Growth inhibition of prostate cell lines in vitro by phyto-oestrogens

Abstract

Objective. To assess a range of phyto-oestrogens as moderators of growth and metabolism in several prostate cell lines. Materials and methods. Four prostate cell lines (PNT-1/A, PNT-2, PC-3 and DU145) were challenged with different doses of five phyto-oestrogens (biochanin A, daidzein, genistein, genistin and nordihydroguaiaretic acid) over 3 days in culture. Cell proliferation was assessed by incorporation of 5-bromo-2'-deoxyuridine (BrdU) and metabolic activity by cleavage of a tetrazolium salt (XTT). Results. Growth and metabolism were inhibited with all compounds and cell lines (e.g. the dose for 50% inhibition of proliferation of PC-3 cells by genistein was 38 μmol/L); differences in the patterns of results suggested that different mechanisms operated, but there was no evidence for any synergistic activity on the inhibition of cell proliferation. Conclusion. These results offer further support for the hypothesized role of phyto-oestrogens as dietary protectors against prostatic cancer.