Glutathione is the principal intracellular antioxidant, and the balance between its reduced and oxidised forms is central to how cells manage oxidative stress.
This research area investigates how cells synthesize, distribute, and regulate glutathione (GSH), a cysteine-containing tripeptide, and how it maintains redox balance during oxidative stress. Studies report that GSH is the most abundant intracellular non-enzymatic antioxidant, present in most cells at roughly 1 to 10 mM and existing predominantly in the reduced (GSH) form, with a smaller oxidized (GSSG) pool. The GSH/GSSG couple functions as a central redox buffer: glutathione peroxidases use GSH to reduce hydrogen peroxide and lipid peroxides, generating GSSG, which glutathione reductase recycles back to GSH using NADPH.
Research suggests the GSH/GSSG ratio serves as an indicator of cellular redox status, with a lower ratio reported under conditions of elevated oxidative stress. Synthesis proceeds through two ATP-dependent steps catalyzed by glutamate-cysteine ligase (the rate-limiting enzyme) and glutathione synthetase, and is controlled by feedback inhibition, cysteine availability, and transcriptional induction through the Nrf2 pathway. Beyond detoxification via glutathione S-transferases, research describes GSH participating in redox signalling through reversible protein S-glutathionylation. This educational summary reflects published scientific findings and does not describe any human use.
Peer-reviewed sources for the research summarised above. Vivo summarises published, third-party science and does not conduct or sponsor this research.