Antimutagenicity mechanisms of the Rhoeo discolor ethanolic extract.
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.
Arriaga-Alba
Myriam
M
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
Blasco
José Luis
JL
Ruíz-Pérez
Nancy Jannete
NJ
Sánchez-Navarrete
Jaime
J
Rivera-Sánchez
Roberto
R
González-Avila
Marisela
M
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
D016587:Antimutagenic Agents; D009153:Mutagens; D010936:Plant Extracts; D000431:Ethanol; D003577:Cytochrome P-450 Enzyme System