Antimutagenicity of 3-allyl-5-substituted 2-thiohydantoins derived from allyl isothiocyanate and amino acids in Salmonella assay

Nine 3-allyl-5-substituted 2-thiohydantoins (ATH-amino acids) which were prepared from allyl isothiocyanate (AITC) and amino acids were studied for their antimutagenic activities against 2-amino-3-methylimidazo [4,5-f] quinoline (IQ) and 4-nitroquinoline 1-oxide (4-NQO) using the Ames assay. The assay against IQ was performed on S. typhimurium TA98 in the presence of a metabolic activation system (S9 mix) and that against 4-NQO was carried out on S.typhimurium TA100 in the absence of S9 mix. When ATH-amino acids except for that prepared from AITC and aspartic acid were simultaneously treated with the bacterial strain and IQ, an inhibition of IQ mutagenicity was observed. Also, all ATH-amino acids showed a suppressive effect on 4-NQO mutagenicity when the bacterial strain was incubated in the presence of both 4-NQO and ATH-amino acids. In contrast, little antimutagenic effect was observed when ATH-amino acids were added to the bacterial strains which has been pretreated with a mixture of IQ and S9 mix or only 4-NQO. These results suggest that ATH-amino acids are capable of acting as inhibitors of the S9 mix-mediated activation of IQ and/or as modulators of the direct-acting mutagen, 4-NQO.