Urinary hydrogen peroxide as biomarker

Hydrogen peroxide can be found in human urine, not only in persons with diseases, but also in healthy individuals. In the body, hydrogen peroxide plays dual roles: on the one hand, it can produce more dangerous reactive oxygen species - hydroxyl radicals, which cause damage to the cells; on the other hand, it is considered as "a signaling molecule" to regulate the cellular processes. In this chapter, we will review the literature linking H₂O₂ excretion in urine of healthy individuals and of persons with diseases and present the available methods that have been used for detection of urinary H₂O₂ in human. We also give a brief overview on the association of urinary levels of H₂O₂ with other oxidative stress biomarkers and discuss the possibility whether urinary H₂O₂ could be a useful biomarker for the assessment of the oxidative status in human and for the prediction of the pathogenesis and progression of diseases.