Abstract
Traditional Chinese medicines (TCM) contain multi-interactive compounds that have been used for treatment of peri-menopausal syndrome and have become a new phytoestrogens resource. The QiBaoMeiRan formula (QBMR), including Polygoni multiflori radix, Angelicae sinensis radix, Achyranthis bidentatae radix, semen Cuscutae, fructus Lycii, Poria, and fructus Psoraleae, has been used clinically for treating osteoporosis in post-menopausal women by virtue of its kidney-invigorating function. However, no evidence base links QBMR to estrogen replacement therapy. In this study, we undertook a characterization of estrogenic activity of QBMR using ovariectomized (OVX) rats. OVX rats were treated with QBMR at doses of 0.875, 1.75, and 3.5 grams/kg per day for 8 weeks. QBMR treatments demonstrated significant estrogenic activity, as indicated by vaginal cornification, reversal of atrophy of uterus, vagina, and mammary gland, and up-regulation of estrogen receptor α (ERα) and estrogen receptor β (ERβ) expression in the reproductive target tissues, where ERβ up-regulation was stronger than that of ERα. Meanwhile, treatment with QBMR significantly increased adrenal weight and serum estradiol levels and tended to decrease serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels in a dose-dependent manner. Moreover, QBMR significantly decreased weight gain and rectal temperature increase caused by ovariectomy, and the largest changes in rectal temperature were found at the lowest dose. The data suggest that QBMR's estrogenic responses show tissue variation that reflects different affinities of ERs for QBMR components. This study demonstrates that QBMR activity is mediated through estrogenic components and provides an evidence base for QBMR treatment of post-menopausal symptoms.