8-hydroxyguanine (8-OHG) helps in determining the reactive oxygen species (ROS)-induced modification of a purine residue in DNA. It is a sensitive marker of oxidative DNA damage. Overexpression of the gene has been observed in diabetic patients, especially those with advanced microvascular complications. Thus, 8-OHG functions as a novel biomarker for identifying oxidative DNA damage in diabetic patients. Plasma level of 8-OHG elevates with the age, with cigarette smoking and during tumorigenesis. 8-OHG levels in urine is considered as a biomarker of the total systemic oxidative stress in vivo. Overexpression of 8-OHG has been observed in various neurodegenerative diseases such as Parkinson′s disease (PD) and multiple system atrophy (MSA).
