Screening for natural medicines effective for the treatment of osteoporosis.

Bone-forming osteoblasts are differentiated from mesenchymal stem cells and dysregulation of this differentiation can lead to osteoporosis. Meanwhile, bone-resorbing osteoclasts are both differentiated and multinucleated from hematopoietic precursor cells of monocyte and/or macrophage lineage. Bone resorption inhibitors such as bisphosphonates and estrogen are used to treat osteoporosis. However, the adverse effects of the long-term use of these medicines are of concern, and so the development of new therapies to ameliorate osteoporosis is desirable. Therefore, in the present study, we screened 22 plant extracts and found that nine methanolic extracts of plants promote the differentiation of MC3T3-E1 cells to osteoblasts. These nine extracts were then evaluated for their inhibitory activity on osteoclast differentiation in RAW264.7 mouse macrophage cells. Of the nine extracts, Daucus carota, Vitis spp., Sasa veitchii, Euptelea polyandra, and Sesamum indicum exhibited pro-osteoblastic and anti-osteoclastic activity with low cytotoxicity, suggesting their potential effectiveness against osteoporosis.