title: Salvianolic acid B stimulates osteogenesis in dexamethasone-treated zebrafish larvae.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors: The State Administration of Traditional Chinese Medicine, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.|Department of Pharmacology, Guangdong Key Laboratory for R&D of Natural Drug, Guangdong Medical University, Zhanjiang 524023, China.
authors: Shi-Ying
authors: SY
authors: Luo
authors: Department of Pharmacology, Guangdong Key Laboratory for R&D of Natural Drug, Guangdong Medical University, Zhanjiang 524023, China.
authors: Jing-Feng
authors: JF
authors: Chen
authors: Affiliated Hospital of Guangdong Medical University, Zhanjiang 524023, China.
authors: Zhi-Guo
authors: ZG
authors: Zhong
authors: Department of Pharmacology, Guangdong Key Laboratory for R&D of Natural Drug, Guangdong Medical University, Zhanjiang 524023, China.
authors: Xiao-Hua
authors: XH
authors: Lv
authors: Department of Pharmacology, Guangdong Key Laboratory for R&D of Natural Drug, Guangdong Medical University, Zhanjiang 524023, China.
authors: Ya-Jun
authors: YJ
authors: Yang
authors: Affiliated Hospital of Guangdong Medical University, Zhanjiang 524023, China.
authors: Jing-Jing
authors: JJ
authors: Zhang
authors: The State Administration of Traditional Chinese Medicine, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.|Department of Pharmacology, Guangdong Key Laboratory for R&D of Natural Drug, Guangdong Medical University, Zhanjiang 524023, China.
authors: Liao
authors: L
authors: Cui
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000494:pharmacology*; D003907:Dexamethasone / Q000633:toxicity*; D005938:Glucocorticoids / Q000633:toxicity*; D010012:Osteogenesis / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects; D020011:Protective Agents / Q000494:pharmacology*; D015027:Zebrafish; D053630:Depsides
chemical_list: D001572:Benzofurans; D003907:Dexamethasone; D005938:Glucocorticoids; D020011:Protective Agents; C076944:salvianolic acid B; D053630:Depsides