title: Antibacterial Activity of Curcumin Against Periodontopathic Bacteria.
abstract: BACKGROUND
  Curcumin is a polyphenol extracted from root of turmeric and known to possess multifunctional properties, including antibacterial activity. Although previous studies have investigated the effects of curcumin on microorganisms, available knowledge on the effects of curcumin on periodontopathic bacteria is still limited. In this study, the antibacterial effect of curcumin on periodontopathic bacteria is investigated, particularly Porphyromonas gingivalis.
  
  
  METHODS
  Representative periodontopathic bacteria were cultured in media with and without various curcumin concentrations, and the optical density at 600 nm was measured for 60 hours. The inhibitory effect of curcumin on P. gingivalis Arg- and Lys-specific proteinase (RGP and KGP, respectively) activities were assessed using spectrofluorophotometric assay. Analysis of biofilm formation by P. gingivalis with or without Streptococcus gordonii was conducted using confocal laser-scanning microscopy (CLSM).
  
  
  RESULTS
  Curcumin inhibited the growth of P. gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Treponema denticola in a dose-dependent manner. Bacterial growth was suppressed almost completely at very low concentrations of curcumin. Conversely, 100 μg/mL curcumin did not suppress the growth of Aggregatibacter actinomycetemcomitans. It also demonstrated inhibitory effects against RGP and KGP activities in a dose-dependent manner. CLSM revealed that curcumin suppressed P. gingivalis homotypic and P. gingivalis-S. gordonii heterotypic biofilm formation in a dose-dependent manner. A concentration of 20 μg/mL curcumin inhibited these P. gingivalis biofilm formations by >80%.
  
  
  CONCLUSIONS
  Curcumin possesses antibacterial activity against periodontopathic bacteria and may be a potent agent for preventing periodontal diseases.
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Shusuke
authors.initials: S
authors.lastname: Izui
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sekine
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Maeda
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Masae
authors.initials: M
authors.lastname: Kuboniwa
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Takada
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Amano
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nagata
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003474:Curcumin / Q000494:pharmacology*; D016966:Porphyromonas gingivalis; D018713:Prevotella intermedia
chemical_list: D000900:Anti-Bacterial Agents; D003474:Curcumin
keywords: Biofilms; Porphyromonas gingivalis; curcumin; periodontal diseases