title: Comparative study of the antimutagenic properties of vitamins C and E against mutation induced by norfloxacin.
abstract: BACKGROUND
  Norfloxacin like other fluoroquinolones, is known to mbe mutagenic for Salmonella typhimurium TA102 strain. This mutagenic effect is due to free oxygen radicals (ROS), because it is inhibited by antioxidants such as beta-carotene and naturally occurring antioxidants of Roheo discolor and other plants. The aim of this work was to evaluate combination therapy with norfloxacin and vitamins C and E, to reduce the possible genotoxic risk associated with fluoroquinolones.
  
  
  METHODS
  The antimutagenicity of alpha-tocoferol (Vitamin E) and ascorbic acid (Vitamin C) against norfloxacin-induced mutation was evaluated on S. typhimurium TA102, using the aroclor-1254-induced S9 rat liver homogenate. The minimum inhibitory concentration (MIC) a measure of the bactericidal effect of norfloxacin, was obtained in vitro by the plate dilution method.
  
  
  RESULTS
  Vitamin E (0.5 mg per Petri dish) induced a statistically significant reduction (P < 0.001) in the mutagenicity of norfloxacin, whereas Vitamin C (1 mg per Petri dish) had no such effect. Neither of these vitamins altered the MIC for norfloxacin against 25 uropathogenic strains of Escherichia coli.
  
  
  CONCLUSIONS
  These results suggest that Vitamin E is a potent antimutagen that would be worthwhile being used in conjunction with fluoroquinolone treatment. The minimal antimutagenic effect of Vitamin C observed under these experimental conditions may have been because Vitamin C in the Ames test induces a Fenton reaction, and if divalent cations are present, it can act as a pro-oxidant rather than an antioxidant. Ascorbic acid should be further evaluated in the presence of different divalent cations concentrations.
authors.affiliation: Hospital Juárez de México, Dirección de Investigación y Enseñanza, Av, Instituto Politécnico Nacional No, 5160, Magdalena de las Salinas, DF, 07760, México. arriaga_alba@yahoo.com
authors.forename: Myriam Arriaga
authors.initials: MA
authors.lastname: Alba
authors.forename: Roberto Rivera
authors.initials: RR
authors.lastname: Sánchez
authors.forename: Nancy Jannet Ruíz
authors.initials: NJ
authors.lastname: Pérez
authors.forename: Jaime Sánchez
authors.initials: JS
authors.lastname: Navarrete
authors.forename: Rocío Flores
authors.initials: RF
authors.lastname: Paz
authors.forename: Araceli
authors.initials: A
authors.lastname: Montoya-Estrada
authors.forename: Juan José Hicks
authors.initials: JJ
authors.lastname: Gómez
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D016587:Antimutagenic Agents / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001711:Biotransformation; D009152:Mutagenicity Tests; D009153:Mutagens / Q000494:pharmacology*; D009154:Mutation; D009643:Norfloxacin / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D012486:Salmonella typhimurium / Q000235:genetics; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D016587:Antimutagenic Agents; D009153:Mutagens; D014810:Vitamin E; D009643:Norfloxacin; D001205:Ascorbic Acid