title: Effect of ascorbate and 5-aminosalicylic acid on light-induced 8-hydroxydeoxyguanosine formation in V79 Chinese hamster cells.
abstract: Recently we showed that ascorbate and 5-aminosalicylic acid (5-ASA) prevented 8-hydroxydeoxyguanosine (8-OHdG) formation in calf thymus DNA exposed to UV-visible light. However, the ultimate defense against oxidative DNA damage depends on an intracellular/intranuclear effect of the compounds. In the present study we investigated the effect of ascorbate and 5-ASA on 8-OHdG formation in V79 Chinese hamster cells exposed to light from a sun-lamp. Exposure for 1 min (4560 mJ/cm2) increased 8-OHdG formation in cellular DNA to 30-40 times background level. Preincubation of the cells with ascorbate or 5-ASA at concentrations of 0.1, 1 and 10 mM diminished the 8-OHdG formation to 0.67, 0.74 and 0.49 times controls (P < 0.05) for ascorbate respectively, and to 0.82, 0.66 and 0.33 times controls (P < 0.05), for 5-ASA. These findings demonstrate that both ascorbate and 5-ASA prevent oxidative DNA damage in cells by acting as intracellular/intranuclear antioxidants.
authors.affiliation: Department of Pharmacology, Panum Institute, University of Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Fischer-Nielsen
authors.forename: S
authors.initials: S
authors.lastname: Loft
authors.forename: K G
authors.initials: KG
authors.lastname: Jensen
mesh_terms: D000636:Aminosalicylic Acids / Q000494:pharmacology*; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D006151:Guanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D008027:Light; D019804:Mesalamine; D014466:Ultraviolet Rays
chemical_list: D000636:Aminosalicylic Acids; D006151:Guanosine; C046215:8-hydroxyguanosine; D019804:Mesalamine; D004247:DNA; D001205:Ascorbic Acid