title: Apoptosis-inducing effects of jujube (Zǎo) seed extracts on human Jurkat leukemia T cells.
abstract: BACKGROUND
  Jujube (Zǎo) seeds exhibited anticancer effects and used in Chinese medicine for many years. This study aims to investigate the apoptosis-inducing effects of seed extracts from eight different cultivated species ('Apple', 'Bombay', 'Jumbo', 'Kaew', 'Nomsod', 'Rianthong', 'Samros', and 'Taiwan') on human Jurkat leukemia T cells.
  
  
  METHODS
  We evaluated the effects of seed extracts from eight jujube cultivated species on human Jurkat leukemia T cells. The crude seed extracts were prepared sequentially by using water, 95 % ethanol, dichloromethane, ethyl acetate, chloroform or hexane. The antiproliferative effects of the jujube seed extracts relative to that of melphalan were evaluated by neutral red assays. Apoptotic cell death induced by the ethanolic extracts at 1 × IC50 and 2 × IC50 concentrations was demonstrated by DAPI staining, gel electrophoresis, flow cytometry with Annexin V/propidium iodide staining, and caspase-3, -8, and -9 enzyme activities.
  
  
  RESULTS
  Ethanolic extracts of 'Taiwan', 'Jumbo', 'Nomsod', 'Rianthong', 'Samros', and 'Bombay', significantly inhibited the proliferation of Jurkat cells compared with untreated cells (all P < 0.001), while the extracts of 'Kaew' and 'Apple' were inactive. The six active extracts preferentially induced apoptotic cell death in a concentration-dependent manner with DNA fragmentation (2 × IC50). Increased caspase-3 activity was detected after treatment with the six extracts. The 'Taiwan', 'Nomsod', 'Jumbo', and 'Rianthong' extracts (2 × IC50) induced both the extrinsic and intrinsic apoptosis pathways by increasing caspase-8 and caspase-9 activity, respectively. Alkaloids (Dragendorff's method) and reducing sugars (Fehling's test) were mainly identified in the apoptosis-inducing extracts.
  
  
  CONCLUSIONS
  The tested of six active extracts ('Taiwan', 'Jumbo', 'Nomsod', 'Rianthong', 'Samros' and 'Bombay') contained alkaloids or reducing sugars, and induced caspase-dependent apoptosis in human Jurkat leukemia T cells.
authors.affiliation: Graduate School, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors.forename: Natthanan
authors.initials: N
authors.lastname: Taechakulwanijya
authors.affiliation: Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors.forename: Natthida
authors.initials: N
authors.lastname: Weerapreeyakul
authors.affiliation: Faculty of Associate Medical Sciences, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors.forename: Sahapat
authors.initials: S
authors.lastname: Barusrux
authors.affiliation: Department of Food Technology and Nutrition, Mahasarakham University, Mahasarakham, 44000 Thailand.
authors.forename: Sirithorn
authors.initials: S
authors.lastname: Siriamornpun
keywords: Apoptosis; Cancer; Jujube; Jurkat leukemia T cells