The protective role of olive oil hydroxytyrosol against oxidative alterations induced by mercury in human erythrocytes.

Hydroxytyrosol (HT) is a phenolic antioxidant naturally occurring in virgin olive oil. In this study, we investigated the possible protective effects of HT on the oxidative and morphological alterations induced by mercury (Hg) in intact human erythrocytes. These cells preferentially accumulate this toxic heavy metal. More importantly, Hg-induced echinocyte formation correlates with increased coagulability of these cells. Our results indicate that HT treatment (10-50 µM) prevents the increase in hemolysis and Reactive Oxygen Species (ROS) generation induced by exposure of cells to micromolar HgCl2 concentrations as well as the decrease in GSH intracellular levels. Moreover, as indicated by scanning electron microscopy, the morphological alterations are also significantly reduced by HT co-treatment. Taken together our data provide the first experimental evidence that HT has the potential to counteract mercury toxicity. The reported effect may be regarded as an additional mechanism underlying the beneficial cardio-protective effects of this dietary antioxidant, also endowed with significant anti-atherogenic and anti-inflammatory properties.