Sex differences in bladder cancer chemoprevention by green tea

Background: In bladder cancer prevention studies, is important to investigate how both sexes respond to different agents. The purpose of this experiment was to evaluate the protective effect of green tea consumption in bladder cancer induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in Mus musculus of both sexes. Methods: 21 male and 20 female mice were randomly assigned into three groups (I-Green tea+BBN, II-BBN and III-Green tea), in both sexes. The green tea was prepared daily at a concentration of 0,5% during 20 weeks and BBN was administrated by gavage in mean doses of 7,25 mg/mouse for week, through 10 weeks. After 20 weeks, animals were sacrificed and all bladders were collected for histological study. Results: In males, the group that showed a higher incidence of lesions was BBN + Green tea group. In females, the BBN group was the one with more histological lesions. A higher incidence of inflammatory infiltrate was observed in group exposed to BBN, followed the BBN+Green tea group, and finally green tea group. These observations were consistent for both sexes. Conclusions: We can conclude that green tea has a potential prevention effect of bladder cancer in females. The histological alterations were probably due to the influence of green tea in the metabolism acceleration of females and the protective effect of estrogens.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Healt