[The anti-mutagenic effects of human saliva investigated by umu-test. Part 1. Effects of filtration and storage at low temperatures].

The anti-mutagenic effects of human saliva were examined by the umu-test. The SOS-inducible DNA-damaging activity of AF-2 was markedly decreased by pre-treatment with human fresh saliva. The anti-mutagenic activity of human saliva was retained even after the filtration (0.45 microns). This activity was also observed after 24 hr-storage at 10 degrees C or -12 degrees C. These results were consistent with previous reports using Ames tests. Significant differences in the activity, however, were observed between sample donors and between experiments with the same sample donor. Further analyses of the effects of the factors contained in saliva as well as the effects of life-styles, including dietary-habits of sample donors will be necessary.