Efficacy of Topical versus Oral 5-Aminosalicylate for Treatment of 2,4,6-Trinitrobenzene Sulfonic Acid-induced Ulcerative Colitis in Rats

5-aminosalicylic acid（5-ASA） is drug of choice for the treatment of ulcerative colitis（UC）. In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced UC. A total of 60 rats were divided into sham operation group（receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube）, model group, topical 5-ASA group, oral Etiasa group（a release agent of mesalazine used as positive control） and oral 5-ASA group（n=12 each）. Different treatments were administered 1 day after UC induction. The normal saline（2 mL） was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group（7.5 g/L, twice per day, 100 mg/kg）, and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa（7.5 g/L, twice per day, 100 mg/kg） and 5-ASA（7.5 g/L, twice per day, 100 mg/kg）, respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography（HPLC）. The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.

Therapeutic and Immunoregulatory Effect of GATA-Binding Protein-3/T-Box Expressed in T-Cells Ratio of Astragalus Polysaccharides on 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Rats

Objective： To analyze the immunological characteristics of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced colitis model and examine the therapeutic effects and mechanisms of Astragalus polysaccharides（APS） treatment. Methods： Thirty-two male specific pathogen free Spragne-Dawley rats were randomly equally assigned to four groups： control, TNBS, APS and prednisone groups. Experimental colitis was induced by enema administration of TNBS. Then rats were treated with APS（0.5 g·kg^（-1）·day^（-1）, once daily） or prednisone（1.0 mg·kg^（-1）·day^（-1）, once daily） by gavage for 14 days. Macroscopic lesion and histological damage were determined, and activity of myeloperoxidase（MPO） was measured in the colonic tissues. Expressions of T-box expressed in T-cells（T-bet） and GATA-binding protein-3（GATA-3） were determined by immunohistochemistry analysis and western blot. Results： Both macroscopic lesion and histological colonic damage induced by TNBS were reduced by APS and prednisone treatment. These were accompanied by significant attenuation of MPO activity（P=0.03）. TNBS intervention enhanced the expression of both GATA-3 and T-bet, but the expression of T-bet was significantly enhanced than that of GATA-3, resulting in significant reduction of GATA-3/T-bet ratio（P=0.025）. APS administration enhanced the expression of T-bet（P=0.04） and GATA-3（P=0.019） in comparison to TNBS group, and resulting in an up-regulated GATA-3/T-bet ratio. Prednisone treatment inhibited both expressions; however it also resulted in up-regulation of the GATA-3/T-bet ratio. Conclusions： These results demonstrated that APS exerted a beneficial immune regulatory effect on experimental colitis. It promoted the expression of T helper cell 1（Th1） and T helper cell 2（Th2） specific transcription factors but ultimately favor a shift toward Th2 phenotype, suggesting that APS possessed therapeutic potential in experimental colitis.

2,4,6-三硝基苯磺酸诱导雏鸡溃疡性结肠炎模型的建立

为探索动物溃疡性肠炎的发生发展机制及其对机体的影响,以10日龄SPF雏鸡为研究对象,以2,4,6-三硝基苯磺酸(TNBS)为诱导剂,分别根据体重应用50、100、150mg·kg-1的TNBS(50%乙醇稀释)通过灌肠途经建立TNBS诱导的雏鸡溃疡性结肠炎动物模型,进而分析TNBS对雏鸡溃疡性结肠炎发生的剂量效应。并对TNBS所致的溃疡性结肠炎雏鸡的临诊症状、眼观和病理组织以及体重等变化进行较全面系统的观察或检测,结果发现,100mg·kg-1 TNBS为制备雏鸡溃疡性结肠炎动物模型的理想给药剂量,其能够得到理想的实验动物临诊症状和病理变化,同时对雏鸡的损伤在可控范围内,不会造成模型动物的大批死亡。本研究成功建立雏鸡溃疡性结肠炎病理模型,为进一步研究溃疡性结肠炎的发生发展奠定了基础。

不同造模次数对2,4,6-三硝基苯磺酸/乙醇诱导重症溃疡性结肠炎模型大鼠的影响

背景:实验采取复合法2,4,6-三硝基苯磺酸(2,4,6-Trinitrobenzenesulfonic acid,TNBS)/乙醇建立溃疡性结肠炎大鼠模型,操作简单,持续时间长且组织学变化与人类溃疡性结肠炎相似,是目前常用的溃疡性结肠炎动物模型之一,但对不同剂量不同造模次数仍存在较大差异。目的:采用相同剂量TNBS/乙醇不同次数诱导重症溃疡性结肠炎大鼠模型,探索重症溃疡性结肠炎适宜的造模次数。方法:选用SPF级SD大鼠80只,购自湖南斯莱克景达实验动物有限公司,实验方案经广西中医药大学第一附属医院动物实验伦理委员会批准[批准号为2013(KF)-E-003]。随机将大鼠分为正常对照组、TNBS+乙醇灌肠1次组、TNBS+乙醇灌肠2次组、TNBS+乙醇灌肠3次组。用药组分别使用灌胃针经大鼠直肠注入相同剂量的100 mg/kg TNBS+等体积乙醇1 d、连续2 d、连续3 d。分别于给药后的3,7 d各处死10只大鼠,观察大鼠生理状态、结肠形态、疾病活动指数及组织病理学改变情况。结果与结论:①造模7 d后大鼠体质量变化,随着造模次数的增加,大鼠体质量呈渐进性下降、症状呈渐进性加重趋势,DAI评分各组呈上升趋势;②TNBS+乙醇灌肠3次组体质量显著低于其他组(P<0.05);DAI评分和大体评分均显著高于其他组(P <0.05);③病理结果示,TNBS+乙醇灌肠3次组病变位于结肠黏膜肌层,杯状细胞丢失,隐窝形态不规则,排列紊乱,大部分可见溃疡面,较TNBS+乙醇灌肠1次组和TNBS+乙醇灌肠2次组更符合重症溃疡性结肠炎的病理表现;④结果说明,TNBS/乙醇造模中,100 mg/kg TNBS+乙醇灌肠3次连续灌肠更符合重症溃疡性结肠炎模型。

γ-氨基丁酸改善2,4,6-三硝基苯磺酸-乙醇诱导的结肠炎肠黏膜屏障损伤作用

目的探讨γ-氨基丁酸(GABA)改善2,4,6-三硝基苯磺酸(TNBS)-乙醇诱导的结肠炎肠黏膜屏障损伤作用。方法 SD大鼠随机分为正常对照组,TNBS-乙醇溶液模型对照组,造模后GABA 200,100,50 mg·kg-1治疗组。造模后连续14 d,观察记录体质量变化、疾病活动指数(DAI);造模第15天,每组取5只,进行伊文思蓝染色。大鼠取结肠,组织学损伤评分,同时量取结肠长度、称重。通过WB法观察实验性结肠炎各组大鼠肠黏膜屏障连接蛋白及LC3表达情况。结果 GABA增加Caco-2细胞单层模型细胞电阻,减少FD4的渗透,降低单层模型通透性。GABA改善实验性结肠炎引起的体质量下降,增加DAI,降低结肠指数。另外,GABA降低实验性结肠炎大鼠伊文思蓝渗透性及结肠病理变化,显著提高大鼠Occludin、Claudin-4、ZO-1蛋白表达。实验性结肠炎大鼠肠细胞出现过度自噬,GABA抑制过度自噬。结论GABA通过改善肠黏膜屏障损伤,缓解TNBS-乙醇溶液诱导的实验性结肠炎,故改善肠黏膜屏障损伤可能是治疗炎症性肠病(IBD)的新方法。

选择性环氧合酶-2抑制剂PC407对TNBS诱导的大鼠溃疡性结肠炎的治疗作用

目的:观察新型选择性环氧合酶-2抑制剂PC407对2,4,6-三硝基苯磺酸(2,4,6-trinitrobenzene sulfonic acid,TNBS)诱导的大鼠溃疡性结肠炎的疗效并探讨其机制.方法:应用TNBS/乙醇灌肠复制大鼠溃疡性结肠炎模型.实验设正常对照组、模型对照组、塞来昔布阳性对照组(18mg/kg)和PC407治疗组(9,18mg/kg),ig给药,每天1次,共6d,观察稀便出现情况.实验第7天,麻醉大鼠,分离大鼠结肠、脾脏、胸腺,观察各组实验动物体质量变化及结肠组织病理学改变,选用稀便率、结肠指数、溃疡比、胸腺指数和脾脏指数作为衡量治疗效果的指标.采用免疫组织化学方法检测结肠黏膜环氧合酶-2(COX-2)和肿瘤坏死因子α(tumornecrosisfactor-alpha,TNF-α)的变化.结果:与模型组相比,18mg/kgPC407治疗可明显阻止结肠炎大鼠的体质量下降(258.9gvs223.6g,P<0.05),降低稀便发生率(30%vs80%,P<0.01),改善大鼠结肠组织损伤及病理学改变,包括降低结肠指数(5.03±1.26mg/gvs7.60±2.07mg/g,P<0.01)及溃疡比(24.69%±2.83%vs36.13%±9.64%,P<0.01);同时,PC407治疗可对抗结肠炎症引起的胸腺萎缩(1.96±0.48mg/gvs1.08±0.32mg/g,P<0.01)和脾脏肿大(2.85±0.33mg/gvs3.87±0.96mg/g,P<0.01),显著降低结肠炎大鼠结肠黏膜COX-2和TNF-α的阳性表达率(30.6%±7.0%vs67.4%±1.2%,19.5%±3.0%vs52%±4.7%,P<0.01).9mg/kgPC407也可以改善以上指数,只是作用没有18mg/kg明显.结论:PC407对TNBS/乙醇诱导的大鼠溃疡性结肠炎治疗作用良好,其机制可能通过下调COX-2及TNF-α的表达,从而缓解结肠炎症.

One-pot, solvent-free and efficient synthesis of 2,4,6-triarylpyridines catalyzed by nano-titania-supported sulfonic acid as a novel heterogeneous nanocatalyst

Nano titania-supported sulfonic acid（n-TSA） has found to be a highly efficient, eco-friendly and recyclable heterogeneous nanocatalyst for the solvent-free synthesis of 2,4,6-triarylpyridines through one-pot three-component reaction of acetophenones, aryl aldehydes and ammonium acetate. This reported method illustrates several advantages such as environmental friendliness reaction conditions,simplicity, short reaction time, easy work up, reusability of catalyst and high yields of the products. One new compound is reported too. Furthermore, the catalyst could be recycled after a simple work-up, and reused at least six times without substantial reduction in its catalytic activity.

Colon-specific prodrugs of 4-aminosalicylic acid for inflammatory bowel disease

Despite the advent of biological products, such as anti-tumor necrosis factor-&#x003b1; monoclonal antibodies (infliximab and adalimumab), for treatment of moderate to severe cases of inflammatory bowel disease (IBD), most patients depend upon aminosalicylates as the conventional treatment option. In recent years, the increased knowledge of complex pathophysiological processes underlying IBD has resulted in development of a number of newer pharmaceutical agents like low-molecular-weight heparin, omega-3 fatty acids, probiotics and innovative formulations such as high-dose, once-daily multi-matrix mesalamine, which are designed to minimize the inflammatory process through inhibition of different targets. Optimization of delivery of existing drugs to the colon using the prodrug approach is another attractive alternative that has been utilized and commercialized for 5-aminosalicylic acid (ASA) in the form of sulfasalazine, balsalazide, olsalazine and ipsalazine, but rarely for its positional isomer 4-ASA - a well-established antitubercular drug that is twice as potent as 5-ASA against IBD, and more specifically, ulcerative colitis. The present review focuses on the complete profile of 4-ASA and its advantages over 5-ASA and colon-targeting prodrugs reported so far for the management of IBD. The review also emphasizes the need for reappraisal of this promising but unexplored entity as a potential treatment option for IBD.

基于CD40/CD40L探讨重楼总皂苷对TNBS诱导的大鼠急性实验性结肠炎作用机制

目的:探讨重楼总皂苷(rhizomaparidis total saponins,RPTS)对三硝基苯磺酸(2,4,6-trinitrobenzene sulfonic acid,TNBS)诱导的急性实验性结肠炎大鼠炎症与凝血的影响及其作用机制。方法:将50只雄性SPF级SD大鼠,随机分为空白组7只,模型组13只,以及美沙拉嗪组、RPTS低剂量组及RPTS高剂量组,每组各10只。通过TNBS建立大鼠急性实验性结肠炎模型,共14天。实验评估终点生存率、DAI评分、CMDI评分、TDI评分等指标,探究RPTS对大鼠急性实验性结肠炎的量效关系。检测全血细胞及凝血等相关指标;采用ELISA方法检测血浆及肝脏组织中CD40/CD40L指标,采用RT-PCR方法检测结肠组织中IL-1β及TNF-α的m RNA水平。结果:模型组终点生存率76.9%,RPTS低剂量组生存率为100%;RPTS低剂量组DAI、CMDI及TDI评分均较模型组显著降低(P﹤0.05);在肝脏组织中的CD40/CD40L表达水平与模型组比较,美沙拉嗪组及RPTS低剂量组均显著增加(P﹤0.0001);同时,在结肠组织的IL-1βm RNA检测中,与模型组比较,RPTS低剂量组IL-1β mRNA降低(P﹤0.05)。结论:RPTS改善了TNBS诱导急性实验性结肠炎大鼠的症状,具有良好的治疗作用,提高了模型鼠的终点生存率;RPTS低剂量组治疗效果更佳,可能通过激活CD40/CD40L共刺激因子,调控实验性结肠炎大鼠的免疫机制,以缓解疾病的炎症反应。

Recombinant adeno-associated virus carrying thymosin β4 suppresses experimental colitis in mice

AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4 (AAV-Tβ4) on murine colitis via intracolonic administration.METHODSAAV-Tβ4 was prepared and intracolonically used to mediate the secretory expression of Tβ4 in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn’s disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ4 on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTSRecombinant AAVs efficiently delivered LacZ and Tβ4 into the colonic tissues of the mice, and AAV-Tβ4 led to a strong expression of Tβ4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ4 also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSIONTβ4 exerts a protective effect on murine colitis, indicating that AAV-Tβ4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.

硒催化CO/H2O体系下常压还原合成3-硝基-5-氨基-2,4,6-三甲基苯磺酸的研究

以硒为催化剂、CO为还原剂、水为氢源、无机弱碱为助催化剂、N,N-二甲基甲酰胺(DMF)作溶剂,常压下将3,5-二硝基-2,4,6-三甲基苯磺酸还原为3-硝基-5-氨基-2,4,6-三甲基苯磺酸。最优反应条件为:3,5-二硝基-2,4,6-三甲基苯磺酸1. 45 g (5 mmol),无水醋酸钠0. 492 g (6 mmol),DMF 30 m L,水3 m L,在95℃下回流反应5h。产物纯度可达87. 92%。

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 dosedependent 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.

基于细胞自噬蛋白LC3、p62研究不同微粒的复方蜥蜴散对大鼠溃疡性结肠炎的作用

目的:基于细胞自噬蛋白LC3、p62研究不同微粒的复方蜥蜴散对2,4,6-三硝基苯磺酸诱导的溃疡性结肠炎模型大鼠的影响。方法:采用5%2,4,6-三硝基苯磺酸和50%的乙醇混合液灌肠制备大鼠溃疡性结肠炎模型,造模成功后将其随机分为模型组、柳氮磺吡啶组、复方蜥蜴散80目、复方蜥蜴散100目、复方蜥蜴散100+80目,另设空白组,干预14 d后,观察大鼠的表观指标;HE染色检测大鼠结肠的病理变化;Western Blot法检测结肠组织中LC3、p62的表达。结果:与模型组比,复方蜥蜴散组大鼠的黏液脓血便逐渐消失、精神状态佳、活跃、毛色光洁;大鼠结肠组织病理有所改善;自噬蛋白p62表达明显上调(P<0.05);LC3 II/LC3 I水平明显降低(P<0.05);以复方蜥蜴散100+80目组为优。结论:复方蜥蜴散治疗溃疡性结肠炎疗效确切,使肠道溃疡创面修复愈合,从而维持正常的细胞自噬。

基于TL1A/DR3探究肠道菌群对TNBS诱导大鼠肠纤维化的作用研究

目的 探究肠道菌群对2,4,6-三硝基苯磺酸(TNBS)诱导的肠纤维化大鼠模型的治疗作用及潜在机制。方法 将24只SD大鼠随机分为正常对照组、模型组、盐酸林可霉素组(85 mg/kg)和益生菌组(850 mg/kg),除正常对照组和模型组给予等体积生理盐水外,其余组给予相应药物灌胃,每日1次,连续5 d,次日除正常对照组外均采用TNBS诱导大鼠肠纤维化模型,再连续给予相应药物7 d。实验过程中观察大鼠一般行为表现,实验结束后收集结肠标本,进行组织学评分,并采用HE染色和Masson染色观察大鼠结肠组织损伤和纤维化程度,免疫组化检测E-cadherin、α-SMA、TGF-β1等蛋白表达,Western Blot检测TL1A、DR3的蛋白表达情况。结果 与正常对照组相比,模型组大鼠结肠受损,胶原纤维表达增加,提示肠纤维模型成功。盐酸林可霉素组可进一步加重结肠损伤和胶原纤维表达,经益生菌治疗结肠损伤和纤维化均有缓解。与模型组相比,盐酸林可霉素组大鼠TL1A/DR3蛋白表达水平升高(P<0.05),E-cadherin蛋白表达水平降低(P<0.05),α-SMA、TGF-β1蛋白表达水平升高(P<0.05),而益生菌组能够显著降低TL1A/DR3、α-SMA、TGF-β1蛋白表达水平,升高E-cadherin蛋白表达水平。结论 菌群紊乱通过激活TL1A/DR3信号调控结肠组织EMT过程促进纤维化发生,而采取益生菌干预能够缓解结肠纤维化发生。

溃疡性结肠炎模型的构建及其炎症反应机制研究

目的：构建2,4,6-三硝基苯磺酸（2,4,6-trinitrobenzene sulfonic acid,TNBS）以及恶唑酮（oxazolone,OXZ）诱导的小鼠溃疡性结肠炎（ulcerative colitis,UC）模型。方法：120只昆明小鼠（）随机分为4组（n=30）。Ⅰ组、Ⅱ组参照Morris及Walter的方法制备小鼠TNBS模型：Ⅰ组（TNBS溶剂对照组）,50%乙醇0.1 m L灌肠;Ⅱ组（TNBS模型组）,0.6%TNBS溶液0.1 m L灌肠;两组灌肠给药一次后在d 1、d 2、d 3、d 5、d 7每组处死6只。Ⅲ组、Ⅳ组参照Heller方法制备小鼠OXZ模型：Ⅲ组（OXZ溶剂对照组）,皮肤涂抹100%乙醇0.1 m L,每天一次,连续2 d,d 7以50%乙醇0.1 m L灌肠;Ⅳ组（OXZ模型组）,皮肤涂抹1%OXZ溶液（100%乙醇溶解）0.1 m L每天一次,连续2 d（致敏）,d 7以0.5%OXZ（50%乙醇溶解）0.1 m L灌肠;两组灌肠给药一次后在d 1~d 5每天处死6只小鼠。观察Ⅰ~Ⅳ组小鼠疾病活动指数（disease activity index,DAI）、结肠组织大体损伤指数（colon macroscopic damage index,CMDI）和病理组织学评分（histopathological score,HPS）,并检测小鼠结肠组织中髓过氧化物酶（myeloperoxidase,MPO）、白细胞介素-4（interleukin-4,IL-4）、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）的水平。结果：两种模型组小鼠DAI,CMDI和HPS均较对照组有明显改变;TNBS和OXZ诱导的结肠炎均可导致MPO明显上升,TNBS结肠炎TNF-α明显上升,OXZ结肠炎IL-4明显下降。结论：TNBS及OXZ均能诱导小鼠溃疡性结肠炎模型。两种模型各有特点,其中TNBS诱导的小鼠溃疡性结肠炎以辅助性T1（helper1,Th1）型炎症反应为主,OXZ诱导的小鼠溃疡性结肠炎以辅助性T2（helper2,Th2）型炎症反应为主。

降解魔芋多糖对三硝基苯磺酸诱导实验性结肠炎的治疗作用

目的:观察降解魔芋多糖(DAKP)治疗2,4,6-三硝基苯磺酸(TNBS)诱导结肠炎的疗效并探讨其作用机制.方法:将SD大鼠随机分为6组:正常对照组、模型组、地塞米松(DX)组及DAKP50,100,200mg/kg3种不同剂量组,每组动物10只.除正常对照组外,其余5组均以TNBS/乙醇造模.造模6h后,DAKP不同剂量组给予DAKP50,100,200mg/kg灌胃;DX组给予DX0.2mg/kg灌胃.均为1次/d,共5d.6d时以乙醚麻醉大鼠致死,并分别腹腔收集巨噬细胞,采用ELISA法检测巨噬细胞分泌肿瘤坏死因子-α(TNF-α)水平;截取8cm结肠,称质量并计算结肠指数及溃疡面积;分离结肠黏膜,液氮速冻,测定髓过氧化物酶(MPO)活性;取2cm结肠组织40g/L甲醛固定,HE染色;摘取胸腺、脾脏称质量.结果:与模型组相比较,DAKP100,200mg/kg剂量组能够降低结肠指数,缓解黏膜水肿并能显著缩小结肠溃疡面积[(31.8±8.1)%,(30.9±6.4)%vs(41.5±9.1)%,P<0.05];降低结肠炎大鼠肠黏膜MPO水平[(96.7±2.2),(85.0±1.0)vs(161.7±2.3),P<0.05].TNF-α表达DAKP100,200mg/kg剂量组低于模型组[(215.1±7.2),(201.3±5.5)vs(306.9±8.1),P<0.05];与DX组相比较其疗效差异无显著性.结论:DAKP对TNBS诱导的大鼠结肠炎具有显著治疗作用.低分子DAKP可能是调节胃肠道功能的主要有效成分.

果胶-酮洛芬前药对大鼠实验性溃疡性结肠炎的治疗作用

目的:研究果胶-酮洛芬(PT-KP)前药对2,4,6-三硝基苯磺酸(TNBS)诱导的大鼠实验性溃疡性结肠炎的治疗作用.方法:采用100mg/kg TNBS诱导大鼠溃疡性结肠炎.将30只溃疡性结肠炎大鼠随机分为PT-KP50,100,200mg/(kg·d)组,模型对照组,正常对照组.除PT-KP50,100,200mg/(kg·d)各组给予不同剂量PT-KP灌胃外,其余各组均给予5mL/L羧甲基纤维素钠溶液灌胃,1次/d,连续6d.实验结束后取大鼠胸腺、脾脏及结肠称质量,计算脏/体系数,并对大鼠结肠进行形态学观察.采用计算机图像处理系统测量溃疡面积并计算溃疡面积百分比.将结肠经40g/L甲醛固定,进行病理组织学检查.实验数据均经统计学处理.结果:PT-KP100,200mg/(kg·d)可使大鼠结肠溃疡面积百分比分别缩小30.43%和5.80%;结肠质量与体质量比减小5.72和3.23.与模型对照组相比较差异均有统计学意义(P<0.05),而对大鼠胸腺及脾脏质量无影响.结论:PT-KP前药对TNBS诱导的大鼠实验性溃疡性结肠炎具有良好的治疗效果.

己酮可可碱对小鼠TNBS结肠炎的药效学研究

目的观察己酮可可碱(PTX)对小鼠TNBS(三硝基苯磺酸)肠炎的作用。方法通过直肠给予雄性BALB/c小鼠TNBS诱导结肠炎,应用PIX对其进行治疗,6日后收集结肠标本评价结肠炎症程度。结果直肠内给予BALB/c小鼠TNBS后可造成小鼠结肠炎性改变PTX治疗可使小鼠疾病活动指数、结肠重量和炎症指数均显著下降(P <0 0 5 )。结论PTX治疗可使TNBS肠炎模型小鼠肠道炎症减轻。

Hypothalamic paraventricular nucleus stimulation reduces intestinal injury in rats with ulcerative colitis

AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.

Probiotic yeasts: Anti-inflammatory potential of various non-pathogenic strains in experimental colitis in mice

AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice.METHODS: In vitro immunomodulation was assessed by measuring cytokines [interleukin (IL)-12p70,IL-10,tumor necrosis factor and interferon γ] released by human peripheral blood mononuclear cells after 24 h stimulation with 6 live yeast strains (Saccharomyces ssp.) and with bacterial reference strains.A murine model of acute 2-4-6-trinitrobenzene sulfonic acid (TNBS)-colitis was next used to evaluate the distinct prophylactic protective capacities of three yeast strains compared with the performance of prednisolone treatment.RESULTS: The six yeast strains all showed similar non-discriminating anti-inflammatory potential when tested on immunocompetent cells in vitro .However,although they exhibited similar colonization patterns in vivo ,some yeast strains showed significant anti-inflammatory activities in the TNBS-induced colitis model,whereas others had weaker or no preventive effect at all,as evidenced by colitis markers (body-weight loss,macroscopic and histological scores,myeloperoxidase activities and blood inflammatory markers).CONCLUSION: A careful selection of strains is required among the biodiversity of yeasts for specific clinical studies,including applications in inflammatory bowel disease and other therapeutic uses.