In Vitro Effects of Extracts of Extra Virgin Olive Oil on Human Colon Cancer Cells

Abstract

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular diseases, and some types of cancer. Recent interest has been focused on the biological activity of phenolic compounds present in extra virgin olive oils (EVOOs). Both in vivo and in vitro studies have shown that EVOO components have positive effects on metabolic parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet function, and antimicrobial activity. We have investigated the possible interactions between 2 extracts of extra virgin olive oil and estrogen receptor β (ERβ) in an in vitro model of colon cancer. The qualification and quantification of the components of the 2 samples tested showed that phenolic compounds—hydroxytyrosol, secoiridoids, and lignans—are the major represented compounds. EVOO extracts were tested on a colon cancer cell line engineered to overexpress ERβ (HCT8-β8). By using custom made Oligo microarray, gene expression profiles of colon cancer cells challenged with EVOO-T extracts when compared with those of cells exposed to 17β-estradiol (17β-E2). This study demonstrated that the EVOO extracts tested showed an antiproliferative effect on colon cancer cells through the interaction with estrogen-dependent signals involved in tumor cell growth. Specifically, the ability of EVOO extracts to inhibit cell proliferation was superimposable to the activation of the ERβ receptor, similar to what was observed after 17β-E2 challenge.