Reactive oxygen species and oxidative stress markers (ROS/OS markers)

Reactive oxygen species (ROS) and oxidative stress markers represent a broad category of chemically reactive molecules and the biological indicators used to measure their impact on cellular health. ROS, including free radicals like superoxide and non-radicals like hydrogen peroxide, are natural byproducts of oxygen metabolism that play essential roles in cell signaling, growth, and the immune response (oxidative burst). However, an imbalance between the production of these species and the body's antioxidant defense mechanisms leads to oxidative stress, which causes cumulative damage to DNA, lipids, and proteins. This damage is quantified through specific biomarkers such as malondialdehyde (MDA) for lipid peroxidation and 8-hydroxy-2'-deoxyguanosine (8-OHdG) for DNA damage, which serve as critical tools for monitoring disease progression in conditions like cancer, neurodegeneration, and cardiovascular disease. While ROS are not traditional receptors, they are central therapeutic targets; drugs may act by scavenging radicals, inhibiting ROS-producing enzymes like NADPH oxidase, or activating the Nrf2 pathway to bolster the cell's natural antioxidant capacity. Conversely, some chemotherapies utilize pro-oxidant strategies to selectively kill cancer cells by overwhelming their redox defenses.

Other names

ROSReactive oxygen speciesOxidative stress biomarkersPro-oxidantsFree radicalsReactive nitrogen species (RNS)

Drugs interact with this system by scavenging reactive species (antioxidants), inhibiting ROS-generating enzymes such as NADPH oxidase or xanthine oxidase, activating antioxidant transcription factors like Nrf2 to induce endogenous defenses, or intentionally inducing ROS to trigger apoptosis in cancer cells (pro-oxidant therapy).