腺花素改善葡聚糖硫酸钠诱导小鼠溃疡性结肠炎的作用

Alleviation of Dextran Sodium Sulfate-induced Ulcerative Colitis in Mice by Adenanthin

摘要:

研究了腺花香茶菜中提取的腺花素（Adenanthin, Ade）在溃疡性结肠炎（Ulcerative Colitis, UC）中的作用及其机制。用硫酸葡聚糖钠盐（Dextran sulfate Sodium Salt, DSS）构建UC动物模型，并对其进行Ade干预后，通过苏木精-伊红染色观察结肠损伤情况，并使用酶联免疫法检测炎症因子水平的变化。随后用HT-29构建体外肠道损伤模型。利用蛋白免疫印迹法评估了Ade对UC小鼠结肠和HT29细胞中Toll样受体4/髓样分化因子88/核因子κB（Toll-Like Receptor 4/Myeloid Differentiation Factor 88/Nuclear Factor-κB, TLR4/MyD88/NF-κB）信号通路和相关凋亡蛋白的影响。体内实验表明，高剂量Ade组的白介素（Interleukin, IL）-1β、IL-6、肿瘤坏死因子-α表达量分别降低至617.71、670.55、442.17 pg/mg。且Ade可以使TLR4/MyD88/NF-κB信号通路蛋白和凋亡蛋白B淋巴细胞瘤-2基因（B-Cell Lymphoma-2, Bcl-2）相关X蛋白（Bcl2-Associated X, Bax）显著降低（P<0.01），Bcl-2表达显著增加（P<0.01）。相较于模型组，高剂量Ade组中的TLR4、Myd88、p-NF-κB/NF-κB、Bax的表达量分别降低40.30%、55.86%、48.23%、49.45%，Bcl2的表达量增加102.37%。综上所述，Ade通过抑制TLR4/MyD88/NF-κB信号通路，降低炎症因子的表达，从而实现改善DSS诱导小鼠UC的作用。

Abstract:

The effects of adenanthin (Ade) extracted from Isodon adenanthus on ulcerative colitis and the associated mechanisms were examined. An animal model of ulcerative colitis was constructed by administering dextran sulfate sodium. After Ade intervention, colonic damage was observed by hematoxylin-eosin staining, and changes in the levels of inflammatory factors were detected using enzyme-linked immunoassay. HT-29 cells were used to construct in vitro intestinal models. The effects of Ade on the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB (TLR4/MyD88/NF-κB) signaling pathway and related apoptotic proteins were evaluated using western blotting. In vivo experiments showed that the expression levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α in the high-dose Ade treatment group were reduced to 617.71, 670.55, and 442.17 pg/mg, respectively. In addition, Ade led to a significant (P<0.01) decrease in the expression of TLR4/MyD88/NF-κB signaling pathway proteins and B-cell lymphoma 2 (Bcl-2)-associated X proteins (Bcl2-associated X, Bax) (P<0.01) and a significant increase in Bcl-2 expression (P<0.01). The expression levels of TLR4, Myd88, p-NF-κB/NF-κB, and Bax in the high-dose Ade group were decreased by 40.30%, 55.86%, 48.23%, and 49.45%, respectively, and the expression level of Bcl2 was increased by 102.37% compared with that in the low-dose Ade group. In summary, Ade reduces the expression of inflammatory factors by inhibiting the TLR4/MyD88/NF-κB signaling pathway, thus improving dextran sulfate sodium-induced ulcerative colitis in mice.