Lactobacillus fermentum, a probiotic capable to release glutathione, prevents colonic inflammation in the TNBS model of rat colitis

Background and aims Inflammatory bowel disease is associated with intestinal oxidative stress. In the present study we test the preventative effect of Lactobacillus fermentum, a probiotic that produces per se glutathione, in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis.Methods Colitis was induced in rats by intracolonic administration of 10 mg of TNBS dissolved in 0.25 ml of 50% ethanol. L. fermentum was administered orally (5×10⁸ CFU suspended in 0.5 ml of skim milk) to a group of rats for 3 weeks, starting 2 weeks before colitis induction. Colonic damage was evaluated both histologically and biochemically, and the colonic luminal contents were used for bacterial studies as well as for short chain fatty acid (SCFA) production.Results L. fermentum treatment resulted in an amelioration of the inflammatory response in colitic rats as evidenced histologically and by a significant reduction of colonic MPO activity (P<0.05). The probiotic partially counteracted the colonic glutathione depletion induced by the inflammatory process. In addition, probiotic-treated colitic rats showed significant lower colonic tumour necrosis factor (TNF)α levels (P<0.01) and inducible nitric oxide synthase (iNOS) expression when compared to non-treated rats. Finally, the probiotic induced growth of Lactobacilli species and production of SCFA in colonic contents in comparison with control colitic rats.Conclusion Administration of the probiotic L. fermentum facilitates the recovery of the inflamed tissue in the TNBS model of rat colitis, an effect associated with increased levels of glutathione as well as with amelioration of the production of some of the mediators involved in the inflammatory response of the intestine, such as TNFα and NO.     

Preventative effects of lactulose in the trinitrobenzenesulphonic acid model of rat colitis

AIMS: Lactulose is a drug used as a laxative that has been shown to promote the growth of lactobacilli and bifidobacteria, acting as a prebiotic and with a potential beneficial effect in inflammatory bowel disease. The present study describes the preventive antiinflammatory activity of lactulose in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. METHODS: Rats were rendered colitic by a colonic instillation of 10 mg of TNBS dissolved in 0.25 mL of 50% ethanol. One group of colitic rats received lactulose, which was incorporated in the drinking water (2.5% wt/vol) for 2 weeks before TNBS instillation, and colonic damage was evaluated 1 week after colitis induction. Different biochemical markers of colonic inflammation were assayed: myeloperoxidase activity, glutathione content, tumor necrosis factor alpha, leukotriene B4 levels, and colonic inducible nitric oxide synthase expression. In addition, bacterial counts (for lactobacilli and bifidobacteria) were performed in colonic contents from colitic rats. RESULTS: The results show that lactulose exerted a preventive antiinflammatory effect in this model of rat colitis, as evidenced by a significant reduction of myeloperoxidase activity and by a decrease of both colonic tumor necrosis factor alpha and leukotriene B4 production. This effect was also characterized by an inhibition of colonic inducible nitric oxide synthase expression, which is unregulated as a consequence of the inflammatory status. This beneficial effect was associated with increased levels of lactobacilli and bifidobacteria species in colonic contents in comparison with untreated colitic rats. CONCLUSION: In conclusion, the intestinal antiinflammatory effect of lactulose could be related to its prebiotic properties, supporting its potential use in human inflammatory bowel disease.     

Expression and significance of nuclear factor κB p65 in colon tissues of rats with TNBS-induced colitis

AIM: To investigate the role of NF-κB in the pathogenesis of TNBS-induced colitis in rats. METHODS: Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups of eight each: normal, NS, model Ⅰ, model Ⅱ groups in our study. Rat colitis model was established through 2-,4-,6-trinitrobenzene sulfonic acid (TNBS) enema. At the end of four weeks, the macroscopical and histological changes of the colon were examined and mucosa myeloperoxidase (MPO)activities assayed. NF-~B p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-α (and ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κB p65 and other parameters were analyzed. RESULTS: TNBS enema resulted in pronounced pathological changes of colonic mucosa in model Ⅱ group (macroscopic and histological injury indices 6.25&#177;1.39 and 6.24&#177;1.04, respectively), which were in accordance with the significantly elevated MPO activity (1.69+0.11). And the nuclear level of NF-κB and expression of TNF-α, ICAM-1 in rats of model Ⅱ group were higher than that of normal control(9.7&#177;1.96 vs 1.7&#177;0.15, 84.09&#177;14.52 vs 16.03&#177;6.21,77.69&#177;8.09 vs 13.41&#177;4.91 P&lt;0.01), Linear correlation analysis revealed that there were strong correlations between the nuclear level of NF-κB and the tissue positive expression of TNF-α and ICAM-1, MPO activities, macroscopical and histological indices in TNBS-induced colitis, respectively (r = 0.8235, 0.8780, 0.8572, 0.9152,0.8247; P&lt;0.05). CONCLUSION: NF-κB plays a pivotal role in the pathogenesis of ulcerative colitis, which might account for the up-regulation the expression of TNF-α and ICAM-1.     

Cyclooxygenase-2 inhibition and experimental colitis: beneficial effects of phosphorothioated antisense oligonucleotide and meloxicam

BACKGROUND: The effects of cyclooxygenase-2 (cox-2) inhibition by a cox-2 selective antisense phosphorothioated oligonucleotide (AS) and meloxicam were examined in experimental colitis. METHODS: Colitis was induced by trinitrobenzenesulphonic acid (TNBS) and acetic acid (Hac) separately in male Sprague-Dawley rats. Both groups of animals were treated daily intraperitoneally with AS and a mismatched control oligo (CO) (3 mg/kg), and orally with meloxicam (7.5 mg/kg) 1 h before induction of colitis. The animals were killed on day 4 (Hac) and on day 5 (TNBS). Tissue samples from colon, ileum, liver, kidney and spleen were collected for mRNA, myeloperoxidase activity (MPO), prostaglandin E2 (PGE2) estimation and for histology, and blood samples for PGE2, thromboxane B2 (TxB2) and TNF-alpha. RESULTS: Both TNBS and Hac increased colonic MPO activity, PGE2 concentrations and infiltration of colonic wall by inflammatory cells. Serum levels of TNF-alpha were increased in both models, whereas PGE2 was increased only in TNBS colitis. Only meloxicam suppressed the level of PGE2 significantly below the basal level. The animals in both models also showed splenomegaly. The colitis-induced changes were significantly suppressed by the treatment of the test compounds but not by the CO. Cox-2 mRNA but not cox-1 was decreased by the AS, but not by meloxicam or in CO-treated colitic animals. CONCLUSION: The findings demonstrate comparable beneficial effects of the cox-2 selective antisense oligonucleotide and meloxicam, which seem to be mediated by a combined inhibition of both PGE2 and TNF-alpha in the present models of colitis.     

Nitric oxide released by Lactobacillus farciminis improves TNBS-induced colitis in rats

BACKGROUND: Beneficial effects of lactobacilli have been reported in experimental colitis. On the other hand, despite the controversial role of nitric oxide (NO) in the inflammatory gut process, a protective action of exogenous NO in inflammation has been suggested. Consequently, this study aimed to determine the effect of (i) sodium nitroprusside (SNP), a NO donor and (ii) treatment with Lactobacillus farciminis, which produces NO in vitro, on trinitrobenzene sulphonic acid (TNBS)-induced colitis in rats and to evaluate the role of exogenous NO in this effect. METHODS: Rats were divided into three groups receiving one of the following: (i) a continuous intracolonic (IC) infusion of SNP for 4 days, (ii) L. farciminis orally for 19 days, or (iii) saline. On day 1 and day 15, respectively, TNBS and saline were administrated IC, followed by a continuous IC infusion of saline or haemoglobin, a NO scavenger. At the end of treatments, the following parameters were evaluated: macroscopic damage of colonic mucosa, myeloperoxidase and nitric oxide synthase activities and colonic luminal NO production. RESULTS: In colitic rats, SNP and L. farciminis treatment significantly (P < 0.05) reduced macroscopic damage scores, myeloperoxidase and nitric oxide synthase activities compared to controls. Haemoglobin infusion abolished the anti-inflammatory effect of both NO donor treatments, but had no effect per se on colitis. CONCLUSION: NO released intraluminally by SNP infusion or by L. farciminis given orally improves TNBS-induced colitis in rats. These results indicate a protective role of NO donation in colonic inflammation and show for the first time a mechanism involving NO delivery by a bacterial strain reducing an experimental colitis.     

Protective effect of angelica sinensis polysaccharide on experimental immunological colon injury in rats

AIM: To study the effect of angelica sinensis polysaccharide (ASP) on immunological colon injury and its mechanisms in rats.METHODS: Immunological colitis model of rats was induced by intracolon enema with 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) and ethanol. The experimental animals were randomly divided into normal control, model control, 5-aminosalicylic acid therapy groups and three doses of ASP therapy groups. The 6 groups were treated intracolonically with normal saline, normal saline, 5-aminosalicylic acid (100 mg.kg-1), and ASP daily (8:00 am) at the doses of 200, 400 and 800 mg.kg-1 respectively for 21 days 7 d following induction of colitis. The rat colon mucosa damage index (CMDI), the histopathological score (HS), the score of occult blood test (OBT), and the colonic MPO activity were evaluated. The levels of SOD, MDA, NO, TNF-α, IL-2 and IL-10 in colonic tissues were detected biochemically and immunoradiometrically. The expressions of TGF-β and EGF in colonic tissues were also determined immunochemically.RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in colitis rats,which manifested as significant increases of CMDI, HS, OBT,MPO activity, MDA and NO contents, as well as the levels of TNF-α and IL-2 in colonic tissues, although colonic TGF-β protein expression, SOD activity and TL-10 content were significantly decreased compared with the normal control (P＜0.01). However, these parameters were found to be significantly ameliorated in colitis rats treated intracolicly with ASP at the doses of 400 and 800 mg@kg-1 (P＜0.05-0.01).Meantime, colonic EGF protein expression in colitis rats was remarkably up-regulated.CONCLUSION: ASP has a protective effect on immunological colon injury induced by TNBS and ethanol enema in rats,which was propably due to the mechanism of antioxidation,immunomodulation and promotion of wound repair.     

Effects of melatonin on the expression of iNOS and COX－2 in rat models of colitis

AIM: To investigate the effects of melatonin (MT) on the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in rat models of colitis. METHODS: Healthy adult Sprague-Dawlay (SD) rats of both sexes, weighing 280+/-30 g, were employed in the present study. The rat models of colitis were induced by either acetic acid or 2,4,6-trinitrobenzene sulfonic acid (TNBS) enemas. The experimental animals were randomly divided into melatonin treatment and model control group that were intracolicly treated daily with melatonin at doses of 2.5, 5.0, 10.0 mg/kg(-1) and equal amount of saline respectively from 24 h following induction of colitis in rats inflicted with acetic acid enema and the seventh day in rats with TNBS to the end of study. A normal control group of rats treated with neither acetic acid nor TNBS but saline enema was also included in the study. On the 28(th) day of the experiment, the rat colon mucosal damage index (CDMI) was calculated, and the colonic prostaglandin E(2) (PGE(2)), nitric oxide (NO), as well as the iNOS and COX-2 expression were also determined biochemically or immunohistochemically. RESULTS: CDMI increased to 2.87+/-0.64 and 3.12+/-1.12 respectively in rats treated with acetic acid and TNBS enema, which was in accordance with the significantly elevated colonic NO and PGE(2) contents, as well as the up-regulated colonic iNOS and COX-2 expression in both of the two rat models of colitis. With treatment by melatonin at the doses of 5.0 and 10.0 mg/kg(-1), CDMI in both models of rat colitis was significantly decreased (P<0.05-0.01), which accorded synchronously and unanimously with the reduced colonic NO and PGE(2) content, as well as the down-regulated expression of colonic iNOS and COX-2. CONCLUSION: Melatonin has a protective effect on colonic injury induced by both acetic acid and TNBS enemas, which is probably via a mechanism of local inhibition of iNOS and COX-2 expression in colonic mucosa.     

Favorable response to subcutaneous administration of infliximab in rats with experimental colitis

AIM: To investigate the influence of infliximab (Remicade) on experimental colitis produced by 2,4,6,trinitrobenzene sulfonic acid (TNBS) in rats. METHODS: Thirty-six Wistar rats were allocated into four groups (three groups of six animals each and a fourth of 12 animals). Six more healthy animals served as normal controls (Group 5). Group 1: colitis was induced by intracolonic installation of 25 mg of TNBS dissolved in 0.25 mL of 50% ethanol and infliximab was subcutaneously administered at a dose of 5 mg/kg BW; Group 2: colitis was induced and infliximab was subcutaneously administered at a dose of 10 mg/kg BW; Group 3: colitis was induced and infliximab was subcutaneously administered at a dose of 15 mg/kg BW; Group 4: colitis was induced without treatment with infliximab. Infliximab was administered on d 2-6. On the 7~(th) d, all animals were killed. The colon was fixed in 10% buffered formalin and examined by light microscopy for the presence and activity of colitis and the extent of tissue damage. Tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were also measured. RESULTS: Significant differences concerning the presence of reparable lesions and the extent of bowel mucosa without active inflammation in all groups of animals treated with infliximab compared with controls were found. Significant reduction of the tissue levels of TNF-α in all groups of treated animals as compared with the untreated ones was found (0.47±0.44, 1.09±0.86, 0.43±0.31 vs 18.73±10.53 respectively). Significant reduction in the tissue levels of MDA was noticed in group 1 as compared to group 4, as well as between groups 2 and 4. CONCLUSION: Subcutaneous administration of infliximab reduces the inflammatory activity as well as tissue TNF-α and MDA levels in chemical colitis in rats. Infliximab at a dose of 5 mg/kg BW achieves better histological results and produces higher reduction of the levels of TNF-α than at a dose of 10 mg/kg BW. Infliximab at a dose of 5 mg/kg BW produces higher reduction of tissue MDA levels than at a dose of 15 mg/ kg BW.     

Probiotic therapy fails to improve gut permeability in a hapten model of colitis

BACKGROUND: Studies in clinical and experimental inflammatory bowel disease (IBD) have shown disturbances in intestinal bacterial flora with an increase in potentially pathogenic and a decrease in protective organisms. It was hypothesized that Lactobacillus plantarum species 299 (LP299), a probiotic, would ameliorate colitis and improve intestinal permeability in experimental colitis. This study investigated the effect of LP299 in the trinitrobenzenesulfonic acid/ethanol (TNBS/E) rat model of colitis. METHODS: Twelve week old male Wistar rats were randomized to receive rectal instillates of either TNBS/E (n = 48) or saline (n = 16). For the next 7 days the animals were gavaged with 2.5 ml of oat fibre suspension containing 10(9) colony forming units (CFU) of LP299 (LP299/OF), oat fibre suspension alone (OF) or no treatment. At the end of the experiment rats received radiolabelled polyethylene glycol and urine was collected for 24 h to assess permeability. Animals were then anaesthetized and colons were harvested for colon macroscopic scoring (CMS). RESULTS: TNBS/E per rectum resulted in a greater CMS (P < 0.001) and gut permeability (P = 0.006) than saline. Administration of LP299/OF or oat fibre alone did not result in a reduction in CMS or gut permeability when compared to colitic controls. CONCLUSIONS: LP299/OF, when administered after TNBS instillation, does not reduce the severity of colitis or improve gut permeability in this hapten model of colitis.     

Nitric oxide released by lactobacillus farciminis improvesTNBS‐induced colitis in rats

Background: Beneficial effects of lactobacilli have been reported in experimental colitis. On the other hand, despite the controversial role of nitric oxide (NO) in the inflammatory gut process, a protective action of exogenous NO in inflammation has been suggested. Consequently, this study aimed to determine the effect of (i) sodium nitroprusside (SNP), a NO donor and (ii) treatment with Lactobacillus farciminis, which produces NO in vitro, on trinitrobenzene sulphonic acid (TNBS)‐induced colitis in rats and to evaluate the role of exogenous NO in this effect. Methods: Rats were divided into three groups receiving one of the following: (i) a continuous intracolonic (IC) infusion of SNP for 4 days, (ii) L. farciminis orally for 19 days, or (iii) saline. On day 1 and day 15, respectively, TNBS and saline were administrated IC, followed by a continuous IC infusion of saline or haemoglobin, a NO scavenger. At the end of treatments, the following parameters were evaluated: macroscopic damage of colonic mucosa, myeloperoxidase and nitric oxide synthase activities and colonic luminal NO production. Results: In colitic rats, SNP and L. farciminis treatment significantly (P?Conclusion: NO released intraluminally by SNP infusion or by L. farciminis given orally improves TNBS‐induced colitis in rats. These results indicate a protective role of NO donation in colonic inflammation and show for the first time a mechanism involving NO delivery by a bacterial strain reducing an experimental colitis.     

The role of mast cells in the development of 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in rats

BACKGROUND: The role of mast cells in Crohn disease (CD) remains to be established. The aim of this study was to elucidate this in the development of CD-like colitis in rats by the use of mast-cell-deficient Ws/Ws and their control W+/W+ rats. METHODS: CD-like colitis was induced in both groups by an enema of 10 mg of 2,4, 6-trinitrobenzene sulfonic acid (TNBS) in 50% ethanol. Colonic damage, adhesion and colonic weight were measured at 7 and 14 days after the TNBS/ethanol enema. Rat mast cell protease-2 (RMCP-2) in the colonic tissue was also measured at 7 days after the enema. RESULTS: There was no significant difference between W+/W+ and Ws/Ws rats in terms of colonic damage, adhesion or colonic weight. The tissue content of RMCP-2 in Ws/Ws rats treated with either saline or TNBS/ethanol was only maintained at a much lower level than that in W+/W+ rats with the corresponding treatment. CONCLUSIONS: These results demonstrate that mast cells are not essential in the development of 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in rats.     

Therapeutic effect of sodium alginate in experimental chronic ulcerative colitis

The aim of this study was to test the therapeutic efficacy of sodium alginate in a rat model of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease. This experiment was carried out using 77 Sprague-Dawley rats which were divided into six groups; normal, control, prophylactic, therapeutic and two experimental groups. Rats were sacrificed 1, 2, 3 and 6 weeks after colitis induction. Severity of colitis was graded macroscopically and assessed using serum and colonic mucosal cytokines and eicosanoids. Intrarectal TNBS (30 mg) produced a significant chronic ulcerative colitis. The lesions were most severe on day seven after TNBS instillation, and then declined, but lesions were still observed after six weeks. TNBS administration also significantly enhanced the serum and colonic mucosal cytokines (TNF-alpha and IL-6) and eicosanoids (LTB4 and PGE2) levels, which paralleled with the severity of colitis. Low viscosity sodium alginate (LVA) solution as therapeutic agent was administered orally as drinking water at concentration of 0.5% (W/V) for six weeks. Results showed that pre-treatment (in prophylactic group) and treatment with LVA were significantly able to reduce colonic damage score, serum level and colonic mucosal production of TNF-alpha, IL-6, LTB4 and PGE2 in pre-treated and treated animals compared with non-treated controls. LVA therapy is able to suppress chronic ulcerative colitis in experimental model.     

The intestinal anti-inflammatory activity of UR-12746S on reactivated experimental colitis is mediated through downregulation of cytokine production

BACKGROUND: UR-12746S (dersalazine sodium) is cleaved by colonic bacteria delivering the PAF antagonist UR-12715 and 5-ASA. This study describes the anti-inflammatory activity of UR-12746S in an experimental model of reactivated colitis and its effects on cytokine production. METHODS: Rats were initially rendered colitic by a colonic instillation of 10 mg of trinitrobenzenesulphonic acid (TNBS) dissolved in 0.25 ml of 50 % ethanol, and colitis was reactivated two weeks after by a second administration of the same dose of TNBS. Two groups of colitic rats received UR-12746S (25 and 50 mg/kg daily, p.o.) and colonic damage was evaluated every week for 4 weeks. Different biochemical markers of colonic inflammation were assayed: MPO activity and cytokine (IL-1beta and TNFalpha) levels. Also, the in vitro effects of UR-12715 and 5-ASA on cytokine production were assayed. RESULTS: UR-12746S showed anti-inflammatory effect in reactivated colitis in rats, as evidenced by a significant reduction in MPO activity. Both doses of UR-12746S decreased IL-1beta production, while only the highest dose assayed inhibited TNFalpha production. In vitro studies revealed that UR-12715 or 5-ASA (from 10(-6) to 10(-4) M) inhibited IL-8 production (30-40%) in HT-29 cells when incubated with LPS. This inhibitory effect was enhanced when both compounds were administered simultaneously at 10(-4) M. In addition, UR-12715 inhibited IL-1beta or TNFalpha production in THP-1 or U937 cells, respectively, when these cells were stimulated by PMA and LPS; whereas 5-ASA only showed a weak effect in inhibiting IL-1beta production. CONCLUSION: UR-12746S was able to prevent relapse in experimental colitis and inhibition of proinflammatory cytokine production participates in the intestinal anti-inflammatory activity exerted by this compound.     

The Role of Mast Cells in the Development of 2, 4, 6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Rats

Background: The role of mast cells in Crohn disease (CD) remains to be established. The aim of this study was to elucidate this in the development of CD-like colitis in rats by the use of mast-cell-deficient Ws/Ws and their control W+/W+ rats. Methods: CD-like colitis was induced in both groups by an enema of 10 mg of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) in 50% ethanol. Colonic damage, adhesion and colonic weight were measured at 7 and 14 days after the TNBS/ethanol enema. Rat mast cell protease-2 (RMCP-2) in the colonic tissue was also measured at 7 days after the enema. Results: There was no significant difference between W+/W+ and Ws/Ws rats in terms of colonic damage, adhesion or colonic weight. The tissue content of RMCP-2 in Ws/Ws rats treated with either saline or TNBS/ethanol was only maintained at a much lower level than that in W+/W+ rats with the corresponding treatment. Conclusions: These results demonstrate that mast cells are not essential in the development of 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in rats.     

Variable response to probiotics in two models of experimental colitis in rats

BACKGROUND AND AIM: Clinical and experimental data suggest an important role for intestinal microflora in the pathogenesis of inflammatory bowel disease, and probiotics have been shown to ameliorate pouchitis. We evaluated the effect of different preparations of probiotic bacteria on experimental colitis in rats. METHODS: Rats were treated daily intragastrically with two probiotic preparations, VSL#3 or strain GG (LGG), 7 days before induction of colitis and for another week thereafter. Colitis was induced by intracolonic administration of either dinitrobenzene sulfonic acid (DNBS) or iodoacetamide. Rats were killed 7 days after induction of colitis, the colon isolated, washed, weighed, lesion area measured, and mucosa processed for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and prostaglandin E2 (PGE2) generation. RESULTS: In rats cotreated with VSL#3 or LGG and iodoacetamide, there was a significant decrease in the lesion area, 98 +/- 37 mm and 142 +/- 43 mm, respectively, as compared with 342 +/- 66 mm in the control group. Colonic wet weight significantly decreased to 1.3 +/- 0.1 g/10 cm and 1.4 +/- 0.1 g/10 cm, respectively, as compared with 1.7 +/- 0.1 g/10 cm. There was also a significant decrease in PGE2 generation, MPO, and NOS activities in the VSL#3 and LGG treatment groups. Presence of VSL#3 bacteria in the rat's colon was confirmed by culture and polymerase chain reaction (PCR) amplification. Neither probiotic preparation had an effect on the extent of colonic damage in DNBS-induced colitis. CONCLUSION: Both VSL#3 and LGG significantly ameliorated colitis induced by the sulfhydryl-blocker iodoacetamide, but had no effect on the immune-mediated DNBS-induced colitis. The results suggest a possible role for sulfhydryl compounds in the protective effect of probiotic bacteria, and support their use in patients with inflammatory bowel disease.     

Ameliorative effects of bombesin and neurotensin on trinitrobenzene sulphonic acid-induced colitis, oxidative damage and apoptosis in rats

AIM： TO investigate the effects of bombesin （BBS） and neurotensin （NTS） on apoptosis and colitis in an ulcerative colitis model.
METHODS： In this study, a total of 50 rats were divided equally into 5 groups. In the control group, no colitis induction or drug administration was performed. Colitis was induced in all other groups. Following the induction of colitis, BBS, NTS or both were applied to three groups of rats. The remaining group （colitis group） received no treatment. On the 11th d after induction of colitis and drug treatment, blood samples were collected for TNF-α and IL-6 level studies. Malondialdehyde （MDA）, carbonyl, myeloperoxidase （MPO） and caspase-3 activities, as well as histopathological findings, evaluated in colonic tissues.
RESULTS： According to the macroscopic and microscopic findings, the study groups treated with BBS, NTS and BBS ＋ NTS showed significantly lower damage and inflammation compared with the colitis group （macroscopic score, 2.1 ± 0.87, 3.7 ± 0.94 and 2.1 ± 0.87 vs 7.3 ± 0.94; microscopic score, 2.0 ± 0.66, 3.3 ± 0.82 and 1.8 ± 0.63 vs 5.2 ± 0.78, P 〈 0.01）. TNF-α and IL-6 levels were increased significantly in all groups
compared with the control group. These increases were significantly smaller in the BBS, NTS and BBS ＋ NTS groups compared with the colitis group （TNF-α levels, 169.69 ± 53.56, 245.86 ± 64.85 and 175.54 ± 42.19 vs 556.44 ± 49.82; IL-6 levels, 443.30 ± 53.99, 612.80 ± 70.39 and 396.80 ± 78.43 vs 1505.90 ± 222.23, P 〈 0.05）. The colonic MPO and MDA levels were significantly lower in control, BBS, NTS and BBS ＋ NTS groups than in the colitis group （MPO levels, 24.36 ± 8.10, 40.51 ± 8.67 and 25.83 ± 6.43 vs 161.47 ± 38.24; MDA levels, 4.70 ± 1.41, 6.55 ± 1.12 and 4.51 ± 0.54 vs 15.60 ± 1.88, P 〈 0.05）. Carbonyl content and caspase-3 levels were higher in the colitis and NTS groups than in control, BBS and BBS ＋ NTS groups （carbonyl levels, 553.99 ± 59.58 and 336.26 ± 35.72 vs 209.7     

Adrenal cortical activation in murine colitis

BACKGROUND & AIMS: Proper adrenal glucocorticoid secretion is crucial in the course of inflammatory diseases. However, the function and structure of the adrenal glands have not been examined in inflammatory bowel diseases. METHODS: After induction of trinitrobenzene sulfonic acid (TNBS) colitis in SJL/J mice, plasma hormone and cytokine levels were measured, adrenal structure was analyzed by immunohistochemistry and electron microscopy, and adrenal cytokine/cytokine receptor expression were studied by RNase protection. RESULTS: Adrenals of colitic animals were enlarged and hypervascularized. These animals had a marked increase in plasma corticosterone levels during the course of colitis (270 +/- 34 vs. 16 +/- 11 ng/mL; P < 0.0001) but only a modest elevation of their concurrent adrenocorticotropin levels (57 +/- 13 vs. 29 +/- 9 pmol/L; NS). On electron microscopy, adrenocortical cells showed ultrastructural signs of marked stimulation, and intra-adrenal lymphocytes were frequently found in direct contact with these cells. Concurrent plasma levels of interleukin (IL)-6, the major cytokine activating the hypothalamic-pituitary-adrenal axis, were markedly increased (495 +/- 131 vs. 20 +/- 1.5 pg/mL; P < 0.0001), and this cytokine directly stimulated corticosterone secretion by adrenocortical cells in vitro. Intra-adrenal expression of IL-6 in animals with colitis was increased 80-fold, and the IL-6 receptor subunits IL-6R alpha and gp130 were present in the adrenal cells. Treatment of animals with neutralizing anti-IL-6 antibody reduced the TNBS-induced growth and activation of the adrenal cortices. CONCLUSIONS: Colitis is associated with a profound stimulation of adrenocortical cell function and glucocorticoid release. Direct immune-adrenal interactions seem to contribute to this activation of the adrenal glands during colitis.     

Effect of traditional Chinese medicinal enemas on ulcerative colitis of rats

AIM: To investigate the effects of traditional Chine semedicinal enema (TCME) on inflammatory and immune response of colonic mucosa of rats with ulcerative colitis(UC), and to observe the pathogenic mechanism.METHODS: Thirty UC rats, induced by intestinal enema together with 2.4-dinitrochlorobenzene (DNCB) and acetic acid, were randomly divided into 3 groups, i.e., GⅠ, GⅡ and GⅢ. Groups GⅠ and GⅡ were administered with TCME and salazosulfapyridine enema (SASPE), respectively. Group GⅢ was clystered with only normal saline (NSE), served as control. Group GIV was taken from normal rats as reference,once daily, from the 7th day after the establishment of UC for total 28 d. Interleukin-6 (IL-6) in the colonic mucosa was assayed by ^3H-TdR incorporation assay. Colonic mucosal lymphocyte subpopulation adhesive molecules, CD4^+CD11a^+,CD4^+CD18^+, CDs^+CD11a^+, CDs^+CD18^+ (LSAM), tumor necrosis factor (TNF)-α, and interferon-γ (IFN-γ), were detected by enzyme linked immunosorbent assay (ELISA). Moreover, the expression of TNF-α mRNA and IFN-γ mRNA in colonicmuc osa were detected by polymerase chain reaction (RT-PCR).RESULTS: Before therapies, in model groups, GⅠ, GⅡ and GⅢ,levels of IL-6, TNF-α, IFN-γ, CDs^+CD11a^+ and CD8^+CD18^+ were significantly different (38.29+2.61 U/mL, 16.54+1.23 ng/L,8.61+0.89 ng/L, 13.51+2.31% and 12.22+1.13% ,respectively) compared to those in GIV group (31.56+2.47 U/mL, 12.81+1.38 ng/L, 5.28+0.56 ng/L, 16.68+1.41% and 16.79+1.11%, respectively). After therapeutic enemas,in GI group, the contents of IL-6 (32.48&#177;2.53 U/m), TNF-α(13.42&#177;1.57 ng/L) and IFN-γ (5.87+0.84 ng/L) were reduced; then, the contents of CD8^+CD11a^+ (16.01+1.05 %)and CD8^+CD18^+ (16.28&#177;0.19%) were raised. There was no significant difference between groups GⅠ and GIV, but the difference between groups GⅠ and GⅡ was quite obvious (P&lt;0.05). The expressions of TNF-α mRNA and IFN-γ mRNAin group GⅢ were much higher than those of group GIV,but those in group GI were significantly suppressed by TCME therapy.CONCLUSION: Ulcerative colitis is related to colonic regional mucosal inflammatory factors and immune imbalance. TCME can effectively inhibit regional mucosal inflammatory factors and improve their disorder of immunity.