Screening of Natural Stilbene Oligomers from <i>Vitis vinifera</i> for Anticancer Activity on Human Hepatocellular Carcinoma Cells

• Main Authors: Iris Aja, M. Begoña Ruiz-Larrea, Arnaud Courtois, Stéphanie Krisa, Tristan Richard, José-Ignacio Ruiz-Sanz
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Antioxidants
• Subjects: stilbene; resveratrol oligomers; natural product; polyphenol; anticancer activity; HepG2 cells
• Online Access: https://www.mdpi.com/2076-3921/9/6/469

The characterization of bioactive resveratrol oligomers extracted from <i>Vitis vinifera</i> canes has been recently reported. Here, we screened six of these compounds (ampelopsin A, <i>trans-</i>ε-viniferin, hopeaphenol, isohopeaphenol, R2-viniferin, and R-viniferin) for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 wild-type HepG2 and p53-null Hep3B. The cytotoxic efficacy depended on the cell line. R2-viniferin was the most toxic stilbene in HepG2, with inhibitory concentration 50 (IC₅₀) of 9.7 ± 0.4 µM at 72 h, 3-fold lower than for resveratrol, while Hep3B was less sensitive (IC₅₀ of 47.8 ± 2.8 µM). By contrast, hopeaphenol (IC₅₀ of 13.1 ± 4.1 µM) and isohopeaphenol (IC₅₀ of 26.0 ± 3.0 µM) were more toxic to Hep3B. Due to these results, and because it did not exert a large cytotoxicity in HH4 non-transformed hepatocytes, R2-viniferin was selected to investigate its mechanism of action in HepG2. The stilbene tended to arrest cell cycle at G2/M, and it also increased intracellular reactive oxygen species (ROS), caspase 3 activity, and the ratio of Bax/Bcl-2 proteins, indicative of apoptosis. The distinctive toxicity of R2-viniferin on HepG2 encourages research into the underlying mechanism to develop the oligostilbene as a therapeutic agent against HCC with a particular genetic background.