| Background and Objectives:Postmenopausal Osteoporosis(PMO) is a progressive, systemic skeletal disease characterized with low bone mass and deterioration of bone micro-architecture, leading to increased bone fragility and susceptibility to fractures, which is associated with estrogen loss in women beyond menopausal age. Epidemiology shows that this kind of disease will become more and more prevalent in the future, with costly implications for public health. Therefore, Prevention of the disease and its consequences, namely fractures, is important for both the individual and the society. The main pathology of PMO is accelerated bone turnover, which increased the loss of bone. PMO is caused by factors of hormone, heredity, nutrition, low weight, high caffeine or nicotine intake and so on. Among these reasons, estrogen deficiency in postmenopausal women is foremost, which is associated with an increase of bone turnover and acceleration of bone loss. Estrogens can regulate bone metabolism, and the biological action of estrogen is mediated by estrogen receptor(ER). ER is a hormone-dependent transcription factor belonging to the nuclear receptor superfamily. There are two kinds of ER, ERa and ERp, which are genetically different but structurally related. ER has been identified in osteoblasts, chondrocytes and osteoclasts, which may act as direct targets for estrogen influence on bone metabolism. Besides, estrogen deficiency leadsto changes of PTH and CT, or other hormone and cell conditioner. In the treatment, Estrogen replacement therapy (ERT) is used mostly. It has a significant effect on the prevention and treatment of bone loss. But recent evidence from the WHI study has cast doubt on the routine role of ERT for its side effects. Selective estrogen receptor modulators (SERMs) are non-hormonal agents that bind to oestrogen receptors with an affinity equivalent to that of oestradio. Compared with ERT, SERMs have several advantages for prevention of PMO. They do not cause vaginal bleeding or breast tenderness and do not increase the risk of cancer of the uterus or breast. Traditional Chinese medicine (TCM) is always famous for its timely, accurate and useful curative effects with fewer side effects. SERMs of TCM has showed more and more promise in treatment of PMO. TCM thought PMO as "bone atrophy", and the essential reason of its pathogenesis is kidney deficiency. Nice efficacy on the disease was gained by using the way of Kidney-tonifying. But on the other hand, lots of disadvantages are existed also. Our traditional Chinese medcine formula YiFuning Soft Gelatin Capsules (YFN) , which is made up of Oviducts Ranae and Rhizoma Curcumae, can nourish the kidney and activate blood. The former experimental results suggested YFN can produce effects on declined neuroendocrine-immune network in menopause from various levels, ways and links by means of regulating the function of plant nerve and reproduction endocrine. YFN can also reduce the content of Ca Ca/Cr Hyp/Cr in the urine, TRACP in serum, increase ALP and CT in serum. All of this indicated the effects of YFN on PMO. The ovariectomized (OVX) rats which is the classical model of PMO was selected in this study, the effects on PMO of YFN by several kinds of indexes were observed. At the same time, the mechanism of the prevention and treatment of PMO was explored also. The content:1. To study the pharmacodynamics on treating PMO with YFN.2. To explore the therapeutic mechanisms by studying its effects. Methods:We selected OVX female rats as the models of Postmenopausal Osteoporosis. 60 female Sprague-Dawley rats were used, 50 of them were ovariectomized and randomly divided into 5 groups: ovariectomy(OVX), OVX with diethylstilbestrol tables(DT), OVX with YFN(high dose, middle dose and low dose), the others were sham-operated group. Began to give the rats drugs in the fifth week after the operation. The rats were sacrificed, then the blood, uterus and bones were collected to be inspected respectively after 12 weeks.The content of sex hormone in serum was detected by radioimmunoassay. The contents of Ca> P^ ALP in serum were detected using the automatic biochemistry analyse device. The uteruses were weighed and the length, width, dry weight and net weight of the shoulder bone were measured. The contents of minerals such as Ca, Mg, Zn, Mn in the bone were measured using the atomic absorption spectrophotometer. The right femurs were detected for BMD using the dual-energy X-ray absorptiometry scanner and the electronic testing device is used to detect the biomechanical properties. The pathology of bone is observed for the HE stain and the area of trabecular is detected. The expression of estrogen receptor in bones was studied by means of immunochemical techniques, luminescent histochemical method and Western blotting. Results:The results indicated that the rat model of PMO was successfully built. With the model group, after administrated the drugs, the content of E2, Ca in serum, the weight of uterus increased significantly. The content of P, ALP in serum decreased obviously which means YFN can slow down the velocity of bone turnover. The contents of Ca, Mg, Zn, Mn in the bone increased, which suggests that YFN can modulate the level of microelements in the bone. The length, width, dry weight and net weight of the shoulder bone increased, as well as the BMD of right femur increased significantly; the observation of HE show different repairing around trabecular. The biomechanical parameters increased also. The results indicate that YFN can effectively prevent the loss of bone in OVX rats and strengthen bone quality. The estrogen receptorexpression in bone increased significantly. Conclusions:YFN showed a good effect on PMO. The therapeutic mechanisms is not only by increasing the content of E2 in serum, but also by increasing the ER expression in bone and increasing the content of microelements in the bone, so as to strengthen the quality of bone, which provides evidence for clinical use. |
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