The steady-state levels of oxidative DNA damage and of lipid peroxidation (F₂-isoprostanes) are not correlated in healthy human subjects

Abstract

Oxidative damage to DNA in human tissues can be determined by measuring multiple products of oxidative damage to the purine and pyrimidine bases using gas chromatography-mass spectrometry (GC-MS). Oxidative damage to lipids (lipid peroxidation) can be quantitated by the mass spectrometry-based determination of F₂-isoprostanes, specific end-products of the peroxidation of arachidonic acid residues in lipids. For both DNA base damage products and 8-epi prostaglandin F_2α (PGF_2α), there is a wide variation in levels between different healthy human subjects. We measured multiple products of oxidative damage to DNA bases in white cells, and 8-epi PGF_2α in plasma, from blood samples obtained from healthy human subjects in the UK and in Portugal. No correlation of 8-epi PGF_2α levels with levels of any modified DNA base (including 8-hydroxyguanine) was observed. We conclude that no single parameter can be measured as an index of “oxidative stress” or “oxidative damage” in vivo.

Keywords:

• Oxidative DNA damage
• lipid peroxidation
• isoprostanes
• F₂-isoprostanes
• 8-hydroxyguanine
• antioxidant