Analysis of 8-OH-dG and 8-OH-Gua as Biomarkers of Oxidative Stress

Abstract

Reactive oxygen species (ROS) are generated by environmental factors, such as ionizing radiation and chemical carcinogens, and also by endogenous processes, including energy metabolism in mitochondria. In 1984, Kasai and colleaguesˆrstcolleaguesˆrst reported the detection of 8-hydroxy-deoxyguanosine (8-OH-dG), a type of oxidative damage in DNA formed by Fenton-type reagents and X-irradiation in vitro. Further studies of the mechanisms of 8-OH-dG formation by various carcinogens suggested that it is generated by a wide variety of agents with diŠerent mechanisms of action. 8-OH-dG is biologically signiˆcant, since it induces mutations and has speciˆc repair systems. 8-OH-dG is one of the major forms of oxidative DNA damage, and it has been well studied because it is relatively easy to detect by using a high performance liquid chromatography-elec-trochemical detector (HPLC-ECD) system. In this review, we summarize the methods to analyze 8-OH-dG in cellular DNA and urine, and the free base, 8-hydroxyguanine (8-OH-Gua), in urine and serum.