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The article offers information on a study that examines the mutagenic activity of isoflavones genistein after treatment with nitrite under acidic conditions. It reports that nitrite-treated genistein exhibits mutagenic activity toward Salmonella typhimurium bacterial strains TA 100 and TA 98. It reports that daily oral intake of genistein and nitrite compounds induces formation of various mutagenic compounds in the body.

Aflatoxin B (AFB) is a potent mycotoxin with mutagenic, carcinogenic, teratogenic, hepatotoxic, and immunosuppressive properties. In order to develop a bioremediation system for AFB-contaminated foods by white-rot fungi or ligninolytic enzymes, AFB was treated with manganese peroxidase (MnP) from the white-rot fungus Phanerochaete sordida YK-624. AFB was eliminated by MnP. The maximum elimination (86.0%) of AFB was observed after 48 h in a reaction mixture containing 5 nkat of MnP. The addition of Tween 80 enhanced AFB elimination. The elimination of AFB by MnP considerably reduced its mutagenic activity in an umu test, and the treatment of AFB by 20 nkat MnP reduced the mutagenic activity by 69.2%. H-NMR and HR-ESI-MS analysis suggested that AFB is first oxidized to AFB-8,9-epoxide by MnP and then hydrolyzed to AFB-8,9-dihydrodiol. This is the first report that MnP can effectively remove the mutagenic activity of AFB by converting it into AFB-8,9-dihydrodiol. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study which investigated the changes in the mutagenic and estrogenic activities of 17β-estradiol after nitrite treatment. The nitrite-treated estradiol showed mutagenic activities toward Salmonella typhimirum strains TA 100 and TA 98. Nitrite-treated 17β-estradiol and 2-nitro-17β-estradiol induced higher frequency of micronucleated reticulocytes in mice. The results suggest that a daily oral intake of 17β-estradiol and nitrite may induce the formation of mutagenic compounds in the human body.

The article discusses the result of the study regarding the isolation of mutagenic β-carboline derivatives after nitrite treatment of Maillard reaction mixtures and the analysis of these compounds from foodstuffs and human urine, in Japan. The mixtures of carbohydrate decomposition products and L-tryptophan which were incubated for several weeks showed certain mutagenic activity toward S. typhimurium TA 100, without metabolic activation after a nitrite treatment.