Asperosaponin VI, A Saponin Component from Dipsacus asper Wall, induces Osteoblast Differentiation through Bone Morphogenetic Protein-2/p38 and Extracellular Signal-regulated Kinase 1/2 Pathway

Osteoporosis is a reduction in skeletal mass because of the loss of osteoblastic activity or an increase in osteoclastic activity. The survival of osteoblast cells plays a crucial role in the development of osteoporosis. Asperosaponin VI (ASAVI) is a kind of saponin in the medicinal herb Dipsacus asper Wall which has long been used as an antiosteoporosis drug. The assay of cell proliferation, alkaline phosphatase ( ALP) activity and measurement of mineralized matrix, showed that ASA VI exhibited a significant induction of proliferation, differentiation and mineralization in MC3T3-E1 and primary osteoblastic cells. Induction of differentiation by ASA VI was associated with increased bone morphogenetic protein-2 (BMP-2), indicating that BMP-2 is essential in ASA VI to mediate osteoblast maturation and differentiation. In addition, ASA VI may induce differentiation by increasing the activity of p38 and ERK1/2. In conclusion, ASA VI may induce osteoblast maturation and differentiation, and then increase bone formation via increasing BMP-2 synthesis, and activating p38 and ERK1/2. Copyright (C) 2011 John Wiley & Sons, Ltd.