The impact of oxidative stress on female reproduction and art: An evidence-based review

Introduction, Aerobic metabolism is associated with the generation of pro-oxidant molecules called free radicals or reactive oxygen species (ROS) that include the hydroxyl radicals, superoxide anion, hydrogen peroxide, and nitric oxide. There is a complex interaction of the pro-oxidants and antioxidants, resulting in the maintenance of the intracellular homeostasis. Whenever there is an imbalance between the pro-oxidants and antioxidants, a state of oxidative stress (OS) is initiated. Overview of os and ros, Under normal conditions, paired electrons create stable bonds in biomolecules. However, if the bond is weak, it might break, leading to the formation of free radicals. Free radicals are defined as any species with one or more unpaired electrons in the outer orbit that include ROS such as superoxide, hydrogen peroxide, hydroxyl, and singlet oxygen radicals. They are generally very small molecules and are highly reactive due to the presence of unpaired valence shell electrons, initiating a cascade of reactions of more free radicals leading to uncontrolled chain reactions (1). Free radicals such as the superoxide radical are formed when high-energy electrons leak from the electron transport chain. The dismutation of superoxide results in the formation of hydrogen peroxide. The hydroxyl ion is a major type of ROS that is highly reactive, having the ability to modify purine and pyrimidines and cause damaging DNA strand breaks (2,3). ROS are formed endogenously as a natural byproduct of aerobic metabolism and through the activity of various metabolic pathways and enzymes of oocytes and embryos.