title: Purple sweet potato pigments scavenge ROS, reduce p53 and modulate Bcl-2/Bax to inhibit irradiation-induced apoptosis in murine thymocytes.
abstract: OBJECTIVE
  Purple sweet potato (PSP) pigments were proved to protect murine thymocytes from (60)Co γ-ray-induced mitochondria-mediated apoptosis in our previous study. In this study, we further investigated the effect of PSP pigments on apoptosis related ROS, p53 and Bcl-2 family.
  
  
  METHODS
  Cell viability was analyzed by MTT. Apoptosis was certified by DNA ladder detection. Reactive oxygen species (ROS) were detected using 2',7',- dichlorofluorescein diacetate (DCFH-DA) probe. P53, Bcl-2 and Bax proteins were analyzed by western blot. The activities of caspase-3 and caspase-9 were determined by fluorogenic substrates detection.
  
  
  RESULTS
  PSP pigments treatment prior to 4Gy (60)Co γ-ray irradiation increased the cell viability and decrease the apoptosis. In the presence of PSP pigments, ROS was scavenged and followed by a p53-depression. A shift in Bcl-2/Bax ratio towards anti-apoptosis was observed as a result of p53-depression. The activities of caspase-9 and caspase-3 were reduced by PSP pigments pretreatment.
  
  
  CONCLUSIONS
  PSP pigments have a cytoprotective activity against γ radiation. The protective effect of PSP pigments may be involving ROS scavenging, p53 depression and Bcl-2/Bax modulation in a caspase-dependent mitochondrial way.
authors.affiliation: Department of Pharmacology, Qingdao University Medical College, Qingdao, PR China.
authors.forename: Yan-Tao
authors.initials: YT
authors.lastname: Han
authors.forename: Xue-Hong
authors.initials: XH
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.forename: Song-Mei
authors.initials: SM
authors.lastname: Zhan
authors.forename: Chun-Bo
authors.initials: CB
authors.lastname: Wang
authors.forename: Le-Xin
authors.initials: LX
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003037:Cobalt Radioisotopes / Q000737:chemistry; D053938:DNA Fragmentation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005720:Gamma Rays; D027723:Ipomoea batatas / Q000737:chemistry; D051379:Mice; D010860:Pigments, Biological / Q000378:metabolism / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060168:Thymocytes / Q000187:drug effects* / Q000528:radiation effects; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D003037:Cobalt Radioisotopes; D004791:Enzyme Inhibitors; D010860:Pigments, Biological; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D053148:Caspase 3; D053453:Caspase 9