Evidence for up-regulation of brain-derived neurotrophic factor mRNA by soy phytoestrogens in the frontal cortex of retired breeder female rats

In this study, we examined the effects of oral micronized estradiol and soy phytoestrogens on the mRNA levels of brain-derived neurotrophic factor (BD NF) in the frontal cortex of ovariectomized retired breeder female rats. Fi fteen ovariectomized rats were randomized into three groups and fed either a soy-free control diet (OVX), a control diet with added soybean estrogens (SBE), or a control diet with added estradiol (E2) for 8 weeks. Frontal cor tex samples were collected for RNA isolation. Northern and Phosphorlmager a nalyses were used to determine the relative levels of BDNF mRNA. Both estra diol and soy phytoestrogens significantly increased the mRNA levels of BDNF compared to ovariectomized controls, suggesting that soy phytoestrogens ma y act as estrogen agonists in regulating BDNF mRNA in the frontal cortex of retired breeder female rats. (C) 1999 Elsevier Science Ireland Ltd. All ri ghts reserved.