Oxidized form of endogenous antioxidant

Oxidized forms of endogenous antioxidants are the chemical products generated when cellular antioxidants, such as glutathione (GSH), vitamin C (ascorbic acid), and vitamin E (tocopherol), neutralize reactive oxygen species (ROS) or reactive nitrogen species (RNS) (Smith et al., 2004; Packer et al., 2001). Key examples include glutathione disulfide (GSSG), dehydroascorbic acid (DHA), and tocopheryl radicals. In healthy cells, these oxidized species are rapidly recycled back to their reduced, active forms by enzymatic systems like glutathione reductase and thioredoxin reductase to maintain redox homeostasis (StatPearls, 2023). However, an accumulation of these oxidized forms is a hallmark of oxidative stress and is associated with the pathophysiology of various diseases, including type 2 diabetes, neurodegenerative disorders, and cardiovascular conditions (NIH, 2022). Therapeutic agents like alpha-lipoic acid (ALA) and N-acetylcysteine (NAC) aim to restore the antioxidant balance by directly reducing these oxidized forms or providing the necessary precursors and cofactors for their enzymatic regeneration (PubChem, 2024).

Other names

Oxidized endogenous antioxidantsAntioxidant radicalsDehydroascorbic acidGlutathione disulfideTocopheryl quinoneOxidized redox couples

Drugs targeting these oxidized forms typically act as reducing agents or cofactors for recycling enzymes, facilitating the conversion of oxidized antioxidants (e.g., GSSG, dehydroascorbic acid) back into their active, reduced states (e.g., GSH, ascorbic acid) to restore cellular antioxidant capacity (Smith et al., 2004; Packer et al., 2001).