Protective effects of olive oil phenolics oleuropein and hydroxytyrosol against hydrogen peroxide-induced DNA damage in human peripheral lymphocytes

Abstract

This study investigates antioxidant capacity and protective effects of phenolic compounds oleuropein (OLP) and hydroxytyrosol (HT), present in olive oil and olive leaves, against H2O2-induced DNA damage in human peripheral lymphocytes. Antioxidant potency was determined using the measurement of radical-scavenging activity (ABTS∙+ assay), ferric reducing power (FRAP assay) and cupric reducing antioxidant capacity (CUPRAC assay). Both substances were found to be potent antioxidant agents due to their free radical-scavenging activities. Antigenotoxic effects of oleuropein and hydroxytyrosol against H2O2-induced damage in human lymphocytes were evaluated in vitro by alkaline comet assay. At tested concentrations (1, 5, 10 µmol L−1), oleuropein and hydroxytyrosol did not induce a significant increase of primary DNA damage in comparison with the negative control. Pretreatment of human lymphocytes with each of the substances for 120 min produced a dose-dependent reduction of primary DNA damage in the tested cell type. Hydroxytyrosol showed a better protective effect against H2O2-induced DNA breaks than oleuropein which could be associated with their free radical-scavenging efficacy.

Hepatopreventive properties of hydroxytyrosol and mannitol-rich extracts obtained from exhausted olive pomace using green extraction methods

“…Recent studies highlighted the anti-genotoxicity in liver tissue of the major metabolites in AE-EOP and AAE-EOP extracts, such as mannitol 48 and hydroxytyrosol. 49 The present findings also revealed that CCl 4 induced perturbation of the lipid profile as observed by considerably increased levels either in plasma and hepatic tissue of TC, TG and LDL-C, while HDL-C levels decreased. These changes in lipids parameters have been observed after CCl 4 administration.…”

“…Recent studies highlighted the anti-genotoxicity in liver tissue of the major metabolites in AE-EOP and AAE-EOP extracts, such as mannitol 48 and hydroxytyrosol. 49…”

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

“…Further studies focusing on the bio-accessibility of polyphenols after enzymatic digestion of different Olea europaea products have been extensively reviewed elsewhere [ 120 ]. Oleuropein and hydroxytyrosol antioxidant activity seemed to be similar in an ex vivo study in humans [ 121 ], while both seemed to be more potent than homovanillic alcohol in vitro [ 122 ]. Hydroxytyrosol plasma concentrations diminish within approximately 1 h after EVOO ingestion, as they are transformed into glucuronidated forms, which have similar antioxidant potency to tyrosol [ 123 ].…”

Melatonin and 1‐methylcyclopropene treatments on delay senescence of apricots during postharvest cold storage by enhancing antioxidant system activity

“…The ABTS radical scavenging activity was measured using the method described by Kosalec et al (Zoric et al, 2021). ABTS radical scavenging activity was expressed in terms of micrograms of Trolox equivalents per gram of FW basis (μg/g).…”