溃疡性结肠炎(UC)是一种日益普遍的疾病,尤其是在发达国家。缺乏令人满意的治疗方法推动了对替代治疗策略的探索。在最近的研究中,小檗碱,一种植物生物碱,在中药中具有悠久的药用历史,已显示出对急性UC动物模型的有益效果。然而,UC通常表现为患者频繁复发的慢性病症。小檗碱对慢性UC的作用尚不清楚。在本研究中,我们采用葡聚糖硫酸钠(DSS)诱导的慢性复发性结肠炎模型来评估小檗碱的改善活性。通过两个周期的2.0%DSS持续5天,然后是14天的饮用水,再加上仅由DSS组成的第三个周期,为期5天,诱发结肠炎。从第13天开始口服给予结肠炎小鼠20mg/kg小檗碱30天,每天监测。体重,大便稠度,并记录大便出血情况以测定疾病活动指数(DAI)。在治疗结束时,处死动物,收集样品并进行组织学检查,RT-qPCR,蛋白质印迹,和LC-MS分析。从脾和肠系膜淋巴结(MLN)中分离淋巴细胞,并培养用于从CD4(+)细胞分泌IL-17和Th17细胞分化的流式细胞术分析。结果表明,小檗碱显著改善DAI,结肠缩短,结肠组织损伤,和减少结肠炎小鼠的紧密连接(TJ)蛋白ZO-1和闭塞蛋白的结肠表达。值得注意的是,小檗碱治疗可明显减少结肠中DSS上调的Th17相关细胞因子(IL-17和ROR-γt)mRNA。此外,小檗碱明显抑制DSS处理小鼠结肠组织中IL-6和IL-23的mRNA表达以及STAT3的磷酸化。此外,小檗碱治疗可明显逆转DSS引起的脾CD4()细胞和MLN分泌IL-17的上调。此外,小檗碱以浓度依赖性方式抑制了从上述DSS结肠炎小鼠分离的幼稚CD4(+)细胞的Th17细胞分化。总之,我们首次证明小檗碱通过抑制Th17反应降低了慢性复发性DSS诱导的结肠炎的严重程度.该小鼠模型中活性的证明支持小檗碱治疗慢性UC的临床功效的可能性。
Ulcerative colitis (UC) is an increasingly common condition particularly in developed countries. The lack of satisfactory treatment has fueled the search for alternative therapeutic strategies. In recent studies, berberine, a plant alkaloid with a long history of medicinal use in Chinese medicine, has shown beneficial effects against animal models of acute UC. However, UC usually presents as a chronic condition with frequent relapse in patients. How berberine will act on chronic UC remains unclear. In the present study, we adopted dextran sulfate sodium (DSS)-induced chronic relapsing colitis model to assess the ameliorating activity of berberine. Colitis was induced by two cycles of 2.0% DSS for five days followed by 14days of drinking water plus a third cycle consisting of DSS only for five days. The colitis mice were orally administered 20mg/kg berberine from day 13 onward for 30days and monitored daily. The body weight, stool consistency, and stool bleeding were recorded for determination of the disease activity index (DAI). At the end of treatment, animals were sacrificed and samples were collected and subjected to histological, RT-qPCR, Western blot, and LC-MS analyses. Lymphocytes were isolated from spleens and mesenteric lymph nodes (MLN) and cultured for flow cytometry analysis of IL-17 secretion from CD4(+) cells and the Th17 cell differentiation. Results showed that berberine significantly ameliorated the DAI, colon shortening, colon tissue injury, and reduction of colonic expression of tight junction (TJ) protein ZO-1 and occludin of colitis mice. Notably, berberine treatment pronouncedly reduced DSS-upregulated Th17-related cytokine (IL-17 and ROR-γt) mRNAs in the colon. Furthermore, the mRNA expression of IL-6 and IL-23, and the phosphorylation of STAT3 in colon tissues from DSS-treated mice were pronouncedly inhibited by berberine. Moreover, the up-regulation of IL-17 secretion from CD4(+) cells of spleens and MLNs caused by DSS were significantly reversed by berberine treatment. Furthermore, Th17 cell differentiation from naive CD4(+) cells isolated from above DSS colitis mice were suppressed by berberine in a concentration-dependent manner. In summary, we demonstrated for the first time that berberine reduced the severity of chronic relapsing DSS-induced colitis by suppressing Th17 responses. The demonstration of activity in this mouse model supports the possibility of clinical efficacy of berberine in treating chronic UC.