Lack of anti-androgenic effects of equol on reproductive neuroendocrine function in the adult male rat
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- 作者：Panida Loutchanwoot ; Prayook Srivilai ; Hubertus Jarry
- 关键词：Endocrine disruptor ; Equol ; Hypothalamic GnRH pulse generator ; Reproductive outcomes ; Reproductive hormones ; Prostate ; Sex-steroid regulated gene expression
- 刊名：Hormones and Behavior
- 出版年：January, 2014
- 年：2014
- 卷：65
- 期：1
- 页码：22-31
- 全文大小：2227 K
文摘
Equol (EQ), a metabolite of the soy isoflavone daidzein, has well known estrogenic properties. Data from animal studies suggested that EQ may act also as an anti-androgen. However, data regarding how EQ may affect brain functions like the regulation of neuroendocrine activity and reproductive outcomes in adult male rats are still lacking. We therefore investigated the effects of EQ on sex-steroid regulated gene expression in the brain [medial preoptic area/anterior hypothalamus (MPOA/AH) and medial basal hypothalamus/median eminence (MBH/ME)], pituitary, and prostate as a reference androgen-dependent organ. Furthermore reproductive outcomes were evaluated. The anti-androgen flutamide (FLUT) served as reference compound. Male rats (n = 12 per group) were treated by gavage for 5 days with either EQ (100 or 250 mg/kg BW/day), or FLUT 100 mg/kg BW/day. All vehicle- and EQ-treated males showed successful reproductive outcomes, whereas FLUT-exposed males had severe reproductive impairments resulted in infertility. FLUT decreased relative weights of prostate, seminal vesicles and epididymides, and increased serum levels of luteinizing hormone, follicle-stimulating hormone, testosterone and 5伪-dihydrotestosterone without altering prolactin levels, whereas EQ exerted opposite effects. Both EQ and FLUT decreased gonadotropin releasing hormone (GnRH) expression in the MPOA/AH. Only FLUT upregulated levels of GnRH receptor expression both in the MBH/ME and pituitary. While EQ downregulated the hypothalamic ER伪 and ER尾 expressions, but FLUT did not. In the prostate, only FLUT upregulated both ER伪 and AR mRNA expression levels. Taken together, our findings are the first data that EQ did not induce anti-androgenic effects on brain, prostate and male reproductive parameters, however, estrogenic neuroendocrine and reproductive effects of EQ were observed.