Up-regulation of VEGF by MC3T3-E1 cells treated with curculigoside

Empirical evidence has shown that curculigoside, the main active compound of the traditionally used Chinese herb, Curculigo orchioides (Amaryllidaceae, rhizome), affects bone formation and fracture healing. However, the mechanistic details of these processes remain unclear. Therefore, the effects of curculigoside on immortalized, pre-osteoblastic mouse MC3T3-E1 cells was investigated. Following treatment with curculigoside, MC3T3-E1 cells exhibited an increased rate of proliferation. Higher levels of vascular endothelial growth factor (VEGF), Fms-like tyrosine kinase-1 (Flt-1) and bone morphogenetic protein-2 (BMP-2) were also detected in cell supernatants and cell lysates by ELISA and western blot analysis, respectively. Furthermore, the stimulatory effect of curculigoside was observed at relatively low doses (i.e. 10-100 μg/mL). In combination, these responses to treatment with curculigoside elucidate mechanistic details underlying the therapeutic effects of Curculigo orchioides on bone, and identifies these molecules as potential targets for the treatment of common metabolic bone diseases.