title: Antibacterial effect of Iranian green-tea-containing mouthrinse vs chlorhexidine 0.2%: an in vitro study.
abstract: OBJECTIVE
  Considering the antioxidant, anti-inflammatory and antimicrobial properties of green tea, this study aimed to evaluate the antibacterial effect of mouthrinses containing green tea extract vs 0.2% chlorhexidine on selected microorganisms in vitro.
  
  
  METHODS
  The antibacterial activity of both mouthrinses and the pure green tea extract was assessed by using disk diffusion and the minimal inhibitory concentration (MIC) methods against five microorganisms: Streptococcus mutans, Streptococcus sanguis, Enterococcus faecalis, Pseudomonas aerogenosa and Escherichia coli. Growth inhibition zones were measured in mm after 24 h of incubation at 37°C. The two mouthrinses were assessed at concentrations of 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 mg/ml to determine the MIC, which was interpreted as the lowest concentration of the agent that completely inhibited the growth of the test species.
  
  
  RESULTS
  0.2% chlorhexidine produced a larger zone of growth inhibition than did the mouthrinse made of green tea extract (P < 0.01). Paradoxically, the growth inhibition zones of the tested bacteria were significantly larger in pure extract of green tea than in 0.2% chlorhexidine (P < 0.01). The chlorhexidine mouthrinse inhibited the growth of all tested species and exhibited significantly lower MICs than did the green tea mouthrinse (P < 0.01).
  
  
  CONCLUSIONS
  Even though the mouthrinse made with green tea extract presented an in vitro antimicrobial activity inferior to 0.2% chlorhexidine, the pure extract had considerable bactericidal effect.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ardakani
authors.forename: Shima
authors.initials: S
authors.lastname: Golmohammadi
authors.forename: Sara
authors.initials: S
authors.lastname: Ayremlou
authors.forename: Soudabeh
authors.initials: S
authors.lastname: Taheri
authors.forename: Sedighe
authors.initials: S
authors.lastname: Daneshvar
authors.forename: Mansour
authors.initials: M
authors.lastname: Meimandi
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology*; D001431:Bacteriological Techniques; D028241:Camellia sinensis; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology*; D013293:Enterococcus faecalis / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D007202:Indicators and Reagents; D008422:Materials Testing; D008826:Microbial Sensitivity Tests; D009067:Mouthwashes / Q000008:administration & dosage / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects; D009580:Nitroblue Tetrazolium; D010587:Phagocytosis / Q000187:drug effects; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013298:Streptococcus sanguis / Q000187:drug effects; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D007202:Indicators and Reagents; D009067:Mouthwashes; D010936:Plant Extracts; D009580:Nitroblue Tetrazolium; D002710:Chlorhexidine