Icarrin increases bone morphogenetic protein 2 and Osterix expression in rat osteoblast

Objective To observe the effect of icarrin on proliferation and differentiation of rat osteoblasts cultured in vitro as well as the expressions of bone morphogenetic protein-2 (BMP-2) and Osterix in rat osteoblast.Methods Calvarial osteoblasts were obtained from newborn (＜ 24 h) SD rats by trypsin-collagenase digestion.The culture medium with different icarrin concentrations and the second generation osteoblasts were mixed.The mRNA expressions of BMP-2,Osterix,ALP,and Col Ⅰ were detected by semiquantative RT-PCR.Then the second generation osteoblasts were cultured in the medium containing icariin (10 ng/ml) with or without BMP-2 antibody.After48 h,RT-PCR was used to estimate the mRNA expression of Osterix.Results In comparison with the control group,the mRNA expressions of BMP-2,Osterix,ALP,Col Ⅰ were increased in a dose-dependent manner (P＜0.05) with a maximal effect at the concentration of 10 ng/ml.The mRNA expression of Osterix treated with the mixture of icarrin and BMP-2 antibody was significant decreased(P＜0.05),and compared with the group of icarrin,however,the difference between the BMP-2 group and the mixture group was not statistically significant (P ＞ 0.05).Conclusions Icarrin stimulates proliferation and differentiation of cultured osteoblast in vitro by increasing the mRNA expression of ALP and Col Ⅰ.Icarrin could stimulate Osterix gene expression by enchancing BMP-2 gene expression,finally,it could induce bone formation and prevent and/or treat osteoporosis. Key words: Icarrin;  Osteoblasts;  Bone morphogenetic protein-2;  Osterix;  Osteoporosis