title: Effects of Pinus massoniana bark extract on cell proliferation and apoptosis of human hepatoma BEL-7402 cells.
abstract: OBJECTIVE
  To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.
  
  
  METHODS
  BEL-7402 cells were incubated with various concentrations (20-200 microg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis, and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.
  
  
  RESULTS
  PMBE (20-200 microg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 microg/mL PMBE for 24, 48, or 72 h, a typical apoptotic "DNA ladder" was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy. Sub-G1 curves were displayed by flow cytometry analysis. PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 microg/mL PMBE.
  
  
  CONCLUSIONS
  PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.
authors.affiliation: The State Key Laboratory for Biocontrol and The Key Laboratory of Gene Engineering of Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, China.
authors.forename: Ying-Yu
authors.initials: YY
authors.lastname: Cui
authors.forename: Heng
authors.initials: H
authors.lastname: Xie
authors.forename: Kang-Biao
authors.initials: KB
authors.lastname: Qi
authors.forename: Yan-Ming
authors.initials: YM
authors.lastname: He
authors.forename: Jin-Fa
authors.initials: JF
authors.lastname: Wang
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D044946:Biflavonoids / Q000737:chemistry / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor / Q000166:cytology / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms; D028223:Pinus; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000737:chemistry / Q000494:pharmacology
chemical_list: D044946:Biflavonoids; D010936:Plant Extracts; D044945:Proanthocyanidins; C479581:procyanidin B3; D002392:Catechin