Glutathione: overview of its protective roles, measurement, and biosynthesis

Summary

This review provided a comprehensive overview of glutathione (GSH), a tripeptide (gamma-glutamyl-cysteinyl-glycine) that is the most abundant non-protein thiol in mammalian cells and serves as the primary intracellular antioxidant defense system. The review detailed glutathione's roles in direct ROS scavenging, enzymatic detoxification via glutathione peroxidases and glutathione S-transferases, and maintenance of cellular redox homeostasis.

Key Findings

• Intracellular glutathione concentrations range from 1-10 mM, making it the most concentrated intracellular antioxidant, with the GSH/GSSG ratio serving as a critical indicator of cellular redox status
• Glutathione serves as a substrate for glutathione peroxidases (detoxifying hydrogen peroxide and lipid hydroperoxides) and glutathione S-transferases (conjugating electrophilic xenobiotics)
• Age-related decline in glutathione synthesis capacity, driven by reduced gamma-glutamylcysteine ligase activity, contributes to increased oxidative stress and susceptibility to disease in aging