Mechanisms behind Anti‐tumor Activity in Dunning R3327‐H Prostate Adenocarcinomas as a result of Tomato & Broccoli Consumption.

Epidemiological studies suggest consuming a variety of fruits and vegetables to reduce prostate cancer risk, thus we investigated whole tomato & broccoli powders in the Dunning R3327‐H prostate adenocarcinoma model. Male Copenhagen rats (n = 206) were fed diets for ~22 wks containing 10% tomato, 10% broccoli, 5% tomato + 5% broccoli, 10% tomato + 10% broccoli, or lycopene (23 or 224 nmole/g diet) starting 1 mo prior to receiving subcutaneous tumor implants. Finasteride (5mg/kg BW orally, 6 day/wk) reduced normal prostate weights ( P < 0.0001), but had no effect on tumors. Castration (2 wks before termination) reduced tumor weights by 62%, tomato by 34%, broccoli by 42%, and 10:10 combination by 52% ( P < 0.05). Castration, high lycopene, tomato, broccoli, 5:5 combination & the 10:10 combination all reduced tumor proliferation as quantified by Proliferating Cellular Nuclear Antigen immunohistochemistry ( P < 0.05). Neither lycopene group altered apoptotic rates via the Apoptag® assay, yet tomato, castration, broccoli, and the 10:10 combination increased apoptosis ( P < 0.01). Enzyme activities & gene expression using RT‐PCR were also evaluated. These studies provide evidence to support public health recommendations for prostate cancer prevention using a combination of whole foods. (AICR 01B061 & USDA/IFAFS 00‐52101‐9695)