Enhancement of the chromosome-damaging action of ascorbate by transition metals.
Freshly prepared ascorbate inhibited mitosis and induced chromosome aberrations in cultured Chinese hamster ovary cells. Cu(II) and Mn(II) (10(-4) or 10(-5) M) enhanced both actions. Fe(II) and Fe(III) (10(-4) or 10(-5) M) reduced or abolished the mitosis-inhibiting action of ascorbate. At 10(-4) M, Fe(II) and Fe(III) strongly enhanced the chromosome-damaging capacity of ascorbate. Up to 100% of all examined metaphase plates had multiple chromosome exchanges or breaks. Since the cytostatic and clastogenic effect of ascorbate of H2O2 to induce chromosome aberrations was examined. H2O2 and a H2O2: Fe(II) mixture (Fenton reagent) induced chromosome breaks and exchanges but to a lesser degree than did ascorbate: Cu(II), Mn(II), Fe(II), or Fe(III) mixtures. Whether the strong chromosome damaging capacity of ascorbate plus transition metals as seen in the in vitro test system poses a health hazard only properly designed in vivo studies can reveal.
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D003300:Copper / Q000494:pharmacology*; D006224:Cricetinae; D004357:Drug Synergism; D005260:Female; D005290:Ferric Compounds / Q000494:pharmacology; D005296:Ferrous Compounds / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D008345:Manganese / Q000494:pharmacology*; D010053:Ovary
D005290:Ferric Compounds; D005296:Ferrous Compounds; D008345:Manganese; D003300:Copper; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid