Abstract: Disclosed is a pharmaceutical composition comprising eupatilin as an active ingredient for suppressing osteoclast differentiation, bone metastasis, and osteolysis and for preventing or treating periodontitis. Found to effectively inhibit the differentiation of osteoclast progenitors into osteoclasts and the fusion of mononucleated osteoclasts into multinucleated osteoclasts, and reduce the bone resorption of W multinucleated osteoclasts, Eupatilin is capable of effectively suppressing bone metastasis and osteolysis and may be used to prevent or treat periodontitis.

Abstract: Disclosed is a composition for inducing the differentiation of osteoclasts containing progranulin as an active ingredient, or a composition for the prevention or treatment of osteoporosis containing a progranulin inhibitor as an active ingredient, wherein progranulin functions as an RANK-dependent cell-communication factor and as a mediator in osteoporosis through inflammation, and exists at a remarkably high concentration, compared to a control, in the serum of prostate cancer patients, osteoporosis patients, and bedridden patients with low bone mineral density, whereby the progranulin can be used as an osteoclast differentiation factor and as a biomarker for osteoporosis or metastatic prostate cancer.