Reactive oxygen species and electrophilic xenobiotics (ROS/Electrophiles)

Reactive oxygen species (ROS) and electrophilic xenobiotics are chemically reactive molecules that play dual roles as essential signaling messengers and mediators of cellular damage. ROS, including superoxide anions and hydrogen peroxide, are primarily generated as byproducts of mitochondrial respiration or by enzymes like NADPH oxidases (NOX), while electrophilic xenobiotics are electron-deficient foreign compounds that can covalently modify cellular nucleophiles such as DNA and proteins (Sies et al., 2017, Nature Reviews Molecular Cell Biology). Under physiological conditions, these species are tightly regulated by antioxidant systems; however, an imbalance leads to oxidative and electrophilic stress, which is a hallmark of chronic diseases including cancer, atherosclerosis, and Alzheimer's disease (Forman & Zhang, 2021, Nature Reviews Drug Discovery). While not traditional protein targets, they are therapeutically addressed through the use of antioxidants that scavenge reactive species or by pharmacological activators of the Nrf2 transcription factor, which upregulates detoxification enzymes (Baird & Dinkova-Kostova, 2011, Archives of Toxicology). Targeting the flux of these reactive species remains a challenge due to the risk of disrupting beneficial redox-sensitive pathways required for normal cell function and immune response.

Other names

Reactive oxygen speciesElectrophilic speciesOxidantsFree radicalsReactive oxygen intermediatesElectrophilic xenobiotics

Direct scavenging of free radicals, neutralization of electrophilic centers through nucleophilic attack, and induction of endogenous antioxidant defenses via the Keap1-Nrf2-ARE signaling pathway.