title: β-elemene induces caspase-dependent apoptosis in human glioma cells in vitro through the upregulation of Bax and Fas/ FasL and downregulation of Bcl-2.
abstract: BACKGROUND
  β-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of β-elemene against glioma cells remains unclear. In the present study, we assessed effects of β-elemene on human glioma cells and explored the underlying mechanism.
  
  
  METHODS
  Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of β-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of β-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and β-elemne treatment group.
  
  
  RESULTS
  With increase in the concentration of β-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability (IC50) was 48.5 μg/mL for 24h. β-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with β-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by β-elemene in a time and does- dependent manner.
  
  
  CONCLUSIONS
  Our results indicate that β-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, China E-mail : zhirenzhang@163.com, jcll6688@163.com.
authors.forename: Chen-Long
authors.initials: CL
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Chang
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.forename: Hui-Bin
authors.initials: HB
authors.lastname: Liu
authors.forename: Qiu-Shi
authors.initials: QS
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Wen-Zhong
authors.initials: WZ
authors.lastname: Du
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jing-Hong
authors.initials: JH
authors.lastname: Xie
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Ming
authors.forename: Yu-Qiong
authors.initials: YQ
authors.lastname: Cui
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Zhang
authors.forename: Chuan-Lu
authors.initials: CL
authors.lastname: Jiang
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D015153:Blotting, Western; D020169:Caspases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D053222:Fas Ligand Protein / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D005910:Glioma / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012717:Sesquiterpenes / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: C491901:FAS protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D012717:Sesquiterpenes; D051028:bcl-2-Associated X Protein; C445979:beta-elemene; D019014:fas Receptor; D020169:Caspases