Study on the Regulatory Mechanism of ICA on Osteogenic Differentiation of Rabbit Bone Marrow Mesenchymal Stem Cells

To explore the regulatory mechanism of icariin (ICA) on osteogenic differentiation of rabbit bone marrow mesenchymal stem cells (BMSCs). A total of 20 healthy adult New Zealand white rabbits were randomly divided into an ICA group and a control group (CG). In the ICA group, rabbits were given icariin at 0.25 g/kg by oral gavage. After the first intragastric gavage, the drug was administered a second time at an interval of 20 hours and the third time after 4 hours. After the third administration in the first hour, blood was taken by cardiac puncture. In the CG, rabbits were given with equal volume of 0.9% sodium chloride solution by oral gavage. The rabbits' serum in the two groups was obtained, and the effects of the different concentrations of drug-containing serum on BMSC proliferation and ALP activity were compared. After ICA induction, the secretion of osteocalcin at different time points, calcium deposition level, and mRNA expression of PI3K and mTOR were determined. The A570 value of the ICA group was higher than that of the CG (P<0.01), and the promotion effect of the 10% ICA group was the most robust. Except for the 10% ICA group, the ALP activity of the other two groups was significantly higher than that of the corresponding control group, and the 5% ICA group showed the highest ALP activity. In the two groups, the osteocalcin secretion from cells reached the highest value at 9 days. The osteocalcin secretion in the ICA group was significantly higher than that in the CG at different time points. In the two groups, the calcium deposition level increased with the prolonged induction of culture time. ICA may promote osteogenic differentiation of rabbit BMSCs through the mTOR pathway.