ABSTRACT
<p><b>OBJECTIVE</b>To explore the effect of anhydroicaritin phytosomes (AIP) in preventing and treating bone loss and enhancing bone quality in ovariectomized osteoporosis rats.</p><p><b>METHOD</b>Seventy-two SD female rats were randomly divided into 6 groups: the sham group, the model group, the estrogen group and AIP groups (low, middle, high). The sham group was only sham operated, and the remaining five groups were ovariectomized. One week after the ovariectomy, the rats were given 17 beta-estrogen and AIP (15, 30, 60 mg x kg(-1)) for consecutively three months, during which period their serum calcium (s-Ca), serum phosphorus(s-P), alkaline phosphate (ALP), urine calcium (u-Ca), urine phosphorus(u-P), urinary deoxypyridinoline (D-Pyr) and creatinine (Cr) were detected. Subsequently, rats were sacrificed, and their thighbone, second lumbar vertebrate and forth lumbar vertebrate were collected to detect bone mineral density (BMD), bone calcium (b-Ca) and phosphorus (b-P), biomechanical properties and bone histomorphometric parameters.</p><p><b>RESULT</b>Compared with the sham group, the model group showed a significant increase in serum ALP, u-Ca and D-Pyr /Cr, and reduction in BMD of femur, b-Ca and b-P, biomechanical properties (elastic load, maximum load, break load, stiffness), static parameters (total tissue area, trabecular area, trabecular perimeter) and dynamic parameters (% L Pm, BFR/BV and BFR/ TV), with metratrophia. Compared with the model group, ALP high and middle-dose groups and the estrogen group showed a decrease in serum ALP, u-Ca and D-Pyr/Cr, and growth in BMD of femur, b-Ca and b-P, biomechanical properties of the forth lumbar vertebrae (elastic load, maximum load, break load, stiffness), static parameters (total tissue area, trabecular area, trabecular perimeter) and dynamic parameters (% L Pm, BFR/BV and BFR/TV). The beta-estrogen group showed endometrial hyperplasia, whereas AIP groups showed no hyperplastic change.</p><p><b>CONCLUSION</b>AIP could inhibit enhanced bone turnover induced by ovariectomy, improve BMD the biomechanical properties of vertebrae, without any stimulation on uterus.</p>