Osteoporosis is a disease characterized by decreased bone strength, decreased bone mass, and bone deterioration. The proliferation and osteogenic capacity of osteoblastic cells needs to be improved, for their use in cell-based therapy, and in the treatment of osteoporosis. Taraxasterol, the main constituent of the traditional Chinese medicinal herb Taraxacum, has been demonstrated to have anti-inflammatory, cholesterol-lowering, anti-rheumatic, anti-cancer, and protective effects. However, the

more »

... rotective effects of taraxasterol, on osteoblastic cells and osteogenic differentiation, have not been reported. Based on the hypothesis that taraxasterol may have an effect on osteoblastic cell growth and differentiation, we studied the effect of taraxasterol on rat osteoblastic cells by detecting cell proliferation, alkaline phosphatase (ALP) activity, and the expression of relevant osteogenic markers. Various concentrations of taraxasterol (0 μM, 6.25 μM, 12.5 μM, and 25 μM) were used for treatment of rat osteoblastic cells, with the cell proliferation to be detected. Bone morphogenetic protein-2 (BMP-2), runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), bone sialoprotein (BSP), type I collagen (COL-I), and osteocalcin (OCN) expression levels were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) using isolated RNA. Our results demonstrated that taraxasterol has a strong stimulatory effect on osteoblastic cell proliferation/enhancement, and on maintaining the phenotype. Taraxasterol also regulated osteoblast differentiation through the upregulation of ALP expression in rat osteoblastic cells. Also, treatment with taraxasterol enhanced the transcript levels of BMP-2, RUNX2, ALP, BSP, COL-I, and OCN. The underlying mechanism might be associated with taraxasterol's antioxidative effect, leading to favorable amounts of reactive oxygen species in the cellular environment. Thus, our study indicated that taraxasterol can be used as an osteogenic proliferation-enhancing agent for the therapy of osteoporosis.