D Sato1. 1. Second Department of Urology, Toho University of Medicine, Tokyo, Japan.
Abstract
BACKGROUND: Recently, the anticarcinogenic effects of green tea have been studied in sites other than the urinary tract. The present study examined the inhibition by green tea of vesical tumors induced in rats by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). METHODS: In the first series of experiments, 0.05% BBN was added to the drinking water of rats and remained present for 5 weeks. In one experiment, six groups of animals received either tap water, green tea, matcha, hojicha, oolong tea or black tea from week 6. In a second experiment, three groups of rats received either tap water, green tea extract or powdered green tea mixed into a pellet diet from week 6. In a third experiment, five groups of rats were fed a pellet diet with addition of either 0, 0.15, 1.5 or 3.0% powdered green tea from week 6. All rats were killed and examined at 40 weeks. RESULTS: Green tea, particularly green tea leaves, dose-dependently inhibited the growth of BBN-induced urinary bladder tumors when given after the carcinogen. CONCLUSIONS: Green tea may inhibit bladder tumor growth.
BACKGROUND: Recently, the anticarcinogenic effects of green tea have been studied in sites other than the urinary tract. The present study examined the inhibition by green tea of vesical tumors induced in rats by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). METHODS: In the first series of experiments, 0.05% BBN was added to the drinking water of rats and remained present for 5 weeks. In one experiment, six groups of animals received either tapwater, green tea, matcha, hojicha, oolong tea or black tea from week 6. In a second experiment, three groups of rats received either tapwater, green tea extract or powdered green tea mixed into a pellet diet from week 6. In a third experiment, five groups of rats were fed a pellet diet with addition of either 0, 0.15, 1.5 or 3.0% powdered green tea from week 6. All rats were killed and examined at 40 weeks. RESULTS: Green tea, particularly green tea leaves, dose-dependently inhibited the growth of BBN-induced urinary bladder tumors when given after the carcinogen. CONCLUSIONS: Green tea may inhibit bladder tumor growth.
Authors: Jason R Gee; Daniel R Saltzstein; KyungMann Kim; Jill Kolesar; Wei Huang; Thomas C Havighurst; Barbara W Wollmer; Jeanne Stublaski; Tracy Downs; Hasan Mukhtar; Margaret G House; Howard L Parnes; Howard H Bailey Journal: Cancer Prev Res (Phila) Date: 2017-03-21
Authors: Jong Min Kim; Jin Yong Kang; Seon Kyeong Park; Jong Hyun Moon; Min Ji Kim; Hyo Lim Lee; Hye Rin Jeong; Jong Cheol Kim; Ho Jin Heo Journal: Antioxidants (Basel) Date: 2021-11-30