An improved method for the extraction of mutagens from human urine and cooked meat using blue rayon

• Published in: Mutation research. Genetic toxicology and environmental mutagenesis 2004-04, Vol.559 (1-2), p.121-130
• Main Authors: Yoxall, Victoria, Wilson, Judith, Ioannides, Costas
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blue rayon; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Heterocyclic amines; Medical sciences; Salmonella typhimurium; Toxicology; Urinary mutagenicity
• ISSN: 1383-5718; 1879-3592
• DOI: 10.1016/j.mrgentox.2004.01.006

A reproducible method has been developed and validated that allows the detection of mutagenic material in human urine following the intake of a meal containing pan-fried beef patties. The mutagens are extracted from the urine with blue rayon and eluted with methanol/ammonia (100:1). Using 14C-2-amino-3-methylimidazo[4,5-f]quinoline (14C-IQ) as a tracer, the extraction efficiency of heterocyclic amines was consistently found to exceed 90%. It was observed that the critical factor in attaining high extraction efficiencies was the concentration of blue rayon, which depended on the nature of the matrix. Constituents of human urine were demonstrated to compete with IQ for the binding sites on the blue rayon. For the determination of the mutagenic activity in the extracted urine, the O-acetylase over-expressing Salmonella typhimurium strain YG1024 was utilised, and the Ames test procedure was optimised with respect to S9 concentration and incorporation of a pre-incubation step. Using the developed procedure, a marked rise in mutagenic activity, determined both in the absence and presence of an activation system, was evident in human urine following the intake of a beef patty meal. Normal mutagenicity levels were restored within 24h. Finally, a method is described, once again employing blue rayon, for the extraction of heterocyclic amines from cooked beef patties with a 92% efficiency, as exemplified by IQ.