Hydroxytyrosol supplementation inhibits oxidative DNA damage, suppresses protein-lipid oxidation and modulates antioxidant enzymes in human peripheral blood lymphocytes

We investigated the oxidative modifications of DNA, proteins and antioxidants enzymes activities, in peripheral blood lymphocytes (PBL) treated with H2O2 in the presence or absence of hydroxytyrosol. Interestingly, we found a potential protection of DNA from fragmentation after hydroxytyrosol supplementation. In addition, this study showed a prospective protective action of hydroxytyrosol of PBL from the attack of reactive oxygen species. In fact, a considerable increase of superoxide dismutase and catalase activities by 76.92 and 21.67%, respectively was showed after 20 µg/ml hydroxytyrosol treatment. Moreover, 20 µg/ml of hydroxytyrosol significantly decreased the lipid peroxidation and protein oxidation rates by 97.89 and 18.5% respectively. In conclusion, the present study reveals the efficacy of hydroxytyrosol in the protection of PBL of DNA fragmentation and oxidative stress induced by H2O2 treatment, which may be attributed to its anti-oxidant potential.   Key words: Hydroxytyrosol, thiol, lymphocytes, conjugated dienes, malondialdehyde, superoxide dismutase, catalase.