Effect of total flavonoids from Drynaria rhizome on bone loss in ovariectomized rats

Purpose: To determine the potential effect of total flavonoids from Drynaria rhizome on bone loss in ovariectomized (OVX) rats. Methods: The rats were divided into four groups: normal control, ovariectomized (OVX) control, and two Drynaria rhizome (DR) flavonoids treatments. Post-operation, osteoporotic OVX rats were given Drynaria rhizome total flavonoids for 3 months. Thereafter, the expressions of bone-related genes and biochemical indices were investigated in samples taken from rat serum and bone. Results: Treatment with total flavonoids from Drynaria rhizome prevented bone mineral loss and improved some related biochemical indices associated with osteoporosis, namely, alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP), bone gla protein (BGP) and estradiol (E2). Reverse transcription-polymerase chain reaction (RT-PCR) data showed that treatment with the total flavonoids significantly downregulated mRNA expression of Wnt10b, beta-catenin, recombinant human bone morphogenetic protein-2 (BMP2) and BMP4 in OVX rats, but significantly reversed OVX-induced downregulation of dickkopf1 (Dkk1) mRNA expression. Conclusion: These results indicate that total flavonoids from Drynaria rhizome exert anti-osteoporotic effects in rats through the WNT signaling and BMP-2 signaling pathways.