The pentose phosphate pathway (PPP) is crucial for erythrocyte survival. In a patient with G6PD deficiency exposed to an oxidant drug, erythrocytes undergo hemolysis. Which molecule, normally maintained in its reduced form by the PPP, is directly responsible for protecting erythrocyte membranes from oxidative damage?

• A NADH
• B Thioredoxin
• C Glutathione (GSH) ✓
• D Ascorbic acid

Explanation

The PPP generates NADPH via glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. NADPH is used by glutathione reductase to reduce oxidized glutathione (GSSG) back to its reduced form (GSH). GSH directly neutralizes hydrogen peroxide and lipid peroxides through glutathione peroxidase, protecting the erythrocyte membrane from oxidative damage. In G6PD deficiency, NADPH is insufficient to regenerate GSH, leading to oxidative hemolysis.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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