Biological effects of the olive polyphenol, hydroxytyrosol: An extra view from genome-wide transcriptome analysis

Epidemiological and clinical studies have established the health benefits of the Mediterranean diet, an important component of which are olives and olive oil derived from the olive tree (Olea Europea). It is now well-established that not only the major fatty acid constituents, but also the minor phenolic components, in olives and olive oil have important health benefits. Emerging research over the past decade has highlighted the beneficial effects of a range of phenolic compounds from olives and olive oil, particularly for cardiovascular diseases, metabolic syndrome and inflammatory conditions. Mechanisms of action include potent antioxidant and anti-inflammatory effects. Further, accumulating evidence indicates the potential of the polyphenols and potent antioxidants, hydroxytyrosol and oleuropein in oncology. Numerous studies, both in vitro and in vivo, have demonstrated the anticancer effects of hydroxytyrosol which include chemopreventive and cell-specific cytotoxic and apoptotic effects. Indeed, the precise molecular mechanisms accounting for the antioxidant, anti-inflammatory and anticancer properties are now becoming clear and this is, at least in part, due to high through-put gene transcription profiling. Initially, we constructed phylogenetic trees to visualize the evolutionary relationship of members of the Oleaceae family and secondly, between plants producing hydroxytyrosol to make inferences of potential similarities or differences in their medicinal properties and to identify novel plant candidates for the treatment and prevention of disease. Furthermore, given the recent interest in hydroxytyrosol as a potential anticancer agent and chemopreventative we utilized transcriptome analysis in the erythroleukemic cell line K562, to investigate the effects of hydroxytyrosol on three gene pathways: the complement system, The Warburg effect and chromatin remodeling to ascertain relevant gene candidates in the prevention of cancer.