探讨山奈素（Kaempferide）对NF-κB通路的影响及对类风湿关节炎（RA）大鼠模型的软骨细胞的作用。

建立Ⅱ型胶原诱导性关节炎（CIA）大鼠模型，将24只SD大鼠随机分为对照组、RA模型组、山奈素低剂量组和山奈素高剂量组，每组6只。采用不同剂量的山奈素治疗4周后，观察各组大鼠膝关节大体标本；番红染色观察软骨情况；免疫组织化学检测软骨组织MMP-13、Aggrecan和NF-κB的表达；Western Blot检测各组大鼠软骨组织MMP-13、Aggrecan和NF-κB的表达。体外培养大鼠关节软骨细胞，使用CCK8法检测软骨细胞在不同浓度山奈素下的活力；设立对照组、IL-1β组、山奈素低剂量组和山奈素高剂量组，qRT-PCR检测软骨细胞IL-6、MMP-13的表达、Western Blot检测各组软骨细胞的IL-6、MMP-13、NF-κB的表达。

与对照组相比，RA模型组大鼠的软骨可观察到明显的损伤，无论低剂量还是高剂量山奈素治疗都可改善RA动物模型的软骨损伤，其中高剂量组效果更加显著。通过番红染色观察到，山奈素处理显著减弱了RA大鼠的软骨损伤（P<0.05）。免疫组化检测结果显示，在经过山奈素处理的RA大鼠中，Aggrecan的表达得到显著上调（P<0.05），而MMP-13的表达显著下降（P<0.05），尤其在高剂量组中效果更为明显。同样，NF-κB通路中p65的磷酸化在山奈素处理组中也有显著下调（P<0.05），且在Western blot分析下也发现同样结果。CCK8检测表明，10 μm和50 μm浓度下的山奈素可显著提高IL-1β处理的大鼠软骨细胞的活性（P<0.05）。qRT-PCR检测显示，山奈素处理后，IL-6和MMP-13的mRNA表达水平在RA细胞模型中显著下降（P<0.05）。Western blot结果显示，山奈素处理后，IL-6、MMP-13和NF-κB通路中p65的磷酸化的蛋白表达水平在RA细胞模型中显著下降（P<0.05）。

山奈素可通过抑制NF-κB通路，减少炎症环境下软骨细胞内IL-6和MMP-13的产生，进而减弱软骨炎症及基质降解，起到保护软骨的作用。

To explore the effects of Kaempferide on the NF-κB pathway and its role in cartilage cells of a rat model of rheumatoid arthritis (RA).

A rat model of collagen-induced arthritis (CIA) was used in this study. Twenty-four SD rats were randomly divided into four groups: control group, RA model group, low-dose Kaempferide group, and high-dose Kaempferide group, with 6 rats in each group. After treatment for four weeks, gross specimens of knee joints were observed in each group; cartilage conditions were examined by safranin staining; immunohistochemistry was used to detect the expression of MMP-13, Aggrecan, and NF-κB in cartilage tissue; and Western blot was performed to measure the expression of MMP-13, Aggrecan, and NF-κB in rat cartilage tissues. Rat joint cartilage cells were cultured in vitro, and their viability in the presence of different concentrations of Kaempferide was assessed by CCK8 assay. The cells were divided into control, IL-1β, low-dose Kaempferide, and high-dose Kaempferide groups, and qRT-PCR was used to detect the expression of IL-6 and MMP-13 in cartilage cells, and Western blot analysis was performed to measure the expression of IL-6, MMP-13, and NF-κB.

Compared to the control group, significant cartilage injury was observed in the RA group, which was mitigated by Kaempferide treatment at both low and high doses, with more significant effects observed in the high-dose group. Safranin staining showed that Kaempferide treatment significantly reduced cartilage injury in RA rats (P<0.05). Immunohistochemical results indicated that, in Kaempferide-treated RA rats, the expression of Aggrecan was significantly upregulated (P<0.05), while the expression of MMP-13 was significantly downregulated (P<0.05), especially in the high-dose Kaempferide group. Similarly, the expression of phosphorylated p65 was significantly reduced in the Kaempferide treatment groups (P<0.05), a finding also observed in Western blot analysis. CCK8 assay showed that Kaempferide at concentrations of 10 μM and 50 μM significantly enhanced the viability of IL-1β-treated rat cartilage cells (P<0.05). qRT-PCR revealed that after Kaempferide treatment, the mRNA expression levels of IL-6 and MMP-13 were significantly decreased in the RA cell model (P<0.05). Western blot results showed that after Kaempferide treatment, the protein expression levels of IL-6, MMP-13, and phosphorylated p65 were significantly decreased in the RA cell model (P<0.05).

Kaempferide can inhibit the activation of NF-κB, and reduce the production of IL-6 and MMP-13 in cartilage cells under inflammatory conditions, thereby decreasing cartilage inflammation and matrix degradation and playing a protective role in cartilage.