| Objective To investigate the effects of cordycepin on fracture healing by regulating cyclooxygenase-2 (COX-2) / prostaglandin E2 (PGE2) signal pathway in rats with osteoporosis. Methods Rat osteoporosis model was prepared. The rats were grouped into Sham group, Model group, Cordycepin group (10 mg/kg intraperitoneal injection), and Cordycepin+NS-398 group (10 mg/kg Cordycepin+10 mg/kg COX-2 inhibitor intraperitoneal injection). The fracture healing, bone mineral density (BMD), and biomechanical properties were measured respectively. HE staining was used to observe the histopathological changes of the callus. Serum levels of ALP, CTX-Ⅰ, OC, and the levels of COX-2, PGE2 and cAMP in the callus tissue were detected with ELISA. The expressions of COX-2 and VEGF in the callus were detected with immunohistochemistry. Results Compared with those in Sham group, the fracture line of Model group was obvious, X-ray score, BMD, maximum load, and stiffness of callus, and the levels of ALP and OC reduced obviously, the expression levels of COX-2, PGE2, cAMP and VEGF in bone tissue decreased obviously, and the level of CTX-Ⅰ increased obviously (P<0.05). Compared with those in the model group, the X-ray score, BMD, maximum load and stiffness of the bone, the levels of ALP and osteocalcin in the Cordycepin group increased obviously, the expression levels of COX-2, PGE2, cAMP, and VEGF in the bone tissue increasedobviously, and the level of CTX-Ⅰ reduced obviously (P<0.05). NS-398 reversed the promoting effect of Cordycepin on fracture healing in osteoporosis rats. Conclusion Cordycepin promotes fracture healing in osteoporosis rats by activating COX-2/PGE2 signal pathway. |