title: Induction of sister chromatid exchanges and chromosome aberrations in cultured mammalian cells treated with aminophenylnorharman formed by norharman with aniline.
abstract: Aminophenylnorharman (APNH) is a newly identified mutagenic heterocyclic amine formed by coupling of norharman with aniline in the presence of S9 mix. Furthermore, mutagenic amino-3'-methylphenylnorharman (AMPNH) and aminophenylharman (APH) have been identified from a reaction mixture of norharman and o-toluidine and that of harman and aniline, respectively, with S9 mix. Among these three heterocyclic amines, APNH shows most potent mutagenic activity towards Salmonella typhimurium TA98 and YG1024 with S9 mix. In the present study, the induction of sister chromatid exchanges (SCEs) by APNH was examined in Chinese hamster lung (CHL) cells in vitro, comparing it to those of AMPNH and APH. On incubation with rat S9 for 6h, followed by a recovery culture period of 18h, a dose-dependent effect was found at concentrations between 0.00125 and 0.01 microg/ml for APNH and between 0.3125 and 5 microg/ml for AMPNH and APH. The approximate chemical concentrations leading to a three-fold of control SCE levels calculated from slopes of the linear regressions of induced SCEs were 0.005 for APNH, 0.51 for AMPNH and 1.7 microg/ml for APH. Because of the very strong SCE-causing ability of APNH, we further explored its genotoxicity by examining the induction of chromosome aberrations in CHL cells. A dose-dependent effect was found for chromosome aberrations at concentrations between 0.00125 and 0.04 microg/ml of APNH. The aberrations observed were primarily chromatid exchanges (cte) and breaks (ctb). In conclusion, the potency of SCE induction and clastogenic activity induced by APNH is stronger than Actinomycin D, Mitomycin C (MMC) or 1,8-dinitropyrene which are considered to be the potent clastogens in the literature. Further studies are needed for elucidating mechanisms of the genotoxic actions of these compounds and for evaluating their potential hazards to human health.
authors.affiliation: Department of Food and Nutrition, Kyoto Women's University, 35 Kitahiyoshi-cho, Imakumano, Higashiyama-ku, 605-8501, Kyoto, Japan. ooe@kyoto-wu.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohe
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takata
authors.forename: Yoko
authors.initials: Y
authors.lastname: Maeda
authors.forename: Yukari
authors.initials: Y
authors.lastname: Totsuka
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Hada
authors.forename: Atsuko
authors.initials: A
authors.lastname: Matsuoka
authors.forename: Noriho
authors.initials: N
authors.lastname: Tanaka
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D000814:Aniline Compounds / Q000378:metabolism*; D000818:Animals; D002243:Carbolines; D002273:Carcinogens / Q000633:toxicity*; D002460:Cell Line; D002869:Chromosome Aberrations / Q000187:drug effects*; D006224:Cricetinae; D003412:Cricetulus; D018736:DNA Adducts / Q000378:metabolism; D006247:Harmine / Q000031:analogs & derivatives* / Q000378:metabolism*; D007211:Indoles / Q000633:toxicity*; D008168:Lung / Q000378:metabolism; D008937:Mitomycins / Q000009:adverse effects; D009153:Mutagens / Q000737:chemistry / Q000378:metabolism*; D011725:Pyridines / Q000633:toxicity*; D012486:Salmonella typhimurium / Q000378:metabolism; D012854:Sister Chromatid Exchange / Q000187:drug effects*
chemical_list: D000814:Aniline Compounds; D002243:Carbolines; D002273:Carcinogens; D018736:DNA Adducts; D007211:Indoles; D008937:Mitomycins; D009153:Mutagens; D011725:Pyridines; D006247:Harmine; C010262:norharman; C421010:9-(4'-aminophenyl)-9H-pyrido(3,4-b)indole; C023650:aniline