Antimutagenic activity of commercial chicken-essence against environmental mutagens

Antimutagenicity of six commercial chicken-essences against environmental mutagens were investigated by Ames test. Kinds and amounts of Maillard reaction products (MRPs) in chicken-essences were analyzed by gas chromatography to clarify the role of antimutagenicity MRPs played in chicken-essences. Six chicken-essence concentrates (CEC) or their dichloromethane extracts (DECE) showed inhibition of the mutagenicity of indirect environmental mutagens such as 2-amino-3-methylimidazo[4,5- f]quinoline (IQ), 3-amino-l-methyl-5-H-pyrido[4,3-b] indole (Trp-P-2), and benzo[a]pyrene (B[a)P), but contrarily had no effect on direct environmental mutagens such as 1-nitropyrene (1-NP) and 4-nitroquinoline-1-oxide (4-NQO). The doses of 50% inhibition ([D₅₀) of CEC were 4.2 ~ 152.8 mg/plate for IQ, 7.9 ~ 199.3 mg/plate for Trp-P-2, 12.1 ~ 301.9 mg/plate for B [a]P, respectively, while those of DECE were 16.2 ~ 296.3 μg/plate for IQ, 40.2 ~ 344.2 μg/plate for Trp-P-2, 94.2 ~ 510.2 μg/plate for B[a]P, respectively. The results of GC-MS revealed that pyrazines, thiazoles, thiophenes, furans and the five major kinds of MRPs in DECE, and among them pyrazines, thiazoles and thiophenes higher in amount. Moreover, among various MRPs, pyrazines, thiazoles and thiophenes all showed inhibition of mutagenicity of IQ as well as Trp-P-2 in a dose-dependent manner, and it was the metabolic activation pathway of mutagens that were inhibited.