Abstract: OBJECTIVE:To investigate the effect of Guijiajiao(Colla Carapacis et Plastri, CCP), the glue of tortoise shell, on bone regeneration in zebrafish and male Wistar rats.METHODS: In this study, we applied in vitro and in vivo models, tissue section analysis, and quantitative polymerase chain reaction to assess the effects of CCP on bone repair. MG-63 cells were used in alkaline phosphatase(ALP) activity and mineralization assays. Zebrafish and male Wistar rats were used to evaluate the effects of CCP on bone repair in vivo.RESULTS: A simple preparation of CCP promoted osteogenesis in vivo and in vitro, and promoted MG-63 cell proliferation as well as ALP activity and mineralization. In addition, CCP activated Akt and extracellular signaling-regulated kinase pathways and significantly increased the expression of ossification-related genes and proteins such as runt-related transcription factor-2, osteocalcin, and osteopontin. The in vivo results revealed promotion of osteogenesis by immersing zebrafish in CCP for 72 h.An oral dose of 1.25 g/kg CCP significantly improved skull defects in rats, which was accompanied by an increase in serum ALP levels.CONCLUSION: One of the ingredients of Guilu Erxianjiao(tortoise shell and deer horn formula) pro-vides a practical alternative therapy for bone regeneration.

Key words: Colla Carapacis et Plastri Testudinis, Bone regeneration, Alkaline phosphatase, Rat, Zebrafish