Evaluating the Antioxidant Effects of 8-Oxo-Deoxyguanosine in Comparison to Different Antioxidants Functioning Within the Human Body

8-Oxo-deoxyguanosine (8-oxodG), a modified form of deoxyguanosine (dG) resulting from the attack of reactive oxygen species on DNA, has been found to possess stronger antioxidant activity compared to various synthetic antioxidants. In the current study, we conducted a comparison of the antioxidant effectiveness of 8-oxodG with compounds that serve as antioxidants within our bodies, considering that 8-oxodG is produced within cells and is present in body fluids. The compounds under comparison include bilirubin, α -lipoic acid, L-carnosine, β -estradiol, α -ketoglutaric acid, melatonin, and uric acid, all of which are naturally synthesized, as well as β -carotene, quercetin, and catechin, obtained from the foods we consume. Additionally, dG and 8-oxoguanosine (8-oxoG) were included due to their structural similarity to 8-oxodG. To assess antioxidant potency, we examined the inhibition of low-density lipoprotein oxidation caused by singlet oxygen, as well as the reduction in cell viability of and U937 cells induced by radiation. Our findings revealed that among all the compounds tested, 8-oxodG exhibited the highest potency across all evaluation methods. These results strongly suggest that 8-oxodG deserves recognition as an endogenous antioxidant.