title: Inhibition of streptococcal biofilm by hydrogen water.
abstract: OBJECTIVE
  The accumulation of oral bacterial biofilm is the main etiological factor of oral diseases. Recently, electrolyzed hydrogen-rich water (H-water) has been shown to act as an effective antioxidant by reducing oxidative stress. In addition to this general health benefit, H-water has antibacterial activity for disease-associated oral bacteria. However, little is known about the effect of H-water on oral bacterial biofilm. The objective of this study was to confirm the effect of H-water on streptococcal biofilm formation.
  
  
  METHODS
  In vitro streptococcal biofilm was quantified using crystal violet staining after culture on a polystyrene plate. The effect of H-water on the expression of genes involved in insoluble glucan synthesis and glucan binding, which are critical steps for oral biofilm formation, was evaluated in MS. In addition, we compared the number of salivary streptococci after oral rinse with H-water and that with control tap water. Salivary streptococci were quantified by counting viable colonies on Mitis Salivarius agar-bacitracin.
  
  
  RESULTS
  Our data showed that H-water caused a significant decrease in in vitro streptococcal biofilm formation. The expression level of the mRNA of glucosyltransferases (gtfB, gtfc, and gtfI) and glucan-binding proteins (gbpC, dblB) were decreased remarkably in MS after H-water exposure for 60s. Furthermore, oral rinse with H-water for 1 week led to significantly fewer salivary streptococci than did that with control tap water.
  
  
  CONCLUSIONS
  Our data suggest that oral rinse with H-water would be helpful in treating dental biofilm-dependent diseases with ease and efficiency.
authors.affiliation: Department of Oral Microbiology and Immunology, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 700-412, South Korea. Electronic address: kimjk0925@nate.com.
authors.forename: Jinkyung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Oral Microbiology and Immunology, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 700-412, South Korea. Electronic address: heonlee@knu.ac.kr.
authors.forename: Heon-Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Oral Microbiology and Immunology, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 700-412, South Korea. Electronic address: hongsu@knu.ac.kr.
authors.forename: Su-Hyung
authors.initials: SH
authors.lastname: Hong
mesh_terms: D001426:Bacterial Proteins / Q000187:drug effects / Q000235:genetics; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015169:Colony Count, Microbial; D004311:Double-Blind Method; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial / Q000187:drug effects / Q000235:genetics; D005936:Glucans / Q000235:genetics / Q000378:metabolism; D005964:Glucosyltransferases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006859:Hydrogen / Q000494:pharmacology*; D066298:In Vitro Techniques; D037102:Lectins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D009067:Mouthwashes / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D012463:Saliva / Q000382:microbiology; D013291:Streptococcus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013295:Streptococcus mutans / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D016986:Streptococcus sobrinus / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D005936:Glucans; D037102:Lectins; D009067:Mouthwashes; D012333:RNA, Messenger; C037937:glucan-binding proteins; D014867:Water; D006859:Hydrogen; D005964:Glucosyltransferases; C409029:GtfR protein, Streptococcus
keywords: Glucan-binding protein; Glucosyltransferase; Hydrogen water; Mutans streptococci; Oral biofilm; Oral rinse