School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, Guangdong, China.
Development Planning Department, Guangzhou University of Chinese Medicine, Guangzhou, 510006, Guangdong, China.
Chem Biol Interact. 2021 Aug 1;344:109512. doi: 10.1016/j.cbi.2021.109512. Epub 2021 May 8.
Inflammatory bowel diseases (IBDs), which mainly include Crohn's disease (CD) and ulcerative colitis (UC), are chronic idiopathic inflammatory disease of the gastrointestinal tract for which effective pharmacological treatments are lacking or options are very limited.
Here, we aim to investigate the therapeutic effects of an iridoid glycoside, asperuloside (ASP) on mice experimental chronic colitis induced by dextran sulfate sodium (DSS) and further explore underlying mechanisms in vitro and in vivo.
LPS-treated RAW 264.7 cells showed inflammation and were assessed for various physiological, morphological and biochemical parameters in the absence or presence of ASP. Chronic colitis was induced by 2% DSS in mice, which were used as an animal model to explore the pharmacodynamics of ASP. We detected p65 and Nrf2 pathway proteins via Western blot and RT-PCR analysis, assessed the cytokines TNF-α and IL-6 via ELISA, tested p65 and Nrf2 nuclear translocation via fluorescence. In addition, the docking affinity of ASP and p65 or Nrf2 proteins in the MOE 2015 software.
We found that ASP attenuated weight loss, disease activity index (DAI) and colonic pathological damage in colitis mice and restored the expressions of inflammatory cytokines in the colon. In addition, ASP restored antioxidant capacity in DSS-induced chronic colitis mice and lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Furthermore, ASP suppressed oxidative stress through increasing Nrf2, HO-1 and NQO-1 proteins expressions, and down-regulated nuclear levels of p65 to inhibit DSS-induced colonic oxidative stress and inflammation. Validation of the molecular docking results also indicated that ASP interacts with Nrf2 or p65 proteins. In summary, ASP improved DSS-induced chronic colitis by alleviating inflammation and oxidative stress, activating Nrf2/HO-1 signaling and limiting NF-κB signaling pathway, which may be an effective candidate for the treatment of IBD.
炎症性肠病（IBD）主要包括克罗恩病（CD）和溃疡性结肠炎（UC），是一种慢性特发性胃肠道炎症性疾病，目前缺乏有效的药物治疗方法，选择非常有限。
本研究旨在探讨裂环环烯醚萜苷类化合物獐牙菜苦苷（ASP）对葡聚糖硫酸钠（DSS）诱导的小鼠慢性结肠炎的治疗作用，并在体内外进一步探讨其作用机制。
用 LPS 处理 RAW 264.7 细胞，观察 ASP 对 LPS 诱导的 RAW 264.7 细胞炎症反应的影响，检测细胞形态学、生理生化等指标。采用 2%DSS 诱导小鼠慢性结肠炎模型，探讨 ASP 的药效学。通过 Western blot 和 RT-PCR 分析检测 p65 和 Nrf2 通路蛋白，ELISA 法检测 TNF-α和 IL-6 细胞因子，荧光法检测 p65 和 Nrf2 核转位。此外，在 MOE 2015 软件中进行 ASP 与 p65 或 Nrf2 蛋白的对接亲和力分析。
ASP 可减轻结肠炎小鼠的体重减轻、疾病活动指数（DAI）和结肠组织病理学损伤，恢复结肠中炎症细胞因子的表达。此外，ASP 可恢复 DSS 诱导的慢性结肠炎小鼠和 LPS 刺激的 RAW 264.7 细胞的抗氧化能力。ASP 通过增加 Nrf2、HO-1 和 NQO-1 蛋白的表达，抑制核内 p65 水平，抑制 DSS 诱导的结肠氧化应激和炎症，从而抑制氧化应激。分子对接结果的验证也表明，ASP 与 Nrf2 或 p65 蛋白相互作用。综上所述，ASP 通过减轻炎症和氧化应激、激活 Nrf2/HO-1 信号通路和限制 NF-κB 信号通路，改善 DSS 诱导的慢性结肠炎，可能是治疗 IBD 的有效候选药物。
