Glutathione (GSH), as an important tripeptide compound in living organisms, has a wide range and critical biological functions, which are mainly reflected in the following aspects:
1. Antioxidant defense
Core mechanism: Neutralize oxygen radicals (e.g. superoxide anion, hydrogen peroxide, etc.) and protect cellular macromolecules (e.g. DNA, proteins, lipids) from oxidative damage through the dynamic conversion of reduced (GSH) and oxidized (GSSG) types.
Synergistic effect: Synergize with antioxidants such as vitamin C and vitamin E to enhance the antioxidant network effect, e.g., promote the regeneration of vitamins C and E to form an antioxidant cycle.
Enzyme system support: as a substrate for glutathione peroxidase (GPx), it participates in the breakdown of lipid peroxidation and hydroperoxides to maintain cellular redox homeostasis.
2. Detoxification and metabolic regulation
Hepatoprotection:
Neutralization of electrophilic substances: the sulfhydryl group (-SH) of GSH binds to toxins (e.g., heavy metals, drug metabolites, environmental pollutants) to form thiol urates, which are excreted via bile or urine.
Enzymatic detoxification: acts as a substrate for glutathione S-transferase (GST), which is involved in the metabolic conversion of exogenous toxins (e.g., carcinogens, chemotherapeutic drugs) to reduce their toxicity.
Metabolic Regulation:
Tricarboxylic acid cycle support: GSH maintains the activity of key enzymes in mitochondria and promotes energy metabolism.
Amino acid transport: participate in γ-glutamyl cycle, regulate intra- and extracellular amino acid balance.
3. Immune regulation and anti-inflammation
Immune cell regulation: enhance the activity of leukocytes (e.g., lymphocytes, macrophages), promote the secretion of cytokines (e.g., IL-2. IFN-γ), enhance the immune response.
Anti-inflammatory mechanisms:
Inhibit inflammatory mediators: reduce the synthesis of pro-inflammatory substances such as prostaglandins and leukotrienes.
Regulation of NF-κB pathway: inhibit the activation of nuclear transcription factor NF-κB, reduce the intensity of inflammatory response.
4. Cell signaling and protein function regulation
Sulfhydryl protection: maintains the reduced state of protein cysteine residues and safeguards the normal function of enzymes (e.g. phosphatases, kinases) and receptors (e.g. insulin receptor).
Signal molecule regulation: involved in the regulation of nitric oxide (NO) synthesis, calcium ion homeostasis and other key signaling pathways, affecting cell proliferation, differentiation and apoptosis.
5. Other biological functions
Anti-apoptotic effects: inhibit mitochondria-mediated apoptosis by regulating the Bcl-2/Bax protein ratio.
DNA repair support: Participate in nucleotide reduction reaction as a reducing agent to guarantee the supply of deoxyribonucleotides for DNA synthesis and repair.
Neuroprotection: In the central nervous system, decreased GSH levels are closely associated with neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease, and GSH supplementation can improve neuronal survival.