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 (BDNF) in the frontal cortex of ovariectomized retired breeder female rats. Fifteen 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 cortex samples were collected for RNA isolation. Northern and Phosphorlmager analyses were used to determine the relative levels of BDNF mRNA. Both estradiol and soy phytoestrogens significantly increased the mRNA levels of BDNF compared to ovariectomized controls, suggesting that soy phytoestrogens may act as estrogen agonists in regulating BDNF mRNA in the frontal cortex of retired breeder female rats.