title: Beta-carotene prevents x-ray induction of micronuclei in human lymphocytes.
abstract: The effects of beta-carotene and ascorbic acid on spontaneous and x-ray-induced appearance of micronuclei (MNs) in human lymphocytes were studied. For 12 d, three groups of healthy volunteers were given beta-carotene-deficient meals containing 100 mg ascorbic acid. There was no supplementation in the first 6 d but, in the last 6 d, the respective groups were given beta-carotene (30 mg), ascorbic acid (300 mg), or placebo. Blood samples were drawn on days 7 and 13 before breakfast, exposed either to x-ray irradiation or left unexposed and were cultured. Lymphocytes containing MNs were then counted. On day 7 the three groups showed comparable MN frequencies. On day 13 lymphocytes containing x-ray-induced MNs became less frequent in the beta-carotene but not the ascorbic acid group. Both before and after the supplementation, the MN frequency of irradiated lymphocytes showed a significant inverse correlation with plasma beta-carotene. These results strongly suggest that beta-carotene protects human lymphocytes from x-ray-induced genetic damage.
authors.affiliation: Division of Applied Food Research, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Umegaki
authors.forename: S
authors.initials: S
authors.lastname: Ikegami
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Ichikawa
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
authors.forename: N
authors.initials: N
authors.lastname: Soeno
authors.forename: K
authors.initials: K
authors.lastname: Tomabechi
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000097:blood / Q000494:pharmacology*; D002338:Carotenoids / Q000097:blood / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage / Q000187:drug effects*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects* / Q000528:radiation effects; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; D004247:DNA; D001205:Ascorbic Acid