Abstract
BACKGROUND: Rhizoma drynariae, a traditional Chinese herb, is commonly used in treatment of bone healing in osteoporotic fractures. However, whether the Rhizoma drynariae total flavonoids (RDTF) can promote the absorption of calcium and enhance the bone formation is unclear. The aim of the present study was to investigate the preventive effects of RDTF combined with calcium carbonate (CaCO(3)) on estrogen deficiency-induced bone loss. METHODS: Three-month-old Sprague-Dawley rats were ovariectomized (OVX) and then treated with CaCO(3,) RDTF, and their admixtures for ten weeks, respectively. The bone trabecular microstructure, bone histopathological examination, and serum biomarkers of bone formation and resorption were determined in the rat femur tissue. The contents of osteoprotegerin (OPG), receptor activator of the NF-κB (RANK), and its ligand (RANKL) in marrow were analyzed by ELISA, and the protein expressions of Wnt3a, β-catenin, and phosphorylated β-catenin (p-β-catenin) were analyzed by Western blot. Statistical analysis was conducted by using one-way analysis of variance (ANOVA) followed by LSD post hoc analysis or independent samples t test using the scientific statistic software SPSS version 20.0 RESULTS: RDTF combined with CaCO(3) could promote osteosis and ameliorate bone loss to improve the repair of cracked bone trabeculae of OVX rats. Furthermore, RDTF combined with CaCO(3) also could prevent OVX-induced decrease in collagen fibers in the femoral tissue of ovariectomized rats and promote the regeneration of new bone or cartilage tissue, while CaCO(3) supplementation promoted the increase in bone mineral content. Nevertheless, there was no difference in the expression of Wnt3a, β-catenin and p-β-catenin between osteopenic rats and RDTF treated rats, but RDTF combined with CaCO(3) could activate the Wnt3a/β-catenin pathway. CONCLUSIONS: RDTF combined with CaCO(3) could ameliorate estrogen deficiency-induced bone loss via the regulation of Wnt3a/β-catenin pathway.