Glutathione (GSH)

Antioxidant Defense#

GSH directly scavenges reactive oxygen species and serves as a cofactor for the glutathione peroxidase (GPx) family of enzymes.

GPX4 (glutathione peroxidase 4) uses GSH to reduce lipid hydroperoxides to non-toxic lipid alcohols—this is the central brake on Ferroptosis. GPX4 is a selenoprotein, linking GSH status to Selenium status.^{[1]Microbial Metallomics and Parkinson's Disease: A Unified Metal-Driven Framework Linking Ferroptosis, Dysbiosis, and alpha-Synuclein PathologyKaren Pendergrass · 2025Open reference 1 ↓}

GSH/GSSG ratio is a primary indicator of cellular redox status; Oxidative Stress shifts this ratio toward GSSG (oxidized glutathione).

Metal Detoxification#

GSH conjugates with Heavy Metals via its thiol group, facilitating their excretion.

Mercury binds GSH thiol groups with extremely high affinity, depleting the intracellular GSH pool and inhibiting glutathione peroxidase.^{[2]Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium, and ArsenicBalali-Mood M, Naseri K, Tahergorabi Z et al. · 2021Open reference 2 ↓}

Cadmium depletes GSH and induces metallothionein as a secondary defense; cadmium (Cd)-GSH conjugates are transported to the kidney, contributing to nephrotoxicity.^{[3]Molecular Mechanisms of Cellular Injury and Role of Toxic Heavy Metals in Chronic Kidney DiseaseManish Mishra, Larry Nichols, Aditi A. Dave et al. · 2022Open reference 3 ↓}

Lead reduces GSH, SOD, catalase, and GPx while increasing lipid peroxidation (MDA) and H2O2 in liver and kidney tissue.^{[2]Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium, and ArsenicBalali-Mood M, Naseri K, Tahergorabi Z et al. · 2021Open reference 2 ↓}

Arsenic consumes GSH during its reduction from As(vanadium (V)) to As(III) and during methylation-based detoxification; GSH depletion is dose-dependent.^{[2]Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium, and ArsenicBalali-Mood M, Naseri K, Tahergorabi Z et al. · 2021Open reference 2 ↓}

Chromium(VI) is reduced to chromium (Cr)(III) by GSH, generating hydroxyl radicals in the process—a paradox where the detoxification reaction itself produces DNA-damaging species.^{[4]Genetic and Epigenetic Mechanisms in Metal Carcinogenesis and Cocarcinogenesis: Nickel, Arsenic, and ChromiumKonstantin Salnikov, Anatoly Zhitkovich · 2008Open reference 4 ↓}

PCOS#

Women with PCOS show significantly lower GSH levels and higher oxidative stress markers compared to controls.^{[5]Antioxidant Status in Relation to Heavy Metals Induced Oxidative Stress in Patients with Polycystic Ovarian Syndrome (PCOS)Manal Abudawood, Hajera Tabassum, Atheer H. Alanazi et al. · 2021Open reference 5 ↓[6]Heavy Metals and Essential Elements in Association with Oxidative Stress in Women with Polycystic Ovary Syndrome -- A Systematic ReviewSmovrsnik T, Virant-Klun I, Pinter B · 2023Open reference 6 ↓}

Heavy metal exposure in PCOS patients compounds the GSH deficit.

Neurodegeneration#

GSH depletion in the substantia nigra is an early finding in Parkinson's disease, preceding dopaminergic neuron loss and contributing to ferroptotic vulnerability.^{[7]Common and Trace Metals in Alzheimer's and Parkinson's DiseasesDoroszkiewicz J, Farhan JA, Mroczko J et al. · 2023Open reference 7 ↓}

In Alzheimer's disease, metal-catalyzed oxidative stress depletes GSH, impairing both antioxidant defense and methylglyoxal detoxification.