Objective: To study the effect of Bushen Jianpi Huoxue recipe(BSJPHX) on bone morphogenetic protein2(BMP2)/Smad signaling pathway in ovariectomized rats.Method: Seventy-two female SD rats aged 6 months were randomly divided into sham group (24) and operation group(48). The rats were ovariectomized to reproduce the model of osteoporosis.After 3 months

12 rats were randomly selected to measure bone mineral density

so as to verify successful modeling in each group.The remaining 36 rats in the operation group were randomly divided into ovarietomized(OVX) group

BSJPHX(2.979 g·kg-1) group and alendronate sodium and vitamin D3 tablets (ALN

1.02 mg·kg-1) group. After 12 weeks

bone mineral density in lumbar vertebrae was measured by dual energy X-ray. Biomechanical test was performed to tibia.Expressions of BMP2

Smad1

Runt related transcription factor 2(Runx2)

and osteoprotegerin(OPG) genes were detected by Real-time PCR. Expressions of BMP2

p-Smad1

Runx2

OPG protein was detected by Western blot.Result: After 3 months of modeling

compared with sham group

the BMD of rats in OVX group was significantly lower

both the maximum load and rigidity reduced (P<0.05); after 3 months of administration

compared with OVX group

the bone mineral density of BSJPHX and ALN groups was significantly higher

both the maximum load and rigidity increased

and expression levels of BMP2

Smad1

Runx2

and OPG genes significantly increased (P<0.05).Conclusion: BSJPHX can not only regulate BMP2/Smad pathway

but also up-regulate the expression of OPG

which may be one of the mechanisms of BSJPHX in prevention and treatment of postmenopausal osteoporosis.