Assessment of the antioxidant activity of an olive oil total polyphenolic fraction and hydroxytyrosol from a Greek Olea europea variety in endothelial cells and myoblasts

Abstract

Olive oil (OO) constitutes the basis of the Mediterranean diet, and it seems that its biophenols, such as hydroxytyrosol (HT) may scavenge free radicals, attracting distinct attention due to their beneficial effects in many pathological conditions, such as cancer. To the best of our knowedge, this is the first study in which the functional properties of an OO total polyphenolic fraction (TPF) and pure HT were examined in order to determine their antioxidant effects at a cellular level in endothelial cells and myoblasts. The test compounds were isolated using a green gradient-elution centrifugal partition chromatography-based method that allows the isolation of large volumes of OO in a continuous extraction procedure and with extremely low solvent consumption. For the isolation of HT, a combination of two chromatographic techniques was used, which is effective for the recovery of pure compounds from complex natural extracts. Moreover, TPF and HT exhibited potent free radical scavenging activity in vitro. The cells were treated with non-cytotoxic concentrations and their redox status [in terms of glutathione (GSH) and reactive oxygen species (ROS) levels] was assessed. TPF extract was less cytotoxic than HT, and the observed differences between the two cell lines used suggest a tissue-specific activity. Finally, flow cytometric analysis revealed that both TPF and HT improved the redox status by increasing the levels of GSH, one of the most important antioxidant molecules, in both endothelial cells and myoblasts, while the ROS levels were not significantly affected.

Enzyme and Biological Activities of the Water Extracts from the Plants Aesculus hippocastanum, Olea europaea and Hypericum perforatum That Are Used as Folk Remedies in Turkey

“…These data support the antioxidant activity findings obtained from the current study. Apart from these, some studies have been conducted on the antioxidant activities of olive oil samples [37][38][39]. However, since the examples used in the current study were not oils, these studies were left out of the discussion.…”

A review on management of cardiovascular diseases by olive polyphenols

“…The bioactive compounds in virgin olive oil (VOO) alter the postprandial hemostatic profile and protect from oxidative stress (Ruano et al., 2007). A number of studies confirmed that various parts of olive such as OO (Covas, Nyyssönen, et al, 2006), EVOO (Borges, Cabrera‐Viqueb, & Seiquer, 2015; Kouka et al., 2017), VOO (Covas, Nyyssönen, et al, 2006; Quintero‐Florez et al, 2017), leaves (Paiva‐Martins et al., 2014), cake (Rubió et al, 2014), wastewater, and pomace oil have strong antioxidant activity due to the presence of tangible amount of biologically active compounds. Around 50% of biologically active compounds present in olive are hydroxytyrosol and their derivatives as described in Table 2 (Gonzalez‐Santiago, Fonolla, & Lopez‐Huertas, 2010; Raederstorff, 2009).…”

“…Kouka et al. (2017) isolated major active compounds in EVOO and investigated antioxidant activity by in vitro assay. The results revealed that EVOO polyphenolic compounds show strong antioxidant activity by increasing GSH levels and have significant effects on the ROS level.…”

The Importance of Redox Status in the Frame of Lifestyle Approaches and the Genetics of the Lung Innate Immune Molecules, SP-A1 and SP-A2, on Differential Outcomes of COVID-19 Infection

“…Several studies have shown that many foods rich in or enriched with polyphenols can have a positive effect on oxidative stress indicators in in vitro and in vivo studies. Studies in the EA.hy926 cell line have confirmed the antioxidant activity of polyphenolic grape and olive extracts by improving GSH levels [ 52 , 53 , 54 , 55 ]. Additionally, studies in livestock such as pigs, hens, and sheep, have found that animal feed supplemented with antioxidants derived from olive oil mill wastes and wine bioproducts, improved the redox status in animals [ 56 , 57 , 58 , 59 ].…”