Antiproliferative and antioxidant effects on breast cancer cells of oleuropein and its semisynthetic peracetylated derivatives

Olive leaves extracts are a natural source of polyphenols, mainly oleuropein, widely considered to be potentially beneficial for health. This study focused on evaluation of the anti-tumoural activities of some oleuropein peracetylated derivatives, obtained with "green chemical" methodologies, against two human breast cancer cell lines. MCF-7 and T-47D cells were treated with oleuropein, peracetylated oleuropein, peracetylated aglycone and peracetylated hydroxytyrosol and the effects on growth and viability were investigated. Antioxidant effects were analysed after treatment with hydrogen peroxide. The peracetylated compounds exerted higher antiproliferative effects than oleuropein, by an arrest of cell cycle progression, associated with a strong antioxidant activity. Our results demonstrate that olive leaves, a by-product of olive manufacture, may provide a precious source of chemical derivatives, obtainable by peracetylation of oleuropein derivatives, which provide beneficial properties for human health. (C) 2011 Elsevier Ltd. All rights reserved.