Green tea polyphenols (
GTP) have been widely investigated for their potential to prevent
prostate cancer. However, results from epidemiological and clinical studies are equivocal. Studies in the TRAMP (TRansgenic
Adenocarcinoma of the Mouse Prostate) mouse suggest that the chemopreventive efficacy of
GTP is higher in young animals with early stages of
carcinogenesis than in old ones. Here, effects of
GTP on prostate
carcinogenesis in TRAMP mice were assessed by comparing pathological changes with (1)H-NMR metabolic profiling of plasma and extracts of prostate tissue. Mice received 0.05%
GTP in their
drinking water for 4 or 25 weeks after weaning. Age-matched wild-type mice were included in the study in order to establish differences in
GTP effects between normal and TRAMP mice. Dietary
GTP did not markedly alter prostate
carcinogenesis as reflected by pathology and prostate tissue metabolic profile. However, a systemic effect of
GTP consumption was observed in young mice, regardless of genotype. Plasma
lipid signals were decreased in 8 week old mice which received
GTP compared to age-matched controls by 19, 61, 27, 34 and 15% (p <or= 0.05) in the CH(2)CH(2)C[double bond, length as m-dash]C (m 2.00 ppm), CH(2)CH(2)CO (m 1.58 ppm), CH(2) (m 1.26 ppm), CH(3) (m 0.88 ppm) and CH(3)
fatty acid resonances (m 0.84 ppm), respectively.
GTP consumption did not affect the plasma metabolic profile in 29 week old mice. These results suggest that age rather than disease state determines systemic effects of
GTP. More studies are required to investigate factors, such as age or metabolic make-up, inherent to a population or an individual, which may modulate the chemopreventive efficacy of
GTP.