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 E₂, 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 E₂ 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.