INHIBITORY EFFECT OF TOMATO JUICE ON RAT URINARY-BLADDER CARCINOGENESIS AFTER N-BUTYL-N-(4-HYDROXYBUTYL)NITROSAMINE INITIATION

The effects of tomato juice on urinary bladder carcinogenesis were stu died in male Fischer 344 rats initiated with N-butyl-N-(4-hydroxybutyl )nitrosamine (BBN) in rats. The animals (6 weeks old) were given 0.05% BBN in their drinking water for 8 weeks, followed by diluted tomato j uice for 12 weeks, and killed at 20 weeks after the beginning of the e xperiment. Lycopene concentrations in the livers of rats given tomato juice were elevated, Histopathological analysis of urinary bladder les ions revealed the numbers, but not incidences, of urinary bladder tran sitional cell carcinomas (TCCs) to be decreased in the group given tom ato juice. No influence on the incidence of simple and nodullopapillar y hyperplasias, invasion or differentiation of TCC was noted. These re sults indicate that tomato juice, presumably the contained lycopene an d other anti-oxidants in combination, exerts an inhibitory effect on t he development of TCCs in the rat urinary bladder.