Legette Leecole L, Martin Berdine R, Shahnazari Mohammad, Lee Wang-Hee, Helferich William G, Qian Junqi, Waters David J, Arabshahi Alireza, Barnes Stephen, Welch Jo, Bostwick David G, Weaver Connie M
Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907, USA.
J Nutr. 2009 Oct;139(10):1908-13. doi: 10.3945/jn.109.108225. Epub 2009 Aug 26.
Soy isoflavones and their metabolites, with estrogenic activity, have been considered candidates for reducing postmenopausal bone loss. In this study, we examined the effect of dietary equol, a bioactive metabolite of the soy isoflavone daidzein, on equol tissue distribution, bone parameters, and reproductive tissue activity using an adult ovariectomized (OVX) rat model. An 8-wk feeding study was conducted to compare 4 dietary treatments of equol (0, 50, 100, 200 mg/kg diet) in 6-mo-old OVX female Sprague-Dawley rats. A dose response increase in tissue equol concentrations was observed for serum, liver, kidney, and heart, and a plateau occurred at 100 mg equol/kg diet for intestine. In OVX rats receiving 200 mg equol/kg diet, femoral calcium concentration was greater than those receiving lower doses but was still less than SHAM (P < 0.05), and other bone measures were not improved. Tibia calcium concentrations were lower in OVX rats receiving 100 and 200 mg equol/kg diet compared with the OVX control rats. Trabecular bone mineral density of tibia was also lower in equol-fed OVX rats. At this dietary equol intake, uterine weight was higher (P < 0.05) than in other OVX groups but lower than the SHAM-operated intact rats. The 200 mg/kg diet dose of dietary equol significantly increased proliferative index in the uterine epithelium. Dietary equol had no stimulatory effect on mammary gland epithelium. We conclude that in OVX rats, a dietary equol dose that had modest effect on bone also exerts mild uterotropic effects.
大豆异黄酮及其具有雌激素活性的代谢产物被认为是减少绝经后骨质流失的候选物质。在本研究中，我们使用成年去卵巢（OVX）大鼠模型，研究了大豆异黄酮黄豆苷元的生物活性代谢产物雌马酚对其组织分布、骨骼参数和生殖组织活性的影响。进行了一项为期8周的喂养研究，以比较6月龄OVX雌性Sprague-Dawley大鼠的4种雌马酚饮食处理（0、50、100、200mg/kg饮食）。血清、肝脏、肾脏和心脏的组织雌马酚浓度呈现剂量反应性增加，而肠道在雌马酚剂量为100mg/kg饮食时达到平台期。在接受200mg雌马酚/kg饮食的OVX大鼠中，股骨钙浓度高于接受较低剂量的大鼠，但仍低于假手术组（P<0.05），其他骨骼指标未得到改善。与OVX对照大鼠相比，接受100和200mg雌马酚/kg饮食的OVX大鼠胫骨钙浓度较低。喂食雌马酚的OVX大鼠胫骨的小梁骨矿物质密度也较低。在这种饮食雌马酚摄入量下，子宫重量高于其他OVX组（P<0.05），但低于假手术的完整大鼠。饮食中200mg/kg剂量的雌马酚显著增加了子宫上皮的增殖指数。饮食雌马酚对乳腺上皮没有刺激作用。我们得出结论，在OVX大鼠中，对骨骼有适度影响的饮食雌马酚剂量也会产生轻度的促子宫生长作用。
