Ameliorative effects of sodium ferulate on experimental colitis and their mechanisms in rats

AIM: To investigate the ameliorative effects of sodium ferulate (SF) on acetic acid-induced colitis and their mechanisms in rats.METHODS: The colitis model of Sprague-Dawley rats was induced by intracolon enema with 8 % (WV) of acetic acid.The experimental animals were randomly divided into model control, 5-aminosalicylic acid therapy group and three dose of SF therapy groups. The 5 groups were treated intracolonically and daily (8:00 am) for 7 days 24 h following the induction of colitis. A normal control group of rats clystered with normal saline instead of acetic acid was also included in the study.Pathological changes of the colonic mucosa were evaluated by the colon mucosa damage index (CMDI) and the histopathological score (HS). The insulted colonic mucosa was sampled for a variety of determinations at the end of experiment when the animals were sacrificed by decapitation.Colonic activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), and levels of malondialdehyde (MDA)and nitric oxide (NO) were assayed with ultraviolet spectrophotometry. Colonic contents of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2)were determined by radioimmunoassay. The expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry.RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with acetic acid, which manifested as the significant increase of CMDI, HS, MPO activities, MDA and NO levels,PGE2 and TXB2 contents, as well as the expressions of iNOS,COX-2 and NF-κB p65 proteins in the colonic mucosa,although the colonic SOD activity was significantly decreased compared with the normal control (CMDI: 2.9±0.6 vs0.0±0.0;HS: 4.3±0.9 vs0.7±1.1; MPO: 98.1±26.9 vs24.8±11.5; MDA:57.53±12.36 vs9.21±3.85; NO: 0.331±0.092 vs0.176±0.045;PGE2: 186.2±96.2 vs 42.8±32.8; TXB2: 34.26±13.51 vs 8.83±3.75; iNOS: 0.365±0.026 vs0.053±0.015; COX-2:0.296±0.028 vs0.034±0.013; NF-κB p65:0.314±0.026 vs 0.039±0.012; SOD: 28.33±1.17 vs36.14±1.91; P<0.01).However, these parameters were found to be significantly ameliorated in rats treated locally with SF at the given dose (CMDI: 1.8±0.8, 1.6±0.9; HS: 3.3±0.9, 3.1±1.0; MPO:63.8±30.5, 36.2±14.2; MDA: 41.84±10.62, 37.34±8.58; NO:0.247±0.042; 0.216±0.033; PGE2: 77.2±26.9, 58.4±23.9;TXB2:18.07±14.83; 15.52±8.62; iNOS:0.175±0.018, 0.106±0.019;COX-2: 0.064±0.018, 0.056±0.014; NF-κBp65: 0.215±0.019,0.189±0.016; SOD: 32.15±4.26, 33.24±3.69; P<0.05-0.01).amelioration of colonic mucosal injury as evaluated by CMDI and HS.CONCLUSION: Administration of SF intracolonically may have significant therapeutic effects on the rat model of colitis induced by acetic acid enema, which was probably due to the mechanism of antioxidation, inhibition of arachidonic acid metabolism and NF-κB expression.     

微生态制剂对实验性大鼠结肠炎的治疗

目的 评价微生态制剂双歧三联活菌对三硝基苯磺酸钠(TNBS)诱导的大鼠结肠炎的疗效,探索炎症性肠病(IBD)治疗的新方法.方法 成年雌性SD大鼠50只,随机分为对照组(G1)、模型组(G2)、双歧三联活菌治疗组(G3)、奥沙拉秦治疗组(G4)、双歧三联活菌和奥沙拉秦联合治疗组(G5),每组10只.ELISA法检测各组的血清C反应蛋白(CRP)、TNFα、IL-10水平,分光光度法检测肠组织髓过氧化物酶(MPO)活力,并对肠组织进行病理组织学分析.结果 治疗后,G1组肠组织结构正常,血清CRP、TNFα、IL-10水平、结肠黏膜损伤指数(CMDI)及肠组织MPO活力显著低于G2组(P<0.001);G2组肠组织炎症程度最莺,血清CRP、TNFα、IL-10水平、CMDI及肠组织MPO活力最高,P<0.05;3个治疗组G3、G4、G5组的肠组织炎症呈不同程度消散,血清CRP、TNFα、IL-10水平及肠组织MPO活力呈不同程度下降,以G5组最显著,P<0.05;G2组血清CRP、TNFα、IL-10及肠组织MPO活力均分别与CMDI呈正相关,P<0.001.结论 双歧三联活菌能有效改善TNBS诱导的大鼠结肠炎,其机制可能与调节细胞因子水平有关.     

开口箭提取物对大鼠实验性结肠炎的治疗机制研究

目的研究中药开口箭有效成分对大鼠实验性结肠炎的治疗作用及其机制。方法建立三硝基苯磺酸大鼠结肠炎模型,用开口箭醇提物（主要成分为甾体皂苷）灌肠治疗2周,计算治疗前后结肠黏膜损伤指数（CMDI）和组织学评分（HS）,测定其结肠组织超氧化物歧化酶（SOD）活性、中性粒细胞髓过氧化物酶（MPO）、丙二醛（MDA）、血小板表面P-选择素（P-选择素）以及血小板最大聚集率（PagT）改变。结果治疗后大鼠CMDI及HS降低,MDA降低,MPO活性下降,PagT和P-选择素计数下降,SOD活性增加。结论开口箭醇提物对大鼠实验性结肠炎有治疗作用,其机制可能为清除氧自由基、减轻脂质过氧化物对组织的损伤以及抑制血小板的聚集与活化,减少炎性因子的释放。     

Establishment of a trinitrobenzene sulfonic acid‐induced rat colitis model

OBJECTIVE : To set up a trinitrobenzene sulfonic acid (TNBS)‐induced colitis model in the rat and to assess its value in research studies of inflammatory bowel disease (IBD). METHODS : A 0.85‐mL enema containing 30 mg TNBS dissolved in 50% ethanol was instilled into the rat colon to induce distal colitis. Control rats were instilled with 50% ethanol or TNBS/saline alone. Macroscopic histological changes of the colon and myeloperoxidase (MPO) activity of the mucosa were evaluated. RESULTS : One week after the TNBS/ethanol enema, hyperemia, edema and ulceration of the colonic mucosa appeared with predominant infiltration of polymorphonuclear leukocytes in the distal colon. Four weeks after TNBS/ethanol enema, ulcers had healed macroscopically and lymphocytes and plasma cells became predominant. The tissue MPO activity increased on the first day after the TNBS/ethanol enema and this increase in MPO activity lasted for 3 weeks, but declined 4 weeks after the TNBS/ethanol enema. In contrast, macroscopic, histological changes and MPO activity returned to normal levels in control rats within the first week. CONCLUSIONS : Trinitrobenzene sulfonic acid/ ethanol‐induced rat distal colitis is an ideal model of IBD and may serve as a tool for the investigation of the pathogenesis of and effects of pharmaceuticals on IBD.     

Effects of garlicin on apoptosis in rat model of colitis

AIM:To investigate the effects of garlicin on apoptosis and expression of bcl-2 and bax in lymphocytes in rat model of ulcerative colitis (UC). METHODS:Healthy adult Sprague-Dawley rats of both sexes, weighing 180±30 g, were employed in the present study. The rat model of UC was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enema. The experimental animals were randomly divided into garlicin treatment group (including high and low concentration), model control group, and normal control group. Rats in garlicin treatment group and model control group received intracolic garlicin daily at doses of 10.0 and 30.0 mg/kg and equal amount of saline respectively 24 h after colitis model was induced by alcohol and TNBS co-enema. Rats in normal control group received neither alcohol nor only TNBS but only saline enema in this study. On the 28~(th) d of the experiment, rats were executed, the expression of bd-2 and bax protein was determined immunohistochemically and the apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. At the same time, the rat colon mucosal damage index (CMDI) was calculated. RESULTS:In garlicin treatment group, the positive expression of bd-2 in lymphocytes decreased and the number of apoptotic cells was more than that in model control group, CMDI was lower than that in model control group. The positive expression of bax in lymphocytes had no significant difference. CONCLUSION:Garlicin can protect colonic mucosa against damage in rat model of UC induced by TNBS enema.     

三硝基苯磺酸结肠炎动物模型的建立

建立三硝基本磺酸（TNBS）诱导的结肠炎动物模型,探讨炎症性肠病（IBD）的发病机制。方法：每只实验组大鼠用0．85ml含30mgTNBS的50％乙醇灌肠1次诱发远端结肠炎,对照组大鼠仅以505乙醇或TNBS盐水溶液灌肠。观察结肠大体形态和组织学改变,并检测肠粘膜髓过氧化物酶（MPO）活性。 结果：灌肠后第1－3周,实验组大鼠远端结肠表现为朗血、水肿及溃疡形成,组织学以中性粒细胞浸润主为：第4－8周,溃疡农渐愈合,组织学表现为淋巴细胞和浆细胞浸润,组织学改变及MPO活必在第1周即恢复正常,结论：LTNBS／乙醇诱导大鼠远端结肠炎是一种较 IBD动物模,可作为研究IBD发机制及评估药物疗效的有益工具。     

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.     

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-κB p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-αand ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κBp65 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±1.39 and 6.24±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±1.96 vs1.7±0.15, 84.09±14.52 vs16.03±6.21,77.69±8.09 vs13.41±4.91 P＜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＜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.     

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.     

白细胞介素-23/-17轴在小鼠急性实验性结肠炎中的表达及作用

目的 研究白细胞介素(IL)-23/IL-17轴在小鼠实验性结肠炎结肠组织中的表达和作用.方法 将64只小鼠分为对照组24只、模型组24只、抗体组8只、正常血清组8只.除对照组外,其余各组建立小鼠急性实验性结肠炎模型.对照组和模型组小鼠分别于造模后24 h、48 h、7 d处死.抗体组和正常血清组小鼠分别于造模前2 h腹腔内注射多克隆大鼠抗小鼠IL-17中和抗体和正常大鼠血清,于造模48 h后处死.检测各组小鼠组织学损伤评分、肠组织髓过氧化物酶(MPO)活性;酶联免疫吸附试验检测结肠组织IL-23p19、IL-17含量;免疫组化染色检测核因子(NF)-κB p65在结肠组织中的表达;实时荧光定量(RT)PCR检测IL-23p19、IL-17、IL-12p35的mRNA表达水平.结果 模型组24 h、48 h、7 d时IL-23p19蛋白表达水平和mRNA表达水平[分别为(15.53±3.32)、(31.16±4.98)、(14.03±3.56)ng/mg蛋白和4.09±0.34、3.39±0.46、6.54±1.82]、IL-17的蛋白表达水平和mRNA表达水平[分别为(0.35±0.06)、(0.38±0.08)、(0.26±0.05)ng/mg蛋白和4.21±2.61、2.65±0.91、5.63±1.43]均显著高于正常对照组(P值均＜0.05),48 h时达高峰.IL-23与IL-17蛋白表达水平和mRNA表达水平呈正相关(r值分别为0.745和0.793,P＜0.05).抗体组IL-23p19和IL-12p35高水平表达,但NF-κB p65阳性细胞率、组织学评分及MPO活性[分别为1.86%±0.36%、0.63±0.52、(0.40±0.03)U/g]明显低于48 h模型组[分别为4.35%±0.37%、5.13±0.64、(2.29±0.40)U/g],说明中和IL-17后能明显减轻结肠炎症,抑制NF-κB活性.结论 IL-23/IL-17轴在急性实验性结肠炎早期阶段起关键作用.IL-17有望成为炎症性肠病治疗的新靶标.     

Butyrate enema therapy stimulates mucosal repair in experimental colitis in the rat.

BACKGROUND--The short chain fatty acid (SCFA) butyrate provides energy for colonocytes, stimulates colonic fluid and electrolyte absorption and is recognised as an effective treatment for multiple types of colitis. AIM--To examine the impact of butyrate enema therapy on the clinical course, severity of inflammation, and SCFA stimulated Na+ absorption in a chronic experimental colitis. METHODS--Distal colitis was induced in rats with a trinitrobenzenesulphonic acid (TNBS) enema. Five days after induction, rats were divided into groups to receive: no treatment, saline enemas, or 100 mM Na-butyrate enemas daily. On day 24, colonic damage score and tissue myeloperoxidase (MPO) activity were evaluated. Colon was mounted in Ussing chambers and Na+ transport and electrical activities were measured during a basal period and after stimulation with 25 mM butyrate. RESULTS--In the untreated and the saline enema treated TNBS groups, diarrhoea and extensive colonic damage were seen, associated with increased tissue MPO activities and absent butyrate stimulated Na+ absorption. In contrast, in the butyrate enema treated TNBS group, diarrhoea ceased, colonic damage score improved, and tissue MPO activity as well as butyrate stimulated Na+ absorption recovered to control values. CONCLUSION--Butyrate enema therapy stimulated colonic repair, as evidenced by clinical recovery, decreased inflammation, and restoration of SCFA stimulated electrolyte absorption.     

姜黄素对溃疡性结肠炎大鼠的抗炎作用及其对肠黏膜IL-23的影响

目的研究姜黄素对溃疡性结肠炎大鼠肠黏膜IL-23表达的影响,进一步探讨姜黄素对溃疡性结肠炎的抗炎作用机制。方法将80只雄性SD大鼠随机分为正常对照组、模型组、姜黄素组、柳氮磺吡啶(SASP)组,每组均为20只。模型组、姜黄素组、SASP组大鼠分别以100 mg/kg TNBS乙醇溶液灌肠制备大鼠结肠炎模型。正常对照组予相同剂量的0.9%氯化钠溶液灌肠;正常对照组、模型组每日予相同剂量的0.9%氯化钠溶液灌胃;姜黄素组、SASP组自造模第2天起每日分别予100 mg/kg姜黄素溶液及SASP溶液灌胃。造模第8天处死大鼠,采集大鼠结肠标本备检。评价各组大鼠的体质量变化,光镜下观察大鼠肠黏膜组织病理改变并进行病理学评分,评价各组大鼠的疾病活动指数(DAI)、肠黏膜损伤指数(CMDI)及组织学损伤情况(HS);采用RT-PCR方法测定肠黏膜组织IL-23 mRNA水平;Western blot测定肠组织IL-23蛋白表达水平。结果与模型组比较,姜黄素组DAI、CMDI、HS评分及IL-23蛋白、mRNA的表达均有明显降低(P均<0.05),与SASP组比较无统计学差异(P>0.05)。结论姜黄素能显著抑制IL-23的表达,对实验性大鼠结肠炎有明显的抑制作用。     

Role of nitric oxide in the impairment of circular muscle contractility of distended, uninflamed mid-colon in TNBS-induced acute distal colitis in rats

AIM: To evaluate the role of nitric oxide (NO) in the motor disorders of the dilated uninflamed mid-colon (DUMC) from trinitrobenzene sulfonic acid (TNBS)-induced acute distal colitis in rats. METHODS: Colitis was induced in male Sprague-Dawley rats by a single intracolonic administration of TNBS. Control rats received an enema of 0.9% saline. The rats were killed 48 h after TNBS or saline administration. Macroscopic and histologic lesions of the colon were evaluated. Myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity were measured on the colonic tissue. In TNBS rats, we evaluated spontaneous and evoked contractile activity in circular muscle strips derived from DUMC in comparison to the same colonic segment of control rats, both in the presence and in the absence of a non-selective NOS isoforms inhibitor N-nitro-L-arginine (L-NNA). Pharmacological characterization of electric field stimulation (EFS)-evoked contractile responses was also performed. RESULTS: In TNBS rats, the distal colon showed severe histological lesions and a high MPO activity, while the DUMC exhibited normal histology and MPO activity. Constitutive NOS activity was similar in TNBS and control rats, whereas inducible NOS activity was significantly increased only in the injured distal colon of TNBS rats. Isometrically recorded mechanical activity of circular muscle strips from DUMC of TNBS rats showed a marked reduction of the force and frequency of spontaneous contractions compared to controls, as well as of the contractile responses to a contracting stimulus. In the presence of L-NNA, the contractile activity and responses displayed a significantly greater enhancement compared to controls. The pharmacological characterization of EFS contractile responses showed that a cooperative-like interaction between cholinergic muscarinic and tachykinergic neurokinin 1 and 2 receptors mediated transmission in DUMC of TNBS rats vs a simple additive interaction in controls. CONCLUSION: The results of this study show that, during TNBS-induced acute distal colitis, circular muscle intrinsic contractile mechanisms and possible enteric neural excitatory activity are inhibited in the distended uninfiamed mid-colon. Suppression of NO synthesis markedly improves spontaneous and evokes muscle contractions, in spite of any evident change in local NO activity.     

银杏叶提取物对实验性结肠炎大鼠肠组织IL-6表达的影响

目的探讨银杏叶提取物(EGB)对实验性结肠炎大鼠肠组织大体形态组织学及炎性指标的影响。方法利用三硝基苯磺酸灌肠制备大鼠实验性结肠炎模型。实验设正常对照组、模型组、5-氨基水杨酸组、EGB组。4周后评价结肠组织大体形态和组织学评分,检测髓过氧化物酶(MPO)活性和IL-6、IL-6 mRNA表达。结果模型组大鼠结肠组织大体形态和组织学评分较对照组显著增加,MPO活性、IL-6、IL-6 mRNA表达水平显著升高;EGB组上述指标较模型组显著下降。结论EGB对大鼠实验性结肠炎有一定治疗作用,其作用机制可能与其降低结肠组织细胞因子IL-6水平有关。     

罗格列酮对大鼠溃疡性结肠炎的疗效及其机制

目的观察罗格列酮对大鼠溃疡性结肠炎的疗效并探讨其可能存在的机制。方法应用三硝基苯磺酸(TNB)/乙醇灌肠制备大鼠溃疡性结肠炎模型。实验设正常对照组、模型对照组、阳性药物组(柳氮磺胺吡啶组,100 mg/kg)、罗格列酮给药组(2 mg、4mg、8 mg/kg),每天灌胃给药1次,给药时间从造模后第2天开始至实验结束共8 d,观察大鼠疾病活动指数(DAI)、结肠黏膜损伤指数(CMDI)及组织学评分(HS)。生化法检测大鼠结肠组织髓过氧化物酶(MPO)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)的含量。结果与正常组相比,模型组大鼠DAI、CMDI、HS明显增加(P<0.01),结肠组织MPO活性、MDA水平显著升高(P<0.01),SOD活性下降(P<0.01)。罗格列酮4 mg、8 mg/kg和SASP可不同程度改善DAI、CMDI和HS(P<0.05,P<0.01),降低MPO活性和MDA水平(P<0.01),增加SOD活性(P<0.01)。结论罗格列酮对大鼠溃疡性结肠炎有保护作用,其机制可能与减少脂质氧化,增加清除氧自由基的能力有关。     

实验性结肠炎p38丝裂原活化蛋白激酶表达的研究

目的观察三硝基苯磺酸（TNBS）诱导的大鼠结肠炎结肠组织p38MAPK表达与激活及大鼠血清TNF-α、IL-10水平变化,探讨p38MAPK在实验性结肠炎中的作用与机制。方法20只SD大鼠随机分为正常对照组（N）与模型组（M）,TNBS／乙醇法构建结肠炎模型,观察炎症活动指数（DAI）、大体形态损伤指数（CMDI）、组织学损伤指数（TDI）,ELISA法检测血清TNF-α、IL-10水平,免疫组化染色检测大鼠结肠p38MAPK、p-p38MAPK表达。结果与N组相比,M组DAI、CMDI、TDI显著升高（P〈0．01）,血清TNF-α升高,IL-10水平下降（P〈0．01）,结肠组织p38MAPK表达增加（P〈0．05）,p-p38MAPK表达显著增加（P〈0．01）。结论p38MAPK在实验性结肠炎的表达与激活均有明显增加,可能通过调节TNF-α、IL-10等细胞因子的表达参与结肠炎的发病。     

英夫利昔、沙利度胺对大鼠实验性结肠炎的治疗作用及其机制研究

炎症性肠病（IBD）是一种病因尚未明确的非特异性肠道炎症性疾病,传统治疗方法疗程长．疗效欠佳,容易反复发作。目的：观察并比较英夫利昔、沙利度胺对TNBS灌肠诱发的大鼠结肠炎治疗效果．并初步探讨两者治疗IBD的作用机制。方法：46只Sprague-Dawley大鼠随机分成正常对照组（n=10）、结肠炎组（n=12）、英夫利昔组（n=12）、沙利度胺组（n=12）,后三组给予TNBS／乙醇灌肠诱导大鼠结肠炎模型。造模后第1d,英夫利昔组、沙利度胺组分别给予英夫利昔腹腔注射5mg·kg-1．d～、沙利度胺管喂200mg．kg-．d～,连续7d后处死。行疾病活动指数（DAI）、大体形态损伤指数（CMDI）和组织损伤指数（TDI）评分;以Real．timePCR、蛋白质印迹法和免疫组化分别检测结肠组织TNF-d、VEGF、caspase-3mRNA和蛋白表达;TUNEL法检测结肠上皮细胞凋亡情况。结果：结肠炎组大鼠DAI、CMDI、TDI评分均显著高于正常对照组（P〈O．05）,TNF-a、VEGF、caspase-3mRNA和蛋白表达显著升高（P〈O．05）．结肠上皮细胞凋亡显著增加;给予英夫利昔或沙利度胺治疗后,上述指标均显著改善（P〈0．05）。结论：本实验成功构建了TNBS大鼠结肠炎模型,英夫利昔、沙利度胺对大鼠结肠炎均有明显的治疗效果,两者通过抑制TNF-a VEGF、caspase-3的表达,对IBD免疫、血管生成、凋亡过程起调节作用。     

实验性结肠炎大鼠结肠黏膜中炎性因子对Th1/Th2平衡的影响及VSL#3的调节作用

目的 观察益生菌VSL#3对减轻TNBS诱导的大鼠急性结肠炎结肠黏膜中IL-4、IL-13、IFN-γ、IL-12表达对Th1/Th2平衡的影响以及益生菌VSL#3的调节作用.方法 30只大鼠随机分为正常对照组、模型组、美沙拉嗪组、VSL#3组、美沙拉嗪＋VSL#3组,建立TNBS大鼠结肠炎模型.观察各组大鼠一般情况、排便情况、组织病理学变化及Th 1/Th2表达情况.取结肠组织做HE染色,观察病理学改变;酶联免疫吸附试验（ELISA）检测肠组织髓过氧化物酶（MPO）的变化;逆转录聚合酶链反应（RT-PCR）及Western blotting法检测各组大鼠结肠黏膜组织中IL-4、IL-13、IFN-γ、IL-12的表达.结果 与TNBS模型组比较,VSL#3组、美沙拉嗪组、VSL#3＋美沙拉嗪组大鼠的疾病活动指数评分（DAI）、肠组织MPO水平、结肠炎大鼠病理评分均降低.RT-PCR及Western blotting检测发现：与TNBS组相比,VSL#3组、美沙拉嗪组和VSL#3＋美沙拉嗪组均可下调促炎因子IL-12、IFN-γ的表达,上调抗炎因子IL-4、IL-13的表达,VSL#3组与美沙拉嗪组比较,差异无统计学意义（P＞0.05）.Th1/Th2的比值依如下顺序减少：TNBS模型组＞VSL#3组＞美沙拉嗪组＞美沙拉嗪＋ VSL#3＞正常对照组,其比值逐渐趋于正常对照组.结论 VSL#3对TNBS诱导的大鼠实验性结肠炎有治疗作用,其作用机制可能与下调IFN-γ、IL-12,上调IL-4、IL-13炎性因子的表达,使Th1/Th2的平衡趋于正常有关.     

Effects of Changtai granules, a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats

AIM: To study the effects of Changtai granules (CTG), a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats. METHODS: Healthy adult Sprague-Dawley (SD) rats of both sexes, weighing 250-300 g, were employed in the present study. The rat colitis models were induced by 2, 4,6-trinitrobenzene sulfonic acid (TNBS) enemas at a concentration of 100 mg/kg in 50% ethanol. The experimental animals were randomly divided into dexamethasone (DX) treatment, CTG treatment, and model control groups, which were intracolicly treated daily with DX (0.2 mg/kg), CTG at doses of 2.9, 5.7 and 11.4 g crude drug/kg, and the equal amount of saline respectively from 6 h following induction of the colitis in rats inflicted with TNBS to the end of study. A normal control group of rats treated without TNBS but saline enema was also included in the study. After 3 wk of treatment, the animals were assessed for colonal inflammatory and ulcerative responses with respect to mortality, frequency of diarrhea, histology and myeloperoxidase activity (MPO). RESULTS: The therapeutic effect of CTG on ulcerative colitis (UC) was better than DX. CTG effectively inhibited the activity of granulocytes, macrophages and monocytes in a dose-dependent manner. Also it reduced MPO and formation of inflammation in colonic mucosal tissue. Furthermore, administration of CTG significantly prevented body mass loss and death, and decreased frequency of diarrhea in UC rats, when compared with the model control group rats. CONCLUSION: CTG would prove to be an ideal drug for chronic UC, and is warranted to be studied further.     

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

Background and Aim

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.

Methods

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, 24 h following stimulation.

Results

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.

Conclusions

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.