Published online by Cambridge University Press: 05 April 2021
Seminal oxidative stress (OS) is a condition where the levels of oxidants overwhelm those of the antioxidants (reductants) present in the semen . The most important oxidants are reactive oxygen species (ROS), a group of oxygen-based molecules including radicals (e.g. superoxide anion – O2-.; hydroxyl radical – OH.; peroxyl radicals – ROO.; alkoxyl radicals – RO.; organic hydroperoxides – ROOH) and non-radical species (hydrogen peroxide – H2O2). Free radicals are molecules with one or more unpaired electrons in the outer orbit, which are highly reactive towards any kind of cellular components (lipids, proteins and DNA).