In carbon tetrachloride (CCl4) hepatotoxicity, the toxic intermediate generated by the cytochrome P450 system that initiates lipid peroxidation is:

• A Phosgene (COCl2)
• B Hydrogen peroxide (H2O2)
• C Trichloromethyl peroxy radical (CCl3OO•) ✓
• D Hydroxyl radical (•OH) via Fenton reaction from free iron

Explanation

CCl4 is a classic model of free radical hepatotoxicity. Hepatic CYP2E1 converts CCl4 to the trichloromethyl radical (•CCl3), which in the presence of O2 rapidly forms the more reactive trichloromethyl peroxy radical (CCl3OO•). This highly reactive species initiates lipid peroxidation of membrane phospholipids, causing membrane damage, Ca2+ influx, and mitochondrial dysfunction — ultimately coagulative (centrizonal) necrosis. The hydroxyl radical via Fenton reaction is relevant to iron toxicity and general oxidative stress, but is not the specific CCl4 metabolite.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

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