phytoestrogens and Necrosis

Phytoestrogens (PE) including isoflavones and lignans, are a group of substances of plant origin which can act as estrogen agonists or antagonists. While the immunomodulatory effects of isoflavones have been studied, little is known about the impact of lignans and other PE metabolites on the immune system. The aim of the present study was to assess whether PE and their metabolites modulate human leukocyte functions in vitro. We investigated the effects of genistein, daidzein, matairesinol, and secoisolariciresinol, including metabolites such as equol, O-desmethylangolensin, enterodiol, and enterolactone on natural killer cell activity, proliferation, cytokine secretion, as well as apoptotic and necrotic rate of human leukocytes. Genistein, daidzein, and its metabolite equol were the most potent inhibitors of leukocyte functions. Ten micromolars of genistein decreased proliferation, lytic activity of natural killer cells, and cytokine secretions. The latter proved to be the most sensitive marker of immune functions. Lignans and their metabolites had minor effects on the immune system. The antiestrogens Tamoxifen and Fulvestrant did not block the inhibition of cytokine secretion by genistein and equol. In conclusion, while physiological concentrations of isoflavones have minor effects on cytokine secretion, lignans including their major metabolites do not modulate human leukocyte functions in vitro.

Topics: Adult; Apoptosis; Biomarkers; Biotransformation; Cell Proliferation; Cytokines; Estrogen Antagonists; Humans; Immunity, Cellular; In Vitro Techniques; Killer Cells, Natural; Leukocytes; Male; Necrosis; Phagocytosis; Phytoestrogens

In this study, we investigated whether dietary intervention could inhibit tumor growth of an androgen-sensitive human prostatic cancer.. LNCaP cells were transplanted subcutaneously in nude-mice. The animals were then put on different diets and tumor take, tumor growth and prostate specific antigen (PSA) secretion were studied during 9 weeks.. Palpable tumors developed in 75% of the tumor-cell injected sites in animals fed a control diet (corn starch, sucrose, etc.) whereas, for animals given rye bran (RB), ethyl acetate extraction from rye bran supplemented cellulose based diets (CCEE), palpable tumors were seen in only 30% and for soy protein based diets (SCC) 50% of the transplantation sites, respectively. The tumors that grew to palpable size in the rye (RB) and soy (SCC) groups were smaller and secreted less PSA than those in the control group. In the rye and soy groups tumor cell apoptosis was increased, but cell proliferation was unaffected. Addition of fat to the rye diet reduced its effect on prostate cancer growth.. Factors in rye bran and soy protein may inhibit prostate cancer growth. The effect is more apparent for rye than for soy. Further studies are needed to identify the effective substances and to explore the mechanism of action.

Topics: Adenocarcinoma; Animals; Apoptosis; Cell Division; Dietary Fiber; Dietary Proteins; Eating; Estrogens, Non-Steroidal; Humans; Isoflavones; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Necrosis; Neoplasm Transplantation; Phytoestrogens; Plant Preparations; Prostate-Specific Antigen; Prostatic Neoplasms; Secale; Soybean Proteins