- Email: [email protected]
Mutagens in foods, and their production by cooking
216 with some of the rec-assay positive samples. Both VOC12 and RhC13 • 3H20 were shown to be real mutagens.
13 Kawachi, T., M. Nagao, N. Matsukura, M. Honda, T. Yahagi, Y. Seino, T. Sugimura, K. Wakabayashi a, K. Tsuji a and T. Kosuge a, National Cancer Center Research Institute, T o k y o and a Shizuoka College of Pharmacy, Shizuoka (Japan) Mutagens in foods, and their production b y cooking Smoke condensates obtained by broiling fish were found to be strongly mutagenic to Salmonella TA98 with metabolic activation (S-9 mix). The mutagenicity of 30 mg of smoke condensate collected from a sardine was equivalent to that of 280 pg of benzo(a)pyrene (BP). The dimethyl sulfoxide (DMSO)extract of the charred surface of a broiled sardine also showed mutagenicity equivalent to that of 400 pg of BP. The DMSO-extract of the charred surface of 200 g of beefsteak was mutagenic with S-9 mix, being equivalent to 850 pg of BP in mutagenicity. However, the actual amounts of BP in these extracts of broiled fish and steak were only 25 ng and 1.6--10 pg, respectively, and thus their mutagenicities cannot be attributable solely to known muta-carcinogens such as BP. Smoke condensates produced by pyrolyzing proteins such as lysozyme and histone at 400°C were strongly mutagenic to Salmonella TA98 with S-9 mix, but pyrolysates of nucleic acids, carbohydrate and vegetable oil were only slightly mutagenic. The pyrolytic products of amino acids were mutagenic, that of D,L-tryptophan showing the highest mutagenic activity• Smoke produced during cooking and charred foods which are eaten daily should be regarded as important environmental mutagens, with the potential to cause human cancer.
S u p p o r t e d b y G r a n t s - i n - A i d for C a n c e r R e s e a r c h f r o m the Ministry of E d u c a t i o n , Science a n d Cult u r e a n d t h e Ministry of H e a l t h a n d Welfare, J a p a n .
14 Kondo, S., H. Ichikawa-Ryo, T. Nomura and H. Takebe, Faculty of Medicine, Osaka University, Osaka (Japan) Antimutagenicity of caffeine and protease inhibitor in Escherichia coli Caffeine post-treatment is known to diminish UV mutagenesis in E. coli (Witkin and Farquharson, Ciba Foundation Symp., 1969). Addition of caffeine (0.1 ~ 0.2%) to semi-enriched agar medium was found to greatly, moderately
13 Kawachi, T., M. Nagao, N. Matsukura, M. Honda, T. Yahagi, Y. Seino, T. Sugimura, K. Wakabayashi a, K. Tsuji a and T. Kosuge a, National Cancer Center Research Institute, T o k y o and a Shizuoka College of Pharmacy, Shizuoka (Japan) Mutagens in foods, and their production b y cooking Smoke condensates obtained by broiling fish were found to be strongly mutagenic to Salmonella TA98 with metabolic activation (S-9 mix). The mutagenicity of 30 mg of smoke condensate collected from a sardine was equivalent to that of 280 pg of benzo(a)pyrene (BP). The dimethyl sulfoxide (DMSO)extract of the charred surface of a broiled sardine also showed mutagenicity equivalent to that of 400 pg of BP. The DMSO-extract of the charred surface of 200 g of beefsteak was mutagenic with S-9 mix, being equivalent to 850 pg of BP in mutagenicity. However, the actual amounts of BP in these extracts of broiled fish and steak were only 25 ng and 1.6--10 pg, respectively, and thus their mutagenicities cannot be attributable solely to known muta-carcinogens such as BP. Smoke condensates produced by pyrolyzing proteins such as lysozyme and histone at 400°C were strongly mutagenic to Salmonella TA98 with S-9 mix, but pyrolysates of nucleic acids, carbohydrate and vegetable oil were only slightly mutagenic. The pyrolytic products of amino acids were mutagenic, that of D,L-tryptophan showing the highest mutagenic activity• Smoke produced during cooking and charred foods which are eaten daily should be regarded as important environmental mutagens, with the potential to cause human cancer.
S u p p o r t e d b y G r a n t s - i n - A i d for C a n c e r R e s e a r c h f r o m the Ministry of E d u c a t i o n , Science a n d Cult u r e a n d t h e Ministry of H e a l t h a n d Welfare, J a p a n .
14 Kondo, S., H. Ichikawa-Ryo, T. Nomura and H. Takebe, Faculty of Medicine, Osaka University, Osaka (Japan) Antimutagenicity of caffeine and protease inhibitor in Escherichia coli Caffeine post-treatment is known to diminish UV mutagenesis in E. coli (Witkin and Farquharson, Ciba Foundation Symp., 1969). Addition of caffeine (0.1 ~ 0.2%) to semi-enriched agar medium was found to greatly, moderately