Carcinogenicity of the food additive furylfuramide in foetal and young mice

Abstract

FURYLFURAMIDE (so-called AF-2), 2-(2-furyl)-3-(5-nitro-2-furyl) acrylic acid amide, had been used widely (probably several tonnes yr⁻¹) as an antimicrobial food additive in such food as fish sausage, mixed meat sausage, boiled fish paste and soybean curd throughout Japan until it was banned in 1974. Tonomura and Sasaki¹ found that furylfuramide induces chromosome aberrations in cultured human lymphocytes and strong mutagenicity was found by Kada² and Kondo and Ichikawa-Ryo³ with E. coil. Miyaji⁴ had reported, however, that neither tumour nor malformation was induced by furylfuramide in rats and mice, although Morris et al.⁵ reported that some other nitrofuran derivatives induced tumours in rats. Ames and his associates^6,7 have shown that almost 90% of chemical carcinogens so far tested are mutagenic in their specified tester strains of Salmonella typhimurium. Thus, furylfuramide has been an important exception to the presumptive rule that a carcinogen is, in principle, a mutagen. As fish sausage has been favoured so much by young Japanese children, it was necessary to reopen the question of the carcinogenicity of furylfuramide in view of its strong mutagenicity. I report here that furylfuramide induces low but significant yields of tumours in mice when administered at the foetal or young stage.