Different Effects Of Five Catechins On 6-Hydroxydopamine-induced Apoptosis In PC12- Cells

Five catechins: (-)-EPigallocatechin gallate ffiGCG), (-)-EPicatechin gallate (ECG),(-)-EPigallocatechin ffiGC), (-)-EPicatechin peC) and (+)-Catechin wer comPared withtheir effects on 6-OHDAinduced aPoptosis in PCl2 cells the model of PD in vbo.Measured by W assay 6-OHDA Mited cell vibility in tiIn- and conceIhation-dePendent manner When PCl2 cells wer pretreated ed five catechins for 30Inin beforeeXPosured to 250pM 6-OgnA, MTT results showed tha flve catechins had differenteffects f EGCG and ECG had obvious concentratondePendent protective effects in theMe of 50-400pM, EC and (+)-C almst had no effects; hoWW cel1 viabilitydecreased in the case of EGC. Catechins also had different effects on aPoPohcmorphology Only in the conceIhatons of 200-400pM EGCG and ECG kePt cellsMg well. Ptwated with other catechins in any concentration, the PCl2 cellsbecame round and some of them wer detached as Which treated with 6-OunA. hiaddition, toical aPoptotic characwhstics of PCl2 cells wee deteded by fluoresentnilcroscopy, flow cytometry and DNA fragmen electrophoresis ther the cells weetreated ch 250pM 6-OHDA for 24h or pretrated with catechins for 30Inin.Preincubation nd 200-400pM EGCG and ECG led to sighfican foritory effectsagM PCl2 cell aPoPosis, as the resul of flow cytometry showing. But othes havelittle Protective effects. TherfOre ch 200-400pM, the Protective effects of fivecatechins decreased in the orde: EC GallGC G>GTP S>>EC>(+)-C>E GC. The data al soindicated tha EGCG and ECG ndght be poten neuroProtective agents for PD. The resultsof fluorescence ndcroscOPy and DNA fragment analysis SUPPorted the conclusion.unchondria are boortan intraCellular organenes in Which energy is generaed.MitoHal PTP OPenin will induce IIiltochOlldrial dysdriction, and then resul in celldeath. The StUdy was cwhed out to inveStigae the influece of GTPs and five ldnds ofcateM on edochondrial PTP opening. The results showed tha GTPs and catechinshave differen effects on H2O,- or Ca2+-indUed dschondrial PTh oPeIiln. GThs and themajor comPonents EGCG, ECG have driitory effects on it While the othe kinds ofcatechin, i.e., EGC, EC and (+)-C could accelerat the process. The results are paralleledto the measurement of the change of dschondrial membran potential throughhehfor l23.Fwt exPeriments exaInind the detalled influence of GTPs on Ca2+ twort andexPort of IintOchondria. The result showed that GTPs haVe remark4bly foritory effecton the Ca2+-induced Ca2+ boort in chchondri4 While it can accelerae the Process ofCa2+irelease from Initochondria- Our data Provide an altheate interpretaon of the potentprotective fimction of GTPs.