The addition of NBIF (1-20 [micro]M) significantly and concentrationdependently enhanced bone nodules formation in MC3T3-E1 cells when compared with control observed at day 14.
Accordingly, we also evaluated and compared the osteogenic effects between NBIF and icariin by analyzing the ALP activity and mineralization in MC3T3-E1 cells.
The effect of NBIF on the bone-specific matrix protein expression were analyzed by determining the mRNA expression of Col-I, BSP and OCN, respectively.
NBIF up-regulates Runx2and Osx expression in MC3T3-E1 cells
We therefore hypothesize that NBIF stimulates osteogenesis by modifying the expression of this transcription factor.
8A indicated that treatment with SB203580 (p38 inhibitor), but not PD98059 (MEK inhibitor) nor SP600125 (JNK inhibitor), significantly repressed NBIF induced enhancement in ALP activity.
After studying the molecular mechanisms, results demonstrated that activation of p38 MAPK signaling pathway might contribute to the induction of bone characteristic transcription factors which subsequently up-regulated the expression of bone matrix protein and induced mineralization by NBIF.
Further, NBIF was more potent than icariin to induce osteogenic differentiation/mineralization in our assay system.
Thus, the inductive effect of NBIF (1-20 [micro]M) on the ALP activity in MC3T3-EI cells is a positive indicator of its ability to promote osteogenesis in this particular cell line.
We have also shown that NBIF induces Runx2 and Osx mRNA expression in MC3T3-E1 .
We also observed an increase in p38 phosphorylation after NBIF stimulation for 30 min.
Here, we showed that NBIF greatly increased Runx2 and Osx mRNA levels and such induction were abolished by SB203580 treatment.