Dietary soy and tea mitigate chronic inflammation and prostate cancer via NFκB pathway in the Noble rat model

Chronic inflammation and nuclear factor-kappa B (NF kappa B) have been implicated in prostate cancer development; thus, dietary factors that inhibit NF kappa B may serve as effective chemo-preventative agents. Prostate cancer risk is significantly lower in Asian countries compared to the United States, which has prompted interest in the potential chemopreventative action of Asian dietary components such as soy and green tea. This study examined the effects of dietary soy and tea on NF kappa B activation and inflammation in vivo using a hormone-induced rat model for prostate cancer. Male Noble rats implanted with estradiol and testosterone were divided into 4 dietary groups: control, soy, tea, or soy+tea. NF kappa B activation and inflammatory cytokines were measured post implantation. The combination of soy and tea suppressed NF kappa B p50 binding activity and protein levels via induction of I kappa B alpha. Soy and tea also decreased prostate inflammatory infiltration, increased Bax/BcL2 ratio and decreased protein expression of tumor necrosis factor-alpha, interleukin (IL)-6 and IL-1 beta compared to control. Soy and tea attenuated prostate malignancy by decreasing prostate hyperplasia. These effects were not apparent in groups treated with soy or tea alone. The ongoing in vivo studies thus far suggest that combination of foods, such as soy and tea, may inhibit hormone-induced proinflammatory NF kappa B signals that contribute to prostate cancer development. Published by Elsevier Inc.