Glutathione (GSH) (GSH)

Glutathione (GSH) is a ubiquitous tripeptide comprising glutamate, cysteine, and glycine, widely regarded as the master endogenous antioxidant due to its central role in maintaining cellular redox homeostasis [4, 10, 14]. It protects cellular structures—including DNA, proteins, and lipids—from oxidative damage by scavenging free radicals and serving as a cofactor for several antioxidant enzymes [7, 13, 15]. Beyond its antioxidant capacity, glutathione is indispensable for phase II detoxification, where it conjugates with a variety of xenobiotics and metabolic toxins through reactions catalyzed by glutathione S-transferases [11, 18, 19]. The term 'Glutathione restoration' refers to the therapeutic objective of replenishing depleted intracellular GSH levels, a condition frequently observed in aging, chronic inflammation, liver disease, and neurodegenerative disorders such as Parkinson's and Alzheimer's diseases [1, 2, 14, 20]. Common pharmacological approaches to achieve this include the administration of the limiting precursor N-acetylcysteine (NAC) or the direct use of liposomal or intravenous glutathione [8, 9, 17]. While restoring glutathione levels is generally associated with improved immune function and cellular resilience, therapeutic interventions must be carefully monitored to avoid adverse effects like bronchospasm or the inadvertent protection of malignant cells during chemotherapy [5, 6, 9].

Other names

Gamma-L-glutamyl-L-cysteinyl-glycineReduced glutathioneL-GlutathioneMaster antioxidantGlutathionumGlutathione replenishment

Glutathione restoration involves the replenishment of intracellular GSH pools either by providing the rate-limiting precursor cysteine, often through N-acetylcysteine (NAC) administration, or via the direct delivery of exogenous glutathione [2, 3, 15]. Once synthesized or absorbed, reduced glutathione (GSH) serves as a critical electron donor that neutralizes reactive oxygen species (ROS) and free radicals, thereby maintaining cellular redox balance [4, 7, 10]. It also functions as a substrate for glutathione S-transferases (GSTs) to form conjugates with xenobiotics and toxic metabolites, facilitating their elimination from the body [11, 18, 19]. Additionally, GSH is a necessary cofactor for glutathione peroxidase (GPx), which catalyzes the reduction of hydroperoxides to safeguard cell membranes from lipid peroxidation [13, 21].