Glutathione-dependent antioxidant system (GSH system)

The glutathione-dependent antioxidant system is a fundamental cellular defense network centered on the tripeptide glutathione (GSH). It comprises several key enzymes, including glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST), which work in concert to maintain redox balance. The system's primary role is the neutralization of reactive oxygen species (ROS) and the detoxification of electrophilic xenobiotics, thereby protecting cellular components from oxidative damage. Dysregulation of this system is implicated in a wide range of pathologies, including neurodegenerative diseases, cardiovascular disorders, and various cancers. In oncology, elevated GSH levels are often associated with tumor progression and resistance to chemotherapy, making the system a target for sensitization strategies. Conversely, in conditions characterized by oxidative stress, such as acetaminophen toxicity or chronic inflammation, therapeutic intervention aims to replenish GSH levels. Common pharmacological agents include N-acetylcysteine, which serves as a GSH precursor, and buthionine sulfoximine, which inhibits GSH synthesis. This system remains a focal point for drug development due to its central role in cellular survival and its potential to modulate the efficacy of existing therapies.

Other names

Glutathione redox systemGSH-dependent systemGlutathione antioxidant pathwayGlutathione metabolism

The system functions by utilizing glutathione as a reducing agent to neutralize reactive oxygen species and detoxify electrophilic compounds through enzymes like glutathione peroxidase and glutathione S-transferase. Drugs interact with this system by replenishing glutathione precursors (e.g., N-acetylcysteine), inhibiting glutathione synthesis to sensitize cancer cells (e.g., buthionine sulfoximine), or mimicking the activity of glutathione-dependent enzymes (e.g., ebselen).