title: Apple- and hop-polyphenols protect periodontal ligament cells stimulated with enamel matrix derivative from Porphyromonas gingivalis.
abstract: BACKGROUND
  Enamel matrix derivative (EMD) is a tissue regenerative agent used clinically as an adjunct to periodontal surgery. It was previously demonstrated that Porphyromonas gingivalis, a periodontal pathogen, significantly diminished the efficacy of EMD with periodontal ligament (PDL) cells through the proteolytic actions of Arg- and Lys-gingipains (Rgp and Kgp). Thus, antiproteolytic supplements are considered clinically desirable for effective periodontal regenerative therapies. In the present study, we examined apple- (AP) and hop-polyphenols to determine their ability to protect EMD-stimulated PDL cells from P. gingivalis.
  
  
  METHODS
  AP, apple condensed tannin (ACT), hop bract polyphenol (HBP), high and low molecular weight fractions of HBP (HMW-HBP and LMW-HBP), and epigallocatechin gallate (EGCg) were used. PDL cells were grown on EMD-coated dishes and infected with P. gingivalis, and cellular migration and proliferation were evaluated with an in vitro assay of wound healing assay in the presence or absence of the polyphenols.
  
  
  RESULTS
  Each polyphenol significantly enhanced the viability of PDL cells infected with P. gingivalis, whereas only EGCg demonstrated cytotoxicity. Further, all polyphenols significantly inhibited Rgp activity, with AP, ACT, and HBP more effective toward Kgp. P. gingivalis markedly diminished the migration and proliferation of EMD-stimulated PDL cells, whereas the addition of AP, ACT, HBP, and HMW-HBP significantly protected the cells from bacterial cytotoxicity. In contrast, EGCg and LMW-HBP did not show protective effects.
  
  
  CONCLUSIONS
  These results suggest that AP, ACT, AP, HBP, and HMW-HBP protect EMD-stimulated PDL cells from P. gingivalis and may be therapeutically useful supplements for EMD therapy.
authors.affiliation: Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Inaba
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Tagashira
authors.forename: Tomomasa
authors.initials: T
authors.lastname: Kanda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohno
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawai
authors.forename: Atsuo
authors.initials: A
authors.lastname: Amano
mesh_terms: D018829:Adhesins, Bacterial / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000633:toxicity; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003546:Cysteine Endopeptidases / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003746:Dental Enamel Proteins / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D000080867:Gingipain Cysteine Endopeptidases; D006801:Humans; D027582:Humulus / Q000737:chemistry*; D027845:Malus / Q000737:chemistry*; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects* / Q000382:microbiology; D010636:Phenols / Q000494:pharmacology*; D059808:Polyphenols; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000502:physiology*; D044945:Proanthocyanidins / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology / Q000633:toxicity; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors
chemical_list: D018829:Adhesins, Bacterial; D015853:Cysteine Proteinase Inhibitors; D003746:Dental Enamel Proteins; D005419:Flavonoids; D000080867:Gingipain Cysteine Endopeptidases; D010636:Phenols; D059808:Polyphenols; D044945:Proanthocyanidins; D011480:Protease Inhibitors; C109069:enamel matrix proteins; D002392:Catechin; C045651:epigallocatechin gallate; D014568:Urokinase-Type Plasminogen Activator; D003546:Cysteine Endopeptidases