Reactive oxygen and nitrogen species and redox-sensitive cellular components (ROS/RNS)

Reactive oxygen and nitrogen species (ROS/RNS) are a diverse group of highly reactive molecules, including superoxide, hydrogen peroxide, and peroxynitrite, that are generated as natural byproducts of cellular metabolism and immune activity (Sies & Jones, 2020, Nature Reviews Molecular Cell Biology). While they function as essential secondary messengers in physiological signaling pathways, an imbalance between their production and the capacity of antioxidant systems leads to oxidative and nitrosative stress. This stress results in the modification of redox-sensitive cellular components, such as the oxidation of cysteine thiols in proteins, lipid peroxidation, and oxidative DNA damage (Di Meo et al., 2016, Oxidative Medicine and Cellular Longevity). Such damage is implicated in the pathogenesis of various conditions, including neurodegenerative diseases, cardiovascular disorders, and chronic inflammation. Therapeutic interventions, such as the use of N-acetylcysteine or Edaravone, aim to neutralize these reactive species or enhance endogenous antioxidant defenses to mitigate cellular injury (Abe et al., 2014, Expert Opinion on Pharmacotherapy). However, targeting these species is challenging due to their dual role in both essential signaling and pathological damage, often leading to poor clinical outcomes for non-specific antioxidant therapies.

Other names

Reactive oxygen speciesReactive nitrogen speciesOxidative stress mediatorsFree radicalsRedox-sensitive thiols

Direct chemical neutralization of free radicals, donation of electrons to reactive species, and induction of endogenous antioxidant enzymes via pathways such as Nrf2-ARE (PMID: 25672622, PMID: 28249519).