Severalstudieshavedemonstratedthattheamountofbeta-amyloid(Aβ)proteininthebraincanbeloweredbydown-regulatingAβproduction,promotingAβdegradation,reducingAβoligomerizationordeposition,therebyalleviatingsymptomsofAlzheimer'sdisease.Curcuminhasbeenknowntobeaperoxisomeproliferatoractivatedreceptorgamma(PPARγ)agonistandcanobviouslyinhibitAβproductionandoligomerization.Thisstudyinvestigatedtheeffectsofcurcuminontheβ-siteAPPcleavingenzyme1(BACE1)activityandPPARγexpressioninhumanneuroblastomaSH-SY5Ycells,andvalidatedtheinhibitoryeffectsofcurcuminonAβ40/42expressioninthebrain.ResultsrevealedthatPPARγmRNAandproteinexpressioninthehumanneuroblastomaSH-SY5Ycellssignificantlyincreasedwithincreasingcurcuminconcentrationandtimecourse(P<0.05);BACE1mRNAandproteinexpressionandAβ40/42productionsignificantlydecreasedwithincreasingcurcuminconcentrationandtimecourse(P<0.05).ThechangesinPPARγandBACE1expressionduringAβproductioncouldbereversedbythePPARγantagonistGW9662.ThesefindingsindicatethatcurcuminreducedAβproductionbyactivatingPPARγexpressionandinhibitingBACE1expressioninaconcentration-andtime-dependentmanner.
