Searching for Urinary Biomarkers of Exposure to Heterocyclic Amines (HCAs)

Searching for urinary biomarkers of exposure to heterocyclic amines

R. Busquets1*, H. Frandsen2, K. Skog3.
1School of Pharmacy and Chemistry, Kingston University, Penrhyn Road, Kingston Upon Thames, Surrey, KT1 2EE.
2National Food Institute, Technical University of Denmark, DK-2860, Søborg, Denmark
3Department of Food Technology, Engineering and Nutrition, Lund University PO Box 124, SE-221-00 Lund, Sweden.

The Maillard reaction takes place in cooking processes and yields a wide range of compounds. Heterocyclic amines (HCAs) are mutagenic products that form in the Maillard when cooking meat or fish [1,2]. The formation of HCAs depends on the cooking conditions, such as temperature and time, and presence of chemical precursors or inhibitors. With the aim to find biomarkers of exposure to HCAs in accessible tissue, metabolites from HCAs have been determined in the urine of a group of 8 volunteers who ate a controlled meal consisting of fried chicken cooked for 6 min at 180 °C. The controlled meal accounted for a total of 6 μg of HCAs. The urine was analysed by a method based on liquid-phase microextraction and liquid chromatography-tandem mass spectrometry developed by our group [3], able to detect HCAs at concentrations as low as 2 pg/ ml urine. A narrow variation of one of the HCAs, 2-amino-6-phenylimidazo[4,5-b]pyridine in urine was observed among the volunteers: 0.91-2.1% of the initial dose from the meal, which let us propose this HCA as potential biomarker [4]. Furthermore, new HCA-related metabolites have been identified in the urine samples. These finding will help to establish a relation between HCAs and cancer.