title: Preventative effects of lactulose in the trinitrobenzenesulphonic acid model of rat colitis.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  In conclusion, the intestinal antiinflammatory effect of lactulose could be related to its prebiotic properties, supporting its potential use in human inflammatory bowel disease.
authors.affiliation: Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain.
authors.forename: Desiree
authors.initials: D
authors.lastname: Camuesco
authors.forename: Laura
authors.initials: L
authors.lastname: Peran
authors.forename: Monica
authors.initials: M
authors.lastname: Comalada
authors.forename: Ana
authors.initials: A
authors.lastname: Nieto
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Di Stasi
authors.forename: M Elena
authors.initials: ME
authors.lastname: Rodriguez-Cabezas
authors.forename: Angel
authors.initials: A
authors.lastname: Concha
authors.forename: Antonio
authors.initials: A
authors.lastname: Zarzuelo
authors.forename: Julio
authors.initials: J
authors.lastname: Galvez
mesh_terms: D000818:Animals; D003092:Colitis / Q000188:drug therapy* / Q000517:prevention & control* / Q000662:veterinary; D004195:Disease Models, Animal; D005260:Female; D005765:Gastrointestinal Agents / Q000494:pharmacology*; D007777:Lactobacillaceae / Q000254:growth & development; D007792:Lactulose / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000096:biosynthesis; D009195:Peroxidase / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014302:Trinitrobenzenesulfonic Acid / Q000008:administration & dosage / Q000009:adverse effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D005765:Gastrointestinal Agents; D014409:Tumor Necrosis Factor-alpha; D007975:Leukotriene B4; D007792:Lactulose; D014302:Trinitrobenzenesulfonic Acid; D009195:Peroxidase