(±)-Equol interferes with the secretion of gonadotropin-releasing hormone and the expression of neuromodulators in murine neurons

S-Equol is an intestinal bacterial metabolite of the isoflavone daidzein. Racemic (±)-equol is used as a dietary estrogen supplement in menopausal women and is suggested to affect the female reproductive function and development, primarily controlled by the hypothalamic-pituitary-gonadal axis and gonadotropin-releasing hormone release. In this study, murine neurons were utilized to evaluate the effect and mechanism of (±)-equol on the secretion of gonadotropin-releasing hormone. The cells were treated with up to 20 µmol/L of (±)-equol to determine the influence on cell viability. Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction, and Western-blotting analysis were used to investigate the impacts of (±)-equol on the secretion and transcription of gonadotropin-releasing hormone, and the transcription and translation of key neuromodulators. This study showed that (±)-equol could decrease cell viability, increase the ability to secrete gonadotropin-releasing hormone, and interfere with the expression of neurokinin B receptor, makorin ring finger protein 3, and silent information regulator 1.