Reactive oxygen species and redox-related free radicals (ROS)

Reactive oxygen species (ROS) and redox-related free radicals are highly reactive chemical molecules formed as natural byproducts of oxygen metabolism, primarily during mitochondrial respiration. These species, which include superoxide, hydrogen peroxide, and hydroxyl radicals, function as critical signaling molecules in processes such as cell growth and the immune response when maintained at low levels (NIH, 2023). However, an imbalance between ROS production and the body's antioxidant defense mechanisms leads to oxidative stress, causing cumulative damage to DNA, proteins, and lipids (PubMed, PMC7673115). This damage is a key driver in the progression of chronic diseases, including cancer, atherosclerosis, and neurodegenerative conditions like Parkinson's disease (StatPearls, NBK545169). Therapeutic approaches targeting ROS involve the use of antioxidant scavengers or the modulation of redox-active enzymes to prevent cellular injury and restore physiological balance.

Other names

Free radicalsOxidantsReactive nitrogen speciesRNSSuperoxideHydrogen peroxideHydroxyl radicalSinglet oxygen

Direct chemical neutralization (scavenging) of reactive species, donation of electrons to stabilize free radicals, and upregulation of endogenous antioxidant enzymes to mitigate oxidative stress.