Potential of olive oil phenols as chemopreventive and therapeutic agents against cancer: A review of in vitro studies

Olive oil is a common component of Mediterranean dietary habits. Epidemiological studies have shown how the incidence of various diseases, including certain cancers, is relatively low in the Mediterranean basin compared to that of other European or North America countries. Current knowledge indicates that the phenolic fraction of olive oil has antitumor effects. In addition to the ability to be chemopreventive, with its high antioxidant activity, the antitumor effects of olive oil phenols (OO-phenols) has been studied because of their capacity to inhibit proliferation and promote apoptosis in several tumor cell lines, by diverse mechanisms. This review will summarize and discuss the most recent relevant results on the antitumor effect of OO-phenols on leukemia tumor cells, colorectal carcinoma cells, and breast cancer (BC) cells. In particular, very recent data will be reported and discussed showing the molecular signaling pathways activated by OO-phenols in different histopathological BC cell types, suggesting the potential use of OO-phenols as adjuvant treatment against several subsets of BC. Data summarized here represent a good starting point for more extensive studies for better insight into the molecular mechanisms induced by OO-phenols and to increase the availability of chemopreventive or therapeutic drugs to fight cancer.