Cnidium lactone stimulates osteogenic differentiation of bone marrow mesenchymal stem cells via BMP-2/smad-signaling cascades mediated by estrogen receptor.

Our aim was to study the osteogenic effect of cnidium lactone for bone marrow mesenchymal stem cells (BMSCs) and its potential mechanism. BMSCs were isolated and identified by flow cytometry and multidirectional differentiation capacity. Cell Counting Kit-8 (CCK-8) was used to identify the optimal concentration of cnidium lactone. Alkaline Phosphatase (ALP) and Alizarin Red S (ARS) was performed to identify whether cnidium lactone has effect on osteogenesis at early and late phase respectively. Moreover, we used estrogen receptor antagonist, ICI182780, to identify the receptor of cnidium lactone. The expression of Runt-related transcription factor 2 (RUNX2), Osterix (OSX), osteopontin (OPN), estrogen receptor (ER), Smad4, p-Smad1, Smad1 and bone morphogenetic protein 2 (BMP-2) protein were measured by PCR and western blot. Cnidium lactone (2 μM) demonstrated increased osteogenesis after osteogenic inducible medium (OIM) induction, as evidenced by more ALP activity and mineralization. When blocked with ICI182780, osteogenesis capacity was decreased. Moreover, the polymerase chain reaction (PCR) and western blotting results indicated that cnidium lactone enhanced ER, BMP2, Smad1, Smad4, RUNX2, OSX, and OPN expression and Smad1 phosphorylation. Cnidium lactone can effectively stimulates osteogenic differentiation of BMSCs via BMP-2/Smad-Signaling cascades mediated by ER.