title: Relationship between cellular levels of beta-carotene and sensitivity to genotoxic agents.
abstract: The usefulness of an in vitro test system to predict the inhibitory effect of beta-carotene on the genotoxic activity of carcinogens/mutagens was explored. To facilitate the comparison of data obtained from cultured cells (CHO) and from exfoliated human cells, endpoints were used which can be quantitated in both cell systems: the frequency of micronuclei for estimating the effect of genotoxic agents, and cellular levels of beta-carotene as a protective agent. In CHO cells, beta-carotene inhibited the clastogenic and micronucleus-forming effect of methyl methanesulfonate (MMS) and 4-nitroquinoline-1-oxide (4NQO), but had no protective action against gallic acid, tannic acid, and aqueous extract of areca nut or H2O2. The extent of inhibition depended on the ratio of beta-carotene to MMS. Doses of beta-carotene which exerted a protective effect in vitro ranged from approximately 2 to 5 ng per 10(6) CHO cells. Comparable levels of beta-carotene were previously found to reduce the frequency of micronucleated exfoliated cells from the buccal mucosa of tobacco and areca-nut chewers (Stich et al., 1984b).
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology*; D002338:Carotenoids / Q000032:analysis*; D002470:Cell Survival / Q000187:drug effects*; D002869:Chromosome Aberrations / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D005707:Gallic Acid / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047348:Hydrolyzable Tannins / Q000494:pharmacology; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D009152:Mutagenicity Tests; D009153:Mutagens / Q000494:pharmacology*; D010053:Ovary / Q000032:analysis / Q000166:cytology / Q000187:drug effects; D019207:beta Carotene
chemical_list: D002273:Carcinogens; D047348:Hydrolyzable Tannins; D009153:Mutagens; D019207:beta Carotene; D002338:Carotenoids; D015112:4-Nitroquinoline-1-oxide; D005707:Gallic Acid; D008741:Methyl Methanesulfonate; D006861:Hydrogen Peroxide