Effects of Pinus massoniana bark extract on cell proliferation and apoptosis of human hepatoma BEL-7402 cells.
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.
Cui
Ying-Yu
YY
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.
Xie
Heng
H
Qi
Kang-Biao
KB
He
Yan-Ming
YM
Wang
Jin-Fa
JF
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
D044946:Biflavonoids; D010936:Plant Extracts; D044945:Proanthocyanidins; C479581:procyanidin B3; D002392:Catechin