The Study On The Anti-postmenopausal Osteoporosis Mechanism Of Eucommia Ulmoides Seed-draff Extract

Immune system is closely related with the bone on postmenopausal osteoporosis (PMOP). The relationship between osteoclasts and osteoblasts is regulated by multiple cytokine through a plurality of signal transduction pathways in the estrogen deficiency. This thesis studied prevention PMOP mechanism and effective substance of Eucommia seed meal extracts based on the whole animal, cellular and molecular experiments. The mRNA expression of both OPG and RANKL in osteoblasts cell cultured in the aucubin (AU) were detected by Realtime-PCR, as while as the protein expression of both OPG and RANKL were detected through western blot. After three dosages administration of Eucommia seed meal extract (ESE) to PMOP rats for 28 weeks, immunohistochemical staining method were used to determine the apoptosis related proteins expression of the largest peripheral immune organs spleen and estrogen receptor expression of the major estrogen target organs uterus. Biochemical indicators in blood and urine were also analyzed using ELISA method. The results are listed as follows:1. The expression of OPG mRNA of osteoblasts cell cultured in AU for 7 days and 14 days was higher than that of the control group (P<0.05). The expression of RANKL mRNA were lower than that of the control group (P<0.05), the most obvious difference happened in the osteoblasts cell intervened by 0.080 ?M AU for 14 days.2. Compared with the control group, AU could increase the OPG protein expression (P< 0.05), the highest value was found in the osteoblasts cell intervened by 0.080 ?M AU for 14 days (P<0.05). The RANKL protein expression of AU intervened osteoblasts cell were lower than those of the control group for 7 days and 14 days (P<0.05).3. After intra gastric administration of different doses ESE to PMOP rats for 28 weeks, the levels of urine deoxy-pyrimidine phosphorus, blood interleukin-1 and parathyroid hormone of middle-dose ESE and high-dose ESE animals were decreased significantly compared with the model group (P<0.05), calcitonin levels were significantly increased, too (P<0.05), this suggested that calcium in the blood were deposited on the bone; Bcl-2 protein expression of high-dose ESE group rats spleen were significantly increased according to the immunohistochemical analysis (P<0.01), as while as the Bax protein expression were significantly reduced, this suggested that ESE could protect immune function. Estrogen receptor ? and ? in uterus of PMOP rats presented significant difference compared with those of the model group (P< 0.01). The body weight and the blood biochemical indicators of rats, including serum urea, urea nitrogen, glycerin trilaurate, total bilirubin and cholesterol, had no significant difference compared with those of the model group. The obvious influence on liver and renal function of PMOP had not been found after taking ESE for 28 weeks.Conclusions:ESE could protect the body immune function to maintain the balance of immune system in PMOP model rats; this might be closely related to regulation the expression of estrogen receptor by ESE. AU could promote osteoblasts cell proliferation and inhibited bone resorption through OPG/RANKL/RANK pathway, the key component of anti-postmenopausal osteoporosis in Eucommia ulmoides seed-draff anti was AU.