Effects of brewed green and black tea on inflammation, apoptosis and oxidation in men with prostate cancer (136.3)

Abstract

Preclinical and epidemiologic studies suggest chemopreventive effects of green tea (GT) and black tea (BT) in prostate cancer. We conducted a phase II randomized controlled trial in which 93 men diagnosed with prostate cancer consumed six cups of brewed GT, BT or water (control) daily prior to radical prostatectomy (RP). GT consumption resulted in lower early pro‐apoptotic events (decreased Bcl‐2 staining (p=0.02)) and lower pro‐inflammatory nuclear staining of nuclear factor kappa B in prostatic tumor epithelial tissue compared to water consumption (p=0.03). Tea consumption did not affect proliferation (Ki67) and showed a non‐significant trend to decreased oxidant DNA damage (8OHdG) in the RP tissue. Tea polyphenols were detected in prostate tissue from 32 of 34 men consuming GT but not in the other groups. BT polyphenols (theaflavins) were not found in prostate tissue from men consuming BT and no significant changes in tissue biomarkers were observed in the BT group. Evidence of a systemic antioxidant effect was observed as a decrease in urinary 8OHdG only with GT consumption. GT, but not BT or water, also led to a small but statistically significant decrease in serum prostate‐specific antigen levels. Given the GT‐induced changes in inflammation, oxidation, and early apoptotic events, future studies are warranted to further examine the role of GT for prostate cancer prevention and treatment.Grant Funding Source: Supported by RO1CA116242 and P50CA092131