title: Eucalyptol suppresses matrix metalloproteinase-9 expression through an extracellular signal-regulated kinase-dependent nuclear factor-kappa B pathway to exert anti-inflammatory effects in an acute lung inflammation model.
abstract: OBJECTIVE
  The acute lung injury (ALI) model is characterised by a severe acute inflammatory response in the lungs that represents the pathogenesis of acute respiratory distress syndrome (ARDS). In this study, we sought to elucidate the anti-inflammatory mechanism of eucalyptol in relation to tissue remodelling in acute lung inflammation.
  
  
  METHODS
  BALB/C mice were intraperitoneally injected with eucalyptol (100, 200 or 400 mg/kg) or dexamethasone (1 mg/kg) 1 h before intratracheal challenge with lipopolysaccharide (LPS; 1.5 mg/kg) and sacrificed after 4 h. The anti-inflammatory effects of eucalyptol were assessed by determining cell counts, measuring cytokine and nitric oxide production and performing Western blotting and histological analyses.
  
  
  RESULTS
  Eucalyptol attenuated inflammation-associated increases in cell numbers, matrix metalloproteinase-9 (MMP-9) expression, production of cytokines (tumour necrosis factor-α and interleukin-6) and nitric oxide, and nuclear factor-kappa B (NF-κB) and phosphorylated extracellular signal-regulated kinase protein levels induced by LPS in bronchoalveolar lavage fluid from ALI mice. Furthermore, pretreatment with 400 mg/kg eucalyptol prevented LPS-induced histopathological changes. Collectively, these results indicate that eucalyptol acts through a mechanism involving decreased MMP-9 expression and an extracellular signal-regulated kinase-dependent NF-κB pathway to exert anti-inflammatory actions in acute lung inflammation.
  
  
  CONCLUSIONS
  Thus, eucalyptol may be a potentially important agent in the treatment of pulmonary inflammation.
authors.affiliation: Department of Basic Nursing Science, School of Nursing, Korea University, Seoul, Republic of Korea.
authors.forename: Ka Young
authors.initials: KY
authors.lastname: Kim
authors.affiliation: Department of Basic Nursing Science, School of Nursing, Korea University, Seoul, Republic of Korea.
authors.forename: Hui Su
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Basic Nursing Science, School of Nursing, Korea University, Seoul, Republic of Korea.
authors.forename: Geun Hee
authors.initials: GH
authors.lastname: Seol
mesh_terms: D055371:Acute Lung Injury / Q000188:drug therapy* / Q000503:physiopathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003511:Cyclohexanols / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis; D003907:Dexamethasone / Q000494:pharmacology; D004195:Disease Models, Animal; D054796:Drug Dosage Calculations; D000077591:Eucalyptol; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D039821:Monoterpenes / Q000494:pharmacology*; D016328:NF-kappa B / Q000096:biosynthesis*; D009569:Nitric Oxide / Q000096:biosynthesis; D015398:Signal Transduction
chemical_list: D000893:Anti-Inflammatory Agents; D003511:Cyclohexanols; D016207:Cytokines; D008070:Lipopolysaccharides; D039821:Monoterpenes; D016328:NF-kappa B; D009569:Nitric Oxide; D003907:Dexamethasone; D048049:Extracellular Signal-Regulated MAP Kinases; D020780:Matrix Metalloproteinase 9; D000077591:Eucalyptol
keywords: LPS; MMP-9; NF-κB; acute lung injury; eucalyptol