Simvastatin increases osteoblasts and osteogenic proteins in ovariectomized rats

Background  Previous reports have indicated that statins could prevent bone loss in ovariectomized (OVX) rats and increase the expressions of osteogenic genes in cultured osteoblasts. In this study, we hypothesized that simvastatin might increase osteoblast number and protein expressions of osteogenic markers localized in bones in concomitance with the prevention of bone loss in OVX rats. Materials and methods  Fifty-four 3-month-old OVX and sham-operated (SHAM) female Sprague–Dawley rats were used. Simvastatin (10–20 mg kg−1 day−1) was administrated orally for 6 weeks. Trabecular volume, osteoblast number and osteogenic proteins including BMP2, collagen type I and osteocalcin on bone sections obtained from lumbar vertebral body, distal femur and proximal tibia were measured. Results  The results showed that SHAM rats had significantly less trabecular bone volume and osteoblast number than that of OVX rats 6 weeks after operation. Oral simvastatin treatment (10–20 mg kg−1 day−1) increased bone volume and osteoblast number in the distal femurs, proximal tibiae and vertebrae of OVX rats. Furthermore, the osteoblastic cells with immuno-stained BMP2, collagen type I and osteocalcin in vertebral bones were significantly increased by simvastatin treatment (20 mg kg−1 day−1) in OVX rats. Conclusions  This study demonstrates that simvastatin enhances the production of osteogenic proteins in bone and this effect may contribute to the prevention of bone loss in OVX rats.