Curculigoside promotes osteogenic differentiation of bone marrow stromal cells from ovariectomized rats

Objectives Curculigoside, a natural compound isolated from the medicinal plant Curculigo orchioides has been reported to prevent bone loss in ovariectomized rats. However, the underlying molecular mechanisms are largely unknown. This study investigated the effects of curculigoside on proliferation and osteogenic differentiation of bone marrow stromal cells (BMSCs). Methods The toxicity, proliferation and osteogenic differentiation of BMSCs cultured with various concentrations (0 as control, 10, 100 and 500 mu m) of curculigoside were measured by viability assay, MTT analysis, alkaline phosphatase (ALP) activity assay, alizarin red staining and mineralization assay, real-time PCR analysis on osteogenic genes including ALP, type I collagen (Col I), osteocalcin (OCN) and osteoprotegerin (OPG), runt-related transcription factor 2 (Runx2), as well as OPG enzyme-linked immunosorbent assay. Key findings No significant cytotoxicity was observed for BMSCs after supplementation with curculigoside. The proliferation of BMSCs was enhanced after administration of curculigoside, especially 100 mu m curculigoside. Moreover, the osteogenic gene expression was significantly enhanced with 100 mu m curculigoside treatment. Importantly, curculigoside significantly increased OPG secretion. Conclusions The data indicate that curculigoside could promote BMSC proliferation and induce osteogenic differentiation of BMSCs. The most profound response was observed with 100 mu m curculigoside. These findings may be valuable for understanding the mechanism of the effect of curculigoside on bone, especially in relation to osteoporosis.