OBJECTIVETo compare the ability of osthole (OST) and genistein (GEN) in enhancing bone peak bone mass of rats to prevent osteoporosis.

METHODSThirty-six female one-month-old SD rats of (125 +/- 3) g body weight were randomly divided into three groups, 12 rats in each group, one group was orally administered osthole at 9 mg x kg(-1) d(-1), one group was given genistein at 10 mg x kg(-1) d(-1) and another was given equal quantity of distilled water as the control. The body weight was monitored weekly and the bone mineral density (BMD) of total body was measured every month. All rats were sacrificed after three months, the femoral bone mineral density, the serum levels of osteocalcin (OC) and anti-tartaric acid phosphatase 5b (TRACP 5b) were measured by Elisa. The bone microarchitectures were analyzed with micro-CT and the bone biomechanics properties were tested with universal material machine.

RESULTSNo significant differences were observed between O-treated or GEN group and the control for the food-intake and body weight during three months. However, the rats treated with OST had significant higher BMD for both total body and femur than the control and GEN group. The O-treated rats also had higher level of serum OC and lower level of TRACP 5b. Besides, they owned bigger bone volume/tissue volume, trabecular thickness, trabecular number but smaller trabecular spacing. In the three point bending tests of femurs,they were found to have larger maximum load, the young's modulus and structural model index (SMI).

CONCLUSIONOrally administered osthole could efficiently increase the peak bone mass of rats,which provide new ideas for preventing osteoporosis.