目的 探究麸炒白术多糖（bran-fried Atractylodes macrocephala polysaccharide，FAMP）对溃疡性结肠炎（ulcerative colitis，UC）小鼠的治疗作用和作用机制。方法 使用高效液相色谱串联蒸发光散射检测器（high-performance liquid chromatography-evaporative light scattering detector，HPLC-ELSD）对FAMP的纯度进行测定；采用气相色谱串联质谱（gas chromatography-mass spectrometry，GC-MS）对FAMP单糖组成进行分析。C57BL/6小鼠随机分为对照组、模型组、柳氮磺吡啶（0.53 g/kg）组和FAMP低、中、高剂量（1.8、3.6、5.4 mg/kg）组，每组8只。除对照组外，其余各组小鼠周期性饮用2.5%葡聚糖硫酸钠（dextran sulfate sodium salt，DSS）水溶液建立UC模型，给予药物干预后，通过疾病活动指数（disease activity index，DAI）评估各组小鼠的疾病程度；测量结肠长度，采用苏木素-伊红（hematoxylin-eosin，HE）染色观察各组小鼠的结肠组织病理变化；计算各组小鼠的脾脏指数，采用ELISA测定血清中肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）、白细胞介素-6（interleukin-6，IL-6）、IL-10、IL-17、IL-22的水平；采用qRT-PCR检测各组小鼠结肠组织中紧密连接蛋白-1（zonula occludens-1，ZO-1）、闭合蛋白（Occludin）、密封蛋白-1（Claudin-1）、肠道黏蛋白-2（mucin-2，MUC2）、芳香烃受体（aryl hydrocarbon receptor，AhR）和细胞色素P450家族成员1A1（cytochrome P450 family 1 subfamily A polypeptide 1，CYP1A1）的mRNA表达；采用Western blotting检测各组小鼠结肠组织中ZO-1、Occludin、Claudin-1、MUC2、AhR和CYP1A1的蛋白表达；使用16S rRNA测序技术检测各组小鼠粪便中肠道菌群的多样性情况，并使用超高效液相色谱串联三重四极杆（ultra-high performance liquid chromatography-tandem mass spectrometry，UHPLC-MS/MS）测定粪便中色氨酸、犬尿氨酸、5-羟色胺、3-吲哚丙酸、3-吲哚乙酸、吲哚-3-乳酸的含量。结果 FAMP主要由甘露糖、鼠李糖、果糖、阿拉伯糖、葡萄糖、半乳糖组成，物质的量比为68.07∶4.10∶4.17∶2.11∶1.72∶1.00。与模型组比较，FAMP可显著减轻DSS诱导的UC小鼠DAI评分升高、结肠长度缩短等症状（P＜0.01），降低血清中促炎因子TNF-α、IL-6、IL-17水平（P＜0.05、0.01），升高血清中抗炎因子IL-10、IL-22水平（P＜0.05、0.01），调控结肠组织中肠黏膜屏障（ZO-1、Occludin、Claudin-1、MUC2）和色氨酸代谢（AhR、CYP1A1）关键基因及蛋白的表达（P＜0.05、0.01），改善色氨酸及其代谢产物的紊乱水平（P＜0.05、0.01），重塑UC小鼠紊乱的肠道菌群多样性情况（P＜0.05、0.01）。结论 FAMP通过调控色氨酸代谢途径来发挥对UC模型小鼠肠黏膜屏障的修复作用。

Objective To explore the therapeutic effect and mechanism of bran-fried Atractylodes macrocephala polysaccharide (FAMP) on ulcerative colitis (UC) mice. Methods High-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) was used to determine the purity of FAMP. The monosaccharide composition of FAMP was analyzed by gas chromatography-mass spectrometry (GC-MS). C57BL/6 mice were randomly divided into control group, model group, sulfasalazine (0.53 g/kg) group and FAMP low-, medium- and high-dose (1.8, 3.6, 5.4 mg/kg) groups, with eight mice in each group. Except for the control group, mice in other groups were subjected to establish UC model by periodic administration of 2.5% dextran sulfate sodium (DSS) solution. After drug intervention, the disease severity of mice in each group was assessed via disease activity index (DAI). The length of colon was measured, hematoxylin-eosin (HE) staining was used to observe the pathological changes in colon tissues of mice in each group. The spleen index of mice was calculated, the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10, IL-17 and IL-22 in serum were measured by ELISA. qRT-PCR was employed to detect the mRNA expressions of zonula occludens-1 (ZO-1), Occludin, Claudin-1, mucin-2 (MUC2), aryl hydrocarbon receptor (AhR) and cytochrome P450 family 1 subfamily A polypeptide 1 (CYP1A1) in colon tissues of mice in each group. Western blotting was used to assess the protein expressions of ZO-1, Occludin, Claudin-1, MUC2, AhR and CYP1A1 in colon tissues of mice in each group. The diversity of gut microbiota in the feces of mice in each group was analyzed using 16S rRNA sequencing technology, and the contents of tryptophan, kynurenine, serotonin, 3-indolepropionic acid, 3-indoleacetic acid and indole-3-lactic acid in the feces were measured by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Results FAMP was primarily composed of mannose, rhamnose, fructose, arabinose, glucose, and galactose, with a molar ratio of 68.07∶4.10∶4.17∶2.11∶1.72∶1.00. Compared with model group, FAMP significantly alleviated symptoms such as elevated DAI scores and shortened colon length in DSS-induced UC mice (P < 0.01), reduced the levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-17 in serum (P < 0.05, 0.01), increased the levels of anti-inflammatory cytokines IL-10 and IL-22 in serum (P < 0.05, 0.01), regulated the expressions of key genes and proteins in the intestinal mucosal barrier (ZO-1, Occludin, Claudin-1, MUC2) and tryptophan metabolism (AhR, CYP1A1) in colon tissue (P < 0.05, 0.01), improved the disrupted levels of tryptophan and its metabolites (P < 0.05, 0.01), and restored the dysbiotic gut microbiota diversity in UC mice (P < 0.05, 0.01). Conclusion FAMP exerts a repairing effect on the intestinal mucosal barrier in UC model mice by regulating tryptophan metabolism pathway.

R285.5

国家自然科学基金青年基金项目（81803726）；辽宁省科技计划联合计划面上项目（2024-MSLH-286）；辽宁省教育厅面上项目（LJKMZ20222205，LJKMZ20221308，LJ212414289001）；辽宁中医药大学青创团队项目（2024-JYTCB-075）；辽宁中医药大学校级课题重点项目（2021LZY054）