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(P186) In vitro studies of human gastrointestinal mobilisation of food-borne PCBs.
Soyibo, Adeola*,1, Beck, Angus1, 1 Imperial College, University of London, United Kingdom
ABSTRACT- PCBs have been implicated as possible agents in causing cancer of internal organs including the colon, breast and pancreas therefore we are seeking to establish, quantitatively, typical human exposure to such compounds. The commonest route of exposure to many PCBs is through food consumption. Here, we report on the potential for gastrointestinal (GI) mobilisation and absorption of food-borne PCBs in humans. The development and validation of a GI simulator and operational protocols, developed in compliance with the requirements of German DIN 19738 risk assessment test procedure, are presented. Food, naturally contaminated with PCBs, was homogenised with simulated saliva fluid and shaken in the GI simulator with simulated gastric fluids (containing pepsin, mucine) for 2h at 37oC. Afterwards, the simulated intestinal fluids (containing pepsin, mucine, trypsin, pancreatin, bile) were added and the mixture shaken for a further 6h prior to centrifugation and filtration using Buchner funnels to separate the undigested GI residues from GI fluids. PCBs were recovered from GI residues and fluids by Soxhlet and liquid-liquid extraction respectively, cleaned up using silica-SFE, and analysed by GC-MSD. Detailed studies with fish indicate variations in mobilisation of SumPCBs (28, 52, 101, 118, 153, 138 and 180). For example, the bioavailable fractions (fractions mobilised) in mussels, salmon and mackerel were 91, 71, and 39% respectively of the SumPCBs initially present in the fish. The bioavailable fraction was dependent on the physicochemical characteristics of the PCBs. In mackerel the bioavailable fraction for individual PCB congers ranged from 9-24%, in salmon from 3-30%, and in mussels from 2-32%. Future studies will focus on understanding better, the variability in bioavailable fractions to be expected for different foodstuffs, the effect of diet and the effects of dietary supplements.
Key words: PCB, in-vitro, gastrointestinal, bioavailable
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