Oxytocin ameliorates oxidative colonic inflammation by a neutrophil-dependent mechanism

Oxytocin (OT), a nonapeptide produced in the paraventricular and the supraoptical nuclei in the hypothalamus has a wide range of effects in the body. However, the role of OT on the gastrointestinal (GI) tract has to be settled. OT may participate in the regulation of motility, secretion, blood flow, cell turnover and release of neurotransmitters and/or peptides in the GI tract, possesses antisecretory and antiulcer effects, facilitates wound healing and is involved in the modulation of immune and inflammatory processes. The present work was conducted to assess the possible therapeutic effects of OT against the acetic acid-induced colonic injury in the rat. METHODS: Colitis was induced by intracolonic administration of acetic acid (5%) in Sprague-Dawley rats (200-250 g). Either saline or OT (0.5 mg/kg) was injected subcutaneously, immediately after the induction of colitis and repeated two times a day for 4 days. On the 4th day, rats were decapitated and distal 8 cm of the colon were removed for the macroscopic and microscopic damage scoring, determination of tissue wet weight index (WI), malondialdehyde (MDA) levels, an end product of lipid peroxidation; glutathione (GSH) levels, a key antioxidant; and myeloperoxidase (MPO) activity, as an indirect index of neutrophil infiltration. Colonic collagen content, as a fibrosis marker was also determined. Lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-alpha) levels were assayed in serum samples. In the acetic acid-induced colitis, macroscopic and microscopic damage scores, WI, MDA and MPO levels were significantly increased, while GSH levels were decreased when compared to control group (p <0.05-<0.001). Treatment with OT abolished the colitis-induced elevations in damage scores, WI, MDA and MPO levels and restored the GSH levels (p <0.05-0.001). Similarly, acetic acid increased the collagen content of colonic tissues and OT-treatment reduced this value to the level of the control group. Serum LDH and TNF-alpha levels were also elevated in the acetic acid-induced colitis group as compared to control group, while this increase was significantly decreased by OT treatment. The results suggest that OT, which improves the antioxidative state of the colonic tissue and ameliorates oxidative colonic injury via a neutrophil-dependent mechanism, requires further investigation as a potential therapeutic agent in colonic inflammation.     

A protective effect of the synthetic coumarine derivative Cloricromene against DNB-colitis in the rat

Biologic therapies, namely antibodies against tumor necrosis factor-alpha (TNF- alpha) or its receptors, have been recently introduced for the treatment of patients with inflammatory bowel disease (IBD). In the present study the effects of cloricromene, an agent with known antithrombotic actions and with demonstrated anti-TNF- alpha activity were investigated in a rat model of experimental colitis induced with dinitrobenzenesulphonic acid (DNB)/ethanol. We investigated three experimental groups: (i) sham-colitis with vehicle-treatment (controls, n = 6), (ii) colitis with vehicle-treatment (saline, 0.1 ml s.c., daily) (DNB-V, n = 7), (iii) colitis with cloricromene-treatment (10 mg/kg/day s.c.; DNB-C, n = 8). After 7 days, the weight gain, colon wet weight, macroscopic damage score, coagulation parameters, colon mucosal myeloperoxidase activity (MPO), and tissue concentrations of TNF- alpha and of macrophage inhibitory peptide-2 (MIP-2) were assessed. The macroscopic damage scores, colon wet weights, and tissue MIP-2 levels were significantly increased in untreated and in cloricromene-treated rats compared with controls. Cloricromene treatment was associated with a minor body weight loss (p < 0.025) and significantly reduced tissue concentrations of MPO and TNF-alpha (p < 0.02, both). Blood coagulation parameters were not affected by treatment. In the DNB-model treatment with cloricromene effectively reduces tissue levels of TNF- alpha and of myeloperoxidase, whereas MIP-2 concentrations were not influenced. Blood coagulation parameters remained unchanged indicating safety of treatment. Since biological therapies frequently fail to improve disease course of IBD, other therapies with similar targets should be further investigated.     

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.     

Protective effect of aqueous extract of Bombax malabaricum DC on experimental models of inflammatory bowel disease in rats and mice

There is little evidence regarding role of B. malabaricum in the treatment of inflammatory bowel disease (IBD); though it is clinically employed as a constituent of a polyherbal preparation for IBD. To establish its role as a monotherapy for IBD, preliminary phytochemical screening of aqueous extract of B. malabaricum (AEBM) was undertaken. Subsequently, its protective effect in indomethacin and iodoacetamide induced colitis in rats (45, 90, 180, 270 mg/kg) and acetic acid induced colitis in mice (65, 130, 250, 500 mg/kg) was assessed. AEBM (270 mg/kg) in indomethacin and iodoacetamide induced colitis significantly reduced the ulcer score and myeloperoxidase (MPO) activity. AEBM/500 mg/kg dose/significantly reduced the ulcer score and MPO activity in acetic acid induced colitis. The extract (270 mg/kg in rats and 500 mg/kg in mice) was found to be comparable with prednisolone (10 mg/kg) and 5-aminosalicylic acid (5-ASA) (100 mg/kg) used as standard treatments. AEBM provided reduction in edema of the intestinal tissues, ulcer protection and lowering of MPO activity in a dose dependent manner. AEBM (500 mg/kg) significantly reduced colonic and serum TNF-alpha level when compared with the positive control in acetic acid induced colitis model. The results suggest a protective role of AEBM in IBD.     

Cell Wall Contents of Probiotics (Lactobacillus species) Protect Against Lipopolysaccharide (LPS)-Induced Murine Colitis by Limiting Immuno-inflammation and Oxidative Stress

Currently, there are no effective therapeutic agents to limit intestinal mucosal damage associated with inflammatory bowel disease (IBD). Based on several clinical studies, probiotics have emerged as a possible novel therapeutic strategy for IBD; however, their possible mechanisms are still poorly understood. Although probiotics in murine and human improve disease severity, very little is known about the specific contribution of cell wall contents of probiotics in IBD. Herein, we investigated the protective effects of cell wall contents of three Lactobacillus species in lipopolysaccharide (LPS)-induced colitis rats. LPS-sensitized rats were rendered colitic by colonic instillation of LPS (500 µg/rat) for 14 consecutive days. Concurrently, cell wall contents isolated from 10⁶ CFU of L. casei (LC), L. acidophilus (LA), and L. rhamnosus (LA) was given subcutaneously for 21 days, considering sulfasalazine (100 mg/kg, p.o.) as standard. The severity of colitis was assessed by body weight loss, food intake, stool consistency, rectal bleeding, colon weight/length, spleen weight, and histological analysis. Colonic inflammatory markers (myeloperoxidase activity, C-reactive protein, and pro-inflammatory cytokines) and oxidative stress markers (malondialdehyde, reduced glutathione, and nitric oxide) were also assayed. Cell wall contents of LC, LA, and LR significantly ameliorated the severity of colitis by reducing body weight loss and diarrhea and bleeding incidence, improving food intake, colon weight/length, spleen weight, and microscopic damage to the colonic mucosa. The treatment also reduced levels of inflammatory and oxidative stress markers and boosted anti-oxidant molecule. In conclusion, cell wall contents of LC, LA, and LR attenuate LPS-induced colitis by modulating immuno-inflammation and oxidative stress.

     

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。     

Protective Effects of Selenium and Vitamin E Combination on Experimental Colitis in Blood Plasma and Colon of Rats

Ulcerative colitis increases oxidative damage accompanied by production of free oxygen radicals. Selenium (Se) and vitamin E are two natural antioxidants. The present study was undertaken to investigate the possible protective role of Se and vitamin E combination in experimental colitis induced by acetic acid (AA) in rats. This study was carried out on three groups, namely the first (control), the second (experimental colitis group, 2 ml 5% acetic acid), and the third groups (2 ml 5% acetic acid, vitamin E (100 mg/kg body weight (bw)) plus Se (0.2 mg/kg bw)). The activities of catalase (CAT), prolidase (PRS), myeloperoxidase (MPO), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), total thiol (T-SH) were determined in plasma and colon samples. Macroscopic and microscopic damages in colon were increased by AA treatment (p < 0.01 and p < 0.01, respectively), whereas they were decreased by selenium and vitamin E treatment (p < 0.05 and p < 0.01, respectively). The activities of CAT and PRS in the plasma and colon were significantly affected (p < 0.05 and p < 0.01) by treatment of AA, Se, and vitamin E. MPO activity in colon was increased (p < 0.01) by AA treatment and decreased (p < 0.05) by Se and vitamin E administration. The values of TOS and OSI in plasma were increased (p < 0.5) by AA. The TAC and T-SH in colon were decreased (p < 0.05) by AA and increased (p < 0.05) by Se and vitamin E. Based upon these results, Se and vitamin E may play an important role in preventive indication of the oxidative damage associated by acetic acid caused inflammation.     

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.     

Effects of antioxidant therapy on leukocyte myeloperoxidase and Cu/Zn-superoxide dismutase and plasma malondialdehyde levels in experimental colitis

The aim of the present study was to evaluate the effects of N-acetylcysteine (NAC) and L-carnitine (LCAR) supplementations on polymorphonuclear leukocytes myeloperoxidase (MPO) and Cu/Zn-superoxide dismutase (Cu/Zn-SOD) and plasma malondialdehyde (MDA) in acetic acid (AA)-induced ulcerative colitis model. The mean polymorphonuclear leukocyte MPO and Cu/Zn-SOD activity was significantly higher in the colitis group than in the control group. Both NAC and LCAR pretreatment markedly decreased MPO and Cu/Zn-SOD activity compared to colitis group. AA administration significantly increased the levels of plasma MDA in comparison with controls. However, NAC and LCAR administration to the AA-treated rats significantly reduced the MDA levels compared to colitis group. In conclusion NAC and LCAR could be beneficial agents in restoring the circulating proinflammatory mediators.     

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.     

DNBS/TNBS Colitis Models: Providing Insights Into Inflammatory Bowel Disease and Effects of Dietary Fat

Inflammatory Bowel Diseases (IBD), including Crohn''s Disease and Ulcerative Colitis, have long been associated with a genetic basis, and more recently host immune responses to microbial and environmental agents. Dinitrobenzene sulfonic acid (DNBS)-induced colitis allows one to study the pathogenesis of IBD associated environmental triggers such as stress and diet, the effects of potential therapies, and the mechanisms underlying intestinal inflammation and mucosal injury. In this paper, we investigated the effects of dietary n-3 and n-6 fatty acids on the colonic mucosal inflammatory response to DNBS-induced colitis in rats. All rats were fed identical diets with the exception of different types of fatty acids [safflower oil (SO), canola oil (CO), or fish oil (FO)] for three weeks prior to exposure to intrarectal DNBS. Control rats given intrarectal ethanol continued gaining weight over the 5 day study, whereas, DNBS-treated rats fed lipid diets all lost weight with FO and CO fed rats demonstrating significant weight loss by 48 hr and rats fed SO by 72 hr. Weight gain resumed after 72 hr post DNBS, and by 5 days post DNBS, the FO group had a higher body weight than SO or CO groups. Colonic sections collected 5 days post DNBS-treatment showed focal ulceration, crypt destruction, goblet cell depletion, and mucosal infiltration of both acute and chronic inflammatory cells that differed in severity among diet groups. The SO fed group showed the most severe damage followed by the CO, and FO fed groups that showed the mildest degree of tissue injury. Similarly, colonic myeloperoxidase (MPO) activity, a marker of neutrophil activity was significantly higher in SO followed by CO fed rats, with FO fed rats having significantly lower MPO activity. These results demonstrate the use of DNBS-induced colitis, as outlined in this protocol, to determine the impact of diet in the pathogenesis of IBD.     

Antioxidants as novel therapy in a murine model of colitis

Reactive oxygen species (ROS) are increased in inflammatory bowel disease (IBD) and have been implicated as mediators of intestinal inflammation. We investigated the hypothesis that antioxidants with diverse properties attenuate disease progression in a murine dextran sodium sulfate (DSS)-induced colitis model. These antioxidants were (A) S-adenosylmethionine, a glutathione (GSH) precursor; (B) green tea polyphenols, a well-known antioxidant; and (C) 2(R,S)-n-propylthiazolidine-4(R)-carboxylic acid (PTCA), a cysteine prodrug, involved in GSH biosynthesis. BALB/c mice were divided into four groups and provided with the above mentioned antioxidants or the vehicle incorporated into chow. The animals were further divided into two subgroups and given normal drinking water (control) or water supplemented with DSS (to induce colitis), and the progression of the disease was studied. DSS-treated mice developed severe colitis as shown by bloody diarrhea, weight loss and pathological involvement (P<.001). However, all the antioxidants significantly improved diarrhea and colon lesions (P<.01), and increased body weights (P<.05). Hematocrits were significantly less affected in DSS-treated animals receiving antioxidants (P<.01). Colon lengths were significantly decreased due to mucosal inflammation in DSS-treated animals, but antioxidant therapy normalized this pathological finding (P<.001). The blood level of reduced GSH was decreased in DSS-treated mice (P<.05) and returned to normal when treated with antioxidants. Serum amyloid A (acute phase protein; P=.0015) and tumor necrosis factor-alpha (TNF-alpha; pro-inflammatory cytokine; P<.01) were significantly increased in DSS-treated animals (161+/-40 pg/ml) and improved with antioxidant treatment (P<.01). Finally, actin cytoskeleton was distorted and fragmented in the mucosa of DSS-treated mice and improved with antioxidant therapy. In conclusion, three structurally dissimilar antioxidants provided protection against DSS-induced colitis in this murine model, supporting a possible role for antioxidant therapy in IBD patients.     

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.     

Fustin ameliorates hyperglycemia in streptozotocin induced type-2 diabetes via modulating glutathione/Superoxide dismutase/Catalase expressions,suppress lipid peroxidation and regulates histopathological changes

Streptozotocin (STZ) 60 mg/kg, i.p.-induced diabetes in rat’s results into hyperglycemia, impaired oxidative stress, lipid profile, insulin levels and changes in body weight. Treatment with antihyperglycemics and antioxidants are accounted to produce favorable effect in this paradigm. Fustin, a flavonoid derived from Rhus verniciflua, extract of Rhus verniciflua reported to exhibit anti-hyperglycemic, antioxidant, anti-microbial, anti-arthritic effects, anti-obesity effects, antiplatelet effects and anti-cancer effects. However, no evidence is existing on effect of fustin on STZ-induction diabetes. Thus, we evaluated its effects against diabetes in STZ-induced rodents. Blood glucose, Insulin, lipid peroxidation (MDA), superoxide dismutase (SOD), catalase activity (CAT), glutathione (GSH) and lipid profile levels was assessed. After 30 days diabetes induction rodents showed a severe increased blood sugar level, MDA, high density lipid and decreased cholestrol, triglyceride, GSH, SOD, CAT, respectively.Oppositely, treatment with fustin (50–100 mg/kg/p.o., two times daily, 30 days) enhanced blood glucose, lipid profile levels Insulin. Meanwhile, reduced MDA and enhanced GSH, SOD, and CAT in diabetic rats. Glibenclamide 5 mg/kg/p.o. also enhanced diabetes-induced complications and decreased oxidative stress. Further histopathology of pancreas confirms the protective effect fustin in STZ-induction diabetes in animals. In conclusion, the study revealed treatments with fustin avoid the changes in body weight, blood glucose, lipid profile and oxidative stress. As a results of these finding may lead to the growth of a choice of medicine for hyperglycemic in the future.     

Modulating effect of Hesperidin on experimental murine colitis induced by dextran sulfate sodium

Hesperidin, a flavanone-type flavonoid, is abundant in citrus fruit and has a wide range of pharmacological effects. Here we investigated the effect of Hesperidin on dextran sulphate sodium (DSS)-induced experimental ulcerative colitis in mice. Sulfasalazine (positive control) and Hesperidin in doses of 10, 40 and 80 mg/kg were administered orally once a day for 7 days, beginning concurrently with exposure to DSS. The symptom of ulcerative colitis was evaluated by disease activity index (DAI) and the wet weight of colon. Myeloperoxidase (MPO) activity, malondialdehyde (MDA) content and the levels of interleukin-4 (IL-4) and interleukin-6 (IL-6) in serum were measured to observe the possible mechanisms. Oral administration of Hesperidin significantly decreased DAI, MPO activity, MDA content and the level of IL-6 in serum (p<0.01), while there was no significantly effect on the level of IL-4 in serum. These results demonstrate that Hesperidin can ameliorate DSS-induced experimental colitis, and may be useful in the prevention and treatment of colitis.     

Glycolysis activity in flight muscles of birds according to their physiological function. An experimental model in vitro to study aerobic and anaerobic glycolysis activity separately

Curcumin, an active ingredient of Curcumin longa mediates its anti-inflammatory effects through inhibition of NFkB. Several pathways including toll-like receptors (TLR) induce NFkB leading to inflammation. In this study, we investigated the effects of curcumin on the expression of TLR-4 and MyD88, the upstream signaling pathway in experimental colitis induced in the Sprague-Dawley male rats by intra-rectal administration of trinitrobenzenesulfonic acid (TNBS). The animals which received TNBS were divided into two groups: Group 1, received aqueous suspension of curcumin (100 mg/Kg body weight) 2 h prior to inducing colitis, and the treatment was repeated every day for 5 days, and Group 2 and non-colitis (Group 3) animals received phosphate buffered saline (PBS) in a similar fashion. Non-colitis animals (Group 4) received curcumin and served as controls. Animals were sacrificed on day 5 post-TNBS by cervical dislocation, colon was taken out, and cleaned with PBS. Levels of TLR-4, MyD88, and NFkB proteins were measured using ECL Western blot analysis, and TLR-4 mRNA by a competitive RT-PCR method. Colitis was confirmed histologically by measuring myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels in the colonic tissues. TNBS-induced increase in the level of MPO activity and MDA concentrations was reversed by curcumin treatment, whereas the same dose of curcumin did not affect their levels in the non-colitis animals. Increases in the levels of TLR-4, MyD88, and NFkB proteins in inflamed tissue were also suppressed significantly by curcumin treatment. The level of TLR-4 mRNA remained unchanged in the colitis animals. These findings demonstrate that signaling pathway of curcumin-induced inhibition of inflammation involves TLR-4 and MyD88, and therefore may serve as an important therapeutic target in IBD.     

Fucoidan Extracts Ameliorate Acute Colitis

Inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn’s disease, are an important cause of morbidity and impact significantly on quality of life. Overall, current treatments do not sustain a long-term clinical remission and are associated with adverse effects, which highlight the need for new treatment options. Fucoidans are complex sulphated, fucose-rich polysaccharides, found in edible brown algae and are described as having multiple bioactivities including potent anti-inflammatory effects. Therefore, the therapeutic potential of two different fucoidan preparations, fucoidan-polyphenol complex (Maritech Synergy) and depyrogenated fucoidan (DPF) was evaluated in the dextran sulphate sodium (DSS) mouse model of acute colitis. Mice were treated once daily over 7 days with fucoidans via oral (Synergy or DPF) or intraperitoneal administration (DPF). Signs and severity of colitis were monitored daily before colons and spleens were collected for macroscopic evaluation, cytokine measurements and histology. Orally administered Synergy and DPF, but not intraperitoneal DPF treatment, significantly ameliorated symptoms of colitis based on retention of body weight, as well as reduced diarrhoea and faecal blood loss, compared to the untreated colitis group. Colon and spleen weight in mice treated with oral fucoidan was also significantly lower, indicating reduced inflammation and oedema. Histological examination of untreated colitis mice confirmed a massive loss of crypt architecture and goblet cells, infiltration of immune cells and oedema, while all aspects of this pathology were alleviated by oral fucoidan. Importantly, in this model, the macroscopic changes induced by oral fucoidan correlated significantly with substantially decreased production of at least 15 pro-inflammatory cytokines by the colon tissue. Overall, oral fucoidan preparations significantly reduce the inflammatory pathology associated with DSS-induced colitis and could therefore represent a novel nutraceutical option for the management of IBD.     

Anthocyanin-containing purple potatoes ameliorate DSS-induced colitis in mice

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately three million people suffer from IBD in the United States alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study evaluated the antiinflammatory potential of purple-fleshed potato using a dextran sodium sulfate (DSS) murine model of colitis. Mice were randomly assigned to control (AIN-93G diet), P15 (15% purple-fleshed potato diet) and P25 (25% purple-fleshed potato diet) groups. Colitis was induced by 2% DSS administration in drinking water for six days. The results indicated that purple-fleshed potato supplementation suppressed the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weights. P15 and P25 diets suppressed the elevation in the intestinal permeability, colonic MPO activity, mRNA expression and protein levels of pro-inflammatory interleukins IL-6 and IL-17, the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae, Escherichia coli (E. coli) and pks⁺ E. coli, and the increased flagellin levels induced by DSS treatment. P25 alone suppressed the elevated systemic MPO levels in DSS-exposed mice, and elevated the relative abundance of Akkermansia muciniphila (A. muciniphila) as well as attenuated colonic mRNA expression level of IL-17 and the protein levels of IL-6 and IL-1β. Therefore, the purple-fleshed potato has the potential to aid in the amelioration of UC symptoms.     

Pediococcus pentosaceus LI05 alleviates DSS-induced colitis by modulating immunological profiles,the gut microbiota and short-chain fatty acid levels in a mouse model

The gut microbiota is considered a key factor in pathogenesis and progression of inflammatory bowel disease (IBD). The bacterium Pediococcus pentosaceus LI05 alleviated host inflammation by maintaining the gut epithelial integrity, modulating the host immunity, gut microbiota and metabolism, but its effect on IBD remains unclear. The present study aimed to investigate the role and mechanisms of P. pentosaceus LI05. Mice were administered P. pentosaceus LI05 or phosphate-buffered saline once daily by oral gavage for 14 days, and colitis was induced by providing mice 2% DSS-containing drinking water for 7 days. P. pentosaceus LI05 ameliorated colitis in mice and reduced the body weight loss, disease activity index (DAI) scores, colon length shortening, intestinal permeability and the proinflammatory cytokine levels. Furthermore, a significantly altered gut microbiota composition with increased diversity and short-chain fatty acid (SCFA) production was observed in mice treated with P. pentosaceus LI05. Several genera, including Akkermansia and Faecalibacterium, were differentially enriched in the P. pentosaceus LI05-treated mice and were negatively correlated with colitis indices and positively correlated with gut barrier markers and SCFA levels. The P. pentosaceus LI05 treatment alleviated intestinal inflammation by maintaining the intestinal epithelial integrity and modulating the immunological profiles, gut microbiome and metabolite composition. Based on our findings, P. pentosaceus LI05 might be applied as potential preparation to ameliorate colitis.     

A lactic acid bacterium isolated from kimchi ameliorates intestinal inflammation in DSS-induced colitis

Some species of lactic acid bacteria have been shown to be beneficial in inflammatory bowel disease (IBD). In the present study, a strain of lactic acid bacterium (Lactobacillus paracasei LS2) was isolated from the Korean food, kimchi, and was shown to inhibit the development of experimental colitis induced by dextran sulfate sodium (DSS). To investigate the role of LS2 in IBD, mice were fed DSS in drinking water for seven days along with LS2 bacteria which were administered intragastrically to some of the mice, while phosphate-buffered saline (PBS) was administered to others (the controls). The administration of LS2 reduced body weight loss and increased survival, and disease activity indexes (DAI) and histological scores indicated that the severity of colitis was significantly reduced. The production of inflammatory cytokines and myeloperoxidase (MPO) activity also decreased. Flow cytometry analysis showed that the number of Th1 (IFN-γ) population cells was significantly reduced in the LS2-administered mice compared with the controls. The administration of LS2 induced the increase of CD4⁺FOXP3⁺ Treg cells, which are responsible for IL-10. Numbers of macrophages (CD11b⁺ F4/80⁺), and neutrophils (CD11b⁺ Gr-1⁺) among lamina propria lymphocytes (LPL) were also reduced. These results indicate that LS2 has an anti-inflammatory effect and ameliorates DSS-induced colitis.