【作者】 初悦雷；

【导师】 李文娟；

【作者基本信息】 南昌大学 ， 食品科学与工程， 2025， 硕士

【摘要】 鱼腥草是一种药食两用的植物,具有良好的食用、药用价值。然而目前关于鱼腥草的研究多集中于其成分分析、工艺优化和抗菌作用等研究,而对于其生物活性的研究还依然缺乏。鱼腥草具有特殊的香气,挥发油被认为是其主要活性成分,本课题以鱼腥草挥发油(Houttuynia cordata Thunb.essential oil,HEO)为实验对象,提取得到HEO,通过成分组成及含量分析运用网络药理学根据其组成成分预测其相应靶点,揭示了HEO的炎症保护作用机制与其抗炎作用的关系;通过动物实验观察HEO对脂多糖(LPS)介导的急性肺损伤(Acute lung injury,ALI)的影响;基于肺病肠治理论阐明HEO对LPS诱导ALI大鼠的肠道损伤保护作用;围绕细胞焦亡,深入研究了HEO通过线粒体融合蛋白2(MFN2)及线粒体相关内质网膜(MAMs)结构,抑制NLRP3炎症小体活化的抗炎机制。主要结论如下:1、网络药理学研究初步判断,HEO能够抑制炎症通路的激活改善炎症。收集了407个HEO的有效成分相关基因和1789个炎症疾病相关基因进行网络药理学分析。分析结果显示,HEO可以通过157个基因发挥抗炎症的作用。通过PPI网络拓扑分析,得到18个置信度较高的核心靶点,表明它们可能是HEO缓解炎症发展的核心基因。并从KEGG数据库中提取出20条与炎症相关性较高(P<0.05)的通路,GO功能富集分析和KEGG途径富集分析得到HEO发挥抗炎作用的信号通路为TRP通道的炎性介质调节(inflammatory mediator regulation of TRP channels)、TNF信号通路(TNF signaling pathway)、Toll样受体信号通路(Toll-like receptor signaling pathway)等多个通路完成。初步判断HEO可以通过抑制炎症通路的激活改善炎症。2、HEO具有抗ALI的肺保护作用,且与抑制ALI大鼠肠道炎症及重塑肠道微生态平衡有关。数据显示,灌胃处理HEO后,可改善ALI大鼠中肺和肠组织的病理性变化,进一步发现该挥发油对血清、肺及肠组织中的促炎细胞因子IL-1β和抑炎因子IL-10及组织中TLR4/NF-κB信号通路,均发挥较好的调控作用。这些数据提示HEO对肺和肠发挥相似的炎症调控作用,且血清数据提示炎性变化有重叠,佐证了肺作为全身炎症反应的典型器官,其损伤与肠道炎症存在一定的关联,且HEO发挥的抗ALI作用与其肠道保护密切相关。同时,构建大鼠小肠隐窝上皮细胞(Intestinal epithelioid cell line 6,IEC-6)的LPS炎症细胞模型,细胞水平证实HEO具有对LPS介导的炎性肠损伤具有保护作用。采集盲肠内容物进行16S r RNA高通量测序,分析HEO对ALI大鼠肠道菌群的影响,并检测了菌群代谢产物短链脂肪酸(SCFAs)含量,数据显示提前1周给予HEO预处理对ALI大鼠肠道菌群具有调控作用,部分SCFAs含量显著增加。这些数据表明HEO具有肺保护作用,可通过微生物-肠-肺轴调控炎症反应和重塑肠道微生物群发挥肺保护作用。3.基于肺病肠治理论阐释HEO对ALI大鼠肠损伤的保护作用及机制。HEO能够改善LPS诱导的ALI大鼠的肠道炎症和氧化应激,发挥了显著的肠道保护作用。HEO具有抑制IL-1β释放TLR4和NF-κB表达的显著抗炎作用,通过上调Nrf2表达、增强SOD活性、减少ROS生成和MDA含量来纠正氧化还原系统。实验结果显示HEO通过提高ZO-1来抑制肠道组织病理变化和恢复肠道机械屏障,从而显著减轻肠道损伤。此外,HEO通过下调ALI大鼠中肠道组织NLRP3和caspase-1的表达抑制NLRP3炎性体的活化。进一步发现HEO处理后肠道组织MFN2表达显著上调,这与抑制NLRP3炎性体激活、增加线粒体膜电位和减少钙超载相平行,表明HEO对ALI大鼠肠损伤保护作用与MAMs-NLRP3通路抑制炎症反应密切相关。更多还原

【Abstract】 Houttuynia cordata Thunb.was a plant with both medicinal and edible value.However,current research on Houttuynia cordata predominantly centered on its component analysis,process optimization,and antibacterial effects,while studies exploring its biological activities remain relatively scarce.Houttuynia cordata possessed a distinctive aroma,and its essential oil was regarded as the primary active constituent.This study focuses on the Houttuynia cordata Thunb.essential oil(HEO)as the experimental subject.HEO was extracted and its component composition and content were analyzed systematically.Network pharmacology was then employed to predict potential targets based on its constituent components,elucidating the relationship between the anti-inflammatory mechanism of HEO and its anti-inflammatory effect.The effect of HEO on LPS-induced acute lung injury(ALI)was observed by animal experiments.Based on the theory of intestinal treatment of lung disease,the protective effect of HEO on intestinal injury in LPS-induced ALI rats was elucidated.Furthermore,by focusing on pyroptosis,this study delves into the anti-inflammatory mechanism of HEO in inhibiting NLRP3 inflammasome activation via mitochondrial fusion protein 2(MFN2)and mitochondrial-associated endoplasmic reticulum membranes(MAMs).The main conclusions were as follows:1.The preliminary network pharmacological analysis suggested that HEO could inhibit the activation of inflammatory pathways to ameliorate inflammation.407genes related to the effective components of HEO and 1789 genes related to inflammatory diseases were collected for network pharmacology analysis.Through PPI network topological analysis,18 core targets with higher confidence were obtained,indicating that they may be the core genes for HEO to alleviate the development of inflammation.And 20 pathways with higher correlation with inflammation(P<0.05)were extracted from the KEGG database.GO functional enrichment analysis and KEGG pathway enrichment analysis revealed that the signaling pathways through which HEO exerts anti-inflammatory effects include inflammatory mediator regulation of TRP channels,TNF signaling pathway,Toll-like receptor signaling pathway and others.These findings preliminarily indicated that HEO could ameliorate inflammation by suppressing the activation of inflammatory pathways.2.The mechanism of HEO against ALI was related to the inhibition of intestinal inflammation and remodeling of intestinal microecological balance in ALI rats.The data showed that HEO could improve the pathological changes in the lung and intestinal tissues of ALI rats.It was further found that HEO had a better regulatory effect on the pro-inflammatory cytokines IL-1βand anti-inflammatory cytokines IL-10 in serum,lung and intestinal tissues and the TLR4/NF-κB signaling pathway in tissues.Meanwhile,the data suggested that HEO exerted similar inflammatory modulating effects on lung and intestine,and the serum data suggested an overlap of inflammatory changes.These evidences confirmed that lung,as a typical organ of systemic inflammatory response,had a certain association between lung injury and intestinal inflammation,and that the anti-acute lung injury effect exerted by HEO was tightly linked to its intestinal protection.Meanwhile,a cell model of LPS inflammation in rat small intestine epithelial cells(IEC-6 cells)was established and the cell level demonstrated that HEO had a protective effect on LPS-mediated inflammatory intestinal injury.Subsequently,the contents of cecum were collected for16S r RNA high-flux sequencing to analyze the effect of HEO on the gut microbiota of ALI rats.Then the content of short-chain fatty acids in the metabolites of gut microbiota was detected.The data showed that pretreatment with HEO given 1 week ahead of time had a regulatory effect on the gut microbiota of ALI rats,and the content of partial SCFAs was significantly increased.Consequently,These data suggested that HEO had a lung-protective effect and could to regulate the inflammatory response and remodel the intestinal microbiota via the microbial-gut-lung axis.3.Based on the theory of intestinal treatment of lung disease,this study explored the protective effect and mechanism of HEO on intestinal injury in rats with acute lung injury.HEO could alleviate intestinal inflammation and oxidative stress in LPS-induced rats with ALI,and exerted a significant protective effect on intestine.HEO had a significant anti-inflammatory effect by inhibiting the release of IL-1βand the expression of TLR4 and NF-κB.It corrected the redox system by up-regulating Nrf2 expression,enhancing SOD activity,reducing ROS production and MDA content.The experimental results showed that HEO inhibited intestinal pathological changes and restored the intestinal mechanical barrier by increasing ZO-1 expression,thus significantly reducing intestinal damage.In addition,HEO inhibited the activation of NLRP3 inflammasome by down-regulating the expression of NLRP3and caspase-1 in intestinal tissue of ALI rats.Furthermore,studies had found that the expression of MFN2 in intestinal was significantly increased after treatment with HEO,which was parallel to inhibiting NLRP3 inflammasome activation,increasing mitochondrial membrane potential and reducing calcium overload.The above results indicated that the protective effect of HEO on intestinal injury in rats with ALI was closely related to the inhibition of inflammatory response by MAMs-NLRP3 pathway.更多还原