[Effects of Dioscorea septemloba on bone metabolism in ovariectomized rats].

OBJECTIVE

To investigate the effects of the decoction of Rhizoma Dioscorea septemlobae (RD) on the bone metabolism in ovariectomized rats.

METHOD

Thirty female, 3-month-old Wistar rats without pregnancy and deliver were randomly divided into 6 groups: sham (sham-operation), ovariectomy (OVX), OVX + diethylstilbestrol, OVX + high dose RD (4 g x kg(-1) x d(-1)), OVX + middle dose RD (2 g x kg(-1) x d(-1)) and OVX + low dose RD (1 g x kg(-1) x d(-1)) (n = 5 in every group). After 12-week period of continuous treatment, the urinary samples and blood samples were collected for the determination of serum estrodiol (E2), calcium (Ca), phosphorus (P), bone glaprotein (BGP), alkaline phosphatase (ALP), urinary calcium/creatinine (Ca/Cr), phosphorus/ creatinine (P/Cr) and deoxypyridioline/creatinine (DPD/Cr). The uteri were removed and weighed. The bone mineral density (BMD) and the biomechanical parameters of the femur of the rats in every group were determined, respectively.

RESULT

The coefficient of uteri in every dose group of OVX + RD was significantly higher than that in the OVX group (P < 0.01). The concentration of serum ALP, BGP and urinary DPD/Cr, Ca/Cr in the OVX group was significantly higher than that in the sham group (P < 0.05), respectively, However, that in the every dose of OVX + RD was lower than that in the OVX group, respectively. There was no significan difference in the concentration of serum Ca, P and urinary P/Cr in every group, respectively. The bone mineral density (BMD) in the OVX group was (0.032 +/- 0.007) g x cm(-2) and was significantly lower than that in the sham group (P < 0.01). However, the value in the group of every dose OVX + RD was significantly higher than that in the OVX group (P < 0.05, P < 0.01), respectively. The maximum loading, deflection and the maximum strain of the femur in the OVX group were (125.78 +/- 15.48) N, (1.87 +/- 0.22) mm, (9.34 +/- 1.10) % and were significantly lower than those in the sham group (P < 0.05, P < 0.01), respectively. The maximum loading and maximum stress were increased in different extent in the every dose group of OVX + RD, respectively.

CONCLUSION

The decoction of RD can inhibit bone absorption, decline bone turnover and improve the loss of bone in ovariectomized rats.