Minor Polar Compounds in Olive Oil and NF- B Translocation

The cardio-protective role of olive oil has been highlighted in several studies and beneficial health effects have been attributed, at least in part, to the presence of non-nutrient minor polar compounds (MPC). As an example, phenolic compounds in virgin olive oil improve endothelial function in hypercholesterolemic patients and inhibit low-density lipoprotein (LDL) oxidation in humans and animals, in vivo and in vitro, hydroxytyrosol and oleuropein being also potent scavengers of several free radicals. After consumption of 25 mL extra virgin olive oil, plasma concentrations of hydroxytyrosol range from 50 to 160 nM. Hydroxytyrosol affects oxidative stress as well as arachidonic acid mobilization and metabolism by macrophage RAW 264.7 cells. In the same cell line, it also reduces iNOS (inducible nitric oxide synthase) and COX-2 (cyclo-oxygenase 2) gene expression, mainly by preventing the activation of NFκB (nuclear factor-kappa B), STAT-1α (signal transducer and activator of transcription-1α), and IRF-1 (interferon regulatory factor-1). At nutritionally relevant concentrations, hydroxytyrosol reduces monocyte adhesion to human endothelial cells, as well as the expression of adhesion molecules such as VCAM-1 (vascular cell adhesion molecule-1), an effect that seems to be mediated by NFκB and activator protein-1 (AP-1). The redox-sensitive transcription factor NFκB can be activated by various stimuli, including reactive oxygen species, oxidized LDL, hypoxia/anoxia, cytokines, and bacterial and viral products, and is largely recognized as a therapeutic target in inflammation and atherosclerosis.