J Vet Sci.  2012 Mar;13(1):7-13. 10.4142/jvs.2012.13.1.7.

Elm tree bark extract inhibits HepG2 hepatic cancer cell growth via pro-apoptotic activity

• Kim TM
• Shin SK
• Kim TW
• Youm SY
• Kim DJ
• Ahn B

• KMID: 1364997
• DOI: http://doi.org/10.4142/jvs.2012.13.1.7

Abstract

Control of inflammation is widely accepted as an important strategy for cancer chemoprevention. Anti-inflammatory effects of bark extracts of elm tree (BEE) have been amply reported. Therefore, BEE may be a good candidate cancer chemopreventive agent. Considering the high incidence of hepatic cancer and limited therapeutic approaches for treating this disease, it is important to develop liver cancer-specific chemopreventive agents. To evaluate the chemopreventive potential of BEE, we investigated the growth inhibition effect of BEE on the HepG2 human hepatocellular carcinoma cell line. We performed a cell counting kit-8 assay to determine cell viability, and 4,6-diamino-2-phenylindole staining and flow cytometry to measure apoptotic cell death. Finally, the expression levels of pro- and anti-apoptotic proteins were measured. BEE inhibited the growth of HepG2 cells and induced apoptosis in a dose-dependent manner. Pro-apoptotic activity was promoted via the mitochondrial pathway of apoptosis, as demonstrated by the activation of pro-apoptotic proteins Bax, caspase-9, caspase-3, and poly (ADP-ribose) polymerase as well as the down-regulation of the anti-apoptotic protein Bcl-2. These results suggest that BEE may have potential use in hepatic cancer chemoprevention by suppressing cancer cell growth via pro-apoptotic activity.

Keyword

apoptosis; elm tree extract; HepG2 cell; Ulmus davidiana

MeSH Terms

Apoptosis/*drug effects
Blotting, Western
Carcinoma, Hepatocellular/*drug therapy/metabolism/pathology
Caspase 3/metabolism
Caspase 9/metabolism
Cell Survival/drug effects
Flow Cytometry
Hep G2 Cells
Humans
Indoles/chemistry
Liver Neoplasms/*drug therapy/metabolism/pathology
Plant Bark/chemistry
Plant Extracts/*pharmacology
Poly(ADP-ribose) Polymerases/metabolism
Ulmus/*chemistry
bcl-2-Associated X Protein/metabolism

Figure

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  Fig. 1 Bark extracts of elm tree (BEE) influences the viability of HepG2 hepatocellular carcinoma (HCC) cells. Data are expressed as the mean ± SD. *Significantly different from the control (p < 0.05).

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  Fig. 2 The fluorescence microscopic morphology of HepG2 cells treated with BEE. Note the enhanced DNA fragmentations and apoptotic body (arrows) formations in cells treated with 200 µg/mL of BEE. ×200.

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  Fig. 3 Effect of BEE on HepG2 HCC cell apoptosis. After 24 h, the collected cells were incubated with a fluorescein isothiocyanate (FITC)-annexin V stain to detect apoptosis (A). BEE increased the number of apoptotic cells in a dose-dependent manner (B). Data represent the mean ± SD. *Significantly different from the control (p < 0.05).

• 

  Fig. 4 Effect of BEE on the expression of apoptotic proteins in HepG2 HCC cells. β-actin was used as an internal control (A). BEE increased the Bax/Bcl-2 ratio and expression of caspase-3, caspase-9, and PARP (B). Data represent the mean ± SD. *Significantly different from the control (p < 0.05).

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