Или desmutagenic substance

Видимо, ослабляет или нейтрализует действие мутагенов

The desmutagenic substances consist of a fibrous constituent of food which was produced from corn fibers. These substances have a function of inactivating mutagens which occur in our daily life environment, for example, dinitropyrene, pyrolysate mutagens of food or the like.
http://www.freepatentsonline.com/5198363.html

Desmutagens and bio-antimutagens - their modes of action
http://www3.interscience.wiley.com/journal/109911929/abstrac...

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Note added at 7 mins (2010-02-16 22:56:20 GMT)
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A Dictionary of Food and Nutrition
desmutagen
Compound acting directly on a mutagen to decrease its mutagenicity.
http://www.encyclopedia.com/doc/1O39-desmutagen.html