Purpose: The decoction of collagen extracted from Carapacis et Plastri Testudinis (CCPT) has been reported to have an effect of anti-osteoporosis. The present study was to investigate the in vitro molecular mechanisms effect of CCPT on ROS1728 differentiation and proliferation.
Methods: Rat osteoblast cell line (ROS 1728) was cultured and exposed to CCPT at different concentrations. The effect of CCPT on the proliferation of ROS1728 was evaluated through detecting the activity of Alkaline Phosphatase (ALP) and the type I collagen (Coll-I) content. The gene expression of ALP, Coll-I, Osteocalcin (OC), Runx2, Osterix (Osx), Osteoprotegerin (OPG) and RANKL (receptor activator of NF-MB ligand) was observed using RT-PCR analysis.
Results: The results showed that CCPT treatment (2.5, 5.0 and 10.0 mg/ml) affected the proliferation of ROS1728 in a concentration-dependent manner. The highest expression was obtained by treatment with 5 mg/ml of CCPT after a nine-day treatment duration based on ALP activity and Coll-I content (P<0.01) with the control group, whereas, the expression of ALP, Coll-I, OC, Runx2, Osx and OPG mRNA was facilitated (P<0.01). Only the level of RANKL mRNA decreased compared with the control group (P<0.01).
Conclusion: Use of CCPT can induce ROS1728 proliferation into osteoblasts and enhance the function of osteogenesis through regulating the gene expression of Runx2 and the osteogenesis-specific transcription factors of Osx, and inhibit bone absorption by OPG/RANKL/RANK signaling pathways.