Green tea and the metabolism of 2-amino-3-methylimidazo [4,5-f]quinoline in F344 rats

The effects of green tea intake on the metabolism of 2-amino-3-methylimidaz o[4,5-f]quinoline (IQ) in the rat was studied. IQ belongs to a new class of mutagens and carcinogens, heterocyclic arylamines, formed during cooking t hrough browning meats and fish, thus, in the food chain of most non-vegetar ians. Ten adult male and female Fischer 344 rats were placed on a 2% soluti on of green tea and 10 control rats were on water for 6 weeks. Then, animal s were administered a single dose of 40 mg/kg body weight of [2-C-14]IQ by oral gavage. Twenty-four hour urine samples were collected and metabolites were separated by HPLC and quantitated by scintillation counting. Two minor and three major metabolites were isolated, including, small quantities of IQ itself. The rats on tea showed significant differences (P < 0.05) in the recovery of the three major metabolites, namely, IQ-sulfamate, IQ-5-O-sulf ate, and IQ-5-O-glucuronide, respectively. Green tea, therefore, influences the manner in which the food carcinogen IQ is metabolized and excreted in urine. Formation of glucuronides, increased by green tea, represent a key m eans of detoxification of the heterocyclic amine, IQ. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.