title: Effect of electron-beam irradiation on antimicrobial, antibiofilm activity, and cytotoxicity of mouth rinses.
abstract: BACKGROUND
  Oral health diseases are common in all regions of the world. Mouth rinses are widely used generally by population as a port of daily oral care regimen. In addition to antimicrobial activity, mouth rinses possess certain cytotoxic effects. Electron-beam (E-beam) radiation is a form of ionizing energy known to induce structural, physical, and chemical changes in irradiated products. In this study, the modulatory effects of E-beam in irradiated mouth rinses were evaluated for its biological activities.
  
  
  METHODS
  The antimicrobial activities of nonirradiated and irradiated mouth rinses were evaluated for its antimicrobial and antibiofilm activities against oral pathogens, Enterococcus faecalis, Streptococcus mutans, Staphylococcus aureus, and Candida albicans. The antimicrobial activity was evaluated by disc diffusion method and antibiofilm activity was evaluated by O'Toole method. The cytotoxicity was evaluated against human gingival fibroblast (HGF) cells by 3-(4, 5 Dimethythiazol-yl)-2,5-Diphenyl-tetrazolium bromide assay.
  
  
  RESULTS
  Colgate Plax (CP) exhibited the antimicrobial activity against the tested pathogens, and a significant (P< 0.05) increase was observed against S. aureus at 750 Gy irradiation. Further, CP significantly (P< 0.05) suppressed S. mutans, S. aureus, and C. albicans biofilm. Listerine (LS) inhibited S. mutans and C. albicans biofilm. Whereas irradiated CP and LS significantly (P< 0.05) suppressed the biofilm formed by oral pathogens. The suppression of biofilm by irradiated mouth rinses was dose- and species-dependent. There was no significant (P > 0.05) difference in the cytotoxicity of irradiated and nonirradiated mouth rinses on HGF cells. However, an increased percentage viability of HGF cells was observed by mouth rinses irradiated at 750 Gy.xs
  
  
  CONCLUSIONS
  The E-beam irradiation enhanced the antibiofilm activity of mouth rinses without modifying the cytotoxicity.
authors.affiliation: Nitte University Centre for Science Education and Research, Nitte University, Mangalore, Karnataka, India.
authors.forename: A
authors.initials: A
authors.lastname: Geethashri
authors.affiliation: NUCSReM, Nitte University, Mangalore, Karnataka, India.
authors.forename: B Mohana
authors.initials: BM
authors.lastname: Kumar
authors.affiliation: NUCSReM, Nitte University, Mangalore, Karnataka, India.
authors.forename: K J
authors.initials: KJ
authors.lastname: Palaksha
authors.affiliation: Department of Biosciences, Mangalore University, Mangalore, Karnataka, India.
authors.forename: K R
authors.initials: KR
authors.lastname: Sridhar
authors.affiliation: Department of Physics, Mangalore University, Mangalore, Karnataka, India.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Sanjeev
authors.affiliation: Department of Microbiology, K. S. Hegde Medical Academy, Nitte University, Mangalore, Karnataka, India.
authors.forename: A Veena
authors.initials: AV
authors.lastname: Shetty
mesh_terms: D000891:Anti-Infective Agents, Local / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D001565:Benzoates; D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects; D002460:Cell Line; D004338:Drug Combinations; D004583:Electrons; D013293:Enterococcus faecalis / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology; D006801:Humans; D009067:Mouthwashes / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D012459:Salicylates; D012967:Sodium Dodecyl Sulfate; D013211:Staphylococcus aureus / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013729:Terpenes
chemical_list: D000891:Anti-Infective Agents, Local; D001565:Benzoates; D004338:Drug Combinations; D009067:Mouthwashes; C070868:Plax; D012459:Salicylates; D013729:Terpenes; D012967:Sodium Dodecyl Sulfate; C057473:Listerine