Effects of Xiaoding Ointment on COX-2/PGE2/cAMP signal pathway expression in fracture healing / 中成药

ABSTRACT

AIM To study the effects and action mechnism of Xiaoding Ointment (Pyrolusite,Catechu,Rhei Radix et Rhizoma,etc.) on rabbits' fracture healing in terms of cyclooxygenase-2 (COX-2),prostaglandin E2 (PGE2),cyclic adenosine monophosphate (cAMP) expressions at different time points.METHODS One hundred and twenty-eight New Zealand white rabbits were randomly divided into blank group,model group,Qingpeng Ointment (Oxytropis Falcatae Herba,Rhei lhasaense Radix et Rhizoma,Terminalia chebula Fructus,etc.) group and Xiaoding Ointment group.All the other groups,except the blank group,were made with ulna 3 mm bone defect,after which external fixation was applied to both the blank group and the model group.On the 3rd,7th,14th and 28th days after the medications,eight rabbits randomly selected from various groups had their callus morphopathology changes observed under optical microscope,their callus tissue COX-2 mRNA expression levels were detected by realtime fluorescence quantitative polymerase chain reaction (qRT-PCR),and their callus tissue PGE2 and cAMP protein expressions were determined by immunohistochemistry.RESULTS Compared with the model group and the Qingpeng Ointment group,the Xiaoding Ointment group exhibited significantly better formation of callus and collagen fibers.The mRNA expression of COX-2,and the protein expressions of PGE2 and cAMP in the Xiaoding Ointment group were remarkably enhanced as revealed on the 7th and 14th days' postoperative check (P ＜ 0.05),and the peak values arrived around the 14th day after the operation.CONCLUSION Xiaoding Ointment's obvious effect on promoting fracture healing may associate with its impact on COX-2/PGE2/cAMP signaling pathway.