Peroxynitrite and reactive nitrogen species (RNS)

Peroxynitrite (ONOO-) is a potent, short-lived oxidant and nitrating agent formed by the diffusion-controlled reaction of nitric oxide and superoxide (Pacher et al., 2007, Physiol Rev). It is a central mediator of nitro-oxidative stress, capable of damaging proteins, lipids, and DNA through mechanisms such as tyrosine nitration and the initiation of radical chain reactions (Radi, 2013, Acc Chem Res). While it contributes to the immune system's antimicrobial defenses, its overproduction is implicated in the pathogenesis of various conditions, including neurodegenerative diseases, cardiovascular dysfunction, and chronic inflammation (Szabo et al., 2007, Nat Rev Drug Discov). Therapeutic strategies targeting peroxynitrite involve the use of scavengers or synthetic decomposition catalysts, such as metalloporphyrins, which facilitate its conversion to less reactive species. These interventions aim to restore redox homeostasis and prevent the activation of pro-apoptotic pathways and inflammatory cascades in diseased tissues. Furthermore, the development of these agents faces challenges due to the high reactivity and short half-life of the target species in vivo.

Other names

Peroxynitrite anionONOO-Reactive nitrogen speciesReactive oxygen speciesROSNitro-oxidative stress mediatorsNitrosating species

Direct scavenging of reactive species, catalytic decomposition into non-toxic products (e.g., nitrate), or inhibition of precursor radical formation from enzymes like iNOS and NADPH oxidase (Szabo et al., 2007, Nat Rev Drug Discov).