杜仲醇提取物对骨关节炎模型大鼠关节软骨的保护

Protective effect of eucommia alcohol extract on articular cartilage of osteoarthritis model rats

背景:目前已有研究发现杜仲水提取物对骨关节炎有明显的改善作用,但是关于杜仲醇提取物对骨关节炎的治疗作用尚未见报道。目的:探究杜仲醇提取物对骨关节炎大鼠的保护作用,以及Janus激酶1(Janus kinase 1,JAK1)/信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)/细胞因子信号转导抑制因子3(suppressor of cytokine signaling 3,SOCS3)通路的作用机制。方法:将SD大鼠随机分成假手术组、模型组、杜仲醇提取物低、高剂量组,每组10只。除假手术组外,其余各组大鼠利用手术横断右膝关节内侧半月板胫骨韧带诱导骨关节炎大鼠模型;杜仲醇提取物低、高剂量组大鼠分别给予50,200 mg/kg的杜仲醇提取物连续灌胃8周治疗。对大鼠进行步态行为测试、缩足机械阈值和缩足热潜伏期的测定;X射线成像评估大鼠关节间隙和软骨表面钙化的变化;检测大鼠血清炎性因子白细胞介素6、白细胞介素1β、肿瘤坏死因子α水平;番红固绿(Safranin O)染色和苏木精-伊红染色观察大鼠关节软骨病理学变化,并采用国际骨性关节炎研究学会评分系统进行评估;Western blot法检测大鼠关节软骨组织中JAK1/STAT3/SOCS3通路蛋白表达水平。结果与结论:①假手术组大鼠软骨表面光滑;模型组大鼠关节软骨组织破坏严重,软骨表面密度增加,关节间隙变窄;杜仲醇提取物低、高剂量组大鼠软骨损伤明显改善,表面钙化程度减轻;②与假手术组相比,模型组大鼠国际骨性关节炎研究学会评分、缩足机械阈值、白细胞介素6、白细胞介素1β、肿瘤坏死因子α水平及基质金属蛋白酶13、JAK1、p-STAT3蛋白表达水平显著升高(P<0.05),步态行为评分、缩足热潜伏期及SOCS3蛋白表达水平显著降低(P<0.05);③与模型组相比,杜仲醇提取物低、高剂量组大鼠国际骨性关节炎研究学会评分、缩足机械阈值、白细胞介素6、白细胞介素1β、肿瘤坏死因子α水平及基质金属蛋白酶13、JAK1、p-STAT3蛋白表达水平显著降低(P<0.05),步态行为评分、缩足热潜伏期及SOCS3蛋白表达水平显著升高(P<0.05);④提示杜仲醇提取物可能通过抑制JAK1/STAT3通路,促进SOCS3蛋白表达,减轻炎症反应,发挥骨关节炎大鼠关节软骨的保护作用。

BACKGROUND:At present,studies have found that eucommia water extract can significant relieve osteoarthritis,but there is no report about the therapeutic effect of eucommia alcohol extract on osteoarthritis.OBJECTIVE:To investigate the protective effect of eucommia alcohol extract on osteoarthritis rats,and the mechanism of action of the janus kinase 1(JAK1)/signal transducer and activator of transcription 3(STAT3)/suppressor of cytokine signaling 3(SOCS3)pathway.METHODS:Sprague-Dawley rats were randomly divided into four groups(n=10 per group):a sham operation group,a model group,a low-dose eucommia alcohol extract group,and a high-dose eucommia alcohol extract group.Transection of the medial meniscotibial ligament of the right knee joint was conducted to induce an osteoarthritis rat model in all the groups except for the sham operation group.Rats in the low-dose and high-dose eucommia alcohol extract groups were given 50 and 200 mg/kg eucommia alcohol extract by intragastric administration for 8 weeks.Gait behaviors were tested,and paw withdrawal mechanical threshold and paw withdrawal thermal latency were determined.The changes of rat joint space and cartilage surface calcification were evaluated with X-ray imaging.The levels of inflammatory factors interleukin 6,interleukin 1β,and tumor necrosis factorαin rat serum were detected.Pathological changes of rat articular cartilage were observed using Safranin-O staining and hematoxylin-eosin staining,and were evaluated by Osteoarthritis Research Society International scoring system.Western blot was used to detect the protein expression of JAK1/STAT3/SOCS3 pathway in rat articular cartilage tissue.RESULTS AND CONCLUSION:The rat cartilage surface was smooth in the sham operation group,but was severely damaged in the model group.Moreover,the cartilage surface density was increased,and the joint space became narrowed in the model group.Low-and high-dose eucommia alcohol extracts significantly relieved cartilage injury,and reduced surface calcification.Compared with the sham operation group,the Osteoarthritis Research Society International score,paw withdrawal mechanical threshold value,levels of interleukin 6,interleukin 1β,and tumor necrosis factorα,and protein expression of matrix metalloproteinase 13,JAK1,and p-STAT3 were significantly increased(P<0.05),while the gait behavior score,paw withdrawal thermal latency and the protein expression of SOCS3 were significantly reduced in the model group(P<0.05).Compared with the model group,the Osteoarthritis Research Society International score,paw withdrawal mechanical threshold value,levels of interleukin 6,interleukin 1β,tumor necrosis factorα,and protein expression of matrix metalloproteinase 13,JAK,and p-STAT3 were significantly reduced(P<0.05),while the gait behavior score,paw withdrawal thermal latency and the protein expression of suppressor of cytokine signaling 3 were significantly increased in the low-and high-dose eucommia alcohol extract groups(P<0.05).Therefore,eucommia alcohol extract can inhibit the JAK1/STAT3 pathway,promote the protein expression of SOCS3 and reduce inflammation,thereby protecting the articular cartilage of osteoarthritis rats.