磁石煅制调节肠道菌群-神经递质/炎症因子抗抑郁作用及机制研究

Research on antidepressant effect and mechanism of magnet processed regulating intestinal microbiota-neurotransmitter/inflammatory factors

关键词:  磁石  炮制  抑郁  肠道菌群  神经递质  炎症

Key words:  magnet  processing  depression  intestinal flora  neurotransmitters  inflammation

摘要:

[目的] 明确磁石煅制对其抗抑郁作用的影响，并基于肠道菌群-神经递质/炎症因子探讨其机制。[方法] 采用慢性不可预知温和性应激（CUMS）诱导大鼠焦虑和抑郁样行为，并将实验分为空白组、模型组、生磁石组、煅磁石组和阳性对照组，生磁石组、煅磁石组、阳性对照组大鼠每日分别灌胃给予3.15、3.15和0.63 mg/kg生磁石、煅磁石和艾司唑仑，空白组和模型组大鼠给予等体积蒸馏水，连续治疗3周。采用糖水偏好实验、旷场实验和高架十字迷宫实验评估大鼠焦虑和抑郁行为；采用高效液相色谱-电化学系统（HPLC-ECD）检测皮质单胺类神经递质多巴胺（DA）、5-羟色胺（5-HT）、去甲肾上腺素（NE）及5-羟基吲哚乙酸（5-HIAA）含量；采用实时荧光定量聚合酶链反应（qPCR）检测海马组织炎症因子白介素-18（IL-18）、白介素-6（IL-6）和白介素-1β（IL-1β） mRNA水平；采用16S rRNA测序肠道微生物结构和组成变化。[结果] 与正常组相比，模型组大鼠糖水偏好率、旷场直立次数以及进入高架十字迷宫开臂的次数和时间均显著降低（P＜0.05），皮质神经递质（5-HT、NE和5-HIAA）含量显著降低（P＜0.05），海马促炎因子（IL-18、IL-6和IL-1β）mRNA水平显著升高（P＜0.05），肠道菌群结构和组成紊乱；与模型组相比，生、煅磁石组大鼠糖水偏好率及进入高架十字迷宫开臂的次数和时间均显著增加（P＜0.05），煅磁石组大鼠在旷场中直立次数增多（P＜0.05）；煅磁石组大鼠脑皮层神经递质含量增加，肠菌中乳杆菌（Lactobacillus）、罗伊氏乳杆菌（Limosilactobacillus）、拟杆菌（Bacteroides）丰度显著升高（P＜0.05），生磁石组大鼠海马组织促炎因子（IL-6和IL-1β）mRNA水平显著降低（P＜0.05），肠菌中Christensenellaceae_R-7_group、NK4A214_group、罗氏菌（Roseburia）丰度显著升高。[结论] 生、煅磁石均有改善CUMS大鼠焦虑和抑郁样行为的作用，煅磁石通过调控肠道乳杆菌、拟杆菌等增加脑神经递质含量相关，而生磁石与调控肠道罗氏菌等降低脑促炎因子水平相关。

Abstract:

[Objective] To clarify the effect of calcined magnet on its antidepressant effect,and to explore its mechanism based on intestinal flora-neurotransmitter/inflammatory factors. [Methods] Chronic unpredicted mild stress(CUMS) was used to induce anxiety and depression-like behavior in rats. The rats were divided into blank group,model group,raw magnet group,calcined magnet group and positive control group. The rats in the raw magnet group,calcined magnet group and positive control group were given 3.15 g/kg,3.15 g/kg and 0.63 mg/kg raw magnet,calcined magnet and estazolam by intragastric administration every day. The rats in the blank group and the model group were given equal volume of distilled water for 3 weeks. Sucrose preference test,open field test and elevated plus maze test were used to evaluate the anxiety and depression behavior of rats. The contents of monoamine neurotransmitters dopamine(DA),5-hydroxytryptamine(5-HT),norepinephrine(NE) and 5-hydroxyindole acetic acid(5-HIAA) in cortex were detected by HPLC-ECD. The levels of inflammatory factors interleukin-18(interleukin-18,IL-18)、interleukin-6(interleukin-6,IL-6) and interleukin-1β(interleukin-1β,IL-1β) mRNA in hippocampus were detected by qPCR. The changes of intestinal microbial structure and composition were analyzed by 16S rRNA sequencing. [Results] Compared with the normal group,the sucrose preference rate,the number of rearing in the open field,the number and time of entering the open arm of the elevated plus maze in the model group were significantly decreased(P<0.05),the contents of cortical neurotransmitters(5-HT,NE and 5-HIAA) were significantly decreased(P<0.05),the mRNA levels of hippocampal pro-inflammatory factors(IL-18,IL-6 and IL-1β) were significantly increased(P<0.05),and the structure and composition of intestinal flora were disordered. Compared with the model group,the sucrose preference rate and the number and time of entering the open arm of the elevated plus maze were significantly increased in the raw and calcined magnet groups(P<0.05). The number of upright times in the open field of rats in the calcined magnet group increased(P<0.05). The content of neurotransmitters in the cerebral cortex of rats in the calcined magnet group increased,and the abundance of Lactobacillus, Limosilactobacillus and Bacteroides in the intestinal bacteria increased significantly (P<0.05). The mRNA levels of pro-inflammatory factors(IL-6 and IL-1β) in the hippocampus of rats in the raw magnet group decreased significantly(P<0.05). The abundance of Christensenellaceae_R-7_group,NK4A214_group and Roseburia in intestinal bacteria increased significantly. [Conclusion] Both raw and calcined magnet can improve the anxiety and depression-like behavior of CUMS rats. Calcined magnet is related to the increase of brain neurotransmitter content by regulating intestinal Lactobacillus and Bacteroides,while raw magnet is related to the regulation of intestinal Roche bacteria and other pro-inflammatory factors.