Objectives: To investigate the effect of electroacupuncture(EA) at "Changbing Decoction" on alleviating ulcerative colitis (UC) and regulating the polarization of colonic macrophages in rats, so as to explore its mechanisms underlying improvement of UC.
Methods: Twenty-six male SD rats were randomly divided into 4 groups：normal group(6 rats), model group(8 rats), EA group(6 rats), and western medication group(6 rats). The rat model of UC was established by using 5% dextran sulfate sodium (DSS) solution drinking water for 7 days, followed by drinking 1% DSS solution during treatment period. After 7-day model establishment, EA treatment(10 Hz/50 Hz, 20 min) was applied to "Zhongwan"(CV12), bilateral "Tianshu"(ST25) and "Shangjuxu"(ST37) for 3 d, and rats in the western medication group were given mesalazine suspension(200 mg/kg) by gavage for 3 d. The body weight, spleen weight and colon length of rats were measured. The disease activity index (DAI) score was evaluated. The morphological changes and inflammatory cell infiltration of colon were detected after HE staining and pathological scores were eva-luated. The contents of tumor necrosis factor α(TNF-α), interleukin(IL)-1β, IL-2 and IL-10 in serum were detected by ELISA. The protein expressions of M1 and M2 macrophage markers nitric oxide synthase (iNOS) and arginase 1(Arg1) were detected by fluorescence double staining and Western blot, respectively. Quantitative real-time PCR was used to detect iNOS and Arg1 mRNA expressions.
Results: Compared with the normal group, rats in the model group had increased pathological damage degree and inflammatory cell infiltration in the colon tissue, slowed-down body weight gain, decreased colon length, spleen weight, serum anti-inflammatory factors IL-2 and IL-10 contents, colonic Arg1/CD68 fluorescence positive expression, and Arg1 protein and mRNA expressions(P<0.01, P<0.05), as well as increased DAI scores, colon histopathological scores, contents of serum pro-inflammatory factors TNF-α and IL-1β, colonic iNOS/CD68 fluorescence positive expression, iNOS protein and mRNA expressions(P<0.01). Compared with the model group, the above indicators were significantly improved in rats of the EA group and the western medication group(P<0.01, P<0.05).
Conclusions: EA of "Changbing Decoction" can improve UC of rats by regulating the polarization of colonic macrophages, inhibiting the generation of M1 macrophages and promoting the generation of M2 macrophages.
目的: 探讨电针“肠病方”通过调节结肠巨噬细胞极化改善大鼠溃疡性结肠炎（UC）的机制。方法: SD大鼠随机分为正常组（6只），模型组（8只），电针组（6只），西药组（6只）。予大鼠饮用5%葡聚糖硫酸钠（DSS）溶液7 d建立UC模型。电针组电针大鼠“中脘”及双侧“天枢”“上巨虚”（10 Hz/50 Hz），20 min/次，西药组予美沙拉嗪混悬液（200 mg/kg）灌胃，均连续治疗3 d。测量大鼠体质量、脾质量、结肠长度，评估疾病活动指数（DAI）评分；HE染色观察大鼠结肠形态学变化和炎性细胞浸润程度，并计算病理学评分；ELISA法检测血清肿瘤坏死因子α（TNF-α）、白细胞介素（IL）-1β、IL-2、IL-10含量；免疫荧光双染及Western blot法检测大鼠结肠M1型和M2型巨噬细胞标记物一氧化氮合酶（iNOS）和精氨酸酶1（Arg1）蛋白的表达水平；实时荧光定量PCR法检测大鼠结肠iNOS和Arg1 mRNA的表达水平。结果: 与正常组相比，模型组大鼠结肠病理组织的损伤程度和炎性细胞浸润加重，体质量增长幅度，结肠长度，脾质量，血清抑炎因子IL-2、IL-10含量，结肠Arg1/CD68荧光阳性表达，Arg1蛋白及mRNA表达显著降低（P<0.01，P<0.05），DAI评分，结肠病理组织学评分，血清中促炎因子TNF-α、IL-1β含量，结肠组织中iNOS/CD68荧光阳性表达，iNOS蛋白及mRNA表达显著升高（P<0.01）。与模型组相比，电针组及西药组大鼠以上指标均有显著改善（P<0.01，P<0.05）。结论: 电针“肠病方”能够通过调节大鼠结肠巨噬细胞极化，抑制M1型巨噬细胞的生成，促进M2型巨噬细胞的生成，进而改善大鼠UC症状，减轻炎性反应。.
Keywords: Electroacupuncture; Macrophages; Polarization; Ulcerative colitis.