【目的】 探讨杨梅黄酮对膝骨关节炎模型大鼠的治疗作用及机制。【方法】 将60 只健康 Lewis 雄性大鼠随机分为 5 组， 即假手术组、模型组和杨梅黄酮低、中、高剂量组。除假手术组，其他各组大鼠行内侧半月板横断（MMT）诱导膝骨关节炎 模型。造模成功后，分组干预。治疗期间每周测量大鼠体质量，进行足平衡刺痛试验评估疼痛状况。治疗结束后，采用苏 木精-伊红（HE）染色、番红 O-固绿以及甲苯胺蓝染色法观察关节软骨组织形态，并依据国际骨关节炎研究会（OARSI）进行 评分。硝酸还原酶法检测关节腔液一氧化氮（NO）水平。酶联免疫吸附分析（ELISA）检测关节腔液炎症因子水平，包括诱导 型一氧化氮合酶（iNOS）、肿瘤坏死因子 α（TNF-α）、白细胞介素 1β（IL-1β）、白细胞介素 6（IL-6）、白细胞介素 10（IL- 10）。实时荧光定量聚合酶链式反应（qPCR）法检测软骨合成代谢因子聚集蛋白聚糖（ACAN）、Ⅱ型胶原α1链（Col2a1）、SRY 相关HMG盒基因9（SOX9）以及分解代谢因子含Ⅰ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶5（ADAMTS5）、基质金属 蛋白酶 3（MMP3）和基质金属蛋白酶 13（MMP13）mRNA 表达。蛋白免疫印迹（Western Blot）法检测软骨 iNOS 蛋白表达以及活 化水平。【结果】 与假手术组比较，模型组大鼠膝关节病理损伤明显，OARSI 评分显著升高，足平衡比率下降，关节软骨组 织中检测到高水平活化的 iNOS 蛋白和 NO 累积以及病理分解代谢因子（ADAMTS5、MMP3、MMP13）mRNA 表达，关节腔液 炎症因子 TNF-α、IL-1β、IL-6水平亦显著上升，而软骨合成代谢因子（ACAN、Col2a1、SOX9）mRNA 表达水平及关节腔液 IL-10水平降低，差异均有统计学意义（P＜0.05），动物体质量未见明显差异（P＞0.05）。与模型组比较，杨梅黄酮低、中、 高剂量大鼠关节局部病理损伤均得到改善，其中，杨梅黄酮中、高剂量组OARSI 评分显著降低（P＜0.05），足平衡比率升高 （P＜0.05）；此外，与模型组比较，杨梅黄酮中、高剂量组iNOS/NO表达和活化水平，促炎因子TNF-α，IL-1β 和 IL-6 水平 显著下降，抗炎因子 IL-10 水平升高，软骨合成代谢因子（ACAN、Col2a1、SOX9）表达升高，分解代谢因子（ADAMTS5、 MMP3、MMP13）表达降低，差异均有统计学意义（P＜0.05），且大鼠体质量无明显变化（P＞0.05），大鼠耐受性良好。【结论】 杨梅黄酮可通过抑制关节腔液、关节软骨组织内 iNOS 蛋白表达和活化，进而抑制NO产生和大量累积，降低炎症因子释放， 减轻疼痛反应，促进软骨合成代谢并抑制分解代谢，维持软骨稳态，最终改善大鼠骨关节炎的软骨病理损害。

Objective To investigate the therapeutic effects and underlying mechanism of myricetin on knee osteoarthritis （KOA） in a rat model. Methods Sixty healthy male Lewis rats were randomly assigned to five groups： sham-operated group，model group，and low-，medium-，and high-dose myricetin treatment groups. Except for the sham-operated group，KOA was induced in all other groups via medial meniscal transection （MMT）. After successful modeling，the respective interventions were administered. During the treatment period，rat body mass was measured weekly，and pain status was assessed using the paw balance test. Upon completion of the treatment，joint cartilage morphology was evaluated by hematoxylin-eosin （HE） staining，Safranin O-Fast Green staining， and Toluidine Blue staining，and scored according to the Osteoarthritis Research Society International （OARSI） scoring system. Nitric oxide （NO） levels in the joint cavity fluid were measured using the nitrate reductase method. Levels of inflammatory factors，including inducible nitric oxide synthase （iNOS），tumor necrosis factor-α（TNF-α）， interleukin-1β（IL-1β）， interleukin-6（IL-6）， and interleukin-10（IL-10）， in the joint cavity fluid were quantified by enzyme-linked immunosorbent assay （ELISA）. The mRNA expression levels of anabolic factors [aggrecan （ACAN）， collagen type II alpha 1 chain （Col2a1）， SRY-box transcription factor 9（SOX9）] and catabolic factors [a disintegrin and metalloproteinase with thrombospondin motifs 5 （ADAMTS5）， matrix metalloproteinase 3（MMP3），matrix metalloproteinase 13（MMP13）] in cartilage were detected by quantitative real-time polymerase chain reaction （qPCR）. iNOS protein expression and activation levels in cartilage were determined by Western Blot. Results Compared with the sham-operated group， the model group exhibited significant pathological damage in the knee joint， a markedly increased OARSI score， and a decreased paw balance ratio. High levels of activated iNOS protein and NO accumulation were detected in the articular cartilage tissue，along with upregulated mRNA expression of catabolic factors （ADAMTS5，MMP3，MMP13）. Levels of the inflammatory factors TNF- α， IL-1β， and IL-6 in the joint cavity fluid were significantly elevated， whereas mRNA expression levels of anabolic factors （ACAN，Col2a1，SOX9） and IL-10 level in the joint cavity fluid were decreased； all these differences were statistically significant （P＜0.05）. No significant difference in body mass was observed between groups （P＞0.05）. Compared with the model group，local pathological damage in the knee joint was ameliorated in all myricetin treatment groups. Specifically，the medium- and high-dose myricetin groups showed significantly reduced OARSI scores （P＜0.05） and increased paw balance ratios （P＜0.05）. Furthermore， compared with the model group， the medium- and high-dose myricetin groups demonstrated significantly suppressed iNOS/NO expression and activation，decreased levels of the pro-inflammatory cytokines TNF- α， IL-1β， and IL-6， elevated level of the anti-inflammatory cytokine IL-10， enhanced expression of cartilage anabolic factors （ACAN，Col2a1，SOX9），and reduced expression of catabolic factors （ADAMTS5， MMP3，MMP13）；all differences were statistically significant （P＜0.05）. No significant changes in body mass were observed （P＞0.05）， and the rats exhibited good tolerance to myricetin. Conclusion Myricetin alleviates cartilage pathological damage in rat osteoarthritis by inhibiting the expression and activation of iNOS in the joint cavity fluid and articular cartilage tissue， thereby reducing NO production and accumulation， decreasing the release of inflammatory factors， mitigating pain responses， promoting cartilage anabolism while suppressing catabolism，and ultimately maintaining cartilage homeostasis.

R285.5

中国博士后科学基金项目（编号：2022M713052）；国家自然科学基金资助项目（编号：31801207）