Modifying action of vegetable juice on the mutagenicity of beef extract and nitrosated beef extract.

The effect of juices of different vegetables on the mutagenicity of beef extract (with S-9 mix) and nitrosated beef extract (with and without S-9 mix) was examined using the Ames test. All the juices affected the induced mutagenicity of beef extract and nitrosated beef extract in the presence of S-9 mix, but not the mutagenicity of nitrosated beef extract in the absence of S-9 mix. As the vegetable juices appear to affect mutagenicity only in the presence of S-9 mix, it is concluded that the constituents of vegetables do not act directly on the mutagens; the effects are apparently caused by an interaction with the metabolic activation system.