title: Oligonucleotides are potent antioxidants acting mainly as metal-ion chelators.
abstract: We explored by ESR the potential of 2'-deoxy-oligonucleotides as biocompatible inhibitors of the Fe(II)/Cu(I)/(II)-induced *OH formation from H(2)O(2). d(A)(5), (2'-OMe-A)(5), d(A)(7), d(A)(20), and d(T)(20), proved highly potent antioxidants (IC(50): 5-17 or 48-85 microM in inhibiting Fe(II)/Cu(I)- or Cu(II)-induced H(2)O(2)- decomposition), representing 40 to 215 - fold increase of potency as compared to Trolox. The antioxidant activity does not depend on the oligonucleotides' length or composition. The primary inhibition mechanism by oligonucleotides is metal-ion chelation and the secondary is radical scavenging. (1)H-, (31)P-NMR and ESR data suggest that Cu coordination involves adenine bases and 1-2 phosphates. We propose the use of short, metabolically stable oligonucleotides as highly potent and long-lived (t(1/2) ca. 20 h) antioxidants that may prevent oxidative damage.
authors.affiliation: Department of Chemistry, Gonda-Goldschmied Medical Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel. bfischer@mail.biu.ac.il
authors.forename: Bilha
authors.initials: B
authors.lastname: Fischer
authors.forename: Eyal
authors.initials: E
authors.lastname: Zobel
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D002614:Chelating Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D003300:Copper / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D006207:Half-Life; D007502:Iron Chelating Agents / Q000737:chemistry; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D002614:Chelating Agents; D007502:Iron Chelating Agents; D009838:Oligodeoxyribonucleotides; D003300:Copper