title: Effects of telithromycin in in vitro and in vivo models of lipopolysaccharide-induced airway inflammation.
abstract: BACKGROUND
  The ketolide antibiotic telithromycin (TEL) exerts immunomodulatory and antiinflammatory effects in vitro and in a mouse model of septic shock. We studied the antiinflammatory activity of TEL in in vitro and in vivo models of airway inflammation induced by lipopolysaccharide (LPS).
  
  
  METHODS
  We measured the effects of TEL on the response of RAW 264.7 macrophages to LPS and of murine lung epithelial (MLE)-12 cells to supernatants of LPS-stimulated RAW 264.7 macrophages. Macrophage inflammatory protein (MIP)-2 and tumor necrosis factor (TNF)-alpha production, nuclear factor (NF)-kappaB activation, and apoptosis were determined. Acute airway inflammation was induced in untreated and TEL-treated BALB/c mice by nebulization with LPS. Total number of leukocytes, macrophages, and neutrophils, the protein concentration, and nitrite and cytokine levels were determined in the BAL fluid.
  
  
  RESULTS
  TEL inhibited in a dose-dependent manner the production of MIP-2 and TNF-alpha by LPS-stimulated RAW 264.7 macrophages, and the production of MIP-2 by MLE-12 epithelial cells to supernatants of LPS-stimulated RAW 264.7 macrophages. NF-kappaB activation was inhibited and apoptosis was increased in both cell lines by TEL. The LPS-induced influx of neutrophils in BAL fluid was decreased by TEL pretreatment. TEL also reduced protein, nitrite, MIP-2, and TNF-alpha levels in the BAL fluid of LPS-nebulized animals.
  
  
  CONCLUSIONS
  We have provided evidence that TEL exerts potent antiinflammatory effects in LPS-induced airways injury. We propose that TEL acts in the early phase of inflammation by reducing the release of inflammatory mediators through NF-kappaB inhibition, and in the later phase through enhancement of inflammatory cell apoptosis.
authors.affiliation: Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada 18071, Spain.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Leiva
authors.forename: Alfonso
authors.initials: A
authors.lastname: Ruiz-Bravo
authors.forename: Maria
authors.initials: M
authors.lastname: Jimenez-Valera
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001992:Bronchoalveolar Lavage Fluid; D002460:Cell Line; D002478:Cells, Cultured; D054426:Chemokine CXCL2 / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D048628:Ketolides / Q000494:pharmacology*; D008070:Lipopolysaccharides; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000378:metabolism; D011014:Pneumonia / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D054426:Chemokine CXCL2; C404915:Cxcl2 protein, mouse; D048628:Ketolides; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; C106791:telithromycin