Oligonol, a Low Molecular Weight Polyphenol, Enhances Apoptotic Cell Death in Ovarian Cancer Cells via Suppressing NF-κB Activation

Abstract

Background: Oligonol, a low molecular weight polyphenol derived from lychee fruit, not only has anti-inflammatory effects in various disease conditions but also has antitumor-promoting effects. We evaluate the nuclear factor-kappa B (NF-κB)-related anticancer effect of oligonol in ovarian cancer using SKOV-3 cells.

Methods: Cell viability was examined after oligonol treatment using MTT assay and reactive oxygen species (ROS) production measurement. Subsequently, apoptotic cell death was visualized by the TdT-mediated dUTP nick-end labeling (TUNEL) method. The effect of oligonol on the NF-κB signaling pathway was evaluated using western blot analysis and luciferase activity measurement of p65, an NF-κB subunit.

Results: Cell viability significantly decreased after oligonol treatment of 72 h. Apoptosis-related markers were highly expressed in oligonol-treated cells, and increased apoptosis after oligonol treatment was also confirmed using the TUNEL assay. Western blotting results showed the expression of NF-κB signaling pathway factors, p-ERK, TRAF2, and p-IκBα, increased following treatment with oligonol, whereas p65 and COX-2 expression decreased. Immunofluorescence imaging results showed p65 luciferase activity in the nucleus as well as a shift to cytoplasmic expression.

Conclusion: Oligonol treatment significantly enhances apoptotic cell death in SKOV-3 cells, with the suppression of NF-κB activation, which plays an essential role in this anticancer effect.

Disclosure Statement

The authors have no relevant conflicts of interest to declare.

Additional information

Funding

This study was supported by grant number 02-2016-007 from the Seoul National University Bundang Hospital Research Fund.