Daidzein-estrogen interaction in the rat uterus and its effect on human breast cancer cell growth.

Sex hormone replacement therapy provides several advantages in the quality of life for climacteric women. However, estrogen-induced cell proliferation in the uterus and mammary gland increases the risk of cancer development in these organs. The lower incidence of mammary cancer in Asian women as compared with Western women has been attributed to high intake of soy isoflavones, including genistein. We have previously shown that genistein induces an estradiol-like hypertrophy of uterine cells, but does not induce cell proliferation, uterine eosinophilia, or endometrial edema. It also inhibits estradiol-induced mitosis in uterine cells and hormone-induced uterine eosinophilia and endometrial edema. Nevertheless, genistein stimulates growth of human breast cancer cells in culture; therefore, it is not an ideal estrogen for use in hormone replacement therapy (HRD). The present study investigated the effect of another soy isoflavone, daidzein (subcutaneous, 0.066 mg/kg body weight), in the same animal model, and its effect on responses induced by subsequent treatment (1 h later) with estradiol-17ß (E(2); subcutaneous, 0.33 mg/kg body weight). In addition, we investigated the effects of daidzein (1 µg/mL) or E(2) on the growth of human breast cancer cells in culture. Results indicate that daidzein stimulates growth of breast cancer cells and potentiates estrogen-induced cell proliferation in the uterus. We suggest caution for the use of daidzein or formulas containing this compound in HRD. Future research strategies should be addressed in the search for new phytoestrogens that selectively inhibit cell proliferation in the uterus and breast.

Estudio de posibles biocontroladores de fitopatógenos de Haba (Vicia faba)y de Papa (Solanum tuberosum) / Study of possible biocontrol of phytopathogenic of bean (Vicia faba) and of Potato (Solanum tuberosum)

El empleo de hongos antagonistas se convierte en una alternativa al uso de pesticidas químicos en el manejo de las enfermedades de plantas. En este contexto se ha realizado un tamizaje, mediante enfrentamientos duales in vitro, frente a Botrytis cinerea; de 60 colonias de hongos (cepario del IIFB) que fueron aisladas de tierras de diversos ecosistemas bolivianos. Las 6 cepas mas activas, fueron sometidas a procesos de fermentación (agitado y no agitado, 80ml); los cultivos en agitadofueron incubados por 16 días y los cultivos no agitados fueron incubados por 29 días; en ambos cultivos sedetermino el pH, consumo de glucosa y la actividad inhibitoria, por el método de dilución en placa, frente a Botrytis cinerea y Alternaria solani.Los filtrados de diferentes tiempos del cultivo no agitado demuestran que, 4 de las 6 cepas tienen actividad contra Botrytis cinerea de las cuales, dos el (8-QD-R y 12-QD-1) son las que presentan mayor actividad inhibitoria.Los filtrados del 12-QD-1 permiten además el control del desarrollo de Alternaria solani. Solo dos de losfiltrados de las 6 cepas (22-QD y 291-QD), en condiciones de cultivo agitado, inhiben el crecimiento de Botrytis cinerea.