荷叶碱对肥胖模型小鼠肠道菌群及慢性炎症的影响

Effect of nuciferine on gut microbiota and inflammatory response in obese model mice

该研究从调节肠道菌群、缓解慢性炎症、改善肠道通透性3个方面探讨荷叶碱缓解肥胖的作用机制。运用高脂饲料建立肥胖小鼠模型,随机分为2组:模型组、荷叶碱组,另设同周龄普通饲料喂养小鼠为正常组,造模同时灌胃给药持续12周;造模给药过程中每周监测各组小鼠体质量和摄食量,造模给药结束后,检测各组小鼠Lee′s指数、腹股沟皮下脂肪质量百分比、血脂含量,HE染色法观察脂肪细胞病理学改变,评价荷叶碱对肥胖模型小鼠的治疗作用;运用16S rRNA测序检测各组小鼠肠道菌群多样性和丰度的变化,评价荷叶碱对肥胖模型小鼠的肠道菌群的影响;ELISA及qPCR法检测各组小鼠脂肪组织炎症因子白细胞介素-1β(interleukin-1β,IL-1β)、白细胞介素-6(interleukin-6,IL-6)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平和相关基因表达情况,评价荷叶碱对肥胖模型小鼠慢性炎症的影响;qPCR法检测结肠组织紧密连接相关闭锁蛋白(occludin),紧密连接蛋白-1(tight junction protein 1,ZO-1)基因的表达情况,评价荷叶碱对肥胖模型小鼠肠道通透性的影响。荷叶碱可降低肥胖小鼠体质量、Lee′s指数、腹股沟皮下脂肪质量百分比(P<0.05),缩小脂肪细胞体积,下调血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)水平(P<0.05),改善肠道菌群失调,增加Alloprevotella,Turicibacter,Lactobacillus的相对丰度,减少Helicobacter的相对丰度,下调脂肪组织炎症因子IL-6,IL-1β,TNF-α基因表达(P<0.01),降低血清炎症因子IL-6,IL-1β,TNF-α水平(P<0.05),上调结肠组织紧密连接相关occludin和ZO-1基因表达(P<0.01)。荷叶碱可能通过改善肠道菌群,降低肠道通透性来缓解慢性炎症进而发挥治疗肥胖的作用。

The aim of this study was to elucidate the mechanism of nuciferine on alleviating obesity based on modulating gut microbiota,ameliorating chronic inflammation,and improving gut permeability.In this study,the obese model mice were induced by high-fat diet and then randomly divided into model group,and nuciferine group;some other mice of the same week age were fed with normal diet as normal group.In the modeling process,the mice were administered intragastrically(ig)for 12 weeks.In the course of both modeling and treatment,the body weight and food intake of mice in each group were measured weekly.After modeling and treatment,the Lee′s index,weight percentage of inguinal subcutaneous fat,and the level of blood lipid in each group were measured.The pathological changes of adipocytes were observed by HE staining to evaluate the efficacy of nuciferine treatment in obese model mice.16 S rRNA sequencing analysis was conducted to study the changes in diversity and abundance of gut microbiota after nuciferine treatment.Enzyme-linked immunosorbent assay(ELISA)and quantitative Real-time polymerase chain reaction(qPCR)were used to detect the levels of inflammatory factors interleukin-6(IL-6),interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α)and the expression of related genes in adipose tissue of mice in each group,so as to evaluate the effect of nuciferine on chronic inflammation of mice in obese model group.qPCR was used to detect the expression of occludin and tight junction protein 1(ZO-1)gene in colon tissure,so as to evaluate the effect of nuciferine on intestinal permeability of mice in obese group.Nuciferine decreased the body weight of obese mice,Lee′s index,weight percentage of inguinal subcutaneous fat(P<0.05),and reduced the volume of adipocytes,decreased the level of total cholesterol(TC),triglyceride(TG),and low density lipoprotein cholesterol(LDL-C)(P<0.05)in serum,improved dysbacteriosis,increased the relative abundance of Alloprevotella,Turicibacter,and Lactobacillus,lowered the relative abundance of Helicobac-ter,decreased the expression of inflammatory cytokines IL-6,IL-1β,and TNF-αgenes in adipose tissue(P<0.01),decreased the levels of inflammatory cytokines IL-6,IL-1β,and TNF-αin serum(P<0.05),and increased the expression of occludin and ZO-1 genes related to tight junction in colon tissue(P<0.01).Nuciferine could treat obesity through modulating gut microbiota,decreasing gut permeability and ameliorating inflammation.