[Effect of Xianling Gubao capsule on bone metabolism in ovariectomized rats].

To investigate the effect of Xianling Gubao capsule in preventing postmenopausal osteoporosis, forty-eight female Wistar rats were randomly divided into four groups: sham group (Sham), ovariectomized group (OVX), ethinylestradiol group (EE) and Xianling Gubao capsule group (XLGB). Rats in each group received ovariectomy, except for sham group. The XLGB group received Xianling Gubao capsule at the dose of 378 mg·kg⁻¹·d⁻¹. The dosage of EE group was 200 μg·kg⁻¹·d⁻¹, and OVX and Sham groups were only fed with equal volume of distilled water. All of the rats were put to death two months later. Bone mineral density, bone biomechanics, bone histomorphometry Micro-CT scanning and organ index of vital organs were calculated and pathologically observed. There was no significant difference in the body weight of rats and organ indexes of lung, kidney, heart and spleen in the experimental groups. There was also no significant change in their pathological observation, but the uterine index of OVX group and XLGB group was significantly lower than that of Sham group. According to the results of BMD test, compared with the OVX group, femurs and vertebrae BMD of the other three groups were increased, with statistically significant differences. On the basis of the results of bone biomechanical test, compared with OVX group, the maximum load values of femur and vertebrae of the other three groups were increased, with statistically significant differences, while the change of elastic modulus was not statistically significant. According to the bone histomorphometry results of VG staining, compared with Sham group, the number of trabecular bone was significantly lower than that in OVX group. Compared with OVX group, the number of trabecular bone in EE group and XLGB group was increased, but with no significant difference between EE and XLGB groups. The results of serum biochemical indexes showed that compared with Sham group, osteocalcin (OC) decreased, while tartrate resistant acid phosphatase 5b (TRACP 5b) increased in OVX group, with statistically significant differences. Compared with OVX group, the OC content of XLGB group and EE group increased, while the content of TRACP 5b decreased, with statistically significant differences. On the basis of the results of Micro-CT scanning, the change trends of femur volume BMD, number of trabecular bone (Tb.N), trabecular bone thickness (Tb.Th), trabecular bone separation (Tb.Sp), bone volume/tissue volume (BV/TV) in the groups were consistent with those of bone histomorphometry. There was no significant change in femoral cortical bone between the two groups. Xianling Gubao capsule can prevent osteoporosis in ovariectomized rats. The possible mechanism is the dual activity of inhibiting bone resorption and improving bone formation.