Carcinogenicity of flour infested with Tribolium castaneum using the Egyptian toad Bufo regularis as a biological test animal.

Feeding the Egyptian toad Bufo regularis for 14 weeks with flour infested for 1 year with Tribolium castaneum, at a dose level of 200 mg/50 g body weight, induced neoplasms in 22 out of 100 toads. These neoplasms comprise 22 primary hepatocellular carcinomas and 6 tumours in the kidney due to metastases from the primary hepatocellular carcinoma. It is speculated that the carcinogenicity of the flour used in this work is due to quinone derivatives secreted by the defensive glands of T. castaneum.