Mechanistic Insights Into the Estrogen-Like Effects of Selenium-Enriched Armillaria on Anti-Osteoporosis in Ovariectomized Rats.

Selenium (Se) is an essential trace element in bone metabolism. Armillaria (AM) has the ability to enrich Se and exhibits the potential for treating osteoporosis. The aim of this study was to evaluate the effect of Se-enriched Armillaria (AM-Se) on osteoporosis in ovariectomized rats. AM-Se was prepared by adding sodium selenite to the liquid fermentation medium of AM. Forty 8-week-old female Sprague-Dawley rats were randomly divided into five groups as follows: (1) Sham operation group (SHAM), (2) Ovariectomy group (OVX), (3) OVX + Estradiol group (E2, 9 µg/kg/day), (4) OVX + AM (AM, 0.4 g/kg/day), and (5) OVX + AM-Se (AM-Se, 0.4 g/kg/day). A rat postmenopausal osteoporosis (PMOP) model was established by bilateral ovariectomy. After 12 weeks of treatment, the results showed that AM or AM-Se alleviated OVX-induced bone trabecular loss, maintained biomechanical properties, and regulated bone metabolism indicators and sex hormone levels in rats. The expression of estrogen receptor α was significantly increased in the hypothalamus, pituitary, and tibia of rats treated with AM or AM-Se. AM-Se is more effective than AM in the treatment of PMOP, and the mechanism involved is related to estrogen-like effects.