Formation of 8-hydroxy-2'-deoxyguanosine following treatment of 2'-deoxyguanosine or DNA by hydrogen peroxide or glutathione

Mutat Res. 1997 Apr 24;390(1-2):45-50. doi: 10.1016/s0165-1218(96)00164-4.


We have demonstrated that free radicals generated by hydrogen peroxide (H2O2), in the presence of divalent iron (Fe2+) and a chelator (EDTA), oxidize 2'-deoxyguanosine (dG) to 8-hydroxy-2'-deoxyguanosine (8-OHdG). The 8-OHdG formed by this reaction was isolated and quantitated using reverse-phase HPLC with UV and electrochemical detection. A 1-h incubation of dG with H2O2 caused a 50% increase in 8-OHdG over background, which increased to 100% after 2 h. However, when an H2O2-generating system [glutathione (GSH), Fe2+, EDTA] was used, there was no increase in 8-OHdG yield after the 1-h incubation, but up to a 50% increase over background was observed with GSH after 2-h incubation. Attempts to detect increased levels of 8-OHdG after H2O2- or GSH-treatment of purified calf thymus or rat DNA, or purified Salmonella typhimurium DNA were not successful. This may have been because the treatment procedures used generated 8-OHdG in the control samples at sufficiently high levels to mask any H2O2-induced responses that may have been present. This artifactual production of 8-OHdG has presented a problem in all in vitro studies to date. In contrast, treatment of Salmonella cells (strain TA104) with increasing concentrations of H2O2, caused a doubling in the 8-OHdG yield. GSH-treatment of strain TA104 cells under the same conditions did not result in an increase of 8-OHdG. The study presented here shows that the ubiquitous molecule H2O2 can play a major role in DNA oxidation, mutation, and damage.

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Animals
  • Antidotes / pharmacology
  • Cattle
  • DNA / drug effects*
  • DNA / isolation & purification
  • DNA / metabolism
  • DNA Damage
  • Deoxyguanosine / analogs & derivatives*
  • Deoxyguanosine / chemistry
  • Deoxyguanosine / metabolism
  • Deoxyribonuclease I / metabolism
  • Dose-Response Relationship, Drug
  • Edetic Acid / chemistry
  • Free Radicals / metabolism
  • Glutathione / pharmacology*
  • Hydrogen Peroxide / pharmacology*
  • Hydrolysis
  • Iron / chemistry
  • Oxidants / pharmacology
  • Rats
  • Salmonella / drug effects
  • Salmonella / genetics*
  • Time Factors


  • Antidotes
  • Free Radicals
  • Oxidants
  • 8-Hydroxy-2'-Deoxyguanosine
  • DNA
  • Edetic Acid
  • Hydrogen Peroxide
  • Iron
  • Deoxyribonuclease I
  • Deoxyguanosine
  • Glutathione