title: Pleasant feeling from watching a comical video enhances free radical-scavenging capacity in human whole saliva.
abstract: OBJECTIVE
  Free radicals have been implicated in aging, mutagenesis, inflammation and other pathological conditions. We conducted a study to clarify the relation between a pleasant feeling as a psychological eustress and free radical-scavenging capacity (FRSC) in saliva.
  
  
  METHODS
  Saliva was collected from 27 healthy volunteers. FRSC before, during and after watching a cheerful comical video for 30 min was measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH).
  
  
  RESULTS
  The median values of FRSC (micromol/ml) before, at 10 and 20 min during and after watching the video were 54.5, 66.8, 66.6 and 69.4, respectively. The FRSC values obtained after watching the video were significantly higher than those before watching it (P<.001). When the FRSC before watching was taken as 1, the value for the group that felt "Very good," "Good" or "Ordinary+Dull" while watching the video for 30 min was 1.38, 1.20 or 0.98, respectively (P<.01).
  
  
  CONCLUSIONS
  Watching a comical video enhanced the FRSC in saliva; in addition, a pleasant feeling boosted it even more.
authors.affiliation: Department of Oral Physiology, Meikai University School of Dentistry, 1-1, Keyakidai, Sakado, Saitama 350-0283, Japan. tosi@dent.meikai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Atsumi
authors.forename: S
authors.initials: S
authors.lastname: Fujisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Nakabayashi
authors.forename: T
authors.initials: T
authors.lastname: Kawarai
authors.forename: T
authors.initials: T
authors.lastname: Yasui
authors.forename: K
authors.initials: K
authors.lastname: Tonosaki
mesh_terms: D000328:Adult; D000339:Affect; D005260:Female; D016166:Free Radical Scavengers / Q000032:analysis*; D006801:Humans; D008297:Male; D012463:Saliva / Q000737:chemistry*; D011795:Surveys and Questionnaires; D014743:Videotape Recording; D014796:Visual Perception; D014925:Wit and Humor as Topic
chemical_list: D016166:Free Radical Scavengers