The preventive and therapeutic roles of phytoestrogen α-Zearalanol on osteoporetic rats due to ovariectomization

OBJECTIVE(S): The aim of this study was to observe the influence of phytoestrogen α-Zearalanol on ovariectomy-induced postmenopausal osteoporosis in rats. MATERIALS AND METHODS: 40 SD female rats were randomly divided into four groups: Sham group, OVX group (ovariectomized and fed estrogen), α-Zearalanol group (ovariectomized and fed α-Zearalanol) and untreated group (ovariectomized). Three weeks later after surgery, α-Zearalanol and estradiol valerate were administered by oral gavage for 12 weeks to the α-Zearalanol group and the OVX group, respectively. In contrast, the sham and untreated controls were treated with distilled water in a daily basis. After the treatments, uterus histomorphometry, bone mechanical strength, bone histomorphometry, bone mineral density (BMD) of femur, and serum biochemical indicators, such as serum E(2), CT and PTH, as well as the levels of TNF and IL-1 were examined. RESULTS: The BMD was overall declined rigorously in the OVX rats, and that could be mitigated through feeding on either estrogen or α-Zearalanol. Estrogen or α-Zearalanol was found to decrease the levels of serum ALP and BGP in OVX rats, while, α-Zearalanol was found to increase the levels of serum E(2) and CT, the thickness of the endometrium, and decrease the levels of PTH, TNF and IL-1 in serum in OVX rats. Feeding the OVX rats on α-Zearalanol improved the bone histomorphometric parameters impaired due to estrogen deficiency and enhanced the bone mechanical properties in the ovariectomized rats. CONCLUSION: α-Zearalanol treated rats reduced the resorption of bone, and showed a preventive and therapeutic effect of α-Zearalanol on postmenopausal osteoporosis.