Inhibition of aminoimidazoquinoxaline-type and aminoimidazol-4-one type mutagen formation in liquid-reflux models by the amino acids L-proline and/or L-tryptophan.

Laboratory models were used to study the inhibition of mutagen formation by Maillard-type reactions during cooking of meats or fish. The amino acid L-proline (L-pro) was an effective, dose-dependent inhibitor of the development of mutagenicity (Ames test) in a liquid-reflux model of glucose + glycine + creatine known to produce IQ-type mutagens (MeIQx and 7,8-DiMeIQx). L-pro also inhibited formation of mutagens in a reflux model of threonine + creatine, developed in our laboratory, which yields a novel class of IQ-"like" aminoimidazol-4-one mutagens. A mixture of L-pro and L-tryptophan (L-trp) at lower concentrations of each yielded increased inhibition, compared with the findings when each inhibitor was tested by itself.