姜黄素重建肠道微生态环境改善溃疡性结肠炎小鼠机制研究

The study on the mechanism of curcumin rebuilding intestinal micro ecological environment and improving ulcerative colitis in mice

目的姜黄素对溃疡性结肠炎(UC)小鼠的肠道菌群、代谢组学及免疫炎症的影响及其潜在的治疗机制。方法C57BL/6小鼠30只随机分为空白对照组(CON)、葡聚糖硫酸钠盐(DSS)诱导结肠炎组和姜黄素治疗组(DSS+CUR),每组各10只。2%DSS诱发小鼠溃疡性结肠炎后用100 mg/kg的姜黄素或磷酸盐缓冲盐水(PBS)进行干预,每天记录小鼠疾病活动指数(DAI)。实验结束后分离小鼠结肠并测量,并进行结肠大体形态损伤指数(CMDI)评估,以及结肠组织苏木精-伊红(HE)染色。收集小鼠粪便进行16SrDNA Miseq测序和磁共振氢谱(1H-NMR)代谢组学检测,结肠细胞因子检测使用ELISA法。结果姜黄素治疗增加UC小鼠结肠长度和改善结肠黏膜损伤和炎症细胞浸润。与CON组比较,DSS组小鼠DAI、CMDI、IL-6、IL-17、IL-23水平均显著上升,IL-10水平显著下降,差异均有统计学意义(P<0.001)。与DSS组比较,DSS+CUR组中小鼠DAI、CMDI、IL-6、IL-17、IL-23水平均显著下降,IL-10水平显著上升,差异均有统计学意义(P<0.05)。姜黄素恢复了肠道微生物群的组成,增加了阿克曼菌、Muribaculaceae_unclassified和Muribaculum的相对丰度(P<0.05),以及增加肠道内丙酸盐、丁酸盐、色氨酸和甜菜碱的浓度(P<0.05)。结论姜黄素对UC小鼠的治疗机制是通过改善肠道菌群失调、代谢紊乱以及调节免疫失衡,从而改善UC小鼠的肠黏膜损伤而发挥治疗作用。

Objective To investigate the effects of curcumin on intestinal flora,metabolomics and inflammatory response in Ulcerative Colitis(UC)mice and its potential mechanisms.Methods C57BL/6 mice were randomly divided into the control group,the dextran sodium sulfate(DSS)induced colitis group and the curcumin treatment group.2%DSS-induced UC in mice was followed by intervention with 100 mg/kg of curcumin or phosphatebuffered saline(PBS).Disease activity index(DAI)of mice were recorded daily.At the end of the experiment,the colon of mice was isolated and measured for length and assessed for colonic macromorphological damage index(CMDI),as well as hematoxylin-eosin(HE)staining of colonic tissues.The feces of mice were collected for 16S rDNA Miseq sequencing and metabolomic detection by proton magnetic resonance(1H-NMR)spectroscopy,and cytokine detection in colonic tissues was performed using ELISA.Results Curcumin supplementation increased colonic length and improved colonic mucosal damage and inflammatory cell infiltration in UC mice.Compared with the CON group,the levels of DAI,CMDI,IL-6,IL-17 and IL-23 were significantly increased but the level of IL-10 was significantly decreased in the DSS group mice(P<0.001).Compared to the DSS group,the levels of DAI,CMDI,IL-6,IL-17 and IL-23 were significantly decreased but the levels of IL-10 were markedly increased in the DSS+CUR group(P<0.05).Curcumin restored the composition of the intestinal microbiota,significantly increasing(P<0.05)the relative abundance of Ackermania,Muribaculaceae_unclassified and Muribaculum,as well as markedly increasing(P<0.05)the intestinal concentrations of propionate,butyrate,tryptophan and betaine.Conclusion The therapeutic mechanism of curcumin in UC mice may be through the improvement of intestinal flora dysbiosis,metabolic disorders and the regulation of immune imbalance in the intestine,thus to improve the intestinal mucosal damage in UC mice.