Acid-induced Colitis In Mice Research Articles

Experimental colitis is comorbid with social interaction deficits and anxiety-like behaviors in mice: mechanistic intuitions into neuroinflammation and Claudin 5 expression in the hippocampus.

Inflammatory bowel disease (IBD) is accompanied by psychiatric disorders, including Schizophrenic-like manifestations. Although incompletely illustrated, intestinal mucosal membrane damage and blood-brain barrier (BBB) penetrability may have significant roles in psychiatric symptoms of IBD. This study aimed to investigate role of the Claudin-5 (CLDN5) (a regulator of the permeability of BBB) and neuroinflammatory response in the comorbid behavioral disorders in experimental colitis in mice. Acetic acid was used to induce colitis in mice. 7 days after induction of colitis, behaviors including social interaction and locomotor activity as well as anxiety-like behaviors were evaluated. Then, the colon was extracted for gross and microscopic evaluations. The expression of CLDN5, TNF-α, IL1β and IL23 was measured by RT-PCR in the colon and hippocampus. Histopathologic evaluations demonstrated mucosal, submucosal, and crypt-related damages in the colon. The negative and positive number of social interactions significantly increased in the colitis group. A considerable increase in locomotor activities (horizontal and vertical components) shown in the colitis group. Mice in colitis group spent less time in the central zone in the open field apparatus. Gene expressions of TNF-α, IL1β, and IL23 increased and CLDN5 decreased in the colitis group. The barrier function of the intestine and brain would be impaired, partially at least, following colitis (as we observed decrease in CLDN5 gene expression). Furthermore, we found that beside inflammatory response in the colon, a neuro-immune response triggered in the hippocampus following colitis. These alterations probably, mediated comorbid behavioral disorders in acetic acid-induced colitis in mice.

Umbelliprenin attenuates comorbid behavioral disorders in acetic acid-induced colitis in mice: mechanistic insights into hippocampal oxidative stress and neuroinflammation.

Inflammatory bowel disease (IBD) is often accompanied by psychiatric disorders. Emerging evidence suggests that neuroinflammation and oxidative stress contribute to the psychiatric symptoms associated with IBD. Umbelliprenin (UMB) possesses several pharmacological properties, including anti-inflammatory and antioxidant effects. This study aimed to investigate the protective effects of UMB on comorbid behavioral disorders in a mouse model of experimental colitis, focusing on its potential anti-neuroinflammatory and antioxidant activities. After inducing colitis with acetic acid, male NMRI mice were treated for 7 consecutive days with UMB, saline, or dexamethasone. Behavioral assessments included the forced swimming test (FST), splash test, open field test (OFT), and elevated plus maze (EPM). Histopathological changes in the colon were evaluated, and total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and the expression of inflammatory genes (TNFα, IL1β, and TLR4) were measured in the hippocampus. Colitis was associated with increased immobility time in the FST, reduced entries and time spent in the open arms of the EPM, decreased grooming behavior in the splash test, and reduced time spent in the central zone of the OFT. Colitis also resulted in a reduction in TAC and an increase in MDA levels and inflammatory gene expression in the hippocampus. UMB treatment mitigated the behavioral disorders associated with colitis, reduced neuroinflammation and oxidative stress in the hippocampus, and alleviated histopathological alterations in the colon. In conclusion, UMB may reduce behavioral disorders induced by colitis by decreasing oxidative stress and neuroinflammation in the hippocampus.

Neuroimmune response and oxidative stress in the prefrontal cortex mediate seizure susceptibility in experimental colitis in male mice.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder. Oxidative stress and inflammatory responses have a vital role in the pathophysiology of IBD as well as seizure. IBD is associated with extraintestinal manifestations. This study aimed to explore the relationship between colitis and susceptibility to seizures, with a focus on the roles of neuroinflammation and oxidative stress in acetic acid-induced colitis in mice. Forty male Naval Medical Research Institute mice were divided into four groups: control, colitis, pentylenetetrazole (PTZ), and colitis + PTZ. Colitis was induced by intrarectal administration of acetic acid, and seizures were induced by intravenous injection of PTZ 7 days postcolitis induction. Following the measurement of latency to seizure, the mice were killed, and their colons and prefrontal cortex (PFC) were dissected. Gene expression of inflammatory markers including interleukin-1β, tumor necrosis factor-alpha, NOD-like receptor protein 3, and toll-like receptor 4, as well as total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels were measured in the colon and PFC. Histopathological evaluations were performed on the colon samples. Data were analyzed by t-test or one-way variance analysis. Colitis decreased latency to seizure, increased gene expression of inflammatory markers, and altered levels of MDA, nitrite, and TAC in both the colon and PFC. Simultaneous induction of colitis and seizure exacerbated the neuroimmune response and oxidative stress in the PFC and colon. Results concluded that neuroinflammation and oxidative stress in the PFC at least partially mediate the comorbid decrease in seizure latency in mice with colitis.

Complanatuside A ameliorates 2,4,6-trinitrobenzene sulfonic acid-induced colitis in mice by regulating the Th17/Treg balance via the JAK2/STAT3 signaling pathway.

Immunity imbalance of T helper 17 (Th17)/regulatory T (Treg) cells is involved in the pathogenesis of Crohn's disease (CD). Complanatuside A (CA), a flavonol glycoside, exerts anti-inflammatory activities and our study aimed to identify its effect on TNBS-induced colitis and the possible mechanisms. We found that CA alleviated the symptoms of colitis in TNBS mice, as demonstrated by prevented weight loss and colon length shortening, as well as decreased disease activity index scores, inflammatory scores, and levels of proinflammatory factors. Flow cytometry analysis showed that CA markedly reduced the percentage of Th17 cells while increasing the percentage of Treg cells in TNBS mice. Under Th17 cell polarizing conditions, CA inhibited the differentiation of Th17 cells while the Treg cell differentiation was elevated under Treg cell polarizing conditions. Furthermore, it was observed that JAK2 interacted with CA through six hydrogen bonds via molecular docking. The phosphorylation of JAK2/STAT3 was reduced by CA, which might be correlated with the protective effect of CA on colitis. In conclusion, CA reduced the imbalance of Th17/Treg cells by inhibiting the JAK2/STAT3 signaling pathway in TNBS-induced colitis, which may provide novel strategies for CD treatment.

Development of trans-Chalcone loaded pectin/casein biodegradable microcapsules: Efficacy improvement in the management of experimental colitis

Improved therapies for inflammatory bowel diseases are sorely needed. Novel therapeutic agents and the development of controlled release systems for targeted tissue delivery are interesting approaches to overcome these barriers. We investigated the activity of trans-chalcone (T) in acetic acid-induced colitis in mice and developed, characterized, and determined the therapeutic effect of pectin/casein polymer microcapsules containing T (MT) in a colitis mouse model. In vitro, compound release was achieved in simulated intestinal fluid but not in the simulated gastric fluid. In vivo, since T at the dose of 3 mg/kg but not 0.3 mg/kg ameliorated colitis, we next tested the effects of MT at 0.3 mg/kg (non-effective dose). MT, but not free T at 0.3 mg/kg, significantly improved colitis outcomes such as neutrophil recruitment, antioxidant capacity, cytokine production, and NF-kB activation. This translated into reduced macro and microscopic damage in the colon. T release from the microcapsules is mediated by a pH-dependent and pectinase-regulated mechanism that provide controlled and prolonged release of T. Moreover, MT lowered the required dose for T therapeutic effect, indicating that could be a suitable pharmaceutical approach to colitis treatment. This is the first demonstration that T or MT is effective at reducing the signs of colitis.

Soluble Protein Hydrolysate Ameliorates Gastrointestinal Inflammation and Injury in 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Mice

Inflammatory bowel diseases (IBD) are chronic, recurring gastrointestinal diseases that severely impair health and quality of life. Although therapeutic options have significantly expanded in recent years, there is no effective therapy for a complete and permanent cure for IBD. Well tolerated dietary interventions to improve gastrointestinal health in IBD would be a welcome advance especially with anticipated favorable tolerability and affordability. Soluble protein hydrolysate (SPH) is produced by the enzymatic hydrolysis of commercial food industry salmon offcuts (consisting of the head, backbone and skin) and contains a multitude of bioactive peptides including those with anti-oxidant properties. This study aimed to investigate whether SPH ameliorates gastrointestinal injury in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Mice were randomly assigned to four groups: Control (no colitis), Colitis, Colitis/CP (with control peptide treatment), and Colitis/SPH (with SPH treatment). Colitis was induced by cutaneous sensitization with 1% TNBS on day −8 followed by 2.5% TNBS enema challenge on day 0. Control peptides and SPH were provided to the mice in the Colitis/CP or Colitis/SPH group respectively by drinking water at the final concentration of 2% w/v daily from day −10 to day 4. Then, the colon was harvested on day 4 and examined macro- and microscopically. Relevant measures included disease activity index (DAI), colon histology injury, immune cells infiltration, pro- and anti-inflammatory cytokines and anti-oxidative gene expression. It was found that SPH treatment decreased the DAI score and colon tissue injury when compared to the colitis-only and CP groups. The protective mechanisms of SPH were associated with reduced infiltration of CD4+ T, CD8+ T and B220+ B lymphocytes but not macrophages, downregulated pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6), and upregulated anti-inflammatory cytokines (transforming growth factor-β1 and interleukin-10) in the colon tissue. Moreover, the upregulation of anti-oxidative genes, including ferritin heavy chain 1, heme oxygenase 1, NAD(P)H quinone oxidoreductase 1, and superoxide dismutase 1, in the colons of colitis/SPH group was observed compared with the control peptide treatment group. In conclusion, the protective mechanism of SPH is associated with anti-inflammatory and anti-oxidative effects as demonstrated herein in an established mice model of colitis. Clinical studies with SPH as a potential functional food for the prevention or as an adjuvant therapy in IBD may add an effective and targeted diet-based approach to IBD management in the future.

THE EFFECT OF SALVIA FRUTICOSA WATER EXTRACT IN ACETIC-ACID-INDUCED COLITIS IN MICE

Inflammatory bowel disease (IBD) including Ulcerative colitis (UC) and Crohn’s disease, is a chronic condition of the intestine characterized by an uncontrolled inflammatory response. Current biologic treatments developed to treat IBD are expensive and associated with significant side effects; thus, alternative approaches are required. Recently, herbal concoctions have emerged as promising intervention. This study investigates the protective effects of Salvia fruticosa (SF) against acetic acid-induced colitis in mice, a model of human inflammatory bowel disease (IBD). Mice were divided into four groups (n=3). IBD was induced with acetic acid (6%). SF was administered by gavage at 1.5ug/kg mimicking folk medicine. SF treatment was given for 2, 4 & 6 days. After treatment, colons were collected for colonic biochemical markers, and histopathological evaluation. SF treatment induced enhancement in the colon’s structure and decreased ulcerations and inflammation. It significantly decreased pro-inflammatory cytokines TNF-α, IL-17 by 2.1-fold and 0.9-fold respectively at day2 and 6 and IL-6 by 2.8-fold at day 2 & 1.7-fold at day 6. Also, pro-inflammatory cytokine INF-γ showed a significant 22-fold decrease at day2 in SF-treated colitic group. Moreover, Myeloperoxidase (MPO) and Malondialdehyde (MDA) levels decreased showing the anti-oxidant property of the extract. Anti-oxidant Glutathione (GSH) level and anti-inflammatory cytokine IL-10, remained at normal levels while an increase by 0.9-fold at day 2 and 0.5-fold at day 6 in anti-inflammatory cytokine TGF-β in healthy SF-treated groups was significant. Hence, Salvia fruticosa exerts an anti-inflammatory and anti-oxidant effects against IBD as well as it help healing colon ulcers and maintain its architecture.

Anethole Ameliorates Acetic Acid-Induced Colitis in Mice: Anti-Inflammatory and Antioxidant Effects.

Anethole has possessed anti-inflammatory and antioxidant responses in numerous studies. Oxidative stress has a pivotal role in the pathophysiology of colitis. The current study is designed to determine the effect of anethole on acetic acid-induced colitis in mice in view of its possible anti-inflammatory and antioxidant properties. In this study, 48 mice were grouped into 6 groups (n = 8), and colitis was induced with 0.2 ml of 7% acetic acid. Mice received intraperitoneally (i.p.) for 7 constant days normal saline and/or anethole at doses of 31.25, 62.5, 125, and 250 mg/kg, respectively. After treatments, the colon was dissected out, and histopathological changes, expression of inflammatory genes (IL-1β, TNF-α, and TLR4), and evaluation of malondialdehyde (MDA) levels and total antioxidant capacity (TAC) were assessed. The results showed that colitis is associated with edema and inflammatory responses in all layers and severe damage to the epithelium of the colon. Colitis causes a decrease in TAC, an increase in MDA levels, and an increase in inflammatory genes in the colon. Findings determined that anethole ameliorated the adverse effects of acetic acid-induced colitis in the colon. It is concluded that anethole, partially at least, possessed protective effects in acetic acid-induced colitis in mice through attenuation of oxidative stress and inflammatory response.

Peptide YY 3–36 attenuates trinitrobenzene sulfonic acid-induced colitis in mice by modulating Th1/Th2 differentiation

ABSTRACT Peptide YY (PYY) 3–36, the main circulatory form of PYY, plays important roles in gastrointestinal motility, secretion, and absorption. However, it is unknown whether PYY 3–36 has underlying functions in colitis. The Crohn’s disease (CD)-like mouse model in which CD is induced by trinitrobenzene sulfonic acid (TNBS) was established and utilized to investigate this potential role for PYY 3–36. The results showed that the expression of colonic mucosal PYY and PYY receptors Y1, Y2, Y4 were significantly increased in mice with TNBS-induced colitis. In vitro, PYY 3–36 remarkably inhibited the production of proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) from lipopolysaccharide (LPS)-induced macrophages. In vivo, a high concentration of PYY 3–36 robustly decreased the weight loss and death rate and attenuated the pathological colon tissue damage observed in mice with TNBS-induced colitis. Further studies uncovered that PYY 3–36 treatment reduced the levels of colon myeloperoxidase (MPO) and both colonic and systemic TNF-α and IL-6 observed in murine colitis. Furthermore, flow cytometric analysis showed PYY 3–36 altered the proportion of Th1/Th2 splenocytes in the disease model of colitis. Collectively, these results suggest that PYY 3–36 may be a promising candidate for the improvement of colitis, reflected by the attenuation of colon inflammatory responses observed in experimental murine colitis.

Ameliorative effect of Leiurus quinquestriatus venom on acetic acid-induced colitis in mice

Scorpion venom has anti-microbial, anti-cancer, and anti-malarial activities. Also, it has an effective role in the treatment of autoimmune disease and as a pain-relieving agent. Ulcerative colitis (UC) is a chronic deteriorating inflammatory bowel disease. It is urgent to find new and safe products with lesser side effects. This study aimed to use scorpion Leiurus quinquestriatus venom (L.Q venom) for the first time as an anti-inflammatory agent to ameliorate the colon condition after UC induction. Also, to detect the effect of the combinatorial treatment of L.Q venom and Meslazine (Mes) drug. Fifty male albino mice were divided into 5 groups (n = 10); the first group (Gp1) served as a negative control. UC was induced in Gp2, Gp3, Gp4 and Gp5 by 4% acetic acid. Gp2 served as a positive control. After 24 h of UC induction, Gp3 was injected with L.Q venom (3.12 µg/kg) inter peritoneal (i.p), and Gp4 was administered orally by Mes (100 mg/kg). Gp5 was treated with L.Q venom and Mes as in Gp3 and Gp4. All treatments were taken for 7 consecutive days. Disease activity index (DAI), the macroscopic and microscopic investigations, TREM-1, MMP-9, caspase-3, NO, MPO levels were measured. Moreover, COX-2 and IL-22 were investigated in colonic tissue and TLR-9 expression was determined by RT-PCR. The results showed that all previous mentioned parameters were increased in the positive control group (Gp2), however, treatment with L.Q venom (Gp3) decreased these parameters. Interestingly, the combinatorial treatment with L.Q venom/Mes showed an additive effect that was able to ameliorate the physiological, biochemical and histopathological changes that were induced in UC-mice. Collectively, the L.Q venom showed a promising anti-inflammatory effect, which could be used to ameliorate the side effects of UC, either alone or in combination with Mes.

Bifidobacteria-Fermented Red Ginseng and Its Constituents Ginsenoside Rd and Protopanaxatriol Alleviate Anxiety/Depression in Mice by the Amelioration of Gut Dysbiosis.

Gut dysbiosis is closely connected with the outbreak of psychiatric disorders with colitis. Bifidobacteria-fermented red ginseng (fRG) increases the absorption of ginsenoside Rd and protopanxatriol into the blood in volunteers and mice. fRG and Rd alleviates 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice. Therefore, to understand the gut microbiota-mediated mechanism of fRG against anxiety/depression, we examined the effects of red ginseng (RG), fRG, ginsenoside Rd, and protopanaxatriol on the occurrence of anxiety/depression, colitis, and gut dysbiosis in mice. Mice with anxiety/depression were prepared by being exposed to two stressors, immobilization stress (IS) or Escherichia coli (EC). Treatment with RG and fRG significantly mitigated the stress-induced anxiety/depression-like behaviors in elevated plus maze, light-dark transition, forced swimming (FST), and tail suspension tasks (TST) and reduced corticosterone levels in the blood. Their treatments also suppressed the stress-induced NF-κB activation and NF-κB+/Iba1+ cell population in the hippocampus, while the brain-derived neurotrophic factor (BDNF) expression and BDNF+/NeuN+ cell population were increased. Furthermore, treatment with RG or fRG suppressed the stress-induced colitis: they suppressed myeloperoxidase activity, NF-κB activation, and NF-κB+/CD11c+ cell population in the colon. In particular, fRG suppressed the EC-induced depression-like behaviors in FST and TST and colitis more strongly than RG. fRG treatment also significantly alleviated the EC-induced NF-κB+/Iba1+ cell population and EC-suppressed BDNF+/NeuN+ cell population in the hippocampus more strongly than RG. RG and fRG alleviated EC-induced gut dysbiosis: they increased Bacteroidetes population and decreased Proteobacteria population. Rd and protopanaxatriol also alleviated EC-induced anxiety/depression and colitis. In conclusion, fRG and its constituents Rd and protopanaxatriol mitigated anxiety/depression and colitis by regulating NF-κB-mediated BDNF expression and gut dysbiosis.

Kakkalide and irisolidone alleviate 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice by inhibiting lipopolysaccharide binding to toll-like receptor-4 and proteobacteria population

The flower of Pueraria lobata (family Fabaceae) has been clinically used in traditional Chinese medicine to counteract symptoms associated with drinking alcohol and liver injury and to alleviate inflammatory diseases. Its major constituent kakkalide is metabolized to irisolidone by gut microbiota. This research study was undertaken to understand the anti-colitis mechanism of kakkalide and irisolidone in vitro and in vivo. Kakkalide and its metabolite irisolidone inhibited lipopolysaccharide (LPS)-stimulated NF-κB activation and TNF-α expression in macrophages. They also inhibited LPS-induced phosphorylation of IRAK1 and TAK1 and activation of NF-κB by inhibiting the binding of Alexa Fluor 488-conjugated LPS in vitro. Orally administered irisolidone or kakkalide alleviated colon shortening and myeloperoxidase activity in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Their treatments also protected epithelial cell disruption and infiltration of CD11b+/CD11c+ cells in the colon. Furthermore, they suppressed TNBS-induced expression of M1 macrophage markers TNF-α, CD80, CD86, and Arg2 expression while the expression of M2 macrophage markers Arg1, CD163, CD206, and IL-10 was induced. They also suppressed the fecal Proteobacteria population. Overall, the anti-colitic effects of irisolidone were superior to those of kakkalide. Kakkalide and its metabolite irisolidone inhibited inflammation in vitro and in vivo by inhibiting LPS binding to toll-like receptor 4 and gut proteobacteria population.

Helminth Antigen–Conditioned Dendritic Cells Generate Anti-Inflammatory Cd4 T Cells Independent of Antigen Presentation via Major Histocompatibility Complex Class II

A recently identified feature of the host response to infection with helminth parasites is suppression of concomitant disease. Dendritic cells (DCs) exposed to antigens from the tapeworm Hymenolepis diminuta significantly reduce the severity of dinitrobenzene sulfonic acid-induced colitis in mice. Here we elucidate mechanisms underlying this cellular immunotherapy. We show a requirement for Ccr7 expression on transferred H. diminuta antigen-treated (HD)-DCs, suggesting that homing to secondary lymphoid tissues is important for suppression of colitis. Furthermore, sodium metaperiodate-sensitive helminth-derived glycans are required to drive the anti-colitic response in recipient mice. Induction of Th2-type cytokines and Gata-3+Cd4+ cells in secondary lymphoid tissues is dependent on major histocompatibility complex class II (MHC II) protein expression on transferred DCs, although remarkably, transfer of MHC II-/- HD-DCs still attenuated dinitrobenzene sulfonic acid-induced colitis in recipient mice. Moreover, transfer of Cd4+ splenicTcells retrieved from mice administered MHC II-/- HD-DCs suppressed dinitrobenzene sulfonic acid-induced colitis in recipient mice. Our studies reveal that HD-DCs can suppress colitis via an alternative MHC II-independent pathway that involves, in part, mobilization of T-cell responses. These data support the utility of HD-DCs in blocking colitis, revealing a requirement for Ccr7 and providing for HD-DC autologous immunotherapy for disease in which MHC II expression and/or function is compromised.

Anti-inflammatory effects of sinapic acid on 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice.

This study was conducted to evaluate the effect of sinapic acid, a cinnamic acid derivative, on inflammatory changes in a mouse model of colitis. Colitis was induced by intracolonic instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS). Sinapic acid (10, 30, and 100mg/kg) and dexamethasone (2mg/kg) were orally administered to Balb/c female mice after TNBS instillation. The anti-inflammatory effect of sinapic acid on colonic injury or damage was assessed by clinical, macroscopic, microscopic, and biochemical analyses. Compared with TNBS control, treatment with sinapic acid significantly improved colonic weight and length and decreased the macroscopic and microscopic changes in TNBS-induced colitis. Furthermore, myeloperoxidase activity and the colonic tissue levels of malondialdehyde and tumor necrosis factor alpha were decreased by administration of sinapic acid. The findings of this study suggest that sinapic acid exerts anti-inflammatory effects on intestinal inflammation and can be selected as a novel therapeutic candidate in the treatment of inflammatory bowel disease.

Fermented Red Ginseng Alleviates Cyclophosphamide-Induced Immunosuppression and 2,4,6-Trinitrobenzenesulfonic Acid-Induced Colitis in Mice by Regulating Macrophage Activation and T Cell Differentiation.

A variety of products have been developed with red ginseng (RG, the steamed roots of Panax ginseng Meyer). To clarify the immunomodulating effects of water-extracted RG (wRG), 50% ethanol-extracted RG (eRG), enzyme-treated eRG (ERG) and probiotic-fermented eRG (FRG), we examined their immunopotentiating and immunosuppressive effects in mice with cyclophosphamide (CP)-induced immunosuppression (CI) or 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis (TC). Oral administration of RG in CI mice significantly increased blood IFN- levels. Treatment with RG also increased the tumoricidal effects of CI mouse splenic cytotoxic T (Tc) and NK cells against YAC-1 cells. Treatment with RGs, in particular FRG and wRG, significantly increased Th1 cell differentiation. Treatment with RG except wRG increased Treg cell differentiation. However, wRG alone increased IL-6 and IL-17 expression in the colon of CI mice. Furthermore, RG alleviated colitis in TC mice. FRG most potently suppressed TNBS-induced colon shortening, NF- B activation and TNF- and IL-17 expression and increased IL-10 expression. RGs inhibited TNF- expression and increased IL-10 expression in lipopolysaccharide-stimulated primary macrophages in vitro while the differentiation of splenic T cells into type 1 T (Th1) and regulatory T (Treg) cells was increased by FRG in vitro. In conclusion, FRG can alleviate immunosuppression and inflammation by inhibiting macrophage activation and regulating Th1 and Treg cell differentiation.

Ocotillol, a Majonoside R2 Metabolite, Ameliorates 2,4,6-Trinitrobenzenesulfonic Acid-Induced Colitis in Mice by Restoring the Balance of Th17/Treg Cells.

In a preliminary experiment, majonoside R2 (MR2), isolated from Vietnamese ginseng (Panax vietnamensis Ha et Grushv.), inhibited differentiation to Th17 cells and was metabolized to ocotillol via pseudoginsenoside RT4 (PRT4) by gut microbiota. Therefore, we examined the inhibitory effects of MR2 and its metabolites PRT4 and ocotillol against Th17 cell differentiation. These ginsenosides significantly suppressed interleukin (IL)-6/tumor growth factor beta-induced differentiation of splenic CD4(+) T cells into Th17 cells and expression of IL-17 in vitro. Among these ginsenosides, ocotillol showed the highest inhibitory effect. We also examined the anti-inflammatory effect of ocotillol in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Oral administration of ocotillol significantly suppressed TNBS-induced colon shortening, macroscopic score, myeloperoxidase activity, and production of nitric oxide and prostaglandin E2. Ocotillol treatment increased TNBS-suppressed expression of tight junction proteins ZO-1, occludin, and claudin-1 in the colon. Treatment with ocotillol inhibited TNBS-induced expression of tumor necrosis factor (TNF)-α and IL-1β, as well as activation of NF-κB and MAPKs. Moreover, treatment with ocotillol inhibited TNBS- induced differentiation to Th17 cells in the lamina propria of colon, as well as expression of T-bet, RORγt, IL-17, and IL-23. Ocotillol treatment also increased Treg cell differentiation and Foxp3 and IL-10 expression. These findings suggest that orally administered MR2 may be metabolized to ocotillol in the intestine by gut microbiota and the transformed ocotillol may ameliorate inflammatory diseases such as colitis by restoring the balance of Th17/Treg cells.

Amelioration of trinitrobenzene sulfonic acid-induced colitis in mice by liquiritigenin.

The anti-inflammatory effects of liquiritigenin, a major flavonoid isolated from Glycyrrhizae uralensis, have been reported in many inflammation models. However, its protective effects have not been reported in a colitis model. This study investigated the anti-inflammatory effect and mechanism of liquiritigenin for trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Male mice imprinting control regions (ICR) were randomly divided into five groups: normal, TNBS-induced colitis, colitis treated with liquiritigenin at low dose (10 mg/kg) and high dose (20 mg/kg), or mesalazine (10 mg/kg). TNBS colitis induction was performed except for in the normal group, and they were treated with liquiritigenin or mesalazine except control group. The treatment effect was measured after three days treatment, by body weight, colon length, macroscopic score, histological score, levels of cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, and IL-10) in colon tissue as well as the nuclear factor kappa-light-chain-enhancer pathway of activated B cells (NF-κB) activation. Mice treated with high-dose liquiritigenin showed significant body weight gain, inhibition of colon shortening, protective effect on histological damages, and myeloperoxidase activity of colon tissue compared with the control group. Furthermore, mice treated with high-dose liquiritigenin experienced significantly suppressed tumor necrosis factor-α, IL-1β, and IL-6 as well as enhanced IL-10 expression (all P < 0.05). High-dose liquiritigenin treatment group showed significant decreases in TNBS-induced phosphorylation of IKKβ, p65, and IκB-α. Liquiritigenin may ameliorate TNBS-induced colitis in mice by suppressing expression of pro-inflammatory cytokines through NF-κB pathway.

Notoginsenoside R1 attenuates experimental inflammatory bowel disease via pregnane X receptor activation.

Notoginsenoside R1 (R1) is the main bioactive component in Panax notoginseng, an old herb medicine widely used in Asian countries in the treatment of microcirculatory diseases. However, little is known about the effect of R1 on inflammatory bowel disease (IBD). The present study demonstrated that R1 alleviated the severity of dextran sulfate sodium-induced colitis in mice by decreasing the activity of myeloperoxidase, the production of cytokines, the expression of proinflammatory genes, and the phosphorylation of IκB kinase, IκBα, and p65 in the colon. Further studies indicated that R1 dose-dependently activated human/mouse pregnane X receptor (PXR), a known target for decreasing inflammation in IBD, and upregulated the expression of genes involved in xenobiotic metabolism in colorectal cells and the colon. Ligand pocket-filling mutant (S247W/C284W or S247W/C284W/S208W) of the human PXR abrogated the effect of R1 on PXR activation. Time-resolved fluorescence resonance energy transfer PXR competitive binding assay confirmed R1 (ligand) binding affinity. In addition, PXR overexpression inhibited nuclear factor-κB (NF-κB)-luciferase activity, which was potentiated by R1 treatment. PXR knockdown by small interfering RNA demonstrated the necessity of PXR in R1-induced upregulation of the expression of xenobiotic-metabolizing enzymes and downregulation of NF-κB activity. Finally, the anti-inflammatory effect of R1 was confirmed in trinitrobenzene sulfonic acid-induced colitis in mice. These findings suggest that R1 attenuates experimental IBD possibly via the activation of intestinal PXR signaling.

Gelling polysaccharide from Chondrus armatus and its oligosaccharides: The structural peculiarities and anti-inflammatory activity

Structural peculiarities of low molecular weight (LMW) sample obtained by mild acid hydrolysis of κ-carrageenan from Chondrus armatus was investigated by a rapid mass spectrometric method. The selected conditions allowed avoiding excess destruction of 3,6-AnGal residues that was shown by using tandem (MS/MS) mode. Main oligosaccharide fraction with molecular weight 2.3kg/mol, obtained by mild acid hydrolysis was chosen for the analysis. It was shown that fragments with even degree of polymerization (DP) were mostly built of (-G4S-DA-)n repeating unit, n=1–5. Some fragments with odd DP were shown to contain -DA2S- insertions, being the fragments of ι-type blocks, which were randomly distributed along the polysaccharide chain as single insertions. The anti-inflammatory activity (on acetic acid-induced colitis in mice) of the initial polymer and its derivatives was studied. The anti-inflammatory effect of the polymer was observed at a dose of 5mg/kg. Polysaccharide decreased the degree of colon damage more than twice and area of damage in 40%.

Anti-inflammatory Effects of Carbon Monoxide-Releasing Molecule on Trinitrobenzene Sulfonic Acid-Induced Colitis in Mice

Recent findings indicate that carbon monoxide (CO) in non-toxic doses exerts a beneficial anti-inflammatory action in various experimental models. However, the precise anti-inflammatory mechanism of CO in the intestine remains unclear. Here, we assessed the effects of a novel water-soluble CO-releasing molecule, CORM-3, on trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. To induce colitis, C57BL/6 male mice received an enema of TNBS. CORM-3 or its inactive compound, iCORM-3, were administered intraperitoneally, once immediately before, and twice daily after receiving an enema of TNBS. Three days after TNBS administration, the distal colon was removed, assessed for colonic damage and histological scores, polymorphonuclear leukocyte recruitment (tissue-associated myeloperoxidase, MPO activity), and TNF-α, IFN-γ and IL-17A expression (mRNA and protein levels in the colon mucosa). CD4(+) T cells isolated from murine spleens were stimulated with anti-CD3/CD28, in the presence or absence of CORM-3/iCORM-3. The cell supernatants were assessed for TNF-α and IFN-γ expression, 24h following stimulation. Colonic damage and histological scores were significantly increased in TNBS-induced mice compared to sham-operated mice. Tissue-associated MPO activity and expression of TNF-α, IFN-γ, and IL-17A in the colonic mucosa were higher in TNBS-induced colitis mice. The above changes were attenuated in CORM-3-treated mice. Further, CORM-3 was effective in reducing TNF-α and IFN-γ production in anti-CD3/CD28-stimulated CD4(+) T cells. These findings indicate that CO released from CORM-3 ameliorates inflammatory responses in the colon of TNBS-challenged mice at least in part through a mechanism that involves the suppression of inflammatory cell recruitment/activation.