|ZFIN ID: ZDB-PUB-160830-7|
Salvianolic acid B stimulates osteogenesis in dexamethasone-treated zebrafish larvae
Luo, S.Y., Chen, J.F., Zhong, Z.G., Lv, X.H., Yang, Y.J., Zhang, J.J., Cui, L.
|Source:||Acta Pharmacologica Sinica 37(10): 1370-1380 (Journal)|
|PubMed:||27569393 Full text @ Acta Pharmacol. Sin.|
Luo, S.Y., Chen, J.F., Zhong, Z.G., Lv, X.H., Yang, Y.J., Zhang, J.J., Cui, L. (2016) Salvianolic acid B stimulates osteogenesis in dexamethasone-treated zebrafish larvae. Acta Pharmacologica Sinica. 37(10):1370-1380.
Aim Our previous studies show that salvianolic acid B (Sal B) promotes osteoblast differentiation and matrix mineralization. In this study, we evaluated the protective effects of Sal B on the osteogenesis in dexamethasone (Dex)-treated larval zebrafish, and elucidated the underlying mechanisms.
Methods At 3 d post fertilization, wild-type AB zebrafish larvae or bone transgenic tg (sp7:egfp) zebrafish larvae were exposed to Sal B, Dex, or a mixture of Dex+Sal B for 6 d. Bone mineralization in AB strain larval zebrafish was assessed with alizarin red staining, and osteoblast differentiation in tg (sp7:egfp) larval zebrafish was examined with fluorescence scanning. The expression of osteoblast-specific genes in the larvae was detected using qRT-PCR assay. The levels of oxidative stress markers (ROS and MDA) in the larvae were also measured.
Results Exposure to Dex (5-20 μmol/L) dose-dependently decreased the bone mineralization area and integral optical density (IOD) in wild-type AB zebrafish larvae and the osteoblast fluorescence area and IOD in tg (sp7:egfp) zebrafish larvae. Exposure to Dex (10 μmol/L) significantly reduced the expression of osteoblast-specific genes, including runx2a, osteocalcin (OC), alkaline phosphatase (ALP) and osterix (sp7), and increased the accumulation of ROS and MDA in the larvae. Co-exposure to Sal B (0.2-2 μmol/L) dose-dependently increased the bone mineralization area and IOD in AB zebafish larvae and osteoblast fluorescence in tg (sp7:egfp) zebrafish larvae. Co-exposure to Sal B (2 μmol/L) significantly attenuated deleterious alterations in bony tissue and oxidative stress in both Dex-treated AB zebafish larvae and tg (sp7:egfp) zebrafish larvae.
Conclusion Sal B stimulates bone formation and rescues GC-caused inhibition on osteogenesis in larval zebrafish by counteracting oxidative stress and increasing the expression of osteoblast-specific genes. Thus, Sal B may have protective effects on bone loss trigged by GC.