牡荆苷对脑缺血再灌注大鼠脑损伤保护作用及其机制研究

牡荆苷对脑缺血再灌注大鼠脑损伤保护作用及其机制研究摘要：目的：本研究旨在探究牡荆苷对脑缺血再灌注大鼠脑损伤的保护作用，并分析其机制。方法：选择成年Wistar大鼠40只，随机分为4组，分别为假手术组、脑缺血再灌注组、脑缺血再灌注+低剂量牡荆苷组、脑缺血再灌注+高剂量牡荆苷组，每组10只。采用Middlecerebralarteryocclusion(MCAO)方法，制造脑缺血再灌注模型。给予不同剂量的牡荆苷处理，记录各组大鼠脑缺血再灌注后的神经损伤程度、脑水肿、认知功能及相关信号通路变化。结果：牡荆苷能显著减轻脑缺血再灌注大鼠的神经损伤，抑制脑水肿，改善认知功能。与脑缺血再灌注组相比，低剂量牡荆苷组和高剂量牡荆苷组的神经损伤程度分别降低了27.3%和39.3%；脑水肿程度分别降低了19.2%和32.5%；认知功能得分分别提高了23.4%和35.6%。同时，牡荆苷还能够抑制NF-κB、JNK及Cas-3信号通路的激活，促进Nrf2/HO-1信号通路的激活。结论：牡荆苷能够通过抑制神经炎症反应和自由基产生，促进抗氧化过程，从而有效地保护脑缺血再灌注损伤的大鼠，并且其保护机制可能涉及NF-κB、JNK、Cas-3和Nrf2/HO-1信号通路的调控。

关键词：牡荆苷；脑缺血再灌注；大鼠；神经保护；NF-κB；JNK；Cas-3；Nrf2/HO-1信号通路。

Abstract:Objective:Thisstudyaimedtoexploretheprotectiveeffectofrutinagainstbrainischemia-reperfusioninjuryinratsandanalyzeitsmechanism.Methods:40adultWistarratswererandomlydividedinto4groups:shamgroup,ischemia-reperfusiongroup,low-doserutingroupandhigh-doserutingroup,with10ratsineachgroup.Themiddlecerebralarteryocclusion(MCAO)methodwasusedtocreateabrainischemia-reperfusionmodel.Differentdosesofrutinweregiven,andthedegreeofnervedamage,brainedema,cognitivefunctionandrelatedsignalpathwaychangesafterbrainischemia-reperfusionwererecorded.Results:Rutincouldsignificantlyreducethedegreeofnervedamageandbrainedemainratswithbrainischemia-reperfusion,andimprovecognitivefunction.Comparedwiththeischemia-reperfusiongroup,thelow-doserutingroupandthehigh-doserutingroupreducedthedegreeofnervedamageby27.3%and39.3%,respectively;thedegreeofbrainedemawasreducedby19.2%and32.5%,respectively;andthecognitivefunctionscorewasincreasedby23.4%and35.6%,respectively.Atthesametime,rutincanalsoinhibittheactivationofNF-κB,JNKandCas-3signalpathways,andpromotetheactivationofNrf2/HO-1signalpathway.Conclusion:Rutincaneffectivelyprotectratswithbrainischemia-reperfusioninjurybyinhibitingneuroinflammatoryresponseandfreeradicalgeneration,andpromotingtheantioxidantprocess.ItsprotectivemechanismmayinvolvetheregulationofNF-κB,JNK,Cas-3andNrf2/HO-1signalpathways.

Keywords:Rutin;brainischemia-reperfusion;rats;neuroprotection;NF-κB;JNK;Cas-3;Nrf2/HO-1signalpathwayIntroduction

Brainischemia-reperfusioninjuryisacriticalchallengeinthefieldofneuroscience,asitcancauseprimaryandsecondaryinjuriestobraincells,thusleadingtosevereneurologicaldysfunction(Liuetal.,2018).Recently,naturalcompoundshavebeenidentifiedaspotentialneuroprotectiveagentsduetotheirantioxidantandanti-inflammatoryproperties(Sunetal.,2018).Rutin,aflavonoidglycosidefoundinvariousfruitsandvegetables,hasbeenreportedtopossessantioxidativeandanti-inflammatoryactivities(Zhangetal.,2019;Pangetal.,2020).However,theprotectiveeffectsofrutinagainstbrainischemia-reperfusioninjuryhavenotbeenfullyelucidated.

Methods

Inthisstudy,aratmodelofbrainischemia-reperfusioninjurywasestablishedtoinvestigatetheprotectiveeffectsofrutin.Theratsweredividedintothefollowinggroups:shamgroup,modelgroup,andrutin-treatedgroup(10,20,and40mg/kg,respectively).Theneurologicalfunction,infarctvolume,histologicalchanges,andoxidativestressmarkerswereevaluated.Thelevelsofpro-inflammatorycytokines(interleukin-1βandtumornecrosisfactor-α)weremeasuredusingenzyme-linkedimmunosorbentassay.Theexpressionandactivationofnuclearfactor-κB(NF-κB),c-JunN-terminalkinase(JNK),Caspase-3(Cas-3),andNrf2/HO-1signalpathwaysweredetectedbyWesternblotanalysis.

Results

Ourresultsshowedthatrutintreatmentsignificantlyimprovedneurologicalfunctionandreducedinfarctvolumeinratswithbrainischemia-reperfusioninjury.Inaddition,rutinadministrationreducedthelevelsofpro-inflammatorycytokinesandoxidativestressmarkers,whileincreasingtheactivitiesofantioxidantenzymesinbraintissue.Furthermore,rutininhibitedtheactivationofNF-κBandJNKsignalpathways,andpromotedtheactivationofNrf2/HO-1signalpathway.

Conclusion

Inconclusion,rutinhaspotentialprotectiveeffectsagainstbrainischemia-reperfusioninjurythroughitsregulationofinflammatoryresponseandantioxidantprocess.TheseeffectsmaybeattributedtothemodulationofNF-κB,JNK,Cas-3,andNrf2/HO-1signalpathways.Thesefindingssuggestthatrutinmayserveasapromisingneuroprotectiveagentforthetreatmentofbrainischemia-reperfusioninjuryBrainischemia-reperfusioninjuryisacomplexpathologicalprocessthatinvolvestheinteractionofvariouscellularandmolecularpathways.Therefore,identifyingtheexactmechanismsofactionofrutinanditspotentialdownstreamtargetsiscrucialforunderstandingitsneuroprotectiveeffectsinbrainischemia-reperfusioninjury.

Previousstudieshavedemonstratedthatrutincanmodulateseveralimportantsignalingpathwaysinvolvedininflammationandoxidativestress,suchasNF-κB,JNK,andNrf2/HO-1signalingpathways.NF-κBisatranscriptionfactorthatplaysakeyroleinregulatinginflammatoryresponses,anditsactivationisassociatedwiththeproductionofpro-inflammatorycytokinesandchemokines.JNKisamemberoftheMAPKfamilythatisactivatedinresponsetocellularstressandisinvolvedinvariouscellularprocesses,includingapoptosis,inflammation,andoxidativestress.Nrf2isatranscriptionfactorthatregulatestheexpressionofantioxidantanddetoxifyinggenes,anditsactivationisassociatedwithprotectionagainstoxidativestress.

RecentstudieshaveshownthatrutincaninhibittheactivationofNF-κBandJNKpathways,whichmaycontributetoitsanti-inflammatoryeffects.Forexample,inaratmodelofcerebralischemia-reperfusioninjury,rutinwasfoundtosuppresstheproductionofpro-inflammatorycytokinesandchemokines,aswellastheactivationofNF-κBsignalingpathway(Wangetal.,2016).Similarly,inaninvitromodelofoxygenandglucosedeprivation(OGD),rutinwasshowntoinhibittheactivationofJNKsignalingpathway,leadingtodecreasedneuronalcelldeathandimprovedcellsurvival(Wangetal.,2015).

Moreover,rutinhasbeenfoundtoactivatetheNrf2/HO-1signalingpathway,whichmaycontributetoitsantioxidanteffects.HO-1isanantioxidantenzymethatcatalyzesthebreakdownofhemeintobiliverdin,carbonmonoxide,andiron,anditsinductionhasbeenshowntoprotectagainstoxidativestressandinflammation.Nrf2isatranscriptionfactorthatregulatestheexpressionofHO-1andotherantioxidantgenes.SeveralstudieshavedemonstratedthatrutincaninducetheupregulationofNrf2/HO-1signalingpathway,leadingtothesuppressionofoxidativestressandthepromotionofcellsurvival.Forexample,inaninvitromodelofoxidativestressinducedbyhydrogenperoxide(H2O2),rutinwasfoundtoinducetheexpressionofNrf2andHO-1,leadingtothesuppressionofoxidativestressandtheprotectionofneuronalcells(Yangetal.,2015).

Takentogether,thesefindingssuggestthatrutinhaspotentialprotectiveeffectsagainstbrainischemia-reperfusioninjurythroughitsregulationofinflammatoryresponseandantioxidantprocess.Furtherstudiesareneededtoinvestigatetheexactmechanismsofactionofrutinanditspotentialdownstreamtargets,aswellasitssafetyandefficacyinclinicalsettings.Nevertheless,thesefindingsprovidevaluableinsightsintothepotentialuseofrutinasapromisingneuroprotectiveagentforthetreatmentofbrainischemia-reperfusioninjuryInadditiontoitspotentialroleinprotectingagainstbrainischemia-reperfusioninjury,rutinhasalsobeenstudiedforitstherapeuticpotentialinotherconditions,suchascardiovasculardisease,diabetes,andcancer.

Cardiovasculardiseaseisaleadingcauseofdeathworldwide,andoxidativestressandinflammationarekeycontributorstoitsdevelopmentandprogression.Rutinhasbeenshowntohaveanti-inflammatoryandantioxidantproperties,whichmayconferprotectiveeffectsagainstcardiovasculardisease.Inanimalstudies,rutinhasbeenfoundtoreduceatheroscleroticplaques,decreasebloodpressure,andimproveendothelialfunction.Clinicalstudieshavealsoshownpromisingresults,withrutinsupplementationleadingtoimprovementsinseveralcardiovascularriskfactors,includingbloodlipids,bloodpressure,andoxidativestressmarkers.

Diabetesisanotherconditionthatisassociatedwithoxidativestressandinflammation,andrutinhasbeenstudiedforitspotentialtherapeuticeffectsinthiscontextaswell.Inanimalmodelsofdiabetes,rutinhasbeenfoundtoimproveinsulinsensitivity,decreasebloodglucoseandlipids,andreduceoxidativestressandinflammation.Clinicalstudieshavealsoshownpromisingresults,withrutinsupplementationleadingtoimprovementsinglycemiccontrolandlipidprofilesinpatientswithtype2diabetes.

Cancerisacomplexdiseasethatinvolvesmultiplebiologicalpathways,butoxidativestressandinflammationarethoughttoplaykeyrolesinitsdevelopmentandprogression.Rutinhasbeenstudiedforitspotentialanti-cancereffects,withseveralstudiesshowingthatithasanti-proliferative,anti-metastatic,andpro-apoptoticpropertiesinvariouscancercelllines.Rutinhasalsobeenfoundtoenhancetheanticancereffectsofchemotherapydrugs,suggestingthatitmayhaveapotentialroleasanadjuvanttherapy.

Whilethesestudiessuggestthatrutinmayhavepote