Urinary excretion of N-OH-2-amino-3-methylimidazo[4,5-f]quinoline-N-glucuronide in F344 rats is enhanced by green tea

The effects of green tea on the metabolism of the food carcinogen 2-amino-3 -methylimidazo[4,5-f]quinoline (IQ) with emphasis on the formation of the d etoxified glucuronides was studied. Two groups of 20 adult male and female Fischer 344 rats consumed 2% green tea or water for 6 weeks before being ad ministered a single dose of 40 mg/kg body weight of [2-C-14]IQ by oral gava ge, Major metabolites in 24 h urine samples were separated by high-performa nce liquid chromatography (HPLC), including N-OH-IQ-N-glucuronide, 5-OH-IQ glucuronide and sulfate, IQ sulfamate and IQ itself. The structures of the main metabolites were established by mobility on the HPLC and by mass spect rometry, Sulfate esters and sulfamate were hydrolyzed by 0.1 N HCl for 15 m in at 100 degreesC, yielding 5-OH-IQ and high levels of IQ, HPLC of the res ulting product showed the N-OH-IQ-N-glucuronide and the 5-OH-IQ glucuronide , as well as IQ, The male and female rats drinking tea displayed a signific antly higher (P < 0.05) excretion of the two major glucuronides. We conclud e that intake of green tea increases the excretion of N-OH-IQ-N-glucuronide , a detoxified metabolite of the proximate carcinogen NOH-IQ.