Mutagenic and cytotoxic action of heated pork meat extracts in human diploid fibroblasts

Extracts from lean pork heated at 200°C have a strong mutagenic activity in the Ames Salmonella assay (strain TA98 + S9). The formation of mutagenicity is highly temperature dependent, thus an extract heated at 100°C is not mutagenic in this system. This paper shows that the 200°C extract also causes mutations at the hprt locus in normal human fibroblasts, as demonstrated by a dose-dependent increase of 6-thioguanine resistant mutants. The mutation frequencies were increased 6 and 13 times, respectively, for extract concentrations corresponding to 100 and 200 mg meat/ml medium. Heterocyclic amines, previously shown to be present in the 200°C extract are conceivably responsible for at least part of the observed mutagenicity. The extracts prepared at 100°C had no significant effect on the mutant frequency in human fibroblasts. A pronounced, dose-dependent, decrease in cell survival was observed with both the 100° and the 200°C extracts. The nature of the cytotoxic components is not clear and might be different in the two extracts.