Effects of icariin on the proliferation and differentiation of MC3T3-E1

Icariin (ICA), the main active flavonoid glucoside isolated from Herbaepimedii (HEF), is an anabolic agent in bone that has been reported to prevent bone loss in ovariectomized rats and postmenopausal women. However, the understanding of its mechanism of this anabolic action of ICA in osteogenesis remains incomplete. Here, we found that Icariin could promote MC3T3-E1 osteoblastic cell proliferation, associated with increased protein levels of the proliferation markergene cyclin D1 and, CDK4. Icariin also enhanced MC3T3-E1 cell differentiation and mineralization demonstrated by increased the expression of differentiation markers, alkaline phosphatase (ALP) and collagen type I (Col I), osteocalcin (OCN) and bone nodule formation via Alizarin red S staining. In addition, the ratio of OPG/RANKL also could be enhanced by ICA. Therefore, in the present study, we investigate the effects of ICA on osteoblast differentiation from at least three perspectives, so as to obtain an understanding of its mechanism of action and elucidate the molecular mechanisms of this drug, which might provide an insight into the rationality and in-depth theoretical basis for the clinical application of ICA in preventing osteoporosis.