Evaluation of phenolic compounds and protective effects of olive (Olea europaea L.) leaf extracts on endothelial cells against hydrogen peroxide-induced toxicity

Torul, Hilal; Küçükboyacı, Nurgun; Tamer, Uğur; Karasu, Çi̇men

doi:10.35333/jrp.2020.198

Cited by 5 publications

(5 citation statements)

References 25 publications

(26 reference statements)

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“…As shown in ( Figure 5 ), the HT, DHPG extracts, and their mixture did not show any growth inhibition effects in human cells in a dose-dependent way. The capacity of HT to protect healthy cells has been reported in other studies where it was observed that HT presented a viability of more than 60%, even when they had undergone previous oxidation with H 2 O 2 [ 29 ]. In fact, the anti-proliferative capacity of HT has been reported in other unhealthy cell lines such as HeLa and DG75 [ 30 ], which was very promising in the fight against neurodegenerative diseases.…”

Section: Resultsmentioning

confidence: 83%

Anti-Inflammatory and Antioxidant Activity of Hydroxytyrosol and 3,4-Dihydroxyphenyglycol Purified from Table Olive Effluents

Fernández-Prior

Bermúdez-Oria

Millán-Linares

et al. 2021

Foods

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New liquid effluents based on the use of acetic acid in the table olive industry make it easier to extract bioactive compounds to be used for food, cosmetic, and pharmaceutical purposes. The use of water acidified with acetic acid or in brine with or without acetic acid for storing the table olive enhances the extraction of two more active phenolic compounds: hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG). This work has two aims: (1) measure the solubilization of phenolics controlled for two years using more than thirty olive varieties with different ripeness index as a potential source of HT and DHPG, and (2) evaluate the anti-inflammatory activity of the purified phenolics. The effluents with a higher concentration of phenolics were used for the extraction of HT and DHPG in order to evaluate its antioxidant and anti-inflammatory activity in vitro by the determination of pro-inflammatory cytokines such as Human Tumor Necrosis Factor-α (TNF), Interleukin-6 (IL-6), and Interleukin-1β (Il-1β). The anti-inflammatory activity of these phenolic extracts was demonstrated by studying the expression of cytokines by qPCR and the levels of these proteins by enzyme-linked immunosorbent assay (ELISA).

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Section: Resultsmentioning

confidence: 83%

Anti-Inflammatory and Antioxidant Activity of Hydroxytyrosol and 3,4-Dihydroxyphenyglycol Purified from Table Olive Effluents

Fernández-Prior

Bermúdez-Oria

Millán-Linares

et al. 2021

Foods

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“…), the elimination of elevated superoxide levels, the reduction in increased NADPH oxidase activity, and the activation of antioxidant cell proteins such as SIRT1 and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) [ 25 , 104 , 105 , 106 ]. Moreover, olive leaf polyphenolic compounds oleuropein and hydroxytyrosol are efficient cytoprotective agents against H 2 O 2 -induced oxidative stress and toxicity in human umbilical vein endothelial cells [ 107 ].…”

Section: Anti-stroke Action Of Olive Polyphenolsmentioning

confidence: 99%

Neuroprotective Panel of Olive Polyphenols: Mechanisms of Action, Anti-Demyelination, and Anti-Stroke Properties

Kezele

Ćurko-Cofek

2022

Nutrients

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Neurological diseases such as stroke and multiple sclerosis are associated with high morbidity and mortality, long-term disability, and social and economic burden. Therefore, they represent a major challenge for medical treatment. Numerous evidences support the beneficial effects of polyphenols from olive trees, which can alleviate or even prevent demyelination, neurodegeneration, cerebrovascular diseases, and stroke. Polyphenols from olive oils, especially extra virgin olive oil, olive leaves, olive leaf extract, and from other olive tree derivatives, alleviate inflammation and oxidative stress, two major factors in demyelination. In addition, they reduce the risk of stroke due to their multiple anti-stroke effects, such as anti-atherosclerotic, antihypertensive, antioxidant, anti-inflammatory, hypocholesterolemic, hypoglycemic, and anti-thrombotic effects. In addition, olive polyphenols have beneficial effects on the plasma lipid profiles and insulin sensitivity in obese individuals. This review provides an updated version of the beneficial properties and mechanisms of action of olive polyphenols against demyelination in the prevention/mitigation of multiple sclerosis, the most common non-traumatic neurological cause of impairment in younger adults, and against cerebral insult with increasing incidence, that has already reached epidemic proportions.

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“…The molecular action of HT downregulates NFκB pathway which improves NO production. HT also promote cellular survival from ROS induction (Torul et al, 2020). These series of evidence, allow us to proposed HT that could promote reendothelization in the site of endothelial injury.…”

Section: Discussionmentioning

confidence: 88%

“…In addition to that, HT also protect cells from H 2 O 2 induced cytotoxicity and apoptosis by decreasing superoxide release (Nakbi et al, 2011;Torul et al, 2020) while activating JNK and p38 MAPKs pathways (Kitsati et al, 2016). Interestingly, a particular study by Zrelli found that HT activate the AMPK-FOXO3 pathway by enhancing catalase activity to reduce oxidative stress (Zrelli et al, 2011b).…”

Section: Ht Role As An Antioxidantmentioning

confidence: 97%

“…These findings strongly support the correlation between oxidation machinery and the prevention of IH. From our database search, 9 studies reported that HT efficiently prevented ROS production (Nakbi et al, 2011;Zrelli et al, 2011a;Zrelli et al, 2011b;Scoditti et al, 2012;Zrelli et al, 2013;Kouka et al, 2017;Torul et al, 2020). HT was also reported to be able to phosphorylate endothelial nitric oxide synthase (eNOS) which increases nitric oxide (NO) synthesis that essentially needed for vascular integrity and protection (Tousoulis et al, 2011;Zhao et al, 2015;Loscalzo and Jin, 2010).…”

Section: Ht Role As An Antioxidantmentioning

confidence: 99%

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Molecular Action of Hydroxytyrosol in Attenuation of Intimal Hyperplasia: A Scoping Review

et al. 2021

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Objective: Hydroxytyrosol (HT), a polyphenol of olive plant is well known for its antioxidant, anti-inflammatory and anti-atherogenic properties. The aim of this systematic search is to highlight the scientific evidence evaluating molecular efficiency of HT in halting the progression of intimal hyperplasia (IH), which is a clinical condition arises from endothelial inflammation.Methods: A systematic search was performed through PubMed, Web of Science and Scopus, based on pre-set keywords which are Hydroxytyrosol OR 3,4-dihydroxyphenylethanol, AND Intimal hyperplasia OR Neointimal hyperplasia OR Endothelial OR Smooth muscles. Eighteen in vitro and three in vitro and in vivo studies were selected based on a pre-set inclusion and exclusion criteria.Results: Based on evidence gathered, HT was found to upregulate PI3K/AKT/mTOR pathways and supresses inflammatory factors and mediators such as IL-1β, IL-6, E-selectin, P-selectin, VCAM-1, and ICAM-1 in endothelial vascularization and functioning. Two studies revealed HT disrupted vascular smooth muscle cells (SMC) cell cycle by dephosphorylating ERK1/2 and AKT pathways. Therefore, HT was proven to promote endothelization and inhibit vascular SMCs migration thus hampering IH development. However, none of these studies described the effect of HT collectively in both vascular endothelial cells (EC) and SMCs in IH ex vivo model.Conclusions: Evidence from this concise review provides an insight on HT regulation of molecular pathways in reendothelization and inhibition of VSMCs migration. Henceforth, we propose effect of HT on IH prevention could be further elucidated through in vivo and ex vivo model.

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Evaluation of phenolic compounds and protective effects of olive (Olea europaea L.) leaf extracts on endothelial cells against hydrogen peroxide-induced toxicity

Abstract: How to cite this article: Torul H, Küçükboyacı N, Tamer U, Karasu Ç. Evaluation of phenolic compounds and protective effects of olive (Olea europaea L.) leaf extracts on endothelial cells against hydrogen peroxide-induced toxicity.

Cited by 5 publications

References 25 publications

Anti-Inflammatory and Antioxidant Activity of Hydroxytyrosol and 3,4-Dihydroxyphenyglycol Purified from Table Olive Effluents

Anti-Inflammatory and Antioxidant Activity of Hydroxytyrosol and 3,4-Dihydroxyphenyglycol Purified from Table Olive Effluents

Neuroprotective Panel of Olive Polyphenols: Mechanisms of Action, Anti-Demyelination, and Anti-Stroke Properties

Molecular Action of Hydroxytyrosol in Attenuation of Intimal Hyperplasia: A Scoping Review

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