Belamcanda chinensis and the thereof purified tectorigenin have selective estrogen receptor modulator activities

• Published in: Phytomedicine (Stuttgart) 2004-07, Vol.11 (5), p.392-403
• Main Authors: Seidlová-Wuttke, D, Hesse, O, Jarry, H, Rimoldi, G, Thelen, P, Christoffel, V, Wuttke, W
• Format: Article
• Language: English
• Subjects: Animals; Belamcanda chinensis; Cell Line - drug effects; Disease Models, Animal; DNA Primers; Dose-Response Relationship, Drug; Estrogen; Estrogen receptor modulation; Female; Hot Flashes - drug therapy; Immunohistochemistry; Iridaceae; Isoflavones; Isoflavones - administration & dosage; Isoflavones - pharmacology; Isoflavones - therapeutic use; Medicinal plants; Ovariectomy; Phytotherapy; Plant Extracts - administration & dosage; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Rats; Rats, Sprague-Dawley; Receptors; Receptors, Estrogen - drug effects; Reverse Transcriptase Polymerase Chain Reaction; Rhizome; Risk factors; RNA, Messenger - analysis; Selective Estrogen Receptor Modulators - administration & dosage; Selective Estrogen Receptor Modulators - pharmacology; Selective Estrogen Receptor Modulators - therapeutic use; Tectorigenin
• ISSN: 0944-7113; 1618-095X
• 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 α or β is unknown at present. Therefore, we performed binding studies with recombinant human ER α and ER β to show that tectorigenin binds to both receptor subtypes. In ER α-expressing MCF7 and ER β-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.