title: Antimutagenicity mechanisms of the Rhoeo discolor ethanolic extract.
abstract: BACKGROUND
  Rhoeo discolor, a medical plant from Mexico, is known to be an antioxidant and chemoprotective antimutagen. Rhoeo discolor ethanolic extract (EERD) is a complex mixture, so in this study its antimutagenic mechanisms were further evaluated.
  
  
  METHODS
  Employing Ames test, with uvrB- and uvrB+ strains, its antimutagenic activity against frameshift mutagens 2-amino-anthracene (AA), and 2 amino-fluorene (AF), alkylating: methyl-N'-nitro-N-nitrosoguanidine (MNNG) and ethyl-N'-nitro-N-nitrosoguanidine (ENNG) and mitomycin C were evaluated. Induction of ogt, alkyl-DNA-glycosylases were studied with Salmonella typhimurium strains deficient in ada and ogt genes (YG7100 ada-/ogt+ YG7104 ada+/ogt-, G7108 ada-/ogt-).
  
  
  RESULTS
  EERD, was not antimutagenic against AA or AF on S. typhimurium TA98 neither in UTH8413 uvrB+ strains. It significantly reduced mutations induced by Mitomycin C on strain TA102. EERD was antimutagenic to mutations induced by alkylating compounds on S. typhimurium TA100 or UTH8414 uvrB+. This antimutagenic effect was not observed on strains lacking ogt gene.
  
  
  CONCLUSIONS
  EERD, did not affect CYP450 in vitro microsomal activation of AF or AA, on the Ames test, neither improved DNA uvrB excision repair system. EERD reduced oxidative damages on strain TA102, caused by Mitomycin C. This plant extract might be used to avoid DNA damage by alkylation, corrected mainly alkylguanine transferase protein encoded by ogt gene.
authors.affiliation: Microbiology Research Laboratory, Hospital Juárez de México, Av Instituto Politécnico Nacional No 5170, Col. Magdalena de las Salinas México D.F. 07760, Mexico. arriaga_alba@yahoo.com
authors.forename: Myriam
authors.initials: M
authors.lastname: Arriaga-Alba
authors.forename: José Luis
authors.initials: JL
authors.lastname: Blasco
authors.forename: Nancy Jannete
authors.initials: NJ
authors.lastname: Ruíz-Pérez
authors.forename: Jaime
authors.initials: J
authors.lastname: Sánchez-Navarrete
authors.forename: Roberto
authors.initials: R
authors.lastname: Rivera-Sánchez
authors.forename: Marisela
authors.initials: M
authors.lastname: González-Avila
mesh_terms: D016587:Antimutagenic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D034821:Commelinaceae / Q000737:chemistry* / Q000254:growth & development; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D000431:Ethanol; D016368:Frameshift Mutation; D008800:Mexico; D009152:Mutagenicity Tests; D009153:Mutagens / Q000737:chemistry / Q000633:toxicity; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D016587:Antimutagenic Agents; D009153:Mutagens; D010936:Plant Extracts; D000431:Ethanol; D003577:Cytochrome P-450 Enzyme System