Reduced carcinogenic effects of aflatoxin in rats given phenobarbitone.

Rats were fed a diet containing 50 per cent peanut meal contaminated with aflatoxins (Rosetti meal) for a period of 9 weeks. All the survivors developed liver tumours in the next 2 yr. Rats given the same diet plus phenobarbitone showed a much delayed appearance of tumours, the malignant characteristics of the tumours were diminished and the premalignant histological changes in the liver were reduced. We suggest that phenobarbitone induces liver hydroxylation enzymes that metabolise aflatoxins to noncarcinogenic products.