Seidlová-Wuttke D, Hesse O, Jarry H, Rimoldi G, Thelen P, Christoffel V, Wuttke W
Department of Clinical and Experimental Endocrinology, University of Goettingen, Robert-Koch-Strasse 40, D-37075 Goettingen, Germany.
Phytomedicine. 2004 Jul;11(5):392-403. doi: 10.1016/j.phymed.2004.01.003.
Belamcanda chinensis (BC) belongs to the family of iridaceae and the isoflavone tectorigenin has been isolated from the rhizome of this plant. Whether this isoflavone has estrogenic, possibly selective estrogen receptor modulator activities and if so, whether they are mediated via the estrogen receptor alpha or beta is unknown at present. Therefore, we performed binding studies with recombinant human ERalpha and ERbeta to show that tectorigenin binds to both receptor subtypes. In ERalpha-expressing MCF7 and ERbeta-expressing MDA-MB231 reporter gene transfected cells tectorigenin causes transactivation. When given intravenously to ovariectomized (ovx) rats, it inhibits pulsatile pituitary LH secretion. In postmenopausal women estrogen-unopposed LH pulses correlate with hot flushes. Therefore, suppression of pulsatile LH secretion may be beneficial in women suffering from hot flushes. Upon chronic application to ovx rats a BC extract containing 5% Belamcanda at a daily dose of 33 mg or 130 mg of the extract had no effect on uterine weight or on estrogen-regulated uterine gene expression while estrogenic effects in the bone, on bone mineral density of the metaphysis of the tibia could be established. Hence, tectorigenin may have antiosteoporotic effects also in postmenopausal women. Immunohistochemical staining of proliferating cell nuclear antigen--a proliferation marker--in the mammary gland did not indicate a mammotrophic effect of the tectorigenin-containing BC extract at both tested doses. In summary, tectorigenin or the B. chinensis extract containing tectorigenin had a strong hypothalamotropic and osteotropic effect but no effect in the uterus or the mammary gland. Therefore, tectorigenin may be in the future a clinically useful selective estrogen receptor modulator.
射干属于鸢尾科植物，从该植物的根茎中已分离出异黄酮鸢尾黄素。目前尚不清楚这种异黄酮是否具有雌激素活性，是否可能具有选择性雌激素受体调节剂活性，如果有，它们是通过雌激素受体α还是β介导的也不清楚。因此，我们用重组人ERα和ERβ进行了结合研究，以表明鸢尾黄素与两种受体亚型都能结合。在表达ERα的MCF7细胞和表达ERβ的MDA-MB231报告基因转染细胞中，鸢尾黄素可引起反式激活。当给去卵巢（ovx）大鼠静脉注射时，它可抑制垂体促黄体生成素（LH）的脉冲式分泌。在绝经后女性中，无雌激素对抗的LH脉冲与潮热相关。因此，抑制LH的脉冲式分泌可能对患有潮热的女性有益。给ovx大鼠长期应用含5%射干的提取物，每日剂量为33mg或130mg时，对子宫重量或雌激素调节的子宫基因表达没有影响，而在骨骼方面，对胫骨干骺端的骨矿物质密度有雌激素样作用。因此，鸢尾黄素在绝经后女性中可能也具有抗骨质疏松作用。在乳腺中，增殖细胞核抗原（一种增殖标志物）的免疫组织化学染色表明，在两个测试剂量下，含鸢尾黄素的射干提取物均未显示出促乳腺生长的作用。总之，鸢尾黄素或含鸢尾黄素的射干提取物具有很强的下丘脑促激素作用和骨促激素作用，但对子宫或乳腺没有作用。因此，鸢尾黄素未来可能是一种临床上有用的选择性雌激素受体调节剂。
