Reactive oxygen species and local redox state (ROS) (ROS)

Reactive oxygen species (ROS) are highly reactive oxygen-derived molecules, including free radicals like superoxide and hydroxyl radicals, as well as non-radicals like hydrogen peroxide [NIH, 2023]. They are primarily generated as byproducts of mitochondrial oxidative phosphorylation or by specialized enzymes such as NADPH oxidases (NOX) [Nature Reviews Molecular Cell Biology, 2020]. At physiological levels, ROS function as essential secondary messengers in signal transduction pathways that regulate cell growth, differentiation, and immune responses [Frontiers in Physiology, 2021]. However, an imbalance between ROS production and the capacity of antioxidant defense systems leads to oxidative stress, causing oxidative damage to DNA, lipids, and proteins [Journal of Clinical Investigation, 2018]. This "local redox state" dysregulation is a central feature in the pathogenesis of various conditions, including cancer, cardiovascular diseases, and neurodegeneration [PubMed, 2022]. Pharmacological intervention typically involves the use of antioxidants to scavenge ROS or the activation of the Nrf2-KEAP1 pathway to enhance endogenous antioxidant expression [PubChem, 2023].

Other names

Oxidative stressRedox environmentReactive oxygen intermediatesROIFree radicals

Drugs targeting the redox state typically function by directly scavenging free radicals, neutralizing reactive oxygen species, activating endogenous antioxidant pathways such as the Nrf2-KEAP1 system, or inhibiting enzymes responsible for ROS production like NADPH oxidase [Nature Reviews Drug Discovery, 2014].