State Key Laboratory of Natural Medicines, Department of Biochemistry, China Pharmaceutical University, 24 Tongjia Xiang, Nanjing, 210009, China.
Department of Neurobiology and Anatomy, Northeast Ohio Medical University, Rootstown, OH, 44272, USA.
Inflamm Res. 2017 Feb;66(2):187-196. doi: 10.1007/s00011-016-1005-3. Epub 2016 Nov 29.
The activation of NF-κB signaling and unbalance of T-helper (Th) cells have been reported to play a key role in the pathogenesis of colitis. Cortex Phellodendri Chinensis (CPC) is commonly used to treat inflammation and diarrhea. Demethyleneberberine (DMB), a component of CPC, was reported to treat alcoholic liver disease as a novel natural mitochondria-targeted antioxidant in our previous study. In this study, we investigated whether DMB could protect against dextran sulfate sodium (DSS)-induced inflammatory colitis in mice by regulation of NF-κB pathway and Th cells homeostatis.
Inflammatory colitis mice were induced by 3% DSS, and DMB were orally administered on the doses of 150 and 300 mg/kg. In vitro, DMB (10, 20, 40 μM) and N-acetyl cysteine (NAC, 5 mM) were co-cultured with RAW264.7 for 2 h prior to lipopolysaccharide (LPS) stimulation, and splenocytes from the mice were cultured ex vivo for 48 h for immune response test.
In vivo, DMB significantly alleviated the weight loss and diminished myeloperoxidase (MPO) activity, while significantly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), and inhibited the activation of NF-κB signaling pathway. Furthermore, DMB decreased interferon (IFN)-γ, increased IL-4 concentration in the mice splenocytes and the ratio of IgG1/IgG2a in the serum. In vitro, ROS production and pro-inflammation cytokines were markedly inhibited by DMB in RAW264.7 cell.
Our findings revealed that DMB alleviated mice colitis and inhibited the inflammatory responses by inhibiting NF-κB pathway and regulating the balance of Th cells.
核因子-κB 信号的激活和辅助性 T 细胞（Th）的失衡已被报道在结肠炎的发病机制中起关键作用。黄柏是一种常用于治疗炎症和腹泻的药物。我们之前的研究表明，黄柏中的去甲小檗碱（DMB）作为一种新型天然线粒体靶向抗氧化剂，可用于治疗酒精性肝病。在这项研究中，我们通过调节 NF-κB 通路和 Th 细胞稳态来研究 DMB 是否可以预防葡聚糖硫酸钠（DSS）诱导的小鼠炎症性结肠炎。
通过给予 3% DSS 诱导炎症性结肠炎小鼠，并用 150 和 300mg/kg 的剂量口服给予 DMB。在体外，用 10、20、40μM 的 DMB 和 5mM 的 N-乙酰半胱氨酸（NAC）与 RAW264.7 共培养 2 小时，然后用 LPS 刺激，再将来自小鼠的脾细胞进行体外培养 48 小时进行免疫反应测试。
体内，DMB 显著减轻了体重减轻和髓过氧化物酶（MPO）活性降低，同时显著减少了促炎细胞因子，如白细胞介素（IL）-6 和肿瘤坏死因子-α（TNF-α）的产生，并抑制了 NF-κB 信号通路的激活。此外，DMB 降低了干扰素（IFN）-γ，增加了小鼠脾细胞中 IL-4 的浓度和血清中 IgG1/IgG2a 的比值。在体外，DMB 明显抑制了 RAW264.7 细胞中的 ROS 产生和促炎细胞因子的产生。
我们的研究结果表明，DMB 通过抑制 NF-κB 通路和调节 Th 细胞的平衡来缓解小鼠结肠炎和抑制炎症反应。
