nounIntermediate
Definition
Tripeptide (γ-glutamyl-cysteinyl-glycine, GSH) that is the most abundant intracellular antioxidant in human cells, reaching millimolar concentrations.

Detailed Explanation

Tripeptide (γ-glutamyl-cysteinyl-glycine, GSH) that is the most abundant intracellular antioxidant in human cells, reaching millimolar concentrations. Glutathione neutralizes reactive oxygen species (ROS) via its cysteine thiol group: 2 GSH → GSSG (oxidized form) + 2H⁺ + 2e⁻. The enzyme glutathione reductase regenerates GSH using NADPH. Beyond antioxidant defense, glutathione is essential for detoxification (Phase II conjugation), immune function, and maintaining the redox state of protein thiols. IV glutathione is popular in integrative medicine, though oral bioavailability of intact glutathione is limited (~3–5%). Liposomal and S-acetyl formulations aim to improve absorption.

Key Facts

  • Tripeptide (γ-glutamyl-cysteinyl-glycine, GSH) that is the most abundant intracellular antioxidant in human cells, reaching millimolar concentrations.
  • Glutathione neutralizes reactive oxygen species (ROS) via its cysteine thiol group: 2 GSH → GSSG (oxidized form) + 2H⁺ + 2e⁻.
  • The enzyme glutathione reductase regenerates GSH using NADPH.
  • Beyond antioxidant defense, glutathione is essential for detoxification (Phase II conjugation), immune function, and maintaining the redox state of protein thiols.
  • IV glutathione is popular in integrative medicine, though oral bioavailability of intact glutathione is limited (~3–5%).
Related Terms Tripeptide Cysteine Amino Acid Bioactive Peptide

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