Reactive oxygen species and ROS-generating systems (ROS)

Reactive oxygen species (ROS) are highly reactive oxygen-containing molecules, such as superoxide radicals and hydrogen peroxide, that are generated as natural byproducts of cellular metabolism (NCBI, PMC3070774). ROS-generating systems include enzymes like NADPH oxidases (NOX), xanthine oxidase, and the mitochondrial electron transport chain, which play vital roles in cell signaling and the immune response (PubMed, 22703241). However, an imbalance between ROS production and antioxidant defenses leads to oxidative stress, which causes damage to DNA, proteins, and lipids (NIH, 2023). This damage is a key driver in the pathogenesis of various conditions, including cancer, cardiovascular diseases, and neurodegenerative disorders like Alzheimer's (PubMed, 28249118). Therapeutic interventions target these systems through direct scavenging of radicals, inhibition of ROS-producing enzymes, or the induction of endogenous antioxidant pathways (PubChem). Despite their potential, therapeutic targeting is complicated by the need to preserve physiological ROS levels required for normal cellular communication and host defense (PubMed, 23953108).

Other names

OxidantsReactive oxygen metabolitesOxygen free radicalsPro-oxidantsOxidative stress systems

Mechanisms include direct neutralization of reactive species (scavenging), inhibition of enzymatic sources such as NADPH oxidase or xanthine oxidase, and pharmacological activation of the Nrf2-mediated antioxidant response.