title: Effect of beta-carotene on clastogenic effects of mitomycin C, methyl methanesulphonate and bleomycin in Chinese hamster ovary cells.
abstract: The effect of beta-carotene on the frequencies of micronuclei (MN) induced in cytochalasin blocked binucleated Chinese hamster ovary cells (CHO) by a bifunctional alkylating agent mitomycin C (MMC), a monofunctional alkylating agent methyl methanesulphonate (MMS) and a radio-mimetic agent bleomycin (BLEO) was investigated. Four different modes of application of the combination of clastogens and beta-carotene were examined (pre-treatment, simultaneous treatment, pre- +simultaneous treatment and post-treatment). The results obtained showed no effect of beta-carotene on the frequencies of MN induced by MMS, a slight but not statistically significant reduction of MMC-induced MN only when beta-carotene was used in low concentrations (0.25 and 0.5 microM) and a potentiation of the clastogenicity of bleomycin by beta-carotene in three of the treatment regimes utilized, post-treatment being ineffective. On the basis of these results it can be concluded that the effect of beta-carotene on clastogenesis induced by chemicals depends on the type and mechanism of action of the clastogen used as well as the treatment protocol employed.
authors.affiliation: MGC Department of Radiation Genetics and Chemical Mutagenesis, Sylvius Laboratory, State University of Leiden, The Netherlands.
authors.forename: D M
authors.initials: DM
authors.lastname: Salvadori
authors.forename: L R
authors.initials: LR
authors.lastname: Ribeiro
authors.forename: A T
authors.initials: AT
authors.lastname: Natarajan
mesh_terms: D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology*; D001761:Bleomycin / Q000037:antagonists & inhibitors / Q000633:toxicity; D016466:CHO Cells / Q000187:drug effects / Q000648:ultrastructure; D002338:Carotenoids / Q000494:pharmacology*; D006224:Cricetinae; D008741:Methyl Methanesulfonate / Q000037:antagonists & inhibitors / Q000633:toxicity; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects* / Q000648:ultrastructure; D016685:Mitomycin / Q000037:antagonists & inhibitors / Q000633:toxicity; D009152:Mutagenicity Tests; D019207:beta Carotene
chemical_list: D016587:Antimutagenic Agents; D019207:beta Carotene; D001761:Bleomycin; D002338:Carotenoids; D016685:Mitomycin; D008741:Methyl Methanesulfonate