Polysaccharides Derived from Drynaria fortunei Attenuated Osteoclast Differentiation Induced by Receptor Activator of Nuclear Factor-κB Ligand by Modulating NFATc1 and c-Fos

The rhizome of Drynaria fortunei (Kunze ex Mett.) J. Sm., which is known as "Golsebo" in Korea, traditionally has been used to heal various inflammatory conditions, including bone metabolism disorders. It relieves blood extravasation, stops bleeding, repairs broken bone tissue, treats bone fractures, and kills bacteria. In this study, we evaluated the modulatory effects of DFP on the differentiation of bone-marrow-derived macrophages into osteoclasts. We performed tartrate-resistant acid phosphatase assays using DFP (at different concentrations and molecular weights) to evaluate the degree of bone resorption in the receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis of bone-marrow-derived macrophages. TRAP activity increased with increasing DFP concentrations (0-200 mu g/mL). Additionally, DFP significantly inhibited RANKL-induced osteoclastogenesis and controlled RANKL-mediated overexpression of c-Fos and nuclear factor of activated T cells 1, thereby downregulating osteoclast-specific gene (Atp6v0d2, cathepsin K, and DC-STAMP) expression. DFP thus has potential as a nutraceutical candidate for treating bone loss diseases, including osteoporosis in postmenopausal women.