Glutathione Reductase

What it does

GR regenerates reduced glutathione (GSH) from oxidized glutathione (GSSG) using NADPH.
This keeps the cell’s antioxidant system charged up and ready.

Reaction:

GSSG + NADPH + H⁺ → 2 GSH + NADP⁺

Why it matters

🛡️ Protects cells from free radicals and oxidative damage
🧠 Important for red blood cells, liver, brain, and immune cells
🔬 Supports detoxification, DNA protection, and enzyme function

Where it’s found

• Cytosol and mitochondria of most cells
• High activity in liver, kidneys, and RBCs

Clinical & lab relevance

• Low GR activity → increased oxidative stress, hemolysis risk
• GR activity is often measured in biochemistry labs (NADPH consumption at 340 nm)
• Depends on riboflavin (vitamin B₂) as a cofactor (via FAD)