Аннотация:The method of micronuclei account allowed to demonstrate protective effect of gossypol and its megacin and batriden on chromosomes of rat malt germ cells from mutagenic effect of nitrosomethylurea (NMU) and, conversely, enhancement of clastogenic effect of another alkylating agent, fotrin. Strong antimutagenic effect of gossypol from NMU was also observed in external granular layer of young rat cerebellum. Possible mechanisms of antimutagenic action of unique polyphenol of cotton plant are discussed