title: Kaempferol inhibits P. intermedia lipopolysaccharide-induced production of nitric oxide through translational regulation in murine macrophages: critical role of heme oxygenase-1-mediated ROS reduction.
abstract: BACKGROUND
  Nitric oxide (NO) could be a potential target for the development of new therapeutic approaches to the treatment of periodontal disease because this molecule plays a significant role in the tissue destruction observed in periodontitis. In this study, the authors investigate the effect of kaempferol on the production of NO by murine macrophage-like RAW264.7 cells stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in periodontal disease, and try to determine the underlying mechanisms of action.
  
  
  METHODS
  NO production was assayed by measuring the accumulation of nitrite in culture supernatants. Real-time polymerase chain reaction was performed to quantify inducible NO synthase (iNOS) and heme oxygenase-1 (HO-1) mRNA expression. iNOS and HO-1 protein expression and phosphorylation of c-Jun N-terminal kinase and p38 were characterized via immunoblot analysis. Reactive oxygen species (ROS) production was measured using the redox-sensitive fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate.
  
  
  RESULTS
  Kaempferol significantly inhibited NO production and expression of iNOS protein in P. intermedia LPS-stimulated RAW246.7 cells without affecting iNOS mRNA expression. Kaempferol upregulated HO-1 expression in LPS-activated cells. Inhibition of HO-1 activity by tin protoporphyrin IX (SnPP) abolished the suppressive effect of kaempferol on NO production. In addition, kaempferol significantly attenuated P. intermedia LPS-induced increase of intracellular ROS, and SnPP blocked this reduction. Treatment with antioxidants downregulated the production of LPS-induced NO.
  
  
  CONCLUSIONS
  Kaempferol inhibits NO production and iNOS protein expression in P. intermedia LPS-stimulated RAW264.7 cells at the translational level via HO-1-mediated ROS reduction and could be an efficient modulator of host response in the treatment of periodontal disease.
authors: Department of Biological Science, College of Medical and Life Sciences, Silla University, Busan, Korea.
authors: In Soon
authors: IS
authors: Choi
authors: Eun-Young
authors: EY
authors: Choi
authors: Ji-Young
authors: JY
authors: Jin
authors: Hae Ryoun
authors: HR
authors: Park
authors: Jeom-Il
authors: JI
authors: Choi
authors: Sung-Jo
authors: SJ
authors: Kim
mesh_terms: D000818:Animals; D002460:Cell Line; D051547:Heme Oxygenase-1 / Q000502:physiology*; D044949:Kaempferols / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D018713:Prevotella intermedia / Q000378:metabolism; D046188:Protein Modification, Translational / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors*
chemical_list: D044949:Kaempferols; D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C006552:kaempferol; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D051547:Heme Oxygenase-1