title: Similar potency of catechin and its enantiomers in alleviating 1-methyl-4-phenylpyridinium ion cytotoxicity in SH-SY5Y cells.
abstract: OBJECTIVE
  Previously, the flavonoid (±)-catechin was shown to exert potent neuroprotective action in the mouse 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease model. The purpose of this study was to investigate whether the different enantiomers of catechin ((+)-catechin, (-)-catechin and (±)-catechin, a 50:50 mixture of (+)-catechin and (-)-catechin) could protect SH-SY5Y cells against 1-methyl-4-phenylpyridinium ion (MPP(+) ) toxicity by decreasing the generation of oxygen free radicals. The inhibitive effect of (±)-catechin on JNK/c-Jun activation was investigated.
  
  
  METHODS
  The effects of (+)-catechin, (-)-catechin or (±)-catechin in protecting against MPP(+) toxicity were evaluated and compared in SH-SY5Y cells by testing the release of lactate dehydrogenase. The generation of reactive oxygen species (ROS) was measured by immunochemistry and the phosphorylation level of JNK/c-Jun was determined by Western blotting.
  
  
  RESULTS
  In SH-SY5Y cells, (+)-catechin, (-)-catechin or (±)-catechin reduced apoptosis induced by MPP(+) and decreased ROS generation caused by MPP(+) . Different enantiomers of catechin showed protective effects at similar potency. Moreover (±)-catechin decreased JNK/c-Jun phosphorylation which was increased by MPP(+).
  
  
  CONCLUSIONS
  Catechin and its two enantiomers could protect SH-SY5Y cells against MPP(+) cytotoxicity at a similar potency. Antioxidative stress and inhibition of the JNK/c-Jun signalling pathway might have been involved in the neuroprotective mechanisms of catechin against MPP(+) cytotoxicity in SH-SY5Y cells.
authors.affiliation: Guangdong Institute for Drug Control, Guangzhou, China.
authors.forename: Hao-lan
authors.initials: HL
authors.lastname: Ruan
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiao-nan
authors.initials: XN
authors.lastname: Zhu
authors.forename: Xue-lan
authors.initials: XL
authors.lastname: Wang
authors.forename: Ru-zhu
authors.initials: RZ
authors.lastname: Chen
mesh_terms: D015655:1-Methyl-4-phenylpyridinium; D017209:Apoptosis / Q000187:drug effects; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020267:MPTP Poisoning / Q000188:drug therapy* / Q000378:metabolism; D018384:Oxidative Stress; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D016755:Proto-Oncogene Proteins c-jun; D017382:Reactive Oxygen Species; D002392:Catechin; D007770:L-Lactate Dehydrogenase; D015655:1-Methyl-4-phenylpyridinium