In general, the rate of synthesis, regeneration, and recycling of glutathione is determined by three key factors 2 : Cellular levels of cysteineCysteine availability is the rate-limiting step in glutathione production, so not enough cysteine and de novo synthesis of glutathione will slow Enzyme glutamate cysteine ligase (GCL) activity, in part regulated by glutathione feedback inhibition Glutathione depletion due to high levels of oxidative stress, inflammation, or exposure to xenobioticsin these situations, de novo synthesis is upregulated Of course, as an antioxidant, one of the most important roles of glutathione is shielding cells from reactive oxygen species and reactive nitrogen species, but thats not its only job
Watanabe, T
A 2012 study published in Journal of Pharmacology and Experimental Therapeutics demonstrated that a seven-day dihexa dosing protocol produced cognitive improvements in rodent models that persisted for at least 30 days post-treatment, despite the compound being undetectable in plasma within 12 hours of the final dose
HMDB: a knowledgebase for the human metabolome
Mobin M, Khan NA (2007) Photosynthetic activity pigment composition and antioxidative response of two mustard cultivars differing in photosynthetic capacity subjected to cadmium stress