title: Inflammatory responses of gingival epithelial cells stimulated with Porphyromonas gingivalis vesicles are inhibited by hop-associated polyphenols.
abstract: BACKGROUND
  Periodontitis is induced by an imbalance between bacterial virulence and host defense ability. Porphyromonas gingivalis, a predominant periodontal pathogen, triggers a series of host inflammatory responses that aggravate the destruction of periodontium. Thus, anti-inflammatory reagents are considered desirable for effective periodontal therapy. In the present study, we examined the inhibitory effects of hop bract polyphenol (HBP) on cellular inflammatory responses induced by P. gingivalis membrane vesicles.
  
  
  METHODS
  Immortalized human gingival epithelial cells were stimulated with P. gingivalis membrane vesicles, and the effects of HBP on mRNA expression of cyclooxygenase (COX)-2, interleukin (IL)-6 and -8, and matrix metalloproteinase (MMP)-1 and -3 were examined using real-time reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  HBP inhibited the mRNA expression of COX-2, IL-6 and -8, and MMP-1 and -3 in a dose-dependent manner, whereas epigallocatechin gallate (a control polyphenol) inhibited COX-2 mRNA expression only. Following further fractionation of HBP to identify the effective components, 2-[(2-methylpropanoyl)-phloroglucinol]1-O-beta-D-glucopyranoside (MPPG) was identified as a significant anti-inflammatory element that completely inhibited the inflammatory mRNA induction. Kaempferol 3-O-beta-glucopyranoside (astragalin) also was found to have anti-inflammatory effects.
  
  
  CONCLUSIONS
  HBP is suggested to be a potent inhibitor of cellular inflammatory responses induced by P. gingivalis vesicles. Further, MPPG and astragalin, identified here as effective components of HBP, also may be useful for the prevention and/or attenuation of periodontitis.
authors.affiliation: Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, Suita-Osaka, Japan.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Kou
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Inaba
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kato
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Tagashira
authors.forename: Daiki
authors.initials: D
authors.lastname: Honma
authors.forename: Tomomasa
authors.initials: T
authors.lastname: Kanda
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ohtake
authors.forename: Atsuo
authors.initials: A
authors.lastname: Amano
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000187:drug effects; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D022162:Cytoplasmic Vesicles / Q000187:drug effects / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D005419:Flavonoids / Q000494:pharmacology*; D005881:Gingiva / Q000187:drug effects / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D027582:Humulus; D016209:Interleukin-8 / Q000037:antagonists & inhibitors; D044949:Kaempferols / Q000494:pharmacology; D020781:Matrix Metalloproteinase 1; D019278:Matrix Metalloproteinase 3; D061965:Matrix Metalloproteinase Inhibitors; D010636:Phenols / Q000494:pharmacology*; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000494:pharmacology; D018515:Plant Leaves; D059808:Polyphenols; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000276:immunology*; D000093242:Interleukin-6 Inhibitors
chemical_list: D000893:Anti-Inflammatory Agents; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D005419:Flavonoids; D016209:Interleukin-8; D044949:Kaempferols; D020781:Matrix Metalloproteinase 1; D019278:Matrix Metalloproteinase 3; D061965:Matrix Metalloproteinase Inhibitors; D010636:Phenols; D010696:Phloroglucinol; D059808:Polyphenols; D000093242:Interleukin-6 Inhibitors; C456439:phlorin phloroglucinol; C001579:astragalin; C511768:MMP3 protein, human; C522360:MMP1 protein, human