessed if the lactic acid bacteria (LAB) from kimchi, suppresses the expression of tumor necrosis factor-alpha (TNF-α) in peritoneal macrophages induced by LPS. Leuconostoc lactis EJ-1, an isolate from LAB, reduced the expression of interleukin-6 (IL-6) and IL-1β in peritoneal macrophages induced by LPS. The study further tested whether EJ-1 alleviates colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice. TNBS significantly increased myeloperoxidase (MPO) expression, macroscopic colitis scores, and colon shortening. Oral administration of L. lactis EJ-1 resulted in an inhibited in TNBS-induced loss in body weight, colon shortening, MPO activity, and NF-κB and inducible nitric oxide synthase expression; it also led to a marked reduction in cyclooxygenase-2 expression. L. lactis EJ-1 also inhibited the TNBS-induced expression of TNF-α, IL-1β, and IL-6; however, it induced the expression of IL-10. The M2 macrophage markers arginase I, IL-10, and CD206 were elevated by EJ-1. Collectively, these results suggest that EJ-1 inhibits the NF-κB signaling and polarizes M1- to M2-macrophage transition, which help in ameliorating colitis.     

Nerolidol,a sesquiterpene,attenuates oxidative stress and inflammation in acetic acid-induced colitis in rats

Targeting oxidative stress and inflammation by novel dietary compounds of natural origin convincingly appears to be one of the most important therapeutic strategies to keep inflammatory bowel diseases (IBD) such as ulcerative colitis disease in remission. It is imperative to investigate naturally occuring plant-derived dietary phytochemicals that are receiving attention for their therapeutic benefits to overcome the debilitating conditions of IBD. In the present study, the effect of nerolidol (NRD), a monocyclic sesquiterpene found in German Chamomile tea, was investigated in acetic acid-induced colitis model in Wistar rats. NRD was orally administered at a dose of 50 mg/kg/day either for 3 days before or 30 min after induction of IBD for 7 days, after intrarectal administration of acetic acid. The body weight, macroscopic, and microscopic analyses of the colon in different experimental groups were observed on days 0, 2, 4, and 7. Acetic acid caused significant reduction in body weight and induced macroscopic and microscopic ulcer along with a significant decline of antioxidants, concomitant to increased malondialdehyde (MDA), a marker of lipid peroxidation, and myeloperoxidase (MPO) activity, a marker of neutrophil activation. Treatment with NRD significantly improved IBD-induced reduction in body weight, improved histology, inhibited MDA formation, and restored antioxidants along with reduced MPO activity. Acetic acid also induced the release of pro-inflammatory cytokines and increased calprotectin, released by neutrophils under inflammatory conditions. NRD treatment significantly reduced calprotectin and pro-inflammatory cytokines. NRD treatment showed potential to improve disease activity and inhibit oxidative stress, lipid peroxidation, and inflammation along with histological preservation of the colon tissues.

     

5-氨基水杨酸纳米粒对TNBS诱导小鼠结肠炎的治疗作用

目的:评价超临界分散法制备的5-氨基水杨酸(5-ASA)结肠定位纳米粒对小鼠结肠炎的治疗作用。方法:将24只6周龄BABL/c小鼠随机分为空白对照组,结肠炎模型组,5-ASA治疗组,5-ASA纳米粒治疗组。三硝基苯磺酸(TNBS)造模后的第2-7 d分别给予0.9%氯化钠,5-ASA和5-ASA纳米粒灌胃,于第8 d处死所有小鼠,评估小鼠的疾病活动指数(DAI),组织病理形态以及结肠组织学损伤情况;检测结肠组织髓过氧化物酶(MPO)活性。结果:5-ASA和5-ASA纳米粒均能明显减轻结肠重量,缩小溃疡面积,降低MPO活性。超临界分散法制备的5-ASA纳米粒在DAI,减轻局部的炎症程度(MPO水平)方面,其疗效与5-ASA组(50 mg/Kg)相当。结论:超临界分散法制备的5-ASA纳米粒对TNBS诱导小鼠的结肠炎有明显的治疗作用。     

On the benefit of whey-cultured Lactobacillus casei in murine colitis

The objective of this study was to examine the prophylactic and therapeutic effect of whey-cultured Lactobacillus casei (L. casei) in a murine model of colitis. Colitis was induced by intracolonic administration of a mixture of 2,4,6-trinitrobenzenesulphonic acid (TNBS)/absolute ethanol in male Wistar rats. Animals were divided into 5 groups including sham (normal group), control (vehicle-treated), positive control (dexamethasone 1 mg/kg/day, orally), prevention (10(8) cfu L. casei/day, orally, 14 days before induction of colitis), and treatment (10(8) cfu L. casei/day, orally, 14 days after induction of colitis). After 14-days treatment, the animals were sacrificed on the day 15. Distal colons were removed for examining histological and biochemical assays. Biomarkers including TNF-α, myeloperoxidase (MPO), and lipid peroxidation (LPO) were measured in the homogenate of colon. Results indicated an apparent improvement in colon histopathology scores, TNF-α, MPO, and LPO in the treatment group, whereas prevention group did not demonstrate positive efficacy in prevention of colonic damage. It is concluded that L. casei grown in whey culture is very effective in ameliorating both biochemical and histopathological markers of colitis if used post induction of colitis but not if used before induction of colitis. The difference between effects of L. casei when used pre-colitis and post-colitis confirms its mechanism of action as an anti toxic stress agent. Further studies should be made in IBD patients.     

The apolipoprotein E-mimetic peptide COG112 inhibits NF-kappaB signaling, proinflammatory cytokine expression, and disease activity in murine models of colitis

Inflammatory bowel disease (IBD), consisting of Crohn's disease and ulcerative colitis, is a source of substantial morbidity and remains difficult to treat. New strategies for beneficial anti-inflammatory therapies would be highly desirable. Apolipoprotein (apo) E has immunomodulatory effects and synthetically derived apoE-mimetic peptides are beneficial in models of sepsis and neuroinflammation. We have reported that the antennapedia-linked apoE-mimetic peptide COG112 inhibits the inflammatory response to the colitis-inducing pathogen Citrobacter rodentium in vitro by inhibiting NF-κB activation. We now determined the effect of COG112 in mouse models of colitis. Using C. rodentium as an infection model, and dextran sulfate sodium (DSS) as an injury model, mice were treated with COG112 by intraperitoneal injection. With C. rodentium, COG112 improved the clinical parameters of survival, body weight, colon weight, and histologic injury. With DSS, COG112 ameliorated the loss of body weight, reduction in colon length, and histologic injury, whether administered concurrently with induction of colitis, during induction plus recovery, or only during the recovery phase of disease. In both colitis models, COG112 inhibited colon tissue inducible nitric-oxide synthase (iNOS), KC, TNF-α, IFN-γ, and IL-17 mRNA expression, and reduced nuclear translocation of NF-κB, as determined by immunoblot and immunofluorescence confocal microscopy. IκB kinase (IKK) activity was also reduced, which is necessary for activation of the canonical NF-κB pathway. Isolated colonic epithelial cells exhibited marked attenuation of expression of iNOS and the CXC chemokines KC and MIP-2. These studies indicate that apoE-mimetic peptides such as COG112 are novel potential therapies for IBD.     

BTZO-15, an ARE-activator, ameliorates DSS- and TNBS-induced colitis in rats

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders that are primarily represented by ulcerative colitis and Crohn's disease. The etiology of IBD is not well understood; however, oxidative stress is considered a potential etiological and/or triggering factor for IBD. We have recently reported the identification of BTZO-1, an activator of antioxidant response element (ARE)-mediated gene expression, which protects cardiomyocytes from oxidative stress-induced insults. Here we describe the potential of BTZO-15, an active BTZO-1 derivative for ARE-activation with a favorable ADME-Tox profile, for the treatment of IBD. BTZO-15 induced expression of heme oxygenase-1 (HO-1), an ARE-regulated cytoprotective protein, and inhibited NO-induced cell death in IEC-18 cells. Large intestine shortening, rectum weight gain, diarrhea, intestinal bleeding, and an increase in rectal myeloperoxidase (MPO) activity were observed in a dextran sulfate sodium (DSS)-induced colitis rat model. Oral administration of BTZO-15 induced HO-1 expression in the rectum and attenuated DSS-induced changes. Furthermore BTZO-15 reduced the ulcerated area and rectal MPO activity in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rats without affecting rectal TNF-α levels. These results suggest that BTZO-15 is a promising compound for a novel IBD therapeutic drug with ARE activation properties.     

Amelioration of dextran sulfate sodium-induced colitis in mice by oral administration of beta-caryophyllene, a sesquiterpene

beta-Caryophyllene (BCP), a naturally occurring plant sesquiterpene, was examined for anti-inflammatory activity in a mouse model of experimental colitis induced by dextran sulfate sodium (DSS). Colitis was induced by exposing male BALB/c mice to 5% DSS in drinking water for 7 days. BCP in doses of 30 and 300 mg/kg was administered orally once a day, beginning concurrently with exposure to DSS. The body weight and colon length were measured, and histological damage and myeloperoxidase (MPO) activity as well as inflammatory cytokines were assessed in both serum and colonic tissue after 7 days of treatment with DSS. The DSS treatment damaged the colonic tissue, increased MPO activity and inflammatory cytokines, lowered the body weight, and shortened the length of the colon. Oral administration of BCP at 300 mg/kg significantly suppressed the shortening of colon length and slightly offset the loss of body weight. BCP treatment (300 mg/kg) also significantly reduced the inflammation of colon and reversed the increase in MPO activity that had been induced by exposure to DSS. Further, BCP significantly suppressed the serum level of IL-6 protein (a 55% reduction) as well as the level of IL-6 mRNA in the tissue. These results demonstrate that BCP ameliorates DSS-induced experimental colitis, and may be useful in the prevention and treatment of colitis.     

The anti-inflammatory effect of leptin on experimental colitis: involvement of endogenous glucocorticoids

The present study was designed to compare the effect of leptin on acute colonic inflammation with that of acute stress exposure, which acts via the hypothalamic-pituitary-adrenal (HPA) axis. Sprague-Dawley rats of both sexes were administered intrarectally with acetic acid. Either leptin (10 microg/kg; i.p.) or saline was injected immediately before and 6 h after the induction of colitis. A group of rats was exposed to water avoidance stress (WAS) for 30 min at the 6th h of colitis induction. RU-486 (2 mg/kg; i.p.), a glucocorticoid receptor antagonist, was injected intraperitoneally, at 12 and 1 h before the initial leptin injection, and at 1 h before the second leptin injection or exposure to WAS. Rats were decapitated at 24 h and the distal 8 cm of the colon were removed for macroscopic and microscopic scoring, determination of tissue wet weight index (WI) and tissue myeloperoxidase activity (MPO). Acetic acid-induced colitis significantly increased macroscopic and microscopic damage scores, WI and MPO, compared to control group. Exposure to acute WAS or treatment with leptin reduced the elevations in damage scores, WI and MPO induced by colitis, but no additive inhibitory effect was observed when WAS and leptin were applied together. RU-486 treatment reversed the inhibitory effects of leptin or WAS on colonic inflammation. Our results demonstrate that exogenous leptin mimics the effects of HPA axis activation on colitis-induced inflammatory process. The results also suggest that the anti-inflammatory effect of leptin involves a tissue neutrophil-dependent mechanism and is dependent on the release of glucocorticoids.     

Efficacy of Setarud (IMod), a novel drug with potent anti-toxic stress potential in rat inflammatory bowel disease and comparison with dexamethasone and infliximab

The inflammatory bowel disease (IBD) is an idiopathic, immune-mediated and chronic intestinal condition. In the present study, the effect of Setarud (IMOD), a novel natural drug with known immunomodulatory, anti-inflammatory and antioxidant properties was investigated in experimental colitis in rats and compared with the dexamethasone and infliximab. Immunologic colitis was induced by intracolonic administration of a mixture of trinitrobenzene sulfonic acid (TNBS) and absolute ethanol in male Wistar rats. Animals were divided into 6 groups of sham (normal group), control (vehicle-treated), positive control (dexamethasone 1 mg/kg/day given orally and infliximab 5 mg/kg/day given subcutaneously) and 3 Setarud-treated groups (13.3, 20, 30 mg/kg/day given intraperitoneally). The treatment continued for 14 consecutive days and then animals were decapitated on the day 15 and distal colons were removed for macroscopic, microscopic, and biochemical assays. Biochemical markers, including TNF-alpha, IL-1beta, ferric reducing/antioxidant power (FRAP), myeloperoxidase (MPO) activity and thiobarbitoric acid-reactive substance (TBARS) were measured in the homogenate of colonic tissue. A remarkable reduction in macroscopic and histological damage scores was observed in the animals treated with Setarud. These findings were confirmed by decreased levels of TNF-alpha, interleukin-1beta, MPO activity and TBARS, and raised levels of FRAP in the colon tissue. These observations confirmed the immunomodulatory, anti-inflammatory and antioxidant properties of Setarud in experimental colitis, which was comparable to those of dexamethasone and infliximab.     

Effects of proanthocyanidins from grape seed on treatment of recurrent ulcerative colitis in rats

The aim of the present study was to investigate the therapeutic effect and mechanism of proanthocyanidins from grape seed (GSPE) in the treatment of recurrent ulcerative colitis (UC) in rats. To induce recurrent colitis, rats were instilled with 2,4,6-trinitrobenzenesulfonic acid (TNBS) (80?mg/kg) into the colon through the cannula in the first induced phase, and then the rats were instilled a second time with TNBS (30?mg/kg) into the colon on the sixteenth day after the first induction UC. Rats were intragastrically administered GSPE (200?mg/kg) per day for 7?days after twice-induced colitis by TNBS. Sulfasalazine at 500?mg/kg was used as a positive control drug. Rats were killed 7?days after GSPE treatment. The colonic injury and inflammation were assessed by macroscopic and macroscopic damage scores, colon weight/length ratio (mg/cm), and myeloperoxidase activity. Then, superoxide dismutase, glutathione peroxidase, inducible nitric oxide synthase (iNOS) activities, and the levels of malonyldialdehyde, glutathione, and nitric oxide in serum and colonic tissues were measured. Compared with the recurrent UC group, GSPE treatment facilitated recovery of pathologic changes in the colon after induction of recurrent colitis, as demonstrated by reduced colonic weight/length ratio and macroscopic and microscopic damage scores. The myeloperoxidase and iNOS activities with malonyldialdehyde and nitric oxide levels in serum and colon tissues of colitis rats were significantly decreased in the GSPE group compared with those in the recurrent UC group. In addition, GSPE treatment was associated with notably increased superoxide dismutase, glutathione peroxidase activities, and glutathione levels of colon tissues and serum of rats. GSPE exerted a protective effect on recurrent colitis in rats by modifying the inflammatory response, inhibiting inflammatory cell infiltration and antioxidation damage, promoting damaged tissue repair to improve colonic oxidative stress, and inhibiting colonic iNOS activity to reduce the production of nitric oxide.     

Role of M-CSF-dependent macrophages in colitis is driven by the nature of the inflammatory stimulus

Although macrophages are considered a critical factor in determining the severity of acute inflammatory responses in the gut, recent evidence has indicated that macrophages may also play a counterinflammatory role. In this study, we examined the role of a macrophage subset in two models of colitis. Macrophage colony-stimulating factor (M-CSF)-deficient osteopetrotic mice (op/op) and M-CSF-expressing heterozygote (+/?) mice were studied following the induction of colitis by either dinitrobenzene sulfonic acid (DNBS) or dextran sulfate sodium (DSS). DNBS induced a severe colitis in M-CSF-deficient op/op mice compared with +/? mice. This was associated with increased mortality and more severe macroscopic and microscopic injury. Colonic tissue myeloperoxidase (MPO) activity as well as concentrations of TNF-alpha, IL-1beta, and IL-6 were higher and IL-10 lower in op/op mice with DNBS colitis. The severity of inflammation and mortality was attenuated in op/op mice that had received human recombinant M-CSF prior to the induction of colitis. In contrast, op/op mice appeared less vulnerable to colitis induced by DSS. Macroscopic damage, microscopic injury, MPO activity, and tissue concentrations of TNF-alpha, IL-1beta, and IL-6 were all lower in op/op mice compared with +/? mice with DSS colitis, and no changes were seen in IL-10. Macrophage inflammatory protein-1alpha concentrations were increased in op/op but not +/? mice following colitis induced by DNBS but not DSS. These results indicate that M-CSF-dependent macrophages may play either a pro- or counterinflammatory role in acute experimental colitis, depending on the stimulus used to induce colitis.     

Investigating Intestinal Inflammation in DSS-induced Model of IBD

Inflammatory bowel disease (IBD) encompasses a range of intestinal pathologies, the most common of which are ulcerative colitis (UC) and Crohn''s Disease (CD). Both UC and CD, when present in the colon, generate a similar symptom profile which can include diarrhea, rectal bleeding, abdominal pain, and weight loss.¹ Although the pathogenesis of IBD remains unknown, it is described as a multifactorial disease that involves both genetic and environmental components.²There are numerous and variable animal models of colonic inflammation that resemble several features of IBD. Animal models of colitis range from those arising spontaneously in susceptible strains of certain species to those requiring administration of specific concentrations of colitis-inducing chemicals, such as dextran sulphate sodium (DSS). Chemical-induced models of gut inflammation are the most commonly used and best described models of IBD. Administration of DSS in drinking water produces acute or chronic colitis depending on the administration protocol.³ Animals given DSS exhibit weight loss and signs of loose stool or diarrhea, sometimes with evidence of rectal bleeding.^4,5 Here, we describe the methods by which colitis development and the resulting inflammatory response can be characterized following administration of DSS. These methods include histological analysis of hematoxylin/eosin stained colon sections, measurement of pro-inflammatory cytokines, and determination of myeloperoxidase (MPO) activity, which can be used as a surrogate marker of inflammation.⁶The extent of the inflammatory response in disease state can be assessed by the presence of clinical symptoms or by alteration in histology in mucosal tissue. Colonic histological damage is assessed by using a scoring system that considers loss of crypt architecture, inflammatory cell infiltration, muscle thickening, goblet cell depletion, and crypt abscess.⁷ Quantitatively, levels of pro-inflammatory cytokines with acute inflammatory properties, such as interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α,can be determined using conventional ELISA methods. In addition, MPO activity can be measured using a colorimetric assay and used as an index of inflammation.⁸In experimental colitis, disease severity is often correlated with an increase in MPO activity and higher levels of pro-inflammatory cytokines. Colitis severity and inflammation-associated damage can be assessed by examining stool consistency and bleeding, in addition to assessing the histopathological state of the intestine using hematoxylin/eosin stained colonic tissue sections. Colonic tissue fragments can be used to determine MPO activity and cytokine production. Taken together, these measures can be used to evaluate the intestinal inflammatory response in animal models of experimental colitis.     

MC-12, an Annexin A1-Based Peptide, Is Effective in the Treatment of Experimental Colitis

Annexin A1 (ANXA1) inhibits NF-κB, a key regulator of inflammation, the common pathophysiological mechanism of inflammatory bowel diseases (IBD). MC-12, an ANXA1-based tripeptide, suppresses NF-κB activation. Here, we determined the efficacy of MC-12 in the control of IBD. Mice with colitis induced by dextran sodium sulfate (DSS) or 2,4,6-trinitro benzene sulfonic acid (TNBS) were treated with various doses of MC-12 administered intraperitoneally, orally or intrarectally. We determined colon length and the histological score of colitis, and assayed: in colon tissue the levels of TNF-α, IFN-γ, IL-1β, IL-6 and IL-10 by RT-PCR; prostaglandin E(2) (PGE(2)), cytoplasmic phospholipase A(2) (cPLA(2)) and myeloperoxidase by immunoassay; and COX-2 and NF- κB by immunohistochemistry; and in serum the levels of various cytokines by immunoassay. In both models MC-12: reversed dose-dependently colonic inflammation; inhibited by up to 47% myeloperoxidase activity; had a minimal effect on cytoplasmic phospholipase A(2); reduced significantly the induced levels of TNF-α, IFN-γ, IL-1β, IL-6 and IL-10, returning them to baseline. DSS and TNBS markedly activated NF-κB in colonic epithelial cells and MC-12 decreased this effect by 85.8% and 72.5%, respectively. MC-12 had a similar effect in cultured NCM460 normal colon epithelial cells. Finally, MC-12 suppressed the induction of COX-2 expression, the level of PGE(2) in the colon and PGE(2) metabolite in serum. In conclusion, MC-12, representing a novel class of short peptide inhibitors of NF-κB, has a strong effect against colitis in two preclinical models recapitulating features of human IBD. Its mechanism of action is complex and includes pronounced inhibition of NF-κB. MC-12 merits further development as an agent for the control of IBD.     

Antibiotic treatment with ampicillin accelerates the healing of colonic damage impaired by aspirin and coxib in the experimental colitis. Importance of intestinal bacteria, colonic microcirculation and proinflammatory cytokines

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for their anti-inflammatory, analgesic and antipyretic effects, however their use is associated with the broad spectrum of side effects observed in human as well as the experimental animals. Despite damaging activity of NSAIDs in upper gastrointestinal (GI) tract, these drugs exert deleterious influence in lower GI tract, including colon. The role of GI microflora in the pathogenesis of NSAIDs-induced experimental colonic damage is not completely understood. The aim of this study was 1) to evaluate the relative importance of the GI microflora on the experimental colonic damage in the presence of caused by NSAID, and 2) to assess the efficacy of antibiotic treatment with ampicillin on the process of healing of colitis. We compared the effect of vehicle, ASA applied 40 mg/kg intragastrically (i.g.) or the selective cyclooxygenase (COX)-2 inhibitor, celecoxib (25 mg/kg i.g.) without or with ampicillin treatment (800 mg/kg i.g.) administered throughout the period of 10 days, on the intensity of TNBS-induced colitis in rats. The severity of colonic damage, the alterations in the colonic blood flow (CBF) and myeloperoxidase (MPO) activity, the mucosal expression of TNF-α, IL-1β, COX-2, VEGF and iNOS and the plasma concentration of TNF-α and IL-1β were assessed. In all rats, the faeces samples as well as those from the colonic mucosa, blood, liver and spleen underwent microbiological evaluation for intestinal bacterial species including Escherichia coli and Enterococcus spp. The administration of TNBS resulted in macroscopic and microscopic lesions accompanied by the significant fall in the CBF, an increase in tissue weight and 4-5-fold rise in the MPO activity and a significant increase in the plasma IL-1β and TNF-α levels. ASA or celecoxib significantly increased the area of colonic lesions, enhanced MPO activity and caused the marked increase in colonic tissue weight and plasma IL-1β and TNF-α levels, as well as an overexpression of mRNA for IL-1β and TNF-α, COX-2, VEGF and iNOS in the colonic tissue. ASA and coxib also resulted also in a significant increase of E. coli counts in the stool at day 3 and day 10 day of the observation compared with the intact rats. Moreover, E. coli translocation from the colon to the blood and extraintestinal organs such as liver and spleen in the group of rats treated without or with ASA and coxib. E. coli was the most common bacteria isolated from these organs. Treatment with ampicillin significantly attenuated the ASA- or celecoxib-induced increase in plasma levels of IL-1β and TNF-α and suppressed the mucosal mRNA expression for IL-1β and TNF-β, COX-2, iNOS and VEGF in the colonic mucosa. Ampicillin administration caused a significant fall in the number of E. coli in the faeces at day 3 and day 10 of observation in ASA- and coxib-treated rats with colitis. Antibiotic therapy markedly reduced bacterial translocation to the colonic tissue and the extraintestinal organs such as the liver and spleen. We conclude that administration of ASA and to lesser extent of celecoxib, delays the healing of experimental colitis and enhances the alterations in colonic blood flow, proinflammatory markers such as IL-1β, TNF-α, COX-2, iNOS and VEGF and increased intestinal mucosal permeability resulting in the intestinal bacterial translocation to the blood, spleen and liver. Antibiotic treatment with ampicillin is effective in the diminishing of the severity of colonic damage, counteracts both the NSAID-induced fall in colonic microcirculation and bacterial E.coli translocation to the extraintestinal organs.     

Green tea polyphenol extract attenuates colon injury induced by experimental colitis

Inflammatory bowel disease (IBD) is characterised by oxidative and nitrosative stress, leukocyte infiltration, and up-regulation of intercellular adhesion molecule 1 (ICAM-1) expression in the colon. The aim of the present study was to examine the effects of green tea extract in rats subjected to experimental colitis induced by intracolonic instillation of dinitrobenzene sulphonic acid (DNBS). At 4 days after DNBS administration the rats were sacrificed. Treatment with green tea extract significantly attenuated diarrhoea and loss of body weight. This was associated with a remarkable amelioration of the disruption of the colonic architecture, significant reduction of colonic myeloperoxidase (MPO) and tumor necrosis factor-alpha (TNF-alpha) production. Green tea extract also reduced the appearance of nitrotyrosine immunoreactivity in the colon and reduced the up-regulation of ICAM-1.     

The role of MIP-1 alpha in the development of systemic inflammatory response and organ injury following trauma hemorrhage

Although MIP-1alpha is an important chemokine in the recruitment of inflammatory cells, it remains unknown whether MIP-1alpha plays any role in the development of systemic inflammatory response following trauma-hemorrhage (T-H). C57BL/6J wild type (WT) and MIP-1alpha-deficient (KO) mice were used either as control, subjected to sham operation (cannulation or laparotomy only or cannulation plus laparotomy) or T-H (midline laparotomy, mean blood pressure 35 +/- 5 mmHg for 90 min, followed by resuscitation) and sacrificed 2 h thereafter. A marked increase in serum alpha-glutathione transferase, TNF-alpha, IL-6, IL-10, MCP-1, and MIP-1alpha and Kupffer cell cytokine production was observed in WT T-H mice compared with shams or control. In addition lung and liver tissue edema and neutrophil infiltration (myeloperoxidase (MPO) content) was also increased following T-H in WT animals. These inflammatory markers were markedly attenuated in the MIP-1alpha KO mice following T-H. Furthermore, compared with 2 h, MPO activities at 24 and 48 h after T-H declined steadily in both WT and KO mice. However, normalization of MPO activities to sham levels within 24 h was seen in KO mice but not in WT mice. Thus, MIP-1alpha plays an important role in mediating the acute inflammatory response following T-H. In the absence of MIP-1alpha, acute inflammatory responses were attenuated; rapidly recovered and less remote organ injury was noted following T-H. Thus, interventions that reduce MIP-1alpha levels following T-H should be useful in decreasing the deleterious inflammatory consequence of trauma.     

Temporal and Spatial Analysis of Clinical and Molecular Parameters in Dextran Sodium Sulfate Induced Colitis

Background

Inflammatory bowel diseases (IBD), including mainly ulcerative colitis (UC) and Crohn''s disease (CD), are inflammatory disorders of the gastrointestinal tract caused by an interplay of genetic and environmental factors. Murine colitis model induced by Dextran Sulfate Sodium (DSS) is an animal model of IBD that is commonly used to address the pathogenesis of IBD as well as to test efficacy of therapies. In this study we systematically analyzed clinical parameters, histological changes, intestinal barrier properties and cytokine profile during the colitic and recovery phase.

Methods

C57BL/6 mice were administered with 3.5% of DSS in drinking water for various times. Clinical and histological features were determined using standard criteria. Myeloperoxidase (MPO) activity, transepithelial permeability and proinflammatory mediators were determined in whole colon or proximal and distal parts of colon.

Results

As expected after administration of DSS, mice manifest loss of body weight, shortening of colon length and bloody feces. Histological manifestations included shortening and loss of crypts, infiltration of lymphocytes and neutrophil, symptoms attenuated after DSS withdrawal. The MPO value, as inflammation indicator, also increases significantly at all periods of DSS treatment, and even after DSS withdrawal, it still held at very high levels. Trans-mucosal permeability increased during DSS treatment, but recovered to almost control level after DSS withdrawal. The production of proinflammatory mediators by colonic mucosa were enhanced during DSS treatment, and then recovered to pre-treated level after DSS withdrawal. Finally, enhanced expression of proinflammatory mediators also revealed a different profile feature in proximal and distal parts of the colon.

Conclusion

Experimental colitis induced by DSS is a good animal model to study the mechanisms underlying the pathogenesis and intervention against IBD, especially UC.     

Part II: beneficial effects of the peroxynitrite decomposition catalyst FP15 in murine models of arthritis and colitis

BACKGROUND: Peroxynitrite is a reactive oxidant species produced from nitric oxide and superoxide, which has been indirectly implicated in the pathogenesis of many inflammatory conditions including arthritis and colitis. Here, using a novel peroxynitrite decomposition catalyst, FP15, we directly investigate the role of peroxynitrite in the pathogenesis of arthritis and colitis in rodent models. METHODS: Arthritis was induced in mice by intradermal collagen injection; incidence and severity of arthritis was monitored using a macroscopic scoring system. At the end of the experiment paws were taken for determination of neutrophil infiltration (myeloperoxidase [MPO] activity), oxidative stress (malondialdehyde [MDA] level), and cytokine/chemokine levels. Colitis was induced in mice by 5% dextran sodium sulfate (DSS) in their drinking water. Colitis symptoms were assessed 10 days later, the parameters determined included body weight, rectal bleeding, colon length, colonic MPO and MDA levels, and colon histologic damage. RESULTS: Treatment with FP15 significantly reduced the inflammation and oxidative stress in arthritis and colitis. FP15 reduced both the incidence and severity of arthritis in mice and this was associated with reduced paw MPO and MDA levels. Similarly, in colitis, FP15 reduced colon damage, and this was associated with reduced colon neutrophil infiltration and oxidative stress. CONCLUSIONS:The protective effect of FP15 suggests that peroxynitrite plays a significant pathogenetic role in arthritis and colitis in the currently employed rodent models. Further work is needed to determine whether neutralization of peroxynitrite also represents a promising strategy to treat human inflammatory diseases such as arthritis and colitis.     

Combination therapy of mesenchymal stromal cells and sulfasalazine attenuates trinitrobenzene sulfonic acid induced colitis in the rat: The S1P pathway

Adipose derived mesenchymal stem cells (ASCs) transplantation is a novel immunomodulatory therapeutic tool to ameliorate the symptom of inflammatory bowel disease (IBD). The objective of this study was to investigate the therapeutic effects of combined sufasalazine and ASCs therapy in a rat model of IBD. After induction of colitis in rats, ASCs were cultured and intraperitoneally injected (3 × 10⁶cells/kg) into the rats on Days 1 and 5 after inducing colitis, in conjunction with daily oral administration of low dose of sulfasalazine (30 mg/kg). The regenerative effects of combination of ASCs and sulfasalazine on ulcerative colitis were assessed by measuring body weight, colonic weight/length ratio, disease activity index, macroscopic scores, histopathological examinations, cytokine, and inflammation markers profiles. In addition, western blot analysis was used to assess the levels of nuclear factor-kappa B (NF-κB) and apoptosis related proteins in colitis tissues. Simultaneous treatment with ASCs and sulfasalazine was associated with significant amelioration of disease activity index, macroscopic and microscopic colitis scores, as well as inhibition of the proinflammatory cytokines in trinitrobenzene sulfonic acid (TNBS)-induced colitis. Moreover, combined ASCs and sulfasalazine therapy effectively inhibited the NF-κB signaling pathway, reduced the expression of Bax and prevented the loss of Bcl-2 proteins in colon tissue of the rats with TNBS-induced colitis. Furthermore, combined treatment with ASCs and sulfasalazine shifted inflammatory M1 to anti-inflammatory M2 macrophages by decreasing the levels of MCP1, CXCL9 and increasing IL-10, Arg-1 levels. In conclusion, combination of ASCs with conventional IBD therapy is potentially a much more powerful strategy to slow the progression of colitis via reducing inflammatory and apoptotic markers than either therapy alone.