关键词:

汉黄芩素, 腺苷酸活化蛋白激酶/沉默信息调节因子1信号通路, 骨质疏松, 骨折愈合

Abstract:

Objective To investigate the effect of wogonin（WOG）on bone fracture healing in rats with osteoporosis（OP）by regulating AMP ⁃activated protein kinase（AMPK）/silent information regulator 1（SIRT1） signaling pathway. Methods Sixty female SPF SD rats were randomly divided into sham operation group（Sham group），osteoporotic fracture（OPF）model group（Model group），low⁃dose WOG group（WOG⁃L group，50 mg/kg）， high ⁃ dose WOG group（WOG ⁃H group，100 mg/kg）and high ⁃ dose WOG +AMPK inhibitor Compound C group （WOG⁃H+CC group，100 mg/kg WOG+0.2 mg/kg Compound C），with 12 rats in each group. Model group，WOG⁃L group，WOG ⁃ H group and WOG ⁃ H + CC group were selected to establish the rat model of osteoporotic fracture （OPF）by bilateral oophorectomy and intramedullary fixation of right femoral shaft fracture. Radiological examina⁃ tion was performed to evaluate the fracture healing. Bone mineral density（BMD）of rat femoral callus was mea⁃ sured by dual energy X⁃ray absorptiometry. The biomechanics of rat femoral bone was tested by three⁃point bending test and compression test. Serum osteocalcin（OC）and procollagen typeⅠcarboxy⁃terminal peptide（PICP）were measured by colorimetry. HE staining was used to observe the pathological changes of callus at the fracture site. Western blot was used to detect the expression of AMPK/SIRT1 signal pathway related proteins in femur. Results Compared with the Sham group，the fracture healing score，BMD of upper and lower femur callus，the maximum displacement，maximum stress and maximum load of callus，the serum OC and PICP levels，AMPK phosphoryla⁃ tion level in femur tissue and SIRT1 protein expression in Model group were obviously reduced（P < 0.05），no callus growth was found at the fracture end，the fracture line was clear，the bone trabecula was thin，the number was reduced，the gap was increased，and the structure was disordered and loose. Compared with the Model group， the fracture healing score，BMD of upper and lower femur callus，the maximum displacement，maximum stress and maximum load of callus，the serum OC and PICP levels，AMPK phosphorylation level in femur tissue and SIRT1 protein expression in the WOG⁃H group were obviously increased（P < 0.05），there was continuous callus wrapping and penetrating the fracture end，the medullary cavity was reopened，the fracture line was unclear，and the shape of bone trabecula was relatively complete. Compound C weakened the promoting effect of WOG on frac⁃ ture healing in OPF rats. Conclusion WOG may promote fracture healing in OPF rats by activating AMPK/SIRT1 signaling pathway.

Key words:

wogonin, AMP?activated protein kinase/silent information regulator 1 signal pathway, os? teoporosis, fracture healing