Acute Colitis In Mice Research Articles

Qing-dai powder promotes recovery of colitis by inhibiting inflammatory responses of colonic macrophages in dextran sulfate sodium-treated mice.

BackgroundQing-dai powder (QDP), comprising Indigo naturalis (Qing-dai) and dried alum (Ku-fan), was used in Chinese medicine to treat the conditions associated with mucosal hemorrhage, such as ulcerative colitis (UC). This study aims to investigate the effects and potential mechanism of QDP on dextran sulfate sodium (DSS)-induced acute colitis in mice and to examine the regulatory effects of QDP on macrophages.MethodsSeven- to eight-week-old male C57BL/6 mice were challenged with 2.0 % DSS in drinking water for 5 days and then the colitic mice were arbitrarily allocated into five groups (n = 10 for each group). QDP (0.77, 1.54 and 3.08 g/kg) and sulfasalazine (SASP) (0.20 g/kg) were orally administered for 7 days. The disease activity index was determined by scores of body weight loss, diarrhea and rectal bleeding; histological signs of damage was analyzed by H&E staining; myeloperoxidase activity was measured by colorimetric method, levels of proinflammatory cytokines were determined by ELISA; changes in macrophages in the colon were analyzed by immunohistochemistry (IHC) and flow cytometry. Lipopolysaccharide (LPS)-induced RAW264.7 cells were treated with or without QDP, then the production of TNF-α and IL-6 were measured by ELISA; and protein molecules such as COX-2, iNOS, IкB-α were determined by Western blot.ResultsOral administration of QDP at dosages of 1.54 and 3.08 g/kg significantly reduced disease activity index on day 12 (P < 0.001 for 1.54 g/kg and P < 0.0008 for 3.08 g/kg), colon shortening (P = 0.012 for 1.54 g/kg, P = 0.001 for 3.08 g/kg), histological damage (P < 0.001 for 1.54 g/kg, P < 0.001 for 3.08 g/kg) and colonic myeloperoxidase activity (P = 0.002 for 1.54 g/kg, P < 0.001 for 3.08 g/kg) of DSS-treated mice. Moreover, QDP treatment (1.54 and 3.08 g/kg) significantly decreased DSS-induced infiltration of macrophages, and production of TNF-α (P = 0.005 for 1.54 g/kg, P = 0.002 for 3.08 g/kg), IL-1β (P = 0.008 for 1.54 g/kg, P = 0.002 for 3.08 g/kg) and IL-6 (P = 0.011 for 1.54 g/kg, P = 0.004 for 3.08 g/kg) in colonic tissues, and also reduced serum MCP-1 levels (P = 0.001 for 1.54 g/kg, P < 0.001 for 3.08 g/kg). In RAW264.7 cells, QDP significantly suppressed LPS-induced production of TNF-α and IL-6 (Both P < 0.001 for 1.0 μg/mL QDP treatment) and expression levels of COX-2 (P = 0.002 and P = 0.001 for 1 and 3 μg/mL QDP treatment, respectively) and iNOS (P < 0.001 for 3 μg/mL QDP treatment) by inhibiting IкB-α degradation (P = 0.007 and P = 0.004 for 1 and 3 μg/mL QDP treatment, respectively) and NF-кB p65 nuclear translocation.ConclusionQDP suppressed the inflammatory responses of colonic macrophages in DSS-induced UC in mice and LPS-induced RAW264.7 cells.

Abstract A92: Small molecules targeting HMGR and HDAC in colorectal cancer

Abstract Background and Aims: Colorectal cancer (CRC) is an important cancer with rising annual incidence worldwide, leading to significant morbidity and mortality. The addition of new anti-CRC drugs significantly improves treatment outcome, indicating that it is crucial to develop new drugs. Chemoprevention is another important approach to reduce cancer-related mortality. We first demonstrated statins with a carboxylic acid-containing long chain inhibiting histone deacetylase (HDAC) activity. To further improve their HDAC inhibition, we designed and synthesized three statin hydroxamates (JMF3086, JMF3171 and JMF3173) that potently inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) and histone deacetylases (HDACs) simultaneously. Their preventive and therapeutic effects on CRC were investigated. Methods: The in vitro anticancer activity was evaluated in human cancer cells. Molecular mechanisms were investigated using genome-wide ChIP-on-chip, Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA). Anti-inflammation was examined by Dextran sulfate sodium (DSS)-induced acute colitis in mice. Prevention or therapy for CRC was examined by AOM/DSS mouse model. Anti-metastasis was examined by splenic and tail vein injected mouse models, and colorectal cancer stem cells were generated to investigate the inhibition of stemness. Results: Statin hydroxamates were effective to inhibit a variety of human cancer cells. ChIP-on-chip analysis demonstrated the down-regulation of inflammatory and stemness genes and up-regulation of tumor suppressor genes. GO and IPA predicted the regulatory role of NF-kB in inflammatory genes and NR3C1 in apoptosis-related genes. The oral administration of JMF3086 prevented DSS-induced colitis and AOM/DSS-induced CRC in mice by inhibiting inflammation. Statin hydroxamates exerted a therapeutic effect in CRC mice by inducing apoptosis. CRC metastasis to the livers and lungs and the propagation of CRC stem cells in vivo were also inhibited by JMF3086. The efficacy of JMF3086 was superior to the combination of lovastatin and SAHA (HDAC inhibitor) with less toxicity. Conclusions: Statin hydroxamates with dual inhibition on HMGR and HDACs show great preclinical efficacy in prevention and treatment of CRC through inhibiting inflammation and inducing apoptosis. Citation Format: Tzu-Tang Wei, Yi-Ting Lin, Yu-Chin Lin, Ching-Chow Chen. Small molecules targeting HMGR and HDAC in colorectal cancer. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A92.

Protection of Sophocarpine on Colonic Barrier in DSS-induced Acute Colitis in Mice by Increasing Expression of HNF4α

ObjectiveTo investigate the possible protective effects of sophocarpine on mucosal injury and epithelial barrier disruption on dextran sulfate sodium (DSS)-induced acute colitis. MethodsMale BALB/c mice were randomly divided into three groups. The mice in normal group were given normal water, and those in model and sophocarpine-treated groups were given 2.5% DSS for 6 d to induce acute colitis. Sophocarpine (30 mg/kg) was ip administered once daily during the study period. Severity of colitis was evaluated by disease activity index (DAI), histological injury and inflammatory cytokine production including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1). The colonic barrier disruption was assessed by testing the expression of junctional adhesion molecule-1 (JAM-1), E-cadherin (E-CAD), and desmocollin-2 (DSC-2) in colon mucosa. Expression of HNF4α in colon mucosa was detected by immunohistochemistry staining and real-time RT-PCR, respectively. ResultsCompared with normal group, DAI, colonic shortening, and histopathological injury in model group were elevated (P < 0.05), but reduced in sophocarpine-treated group (P < 0.05). Compared with model group, the mRNA expression of inflammatory cytokines (TNF-α, IL-1β, MCP-1) were obviously lower in sophocarpine-treated group (P < 0.05), while the cellular junction proteins (E-CAD, JAM-1, and DSC-2) were higher (P < 0.05). The expression of HNF4α at mRNA and protein levels was decreased significantly in model group, but increased apparently in sophocarpine-treated group. ConclusionSophocarpine can enhance the expression of HNF4α, promote the expression of colonic intrecellular junctions, thus, maintain the integrity of the colonic barrier and inhibit the colitis process. We suggest that sophocarpine could enhance the production of cellular junction proteins to protect the intestinal barrier fuction, at least partly, in HNF4α-dependent pathway.

Specific accumulation of orally administered redox nanotherapeutics in the inflamed colon reducing inflammation with dose–response efficacy

Although current medications for ulcerative colitis (UC) are effective to some extent, there are still some limitation of their use due to the non-specific distribution, drug metabolism in the gastrointestinal tract, and severe adverse effects. In our previous studies, we developed oral redox nanoparticles (RNPO) that specifically accumulated and scavenged overproduced reactive oxygen species (ROS) in an inflamed colon. However, the mechanism leading to specific accumulation of RNPO in an inflamed colon is still unclear. In this study, we investigated the cellular uptake of RNPO into ROS-treated epithelial colonic cells in vitro, and compared to the untreated cells, found a significantly increased uptake in ROS-treated cells. In vivo, we discovered that orally administered RNPO were not internalized into the cells of a normal colon. A significant amount of disintegrated RNPO was detected in the cells of an inflamed colon of dextran sodium sulfate (DSS)-induced colitis mice, resulting in scavenging of ROS and suppression of inflammation with low adverse effects. Furthermore, we confirmed a significant reduction of disease activity and a robust dose response efficacy following RNPO treatment in acute DSS-induced colitis mice, outperforming the positive control 5-aminosalicylic acid. Oral administration of RNPO is a promising approach to develop a new therapy for UC disease.

Effects of dietary virgin olive oil polyphenols: hydroxytyrosyl acetate and 3, 4-dihydroxyphenylglycol on DSS-induced acute colitis in mice

Hydroxytyrosol, a polyphenolic compound from extra virgin olive oil (EVOO) has exhibited an improvement in a model of DSS-induced colitis. However, other phenolic compounds present such as hydroxytyrosyl acetate (HTy-Ac) and 3,4-dihydroxyphenylglycol (DHPG) need to be explored to complete the understanding of the overall effects of EVOO on inflammatory colon mucosa. This study was designed to evaluate the effect of both HTy-Ac and DHPG dietary supplementation in the inflammatory response associated to colitis model. Six-week-old mice were randomized in four dietary groups: sham and control groups received standard diet, and other two groups were fed with HTy-Ac and DHPG, respectively, at 0.1%. After 30 days, all groups except sham received 3% DSS in drinking water for 5 days followed by a regime of 5 days of water. Acute inflammation was evaluated by Disease Activity Index (DAI), histology and myeloperoxidase (MPO) activity. Colonic expression of iNOS, COX-2, MAPKs, NF-kB and FOXP3 were determined by western blotting. Only HTy-Ac-supplemented group showed a significant DAI reduction as well as an improvement of histological damage and MPO. COX-2 and iNOS protein expression were also significantly reduced. In addition, this dietary group down-regulated JNK phosphorylation and prevented the DSS-induced nuclear translocation level of p65. However, no significant differences were observed in the FOXP3 expression. These results demonstrated, for the first time, that HTy-Ac exerts an antiinflammatory effect on acute ulcerative colitis. We concluded that HTy-Ac supplement might provide a basis for developing a new dietary strategy for the prevention of ulcerative colitis.

MicroRNA-133α regulates neurotensin-associated colonic inflammation in colonic epithelial cells and experimental colitis.

Ulcerative colitis (UC) and Crohn's Disease (CD) are the two most common forms of Inflammatory Bowel Diseases (IBD) marked by chronic and persistent inflammation. Neurotensin (NT), together with its receptor, NT receptor 1 (NTR1), are important mediators in intestinal inflammation and their expression is upregulated in the intestine of experimental colitis models and UC colonic biopsies. MicroRNAs (miRNAs) are short, non-coding RNA molecules which act as transcription repressors. We have previously shown that NT exposure upregulates miR-133α expression in human colonocytes NCM460 cells overexpressing NTR1 (NCM460-NTR1). Recently, miR-133α was further examined forits role in NT-associated proinflammatory signaling cascades and acute colitis in vivo. Our study shows that NT-induced miR-133α upregulation modulates NF-κB phosphorylation and promotes proinflammatory cytokine production. In addition, intracolonicinjection of antisense-miR-133α before colitis induction improves histological scores and proinflammatory cytokine transcription. More importantly, dysregulation of miR-133α levels and aftiphilin (AFTPH), a newly-identified miR-133α downstream target, is found only in UC patients, but not in patients with CD. Taken together, we identified NTR1/miR-133α/aftiphilin as a novel regulatory axis involved in NT-associated colonic inflammation in human colonocytes, acute colitis mouse model and in colonic biopsies from UC patients. Our results also provide evidence that colonic levels of NTR1, miR-133α and aftiphilin may also serve as potential biomarkers in UC.

IL-33 Aggravates DSS-Induced Acute Colitis in Mouse Colon Lamina Propria by Enhancing Th2 Cell Responses.

Interleukin- (IL-) 33, a member of the IL-1 cytokine family, is an important modulator of the immune system associated with several immune-mediated diseases. IL-33 was expressed in high level on epithelial cells of intestinal tract. It suggested that IL-33 plays a potential role in inflammatory bowel diseases (IBD). We investigated the role of interleukin- (IL-) 33 in dextran sulphate sodium- (DSS-) induced acute colitis in mice using recombinant mouse IL-33 protein (rIL-33). We found that DSS-induced acute colitis was aggravated by rIL-33 treatment. rIL-33-treated DSS mice showed markedly reduced levels of interferon- (IFN-)γ and IL-17A in their colon lamina propria lymphocytes (LPL), but the levels of Th2 cytokines, such as IL-5 and IL-13, in these cells were significantly increased, compared to DSS mice treated with PBS. Our results suggested that IL-33 stimulated CD4+T cells and caused the cell to adopt a Th2-type response but at the same time suppressed Th17 and Th1 cell responses. Therefore, IL-33 may be involved in pathogenesis of DSS-induced acute colitis by promoting Th2 cell response in intestinal mucosa of mice. Modulation of IL-33/ST2 signaling by monoclonal antibody (mAb) could be a novel biological therapy in DSS-induced acute colitis.

P-164 Promoting Inflammatory Lymphangiogenesis by VEGF–C Aggravates Intestinal Inflammation in Experimental Acute Colitis in Mice

P-164 Promoting Inflammatory Lymphangiogenesis by VEGF–C Aggravates Intestinal Inflammation in Experimental Acute Colitis in Mice

Anti-inflammatory effect of a standardized triterpenoid-rich fraction isolated from Rubus coreanus on dextran sodium sulfate-induced acute colitis in mice and LPS-induced macrophages

Ethnopharmacological relevanceRubus coreanus Miquel (Rosaceae), the Korean black raspberry, has traditionally been used to treat inflammatory diseases including diarrhea, asthma, stomach ailment, and cancer. Although previous studies showed that the 19α-hydroxyursane-type triterpenoids isolated from Rubus coreanus exerted anti-inflammatory activities, their effects on ulcerative colitis and mode of action have not been explored. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms involving19α-hydroxyursane-type triterpenoid-rich fraction from Rubus coreanus (TFRC) on a mice model of colitis and lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Materials and methodsExperimental colitis was induced by DSS for 7 days in ICR mice. Disease activity indices (DAI) took into account body weight, stool consistency, and gross bleeding. Histological changes and macrophage accumulation were observed by immunohistochemical analysis. Pro-inflammatory markers were determined using immunoassays, RT-PCR, and real time PCR. Signaling pathway involving nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation was determined by luciferase assay and Western blotting. ResultsIn DSS-induced colitis mice, TFRC improved DAIs and pathological characteristics including colon shortening and colonic epithelium injury. TFRC suppressed tissue levels of pro-inflammatory cytokines and reduced macrophage infiltration into colonic tissues. In LPS-induced RAW 264.7 macrophages, TFRC inhibited the production of NO, PGE2, and pro-inflammatory cytokines by down-regulating the activation of NF-κB and p38 MAPK signaling. ConclusionThe study demonstrates that TFRC has potent anti-inflammatory effects on DSS-induced colonic injury and LPS-induced macrophage activation, and supports its possible therapeutic and preventive roles in colitis.

Sa1742 Microbiome and Host Factors Communicate Protection Against Acute Murine Colitis Following Omega-6 Fatty Acid Induced Transient Pediatric Obesity

Background: Dietary influences may affect microbiota composition and host immune responses at the intestinal surface. These nutritionally induced biologic component changes may modulate propensity towards inflammatory bowel diseases (IBD), including Crohn disease (CD) and ulcerative colitis (UC). IBD present most commonly in young adults, indicating childhood as a potentially vulnerable developmental period for disease pathogenesis. Dietary omega-6 fatty acids (ω-6) have been associated with UC in prospective human epidemiologic studies. However, the critical developmental period, when ω-6 consumption may induce UC is not known. We examined the prolonged effects of transient high ω-6 diet during pediatric development in a murine colitis model. Methods: C57Bl/6J mice received high (40% caloric content [cc]), or control (12% cc) ω-6 diet from postnatal day 30 (P30) to P80, then reversed to control diet for 40 days (P120). Body composition was examined by qMRI. Colitis was induced by dextran sulfate sodium (DSS). The severity of colitis was assessed by weight loss and histological scoring. Selective microbiome effects on DSS colitis were studied following fecal transplantation into germ-free mice. The mucosal microbiome was interrogated by next-generation pyrosequencing of the bacterial 16S rRNA gene. Microarrays to study DNA methylation and gene expression from colonic mucosa were utilized. T cell populations in mesenteric lymph nodes (MLNs) and spleen were analyzed by flow cytometry. Plasma of 12 treatment Naive (TN) UC, 11 TN CD and 10 controls were used for quantification of circulating CXCL13 levels by ELISA. Results: Mice transiently became obese on high ω-6 diet. Surprisingly, those were protected against DSS colitis. Protection against colitis was fat type and dietary reversal dependent. Germ-free mice receiving cecal content from the transiently obese mice were protected against colitis. No significant colonic mucosal DNA methylation or gene expression changes were detected. In the meantime, the number of CD4+ cells was decreased in both the spleens and MLNs of the high ω-6 reversed mice. MLN Cxcr5+/CD4+ cells, specifically, were decreased following transient obesity. AntiCxcl13 (the ligand of Cxcr5) antibody treatment decreased DSS induced histological colitis severity. Elevated CXCL13 concentrations (CD: 1.8-fold, p=0.0077; UC: 1.9-fold, p=0.056) were found in the serum of human pediatric IBD patients. Summary: Loss of ω-6 diet induced pediatric obesity protected against acute colitis inmice. This phenotype was communicated by prolongedmicrobiome changes and associatedwith immune organ compositionmodification. The Cxcr5-Cxcl13 pathway was indicated to be an important host factor in modulating DSS colitis severity following the dietary reversal. Our human serologic observations supported the translational relevance of our findings.

Gelatin tannate ameliorates acute colitis in mice by reinforcing mucus layer and modulating gut microbiota composition: Emerging role for 'gut barrier protectors' in IBD?

Gelatin tannate, a gelatin powder containing tannic acids, is commonly employed as an intestinal astringent. Neither information nor animal model exist to confirm its efficacy or unravel mechanisms of action. To evaluate the action of gelatin tannate in murine dextran sodium sulphate (DSS)-induced acute colitis. Mice were exposed to DSS and received gelatin tannate by gavage. At sacrifice, colon histological degree of inflammation was assessed. Stool samples were cultured for microbiological analysis. Colon samples were analysed by two-photon confocal microscopy and atomic force microscopy. Elisa was performed on murine serum to assess lipopolysaccharide and peptidoglycan levels. Gelatin tannate treatment reduced disease activity, bodyweight loss, and preserved colonic length. It produced a decrease in the amount of enterobacteria and enterococci. At confocal microscopy, intestinal samples from healthy and treated mice displayed similar structure in mucus layer thickness and composition; samples from placebo group had no mucus layer or a thinner stratus. Atomic force microscopy confirmed these findings. Treated mice showed lower blood LPS levels vs. control. Gelatin tannate decreased the severity of colitis. Acting as a gut barrier enhancer, it re-establishes gut homeostasis by recovering intestinal permeability and mucus layer integrity in gut mucosa and by modulating microbiota composition.

Aegle marmelos fruit extract abates dextran sodium sulfate induced acute colitis in mice: Repression of pro-inflammatory cytokines during colonic inflammation

Ulcerative colitis (UC) is a common inflammatory bowel disease which on prolongation causes colorectal cancer (CRC) making UC as the highest risk factor for CRC development. Despite the use of Aegle marmelos in folk medicine, few studies have reported its colonic healing activity. We exploited the use of dextran sodium sulfate (DSS) in inducing colitis in Swiss albino mice and examine the inflammatory modulating effect of A. marmelos fruit extract (AME). HPLC analysis confirmed the presence of two biologically active compounds namely umbelliferon (a coumarin-derivative) and lupeol (triterpenoid). Fourteen days feeding of DSS to mice elicited colitis, with drastically reduced body weight with altered clinical severity score, combined with shortening of colon length. Oral administration of AME (50mg/kg) evidenced a significant suppression of disease symptoms. The increased mRNA expressions of interleukin (IL) 2, IL-6 and tumor necrosis factor α during colitis, were also reduced significantly. Notable reduction in the NF-κB expression in the colonic region was also noted which is substantiates with docking analysis were UMB and LUP found in AME bounds with NF-κB. Furthermore, DSS-altered histopathological features of colon were also recovered on treatment with AME. Thus the observation revealed the restorative significance of AME in healing the DSS-induced colitis in mice by modulating NF-κB and regulating pro-inflammatory mediators involved in the colonic injury.

Budesonide loaded nanoparticles with pH-sensitive coating for improved mucosal targeting in mouse models of inflammatory bowel diseases

The purpose of this study was to investigate the therapeutic potential of budesonide loaded nanocarriers for the treatment of inflammatory bowel disease (IBD). First, budesonide was encapsulated in poly(lactic-co-glycolic) acid (PLGA) nanoparticles by an oil in water (O/W) emulsion technique. A second batch of the same nanoparticles was additionally coated with a pH-sensitive methyl-methacrylate-copolymer. The particle sizes of the plain and the coated PLGA were 200±10.1nm and ~240±14.7nm, respectively. As could be shown in vitro, the pH-sensitive coating prevented premature drug release at acidic pH and only releases the drug at neutral to slightly alkaline pH. The efficacy of both coated and plain nanoparticle formulations was assessed in different acute and chronic colitis mouse models, also in comparison to an aqueous solution of the drug. The dose was always the same (0.168mg/kg).It was found that delivery by coated PLGA nanoparticles alleviated the induced colitis significantly better than by plain PLGA particles, which was already more effective than treatment with the same dose of the free drug. These data further corroborate the potential of polymeric nanocarriers for targeted drug delivery to the inflamed intestinal mucosa, and that this concept can still be further improved regarding the oral route of administration by implementing pH-dependent drug release characteristics.

Oral Administration of Bovine Milk from Cows Hyperimmunized with Intestinal Bacterin Stimulates Lamina Propria T Lymphocytes to Produce Th1-Biased Cytokines in Mice

The goal of this study was to examine the effects of oral administration of bovine milk from cows hyperimmunized with a proprietary bacterin (immune milk “Sustaina”) on mucosal immunity in the intestine of adult mice. C57BL/6 mice were orally given immune or control milk for two weeks, and then lymphocyte population and the cytokine production in lamina propria of colon in normal mice and mice induced colitis by dextran sulphate sodium (DSS) were detected. We found that the levels of IFN-γ and IL-10 increased, but the levels of IL-17A and IL-4, decreased in lamina propria of colon in immune milk-fed mice as compared with those in control milk-fed mice. Interestingly, oral administration of immune milk partially improved the acute colitis induced by DSS. The levels of TNF-α and IFN-γ increased, but IL-6, IL-17A and IL-4 decreased in lamina propria (LP) of colon in immune milk-fed mice with DSS-induced colitis. Our results suggest that immune milk may stimulate CD4+ T cells to polarize towards a Th1 type response, but contrarily suppress Th17 and Th2 cells responses in large intestinal LP of mice. The results indicate that this kind of immune milk has is able to promote the maintainance of intestinal homeostasis and enhance protection against infection, and could alleviate the symptoms of acute colitis in mice.

Induction of TGF-β and IL-10 production in dendritic cells using astilbin to inhibit dextran sulfate sodium-induced colitis

Astilbin, a major bioactive compound from Rhizoma smilacis glabrae, has been reported to possess anti-inflammatory properties. Our study first evaluated astilbin on dextran sulfate sodium (DSS)-induced acute colitis in mice. By intraperitoneal injection of astilbin, the severity of colitis was attenuated, and the serum levels of IL-10 and TGF-β were increased. Using flow cytometry, a higher number of IL-10+ dendritic cells (DCs) and TGF-β+ DCs and a lower number of CD86+ DCs, IL-12 p40+ DCs, and IL-1β+ DCs were detected in the spleen of mice with colitis after astilbin treatment. The administration of astilbin also resulted in the upregulation of CD103+ expression in colonic DCs. In a coculture system, murine bone marrow-derived DCs pretreated with astilbin resulted in an enhanced production of CD4+CD25+Foxp3+ T cells. The results of this study show that astilbin could be a candidate drug for inflammatory bowel disease by mediating the regulatory functions of DCs.

Anti-inflammatory effect of Phellinus linteus grown on germinated brown rice on dextran sodium sulfate-induced acute colitis in mice and LPS-activated macrophages

Ethnopharmacological relevance and aim of the studyPhellinus linteus is a herb used in traditional Asian medicine to treat stomachache, inflammation, and tumors. Recent studies show that the extract of Phellinus linteus has anti-inflammatory and antitumor activities. However, Phellinus linteus extract has limitation of high cost and limited availability because of supply shortage. Here, we grew Phellinus linteus on germinated brown rice to address the issue of supply shortage and investigated anti-inflammatory effect in vivo as well as in vitro. Materials and methodsPhellinus linteus grown on germinated brown rice (PBR) were extracted using filtration steps, which included γ-aminobutyric acid (GABA). The PBR (200, 500mg/kg/day) was applied into the mouse model of dextran sodium sulfate (DSS)-induced colitis and lipopolysaccharide (LPS)-stimulated mouse macrophage RAW264.7 cells. We used sulfasalazine as a reference drug. In addition, mechanism related to anti-inflammatory was investigated by Western blotting. ResultsIn the mouse model of DSS-induced colitis, PBR ameliorated the pathological characteristics of colitis such as shortening of colon length and improved the disease activity index score. In addition, we showed that PBR reduced the expression of nuclear factor-kappa B (NF-κB) in colitis. Western blotting showed that PBR decreased the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (Cox-2) proteins. Further, PBR treatment reduced the expression of mitogen-activated protein kinases (MAPKs) (e.g., extracellular signal-regulated protein kinase (ERK) and p38) in the mouse model of DSS-induced colitis. ConclusionsTreatment of RAW 264.7 macrophages with a combination of PBR and LPS showed a significant concentration-dependent inhibition of nitric oxide (NO) and prostaglandin E2 (PGE2) production. In addition, we determined the ability of PBR to reduce the iNOS and tumor necrosis factor (TNF)-α expression. PBR inhibited the expression of iNOS, NF-κB, and Cox-2 proteins in LPS-stimulated RAW264.7 macrophages. This study presents the potential use of PBR as a drug candidate against colitis.

Switching cannabinoid response from CB2 agonists to FAAH inhibitors

A series of 3-carboxamido-5-aryl-isoxazoles designed as CB2 agonists were evaluated as FAAH inhibitors. The pharmacological results led to identify structure–activity relationships enabling to switch cannabinoid response from CB2 agonists to FAAH inhibitors. Two compounds were selected for their FAAH and/or CB2 activity, and evaluated in a colitis model for their anti-inflammatory activity. Results showed that compounds 10 and 11 inhibit the development of DSS-induced acute colitis in mice and then, are interesting leads to explore new drug candidates for IBD.

The Commensal Bacterium Faecalibacterium prausnitzii Is Protective in DNBS-induced Chronic Moderate and Severe Colitis Models

The abundance of Faecalibacterium prausnitzii, an abundant and representative bacterium of Firmicutes phylum, has consistently been observed to be lower in patients with Crohn's disease than in healthy individuals. We have shown that both F. prausnitzii and its culture supernatant (SN) have anti-inflammatory and protective effects in a TNBS-induced acute colitis mouse model. Here, we tested the effects of both F. prausnitzii and its SN in moderate and severe DNBS-induced chronic colitis mouse models. Colitis was induced by intrarectal administration of DNBS. After either 4 or 10 days of recovery (severe and moderate protocols, respectively), groups of mice were intragastrically administered either with F. prausnitzii A2-165 or with its culture SN for 7 or 10 days. Three days before being sacrificed, colitis was reactivated by administration of a lower dose of DNBS. The severity of colitis at the time of being sacrificed was assessed by weight loss and macroscopic and microscopic scores. Myeloperoxidase (MPO) activity, cytokine levels, lymphocyte populations, and changes in microbiota were studied. Intragastric administration of either F. prausnitzii or its SN led to a significant decrease in colitis severity in both severe and moderate chronic colitis models. The lower severity of colitis was associated with down-regulation of MPO, pro-inflammatory cytokines, and T-cell levels. We show, for the first time, protective effects of both F. prausnitzii and its SN during both the period of recovery from chronic colitis and colitis reactivation. These results provide further evidence that F. prausnitzii is an anti-inflammatory bacterium with therapeutic potential for patients with inflammatory bowel disease.

Oral administration of the flavonoid myricitrin prevents dextran sulfate sodium-induced experimental colitis in mice through modulation of PI3K/Akt signaling pathway

We investigated the protective effect of the flavonoid myricitrin in dextran sulfate sodium (DSS) induced colitis as promising candidate for the treatment of ulcerative colitis which is considered an important worldwide public health problem. Male CD1 mice were provided with a solution of filtered water containing 3% w/v DSS ad libitum over a 5-day period followed by 2 days with normal drinking water. Myricitrin was administered orally, once a day, at the doses 1, 3, and 10 mg/kg of body weight. At the end of day 7th, the animals were euthanized and the colonic tissue was collected to be analyzed by RT-PCR, immunohistochemistry and Western blot. Our results showed that oral treatment with myricitrin exerts consistent anti-inflammatory action in DSS-induced acute colitis in mice by the inhibition of the Akt/phosphatidylinositol-3 kinase-dependent phosphorylation. Consequently, the phosphorylation of mitogen-activated protein kinases (MAPK) p38, extracellular signal-regulated protein kinase (ERK1/2), and c-Jun N-terminal kinase and of the nuclear factor B (NF-κB) was reduced and prevented an increase in the cytokines/chemokines levels. Together, these data reveal that the anti-inflammatory effect of myricitrin in DSS-induced colitis in mice is likely associated with its ability to prevent the activation of upstream kinases, such as phosphatidylinositol-3 kinase-dependent Akt, NF-κB, and mitogen-activated protein kinase.

Transcriptional modulation of pattern recognition receptors in acute colitis in mice

Pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs), contribute to the development of intestinal inflammatory diseases, like inflammatory bowel disease (IBD). Supporting investigations of the underlying mechanisms of IBD, this study provides an extensive PRR expression survey together with T-cell associated factors along the murine colon during experimental colitis. 8–12 week-old C57BL/6 mice were treated with dextran sodium sulfate (DSS) to induce colitis. The mRNA expression levels of Tlr1–9, Nod1, Nod2, T cell subset-associated master transcription factors and cytokines were determined using qPCR. The expression of TLR2, 4, 5 and 6 was determined with immunohistochemistry. Th1 and Th17 associated responses were quantified in the mesenteric lymph nodes (mLNs) using flow cytometry. In DSS treated mice, the mRNA expression of the majority of PRRs was increased relative to healthy controls and correlated with the degree of inflammation. The exceptions were Tlr1 and Tlr5, which displayed unchanged and down-regulated transcription, respectively. Furthermore, in healthy animals, there was increased transcription of Tlr2, 3 and 5 near the caecum as opposed the region near the rectum. Within the inflamed regions, the mRNA expression of Th1-, Th17- and regulatory T-cell associated cytokines was enhanced, while there was no change for Th2-associated cytokines. In agreement with the mRNA expression, enhanced IFNγ and IL-17 producing cells were observed in stimulated mLNs. This study provides an extensive expression survey of PRRs along the colon during the acute colitis and shows that the induced inflammation is characterized by a Th1- and IL-17 mediated cytokine response.