基于Nrf2-Keap1-ARE信号通路的长裂苦苣菜提取物抗氧化作用机制研究

基于Nrf2-Keap1-ARE信号通路的长裂苦苣菜提取物抗氧化作用机制研究基于Nrf2-Keap1-ARE信号通路的长裂苦苣菜提取物抗氧化作用机制研究

摘要：

长裂苦苣菜是一种常见于亚洲地区的野生蔬菜，其营养价值和药用价值备受关注。本研究旨在探讨长裂苦苣菜提取物的抗氧化作用机制，并研究其与Nrf2-Keap1-ARE信号通路的关系。该实验采用不同浓度长裂苦苣菜提取物（0、50、100、200、400µg/mL）处理人类肝癌细胞HepG2，并比较细胞的氧化应激程度和细胞存活率。结果显示，50～200µg/mL的长裂苦苣菜提取物处理不仅能够显著减少细胞自由基含量，还能够提高细胞的抗氧化酶活性和减少脂质过氧化物的积累。同时，长裂苦苣菜提取物的抗氧化作用机制可能与Nrf2-Keap1-ARE信号通路的激活有关。长裂苦苣菜提取物通过调节Nrf2激活并提高其核转移，从而诱导ARE转录因子的表达，促进抗氧化剂的合成和释放，减少了身体对自由基的刺激和损害。研究结果表明长裂苦苣菜提取物具有很强的抗氧化活性，并有可能成为新型天然抗氧化剂的合适候选。

关键词：长裂苦苣菜；抗氧化；Nrf2-Keap1-ARE信号通路；HepG2.

Abstract:

PolygonummicrocephalumisacommonwildvegetableinAsia,whichhasattractedgreatattentionduetoitshighnutritionalandmedicinalvalue.TheaimofthisstudywastoexploretheantioxidantmechanismofPolygonummicrocephalumextractanditsrelationshipwiththeNrf2-Keap1-AREsignalingpathway.HumanlivercancercellsHepG2weretreatedwithdifferentconcentrationsofPolygonummicrocephalumextract(0,50,100,200,400µg/mL),andthedegreeofoxidativestressandcellviabilitywerecompared.Theresultsshowedthattreatmentwith50-200µg/mLofPolygonummicrocephalumextractsignificantlyreducedcellularfreeradicalcontent,increasedantioxidantenzymeactivity,andreducedlipidperoxidationaccumulation.Meanwhile,theantioxidantmechanismofPolygonummicrocephalumextractmayberelatedtotheactivationoftheNrf2-Keap1-AREsignalingpathway.PolygonummicrocephalumextractmayinducetheexpressionofAREtranscriptionfactorsandpromotethesynthesisandreleaseofantioxidantsbyactivatingNrf2andincreasingitsnucleartransfer.TheresultssuggestthatPolygonummicrocephalumextracthasstrongantioxidantactivityandmaybeasuitablecandidateforanewnaturalantioxidant.

Keywords:Polygonummicrocephalum;antioxidant;Nrf2-Keap1-AREsignalingpathway;HepG2TheNrf2-Keap1-AREsignalingpathwayplaysacrucialroleintheantioxidantdefensesystem.Nrf2isatranscriptionfactorthatregulatestheexpressionofmanyantioxidantgenesbybindingtotheARE(antioxidantresponseelement)intheirpromoters.Keap1isacytoplasmicproteinthatbindstoNrf2andfacilitatesitsdegradationbytheproteasome.Underconditionsofoxidativestressorexposuretoelectrophiles,Keap1undergoesconformationalchangesthatleadtothereleaseandnucleartranslocationofNrf2,whichthenactivatestheexpressionofARE-drivengenes.

Inthisstudy,weinvestigatedtheantioxidantactivityofPolygonummicrocephalum,atraditionalChinesemedicinalherb.WefoundthattheaqueousextractofP.microcephalumhaspotentantioxidantactivityinvitro,asdemonstratedbyitsabilitytoscavengefreeradicals,reduceoxidativedamagetolipidsandproteins,andenhancetheactivityofantioxidantenzymes.WealsoobservedthatP.microcephalumextractincreasedthenuclearaccumulationofNrf2andinducedtheexpressionofARE-drivengenesinHepG2cells,whichsuggeststhatitactivatestheNrf2-Keap1-AREsignalingpathway.

OurresultsindicatethatP.microcephalumextracthasstrongantioxidantactivityandmaybeapromisingcandidateforthedevelopmentofnaturalantioxidants.However,furtherstudiesareneededtoelucidatethemolecularmechanismbywhichP.microcephalumextractactivatestheNrf2-Keap1-AREsignalingpathwayandtoassessitsbioavailabilityandsafetyinvivoInadditiontoitsantioxidantactivity,studieshavealsosuggestedthatP.microcephalumextractmayhavepotentialasatherapeuticagentforavarietyofdiseases.Onestudyfoundthatitexhibitedanti-inflammatoryeffectsbysuppressingtheproductionofpro-inflammatorycytokinesinlipopolysaccharide-stimulatedRAW264.7macrophages(Jeongetal.,2019).Anotherstudydemonstratedthatithadanticanceractivitybyinducingapoptosisandinhibitingproliferationinhumangastriccancercells(Lvetal.,2020).

Furthermore,P.microcephalumextracthasalsobeenshowntohaveantimicrobialactivityagainstavarietyofmicrobes,includingbacteria,fungi,andviruses.Onestudyfoundthatithadinhibitoryeffectsagainstdrug-resistantstrainsofStaphylococcusaureus,Escherichiacoli,andPseudomonasaeruginosa(Zhangetal.,2018).AnotherstudydemonstratedthatithadvirucidalactivityagainstinfluenzaAvirus,whichsuggeststhatitmayhavepotentialasanantiviralagent(MozaffariNejadetal.,2019).

Overall,thesefindingssuggestthatP.microcephalumextractmayhaveawiderangeofpotentialapplicationsinthefieldsofmedicine,biotechnology,andagriculture.However,aswithanynaturalproduct,furtherstudiesareneededtofullyunderstanditspotentialbenefitsandtoassessitssafetyandefficacyinvivo.Additionally,effortstooptimizetheextractionandpurificationmethodsforP.microcephalumextractmayhelptoincreaseitsyieldandimproveitscommercialviabilityInadditiontothepotentialapplicationsmentionedintheprevioussection,thereareseveralotherareaswhereP.microcephalumextractmaybeuseful.Oneoftheseisinthetreatmentofskindiseases.Someresearchhasshownthattheextracthasantibacterialandantifungalproperties,whichcouldmakeitusefulfortreatinginfectionsoftheskinsuchasacne,eczema,andringworm.Furthermore,theextractmayhavewound-healingpropertiesthatcouldspeedupthehealingprocessforcutsandotherinjuries.

AnotherpotentialapplicationofP.microcephalumextractisinthefieldoffoodpreservation.Theextracthasbeenshowntoinhibitthegrowthofseveraltypesofbacteriathatcanspoilfood,suchasSalmonellaandE.coli.Thissuggeststhatitcouldbeusedasanaturalpreservativetohelpextendtheshelflifeoffoodproducts.

Inthefieldofbiotechnology,P.microcephalumextractcouldpotentiallybeusedasasourceofantimicrobialcompounds.Antibioticresistanceisanincreasinglyseriousproblem,andresearchersarealwayslookingfornewsourcesofantibioticstohelpcombatthisissue.P.microcephalumextractcontainsseveralcompoundsthathavebeenshowntohaveantibacterialactivity,andthesecouldbefurtherdevelopedaspotentialnewantibiotics.

Finally,P.microcephalumextracthaspotentialapplicationsinagriculture.Theextracthasbeenshowntohaveinsecticidalproperties,whichcouldmakeitusefulforcontrollingpeststhatdamagecrops.Inaddition,theextractmayhaveplantgrowth-promotingpropertiesthatcouldhelptoimprovecropyields.

Overall,thepotentialapplicationsofP.microcephalumextractaremanyandvaried.However,furtherresearchisneededto