Objective: To observe the effect of Bushen Huoxue granule (BSHXG) on osteoporosis model induced by retinoic acid in rats

and to explore its mechanism of action. Method: Forty-eight SD rats were randomly divided into normal group

model group

BSHXG low

middle and high dose groups

and Xianling Gubao (XLGB) group. All other groups except the normal group were orally administered with retinoic acid daily 70 mg·kg-1

continuous for 14 d. Modeling and administration were done at the same time. The low

middle and high dose groups were given with BSHXG 10

20

40 g·kg-1;XLGB group was given with XLGB liquid 0.3 g·kg-1;model group and normal group were administered with equal volume of normal saline. After 4 weeks of dosing

orbital blood was taken to measure the bone alkaline phosphatase (BALP)

bone gamma-carboxyglutamic-acid-containing proteins (BGP)

and tartrate-resistant acid phosphatase (TRACP-5β) in serum;after the animals were sacrificed

left femur was taken to make tissue pathological slices and right femur was taken to measure bone mineral density. Result: Compared with the normal group

the body weight in the rats of model group increased slowly (P<0.05);the serum levels of BALP

TRACP-5β increased significantly (P<0.01);BGP decreased significantly (P<0.05);and bone density was significantly decreased (P<0.05). Compared with model group

the body weight in various administration groups increased rapidly (P<0.05) and BALP was significantly decreased (P<0.01). BSHXG middle and high dose groups and XLGB group could significantly increase BGP (P<0.05)

decrease TRACP-5β (P<0.01)

and significantly increase bone mineral density (P<0.05). Conclusion: Bushen Huoxue granule has the effect in preventing and treating osteoporosis

regulating the disorder state of bone formation and bone destruction

improving bone microstructure

and increasing bone mineral density and bone turnover rate.