Effect and Mechanism of Guhong Injection Promoting Fracture Healing in Rats / 中国药学杂志

ABSTRACT

OBJECTIVE: To observe the effect of guhong injection(GHI) on tibial fracture healing in rats and to explore the mechanism of the action of GHI. METHODS: One hundred and eighty male SD rats were randomly divided into 6 groups with 30 rats in each group sham operation group, model group, positive drug group(compound ossotide injection, 5 mL•kg-1), low, medium and high dose of GHI groups(2.5, 5, 10 mL•kg-1). In addition to the sham operation group, the other groups established the rat model of tibial fracture. All were given once daily intraperitoneal injections and samples were taken at 1st, 2nd, 4th and 6th week. Blood biochemical analysis and Elisa kit detection were performed on blood samples. X-rays, biomechanical tests, immunohistochemistry and RT-PCR were performed on the tibial samples. RESULTS: ①After administration for one, two and four weeks, the levels of serum calcium(Ca) and phosphorus(P) in medium and high dose of GHI groups were higher than those in model group(P<0.05). ②X-ray showed that the outer callus growth and the disappearance of fracture line in all dose groups of GHI were faster than those in model group. ③Compared with model group, the maximum load and rigidity of medium and high dose of GHI groups were increased at each time point(P<0.05), and the trend of stress line graph were improved obviously. The content of alkaline phosphatase(ALP) in medium and high dose of GHI groups were higher than that in model group at each time point(P<0.05). Compared with model group, the serum levels of PDGF were increased in all dose groups of GHI(P<0.05 or P<0.01). After administration for one, two and four weeks, the serum BMP-2 in all dose groups of GHI were higher than those in model group(P<0.05 or P<0.01). ⑤Compared with model group, the expression of Runx2 mRNA were increased in medium and high dose of GHI groups, as well as Smad5 protein expression(P<0.05 or P<0.01). CONCLUSION: GHI could significantly improve the biomechanical properties of bone in fracture rats. The promotion of fracture healing might be through the upregulation of PDGF and BMP-2 expression in different stages of bone healing, and the regulation of BMP/Smad5/ Runx2 signaling may be one of the mechanisms of promoting fracture healing.