title: Relationship among salivary antioxidant activity, cytokines, and periodontitis: the Nagasaki Island study.
abstract: OBJECTIVE
  Antioxidant activities and cytokine levels in human body fluids are considered to be strongly associated with periodontitis. The aim of this study was to elucidate the relationship between salivary antioxidant activities against superoxide or hydroxyl radical, cytokines, and periodontal conditions through a community-based cross-sectional study conducted in Goto city, Japan.
  
  
  METHODS
  Saliva samples were analysed for superoxide or hydroxyl radical scavenging activities and cytokine levels from 160 participants. We demonstrated that saliva contained superoxide and hydroxyl radical scavenging activities by using electron spin resonance with a spin-trapping agent. The concentrations of eight cytokines were measured using multiplex bead assays.
  
  
  RESULTS
  There were significant differences in salivary superoxide or hydroxyl radical scavenging activity, and the levels of Interleukin-1β, Interleukin-6, and Interleukin-8 between periodontitis classifications. Multivariate stepwise logistic regression model showed that salivary superoxide and hydroxyl radical scavenging activities were significantly associated with the classification of periodontitis. In addition, salivary superoxide scavenging activity was found to have significant association with all periodontal parameters using multiple linear regression analysis.
  
  
  CONCLUSIONS
  These findings suggest that the evaluation of salivary antioxidant activities, as assessed by electron spin resonance, are associated with periodontitis and various clinical variables in community-dwelling participants (ClinicalTrials.gov number NCT01742728).
authors.affiliation: Department of Preventive Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Naofumi
authors.initials: N
authors.lastname: Tamaki
authors.affiliation: Division of Photomedical Dentistry, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Kanagawa, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yoshino
authors.affiliation: Department of Preventive Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Fukui
authors.affiliation: Department of Oral Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hayashida
authors.affiliation: Division of Photomedical Dentistry, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Kanagawa, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Yoshida
authors.affiliation: Department of Oral Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Masayasu
authors.initials: M
authors.lastname: Kitamura
authors.affiliation: Department of Oral Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Oral Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Furugen
authors.affiliation: Community Medical Network Center, Nagasaki University Hospital, Nagasaki, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawasaki
authors.affiliation: Department of Island and Community Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Nakazato
authors.affiliation: Department of Island and Community Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Maeda
authors.affiliation: Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kokeguchi
authors.affiliation: Department of Dental Sociology, Graduate School of Dentistry, Kanagawa Dental University, Kanagawa, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Yokosuka-Shonan Disaster Health Emergency Research Center & ESR Laboratories, Graduate School of Dentistry, Kanagawa Dental University, Kanagawa, Japan.
authors.forename: Masaichi Chang-Il
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Department of Preventive Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Hiro-O
authors.initials: HO
authors.lastname: Ito
authors.affiliation: Department of Oral Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Saito
keywords: antioxidant effect; electron spin resonance; epidemiology; oxidative stress; reactive oxygen species; saliva