K4 Elite
K4 Elite
L-Glutathione (GSH) is the principal intracellular thiol antioxidant, a tripeptide of glutamate, cysteine, and glycine studied for its central roles in redox balance, detoxification, and cellular defense.
L-Glutathione (GSH) is a tripeptide formed from L-glutamate, L-cysteine, and glycine, distinguished by an unusual gamma-peptide bond between the glutamate side chain and cysteine. It is the most abundant low-molecular-weight thiol in most cells and is central to intracellular redox homeostasis.
The reduced form (GSH) and its oxidized dimer (GSSG) constitute the primary cellular redox buffer, and the GSH/GSSG ratio is one of the most widely used experimental indicators of oxidative status. GSH participates in detoxification of reactive electrophiles and peroxides and in the regeneration of other antioxidants.
Because glutathione status changes with age, oxidative stress, and disease, it is one of the most extensively studied molecules in redox biology, longevity research, and toxicology.
GSH acts as an electron donor: its cysteine thiol reduces reactive oxygen and nitrogen species and serves as a cofactor for glutathione peroxidases, which reduce hydroperoxides. In the process GSH is oxidized to GSSG, which glutathione reductase regenerates using NADPH, sustaining the intracellular thiol pool.
GSH also conjugates to xenobiotics and reactive electrophiles via glutathione S-transferases, a documented phase-II detoxification pathway, and it participates in regenerating oxidized vitamins C and E in cell models, linking it to a broader antioxidant network.
Meister and Anderson's foundational review (1983, Annual Review of Biochemistry) synthesized the biochemistry of glutathione, establishing the enzymatic cycle of synthesis, oxidation, and reduction that underlies the experimental use of the GSH/GSSG ratio as a redox readout.
Sekhar and colleagues (2011, American Journal of Clinical Nutrition) reported a controlled study measuring glutathione synthesis in older versus younger subjects and the effect of supplying its amino-acid precursors, describing intracellular GSH concentrations and synthesis rates as the measured endpoints in that human research.
Numerous cell and rodent studies reviewed by Ballatori et al. (2009, Biological Chemistry) describe manipulation of glutathione levels—via precursor supply or synthesis inhibitors—and the resulting changes in oxidative-stress and detoxification markers, as experimental interventions in laboratory systems.
Combinations examined in the research literature. Descriptive only — not a recommendation to combine compounds.
References are being compiled for this entry.