title: beta-Carotene inhibition of chemically induced toxicity in vivo and in vitro.
abstract: In the past several years there has been a great deal of interest in the antioxidant beta-carotene and other micronutrients for their protective potential against various toxic insults. Two studies concerning the protective effects of beta-carotene, which were conducted in our laboratory, are reported here. The first involved the role of beta-carotene in modifying two-stage skin tumorigenesis initiated by 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by phorbol 12-myristate 13-acetate (PMA, TPA). In this study, the protective effects of two types of dietary beta-carotene, a beadlet formulation and crystalline beta-carotene, were compared in two strains of mice (Skh:HR-1 and CR:ORL Sencar). Mice were maintained on food fortified with 3% beta-carotene or on control diets. Mice receiving the beta-carotene-supplemented diets had fewer tumours than mice in the control groups. However, only in the Skh strain of mice was this difference statistically significant. In the second study, an in vitro experiment, BALBc 3T3 mouse fibroblasts were used to determine beta-carotene's accumulation in cells and the ability of these cells to metabolize beta-carotene to vitamin A. This in vitro model was also used to show a beta-carotene protective effect towards 8-MOP phototoxicity. These studies contributed to the increasing evidence of in vivo and in vitro protection by beta-carotene against chemically induced toxicity.
authors.affiliation: Center for Food Safety and Applied Nutrition, Food and Drug Administration, Washington, DC 20204.
authors.forename: A
authors.initials: A
authors.lastname: Kornhauser
authors.forename: W G
authors.initials: WG
authors.lastname: Wamer
authors.forename: L A
authors.initials: LA
authors.lastname: Lambert
authors.forename: R R
authors.initials: RR
authors.lastname: Wei
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000821:Animal Feed; D000818:Animals; D002338:Carotenoids / Q000627:therapeutic use*; D002460:Cell Line; D004032:Diet; D005347:Fibroblasts / Q000187:drug effects; D051379:Mice; D012878:Skin Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D013755:Tetradecanoylphorbol Acetate; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D002338:Carotenoids; D015127:9,10-Dimethyl-1,2-benzanthracene; D013755:Tetradecanoylphorbol Acetate