ANTI-OSTEOPOROSIS ACTIVITY OF EUCOMMIA, CUSCUTA AND DRYNARIA EXTRACTS IN THE OVARIECTOMIZED RATS

To observe the effect of Eucommia, Cuscuta, and Drynaria (E.C.D.) extracts in ovariectomized rats and explore the possible mechanisms. Forty-five female Sprague Dawley rats were randomly divided into 5 groups: sham operation group (Sham), ovariectomized group (Model) and ovariectomized rats + treatment group (estradiol valerate of 104.17 mg/kg/day (EV), E.C.D. extracts of 50.08 mg/kg/day (E.C.D.-L), or E.C.D. extracts of 104.17 mg/kg/day (E.C.D.-H), and all the rats were treated by gavage for 8 weeks). Bone metabolism, estrogen index, phosphorus and calcium were compared, and the right femur structural parameters were evaluated by micro-CT. The rat femoral bone specimens were stained using hematoxylin and eosin for pathological examination, and mRNA expression of related genes in bone tissue was detected by real-time quantitative polymerase chain reaction (PCR). We observed E. C. D.-H groups significantly increased serum estrogen levels, and significantly elevated the maximum load and bone mineral density (BMD) levels in bone tissues. EV group and E. C. D.-H groups improved bone metabolism, biomechanical properties, serum phosphorus and calcium indexes. Compared with the model group, bone morphogenetic protein 2 (BMP2), small mothers against decapentaplegic 5 (Smad5), runt-related transcription factor 2 (Runx 2), Wnt3a of the E. C. D.-H groups were significantly increased (p<0.05), the NF-κβ was significantly decreased (p<0.05). In conclusion, E.C.D. extracts can increase the content of serum estradiol E2, improve the BMD and promote bone formation in ovariectomized rats, and the mechanism may be related to the regulation of BMP/Smads pathway and Wnt/β-catenin pathway.