title: [The protective effect of chlorophyllin against oxidative damage and its mechanism].
abstract: OBJECTIVE
  To investigate whether chlorophyllin could protect human umbilical vein endothelial cell (HUVEC) against oxidative damage by inducing the expression of heme oxygenase-1 (HO-1) and to explore the underlying mechanism.
  
  
  METHODS
  The cellular protection of chlorophyllin against oxidative damage was detected by cell-survival assay with flow cytometry. The level of free radicals was detected directly by electron spin resonance spectra. The induced expression of HO-1 was shown by RT-PCR, Western blot, immunofluorescence confocal laser microscopy and enzymatic activity test. Whether the activation of PI3K/Akt pathway was involved was detected by Western blot.
  
  
  RESULTS
  Chlorophyllin could protect HUVEC against oxidative damage caused by H2O2 via scavenging the excessive free radicals. Chlorophyllin treatment could induce expression of HO-1 in a dose- and time-dependent manner. The activation of PI3K/Akt pathway was required in the induction of HO-1. LY294002, the specific inhibitor of PI3K, could suppress the activation of PI3K/Akt and the induced expression of HO-1 in a dose-dependent manner.
  
  
  CONCLUSIONS
  Chlorophyllin shows cellular protection against oxidative damage by counteracting the excessive free radicals. Up-regulation of HO-1 expression plays a pivotal role in the protection of chlorophyllin, while the activation of PI3K/Akt signaling pathway is required in the induction of HO-1.
authors.affiliation: Research Center of Occupational Medicine, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Yan-lin
authors.initials: YL
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Guan
authors.forename: Pei-hua
authors.initials: PH
authors.lastname: Zhou
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Mao
authors.forename: Zan-mei
authors.initials: ZM
authors.lastname: Zhao
authors.forename: Shu-qiang
authors.initials: SQ
authors.lastname: Li
authors.forename: Xi-xian
authors.initials: XX
authors.lastname: Xu
authors.forename: Cui-cui
authors.initials: CC
authors.lastname: Cong
authors.forename: Ming-xia
authors.initials: MX
authors.lastname: Zhu
authors.forename: Jin-yuan
authors.initials: JY
authors.lastname: Zhao
mesh_terms: D002478:Cells, Cultured; D002735:Chlorophyllides / Q000494:pharmacology*; D002867:Chromones / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D051547:Heme Oxygenase-1; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D002735:Chlorophyllides; D002867:Chromones; D016166:Free Radical Scavengers; D009025:Morpholines; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017382:Reactive Oxygen Species; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D051057:Proto-Oncogene Proteins c-akt; C007020:chlorophyllin