Liver Cancer
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 14, 2005; 11(34): 5277-5282
Published online Sep 14, 2005. doi: 10.3748/wjg.v11.i34.5277
Effects of Pinus massoniana bark extract on cell proliferation and apoptosis of human hepatoma BEL-7402 cells
Ying-Yu Cui, Heng Xie, Kang-Biao Qi, Yan-Ming He, Jin-Fa Wang
Ying-Yu Cui, Kang-Biao Qi, Yan-Ming He, Jin-Fa Wang, 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, China
Heng Xie, Institute of Songzhen Nutritional Resource, Guangzhou 510645, Guangdong Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Professor Jin-Fa Wang, 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, China. ls19@zsu.edu.cn
Telephone: +86-20-84039179 Fax: +86-20-84039179
Received: September 16, 2004
Revised: November 14, 2004
Accepted: November 19, 2004
Published online: September 14, 2005
Abstract

AIM: 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 µg/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 µg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 µg/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 µg/mL PMBE.

CONCLUSION: 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.

Keywords: Pinus massoniana bark extract, Procyanidins, Human hepatoma, BEL-7402 cell, Cell proliferation, Apoptosis, bcl-2 gene