Hydroxytyrosol Ameliorates Endothelial Function under Inflammatory Conditions by Preventing Mitochondrial Dysfunction

Hydroxytyrosol: A Promising Therapeutic Agent for Mitigating Inflammation and Apoptosis

Inflammation and apoptosis are interrelated biological processes that have a significant impact on the advancement and growth of certain chronic diseases, such as cardiovascular problems, neurological conditions, and osteoarthritis. Recent research has emphasized that focusing on these mechanisms could result in novel therapeutic approaches that aim to decrease the severity of diseases and enhance patient outcomes. Hydroxytyrosol (HT), which is well-known for its ability to prevent oxidation, has been identified as a possible candidate for regulating both inflammation and apoptosis. In this review, we will highlight the multifaceted benefits of HT as a therapeutic agent in mitigating inflammation, apoptosis, and associated conditions. This review provides a comprehensive overview of the latest in vitro and in vivo research on the anti-inflammatory and antiapoptotic effects of HT and the mechanisms by which it works. Based on these studies, it is strongly advised to use HT as a bioactive ingredient in pharmaceutical products intended for mitigating inflammation, as well as those with apoptosis applications.

Olea europaea L. Leaf Extract Alleviates Fibrosis Progression and Oxidative Stress Induced by Bleomycin on a Murine Model of Lung Fibrosis

In this study, we aim to investigate the effect of industrial Olea europaea L. leaf extract (OLE) against bleomycin (BLM)-induced pulmonary fibrosis (PF) in rats. Male Wistar rats were treated with a single intratracheal injection of BLM (4 mg/kg) and a daily intraperitoneal injection of OLE (10, 20, and 40 mg/kg) for 4 weeks. Results of HPLC and LC-MS analysis revealed a large amount of oleuropein (15.43%/DW) in OLE. BLM induced apparent damage of lung architecture with condensed collagen bundles, increased lipid peroxidation which has been deduced from malondialdehyde (MDA) levels: (.9 ± .13 vs .25 ± .12 nmol/mg protein) and hydroxyproline content (.601 ± .22 vs .154 ± .139 mg/g of lung tissue) and decreased catalase (CAT) (5.93.10-5 ± 4.23.10-5 vs 6.41.10-4 ± 2.33.10-4 μmol/min/mg protein) and superoxide dismutase (SOD) (28.73 ± 3.34 vs 50.13 ± 2.1 USOD/min/mg protein) levels compared to the control. OLE treatment (40 mg/kg) stabilized MDA content (.32 ± .15 and .27 ± .13 vs .9 ± .13 nmol/mg protein), normalized SOD (61.27 ± 13.37 vs 28.73 ± 3.34 USOD/min/mg protein), and CAT (5.2.10-4 ±1.8.10-4 vs 5.93.10-5 ± 4.23.10-5 μmol/min/mg protein) activities and counteracted collagen accumulation and hydroxyproline content (.222 ± .07 vs .601 ± .22 mg/g of lung tissue) in the lung parenchyma. Finally, OLE might have a potent protective effect against PF by regulating oxidative parameters and attenuating collagen deposition, due to the existence of large amount of bioactive phenolic molecules.

Effects of Hydroxytyrosol in Endothelial Functioning: A Comprehensive Review

Pharmacologists have been emphasizing and applying plant and herbal-based treatments in vascular diseases for decades now. Olives, for example, are a traditional symbol of the Mediterranean diet. Hydroxytyrosol is an olive-derived compound known for its antioxidant and cardioprotective effects. Acknowledging the merit of antioxidants in maintaining endothelial function warrants the application of hydroxytyrosol in endothelial dysfunction salvage and recovery. Endothelial dysfunction (ED) is an impairment of endothelial cells that adversely affects vascular homeostasis. Disturbance in endothelial functioning is a known precursor for atherosclerosis and, subsequently, coronary and peripheral artery disease. However, the effects of hydroxytyrosol on endothelial functioning were not extensively studied, limiting its value either as a nutraceutical supplement or in clinical trials. The action of hydroxytyrosol in endothelial functioning at a cellular and molecular level is gathered and summarized in this review. The favorable effects of hydroxytyrosol in the improvement of endothelial functioning from in vitro and in vivo studies were scrutinized. We conclude that hydroxytyrosol is capable to counteract oxidative stress, inflammation, vascular aging, and arterial stiffness; thus, it is beneficial to preserve endothelial function both in vitro and in vivo. Although not specifically for endothelial dysfunction, hydroxytyrosol safety and efficacy had been demonstrated via in vivo and clinical trials for cardiovascular-related studies.

Protective Effect of Treated Olive Mill Wastewater on Target Bacteria and Mitochondrial Voltage-Dependent Anion-Selective Channel 1

Olive mill wastewater, a by-product of the olive oil industry, represents an important resource, rich in bioactive compounds with antioxidant activity. In this study, two strategies to concentrate the bioactive components were used: the tangential membrane filtration (ultrafiltration and reverse osmosis) and the selective resin extraction. The concentrates were evaluated for physico-chemical characteristics and antioxidant activity. Furthermore, the antimicrobial activity and the effect on the mitochondrial voltage-dependent anion selective channel 1 were evaluated. The chemical results highlighted that the highest concentration of hydroxytyrosol (as 7204 mg/L) was revealed in the sample obtained by inverse osmosis while the highest concentration of oleuropein (10005 mg/L) was detected in the sample obtained by resin extraction. The latter sample exhibited the highest antimicrobial effects against Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Both samples exhibited a high impact on the electrophysiological parameters of VDAC1 activity. These results showed that both valorization techniques, which can be reproduced at industrial scale, provided phenolic concentrates with antioxidant and antimicrobial activity useful for different future perspectives.

Hydroxytyrosol Reduces Foam Cell Formation and Endothelial Inflammation Regulating the PPARγ/LXRα/ABCA1 Pathway

Cholesterol accumulation in macrophages leads to the formation of foam cells and increases the risk of developing atherosclerosis. We have verified whether hydroxytyrosol (HT), a phenolic compound with anti-inflammatory and antioxidant properties, can reduce the cholesterol build up in THP-1 macrophage-derived foam cells. We have also investigated the potential mechanisms. Oil Red O staining and high-performance liquid chromatography (HPLC) assays were utilized to detect cellular lipid accumulation and cholesterol content, respectively, in THP-1 macrophages foam cells treated with HT. The impact of HT on cholesterol metabolism-related molecules (SR-A1, CD36, LOX-1, ABCA1, ABCG1, PPARγ and LRX-α) in foam cells was assessed using real-time PCR (RT-qPCR) and Western blot analyses. Finally, the effect of HT on the adhesion of THP-1 monocytes to human vascular endothelial cells (HUVEC) was analyzed to study endothelial activation. We found that HT activates the PPARγ/LXRα pathway to upregulate ABCA1 expression, reducing cholesterol accumulation in foam cells. Moreover, HT significantly inhibited monocyte adhesion and reduced the levels of adhesion factors (ICAM-1 and VCAM-1) and pro-inflammatory factors (IL-6 and TNF-α) in LPS-induced endothelial cells. Taken together, our findings suggest that HT, with its ability to interfere with the import and export of cholesterol, could represent a new therapeutic strategy for the treatment of atherosclerotic disease.

Hydroxytyrosol: Its role in the prevention of cardiovascular diseases

In recent years, non-pharmacology treatments and their effectiveness have gained popularity due to their beneficial properties in the prevention of cardiovascular diseases. Phenolic compounds intake provides a natural means of improving in vivo antioxidant status. Thus, the purpose of this review is to discuss the potential benefits of hydroxytyrosol (HT), a phenolic compound with powerful antioxidant and anti-inflammatory properties, in preventing and reducing cardiovascular risk factors, concretely atherosclerosis. Closer inspection of the studies showed a significant improvement of lipid profile, antioxidant capacity and inflammatory state. A note of caution is due in vitro studies because the lack of validated approaches difficult the goodness of fit with the in vivo and clinical research. However, animal and clinical studies were very encouraging, determining HT supplementation useful on inflammation, oxidative stress, endothelial function and cardiovascular diseases in general.

Use of CGF in Oral and Implant Surgery: From Laboratory Evidence to Clinical Evaluation

Edentulism is the condition of having lost natural teeth, and has serious social, psychological, and emotional consequences. The need for implant services in edentulous patients has dramatically increased during the last decades. In this study, the effects of concentrated growth factor (CGF), an autologous blood-derived biomaterial, in improving the process of osseointegration of dental implants have been evaluated. Here, permeation of dental implants with CGF has been obtained by using a Round up device. These CGF-coated dental implants retained a complex internal structure capable of releasing growth factors (VEGF, TGF-β1, and BMP-2) and matrix metalloproteinases (MMP-2 and MMP-9) over time. The CGF-permeated implants induced the osteogenic differentiation of human bone marrow stem cells (hBMSC) as confirmed by matrix mineralization and the expression of osteogenic differentiation markers. Moreover, CGF provided dental implants with a biocompatible and biologically active surface that significantly improved adhesion of endothelial cells on CGF-coated implants compared to control implants (without CGF). Finally, data obtained from surgical interventions with CGF-permeated dental implants presented better results in terms of optimal osseointegration and reduced post-surgical complications. These data, taken together, highlight new and interesting perspectives in the use of CGF in the dental implantology field to improve osseointegration and promote the healing process.

Investigation on wound healing effect of Mediterranean medicinal plants and some related phenolic compounds: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The human skin constitutes a biological barrier against external stress and wounds can reduce the role of its physiological structure. In medical sciences, wounds are considered a major problem that requires urgent intervention. For centuries, medicinal plants have been used in the Mediterranean countries for many purposes and against wounds.

AIM OF THIS REVIEW

Provides an outlook on the Mediterranean medicinal plants used in wound healing. Furthermore, the wound healing effect of polyphenolic compounds and their chemical structures are also summarized. Moreover, we discussed the wound healing process, the structure of the skin, and the current therapies in wound healing.

MATERIALS AND METHODS

The search was performed in several databases such as ScienceDirect, PubMed, Google Scholar, Scopus, and Web of Science. The following Keywords were used individually and/or in combination: the Mediterranean, wound healing, medicinal plants, phenolic compounds, composition, flavonoid, tannin.

RESULTS

The wound healing process is distinguished by four phases, which are respectively, hemostasis, inflammation, proliferation, and remodeling. The Mediterranean medicinal plants are widely used in the treatment of wounds. The finding showed that eighty-nine species belonging to forty families were evaluated for their wound-healing effect in this area. The Asteraceae family was the most reported family with 12 species followed by Lamiaceae (11 species). Tunisia, Egypt, Morocco, and Algeria were the countries where these plants are frequently used in wound healing. In addition to medicinal plants, results showed that nineteen phenolic compounds from different classes are used in wound treatment. Tyrosol, hydroxytyrosol, curcumin, luteolin, chrysin, rutin, kaempferol, quercetin, icariin, morin, epigallocatechin gallate, taxifolin, silymarin, hesperidin, naringin, isoliquiritin, puerarin, genistein, and daidzein were the main compounds that showed wound-healing effect.

CONCLUSION

In conclusion, medicinal plants and polyphenolic compounds provide therapeutic evidence in wound healing and for the development of new drugs in this field.

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

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.

5-Heptadecylresorcinol Protects against Atherosclerosis in Apolipoprotein E-Deficient Mice by Modulating SIRT3 Signaling: The Possible Beneficial Effects of Whole Grain Consumption

SCOPE

Whole grain consumption has been proven to be inversely associated with the risk of cardiovascular diseases. As a biomarker for whole grain dietary intake, 5-heptadecylresorcinol (AR-C17) has attracted increased attention due to its potential health-improving activity. However, the beneficial effect of AR-C17 on atherosclerosis prevention and the underlying mechanism remain unclear.

METHODS AND RESULTS

High-fat diet fed apolipoprotein E-deficient (ApoE^-/- ) mice are administrated with or without AR-C17 (30 and 150 mg kg^-1 ) for 16 weeks. Histological staining is performed for plaque analysis. Immunofluorescence, western blot, and seahorse cell analysis are carried out to investigate the action of mechanism of AR-C17. The results indicate that AR-C17 supplementation lowered serum total cholesterol, triglyceride, VLDL-C, and LDL-C levels. Moreover, the atherosclerotic plaques in the aortic root region of mice heart are significantly reduced by AR-C17 intervention compared with ApoE^-/- control group. In addition, AR-C17 treatment alleviates endothelial cell damage and apoptosis by improving mitochondrial function via sirtuin3 signaling pathway both in ApoE^-/- mice and oxidized-LDL-treated human umbilical vein endothelial cells.

CONCLUSION

AR-C17 may be applied as a promising grain-based dietary bioactive ingredient for atherosclerosis prevention. Meanwhile, as a mitochondrial protective agent, it can offer support for the suggested health claim of whole grain diet.

Grape Pomace Extract Attenuates Inflammatory Response in Intestinal Epithelial and Endothelial Cells: Potential Health-Promoting Properties in Bowel Inflammation

Inflammatory bowel disease (IBD) implies the chronic inflammation of the gastrointestinal tract, combined with systemic vascular manifestations. In IBD, the incidence of cardiovascular disease appears to be related to an increase of oxidative stress and endothelial dysfunction. Grape pomace contains high levels of anti-oxidant polyphenols that are able to counteract chronic inflammatory symptoms. The aim of this study was to determine whether grape pomace polyphenolic extract (GPE) was able to mitigate the overwhelming inflammatory response in enterocyte-like cells and to improve vascular function. Intestinal epithelial Caco-2 cells, grown in monolayers or in co-culture with endothelial cells (Caco-2/HMEC-1), were treated with different concentrations of GPE (1, 5, 10 µg/mL gallic acid equivalents) for 2 h and then stimulated with lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α for 16 h. Through multiple assays, the expression of intestinal and endothelial inflammatory mediators, intracellular reactive oxygen species (ROS) levels and NF-κB activation, as well as endothelial-leukocyte adhesion, were evaluated. The results showed that GPE supplementation prevented, in a concentration-dependent manner, the intestinal expression and release of interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, and matrix metalloproteinases (MMP)-9 and MMP-2. In Caco-2 cells, GPE also suppressed the gene expression of several pro-inflammatory markers, such as IL-1β, TNF-α, macrophage colony-stimulating factor (M-CSF), C-X-C motif ligand (CXCL)-10, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and cyclooxygenase (COX)-2. The GPE anti-inflammatory effect was mediated by the inhibition of NF-κB activity and reduced intracellular ROS levels. Furthermore, transepithelial GPE suppressed the endothelial expression of IL-6, MCP-1, VCAM-1, and ICAM-1 and the subsequent adhesion of leukocytes to the endothelial cells under pro-inflammatory conditions. In conclusion, our findings suggest grape pomace as a natural source of polyphenols with multiple health-promoting properties that could contribute to the mitigation of gut chronic inflammatory diseases and improve vascular endothelial function.

Nutrigenomic Effect of Hydroxytyrosol in Vascular Endothelial Cells: A Transcriptomic Profile Analysis

Hydroxytyrosol (HT), a peculiar olive and olive oil phenolic antioxidant, plays a significant role in the endothelial and cardiovascular protection associated with olive oil consumption. However, studies examining the effects of HT on the whole-genome expression of endothelial cells, which are prominent targets for vasculo-protective effects of olive oil polyphenols, have been lacking. This study aims to comprehensively evaluate the genomic effects exerted by HT, at the transcriptional level, in endothelial cells under resting or proinflammatory conditions. Human umbilical vein endothelial cells (HUVECs) were treated with 10 µmol/L HT for 1 h and then stimulated with 5 ng/mL interleukin (IL)-1β for 3 h. Total RNA was extracted, and gene expression profile assessed with microarray analysis. Functional enrichment analysis and pathway analysis were performed by Ingenuity Pathways Analysis. Microarray data were validated by qRT-PCR. Fixing a significance threshold at 1.5-fold change, HT affected the expression of 708 and 599 genes, respectively, in HUVECs under resting and IL-1β-stimulated conditions; among these, 190 were common to both conditions. Unfolded protein response (UPR) and endoplasmic reticulum stress resulted from the two top canonical pathways common between HT and HT-IL-1β affected genes. IL-17F/A signaling was found in the top canonical pathways of HT modified genes under resting unstimulated conditions, whereas cardiac hypertrophy signaling was identified among the pathways affected by HT-IL-1β. The transcriptomic analysis allowed pinpointing immunological, inflammatory, proliferative, and metabolic-related pathways as the most affected by HT in endothelial cells. It also revealed previously unsuspected genes and related gene pathways affected by HT, thus broadening our knowledge of its biological properties. The unbiased identification of novel genes regulated by HT improves our understanding of mechanisms by which olive oil prevents or attenuates inflammatory diseases and identifies new genes to be enquired as potential contributors to the inter-individual variation in response to functional food consumption.

Potential Effects of Phenolic Compounds That Can Be Found in Olive Oil on Wound Healing

The treatment of tissue damage produced by physical, chemical, or mechanical agents involves considerable direct and indirect costs to health care systems. Wound healing involves a series of molecular and cellular events aimed at repairing the defect in tissue integrity. These events can be favored by various natural agents, including the polyphenols in extra virgin olive oil (EVOO). The objective of this study was to review data on the potential effects of different phenolic compounds that can also be found in EVOO on wound healing and closure. Results of in vitro and animal studies demonstrate that polyphenols from different plant species, also present in EVOO, participate in different aspects of wound healing, accelerating this process through their anti-inflammatory, antioxidant, and antimicrobial properties and their stimulation of angiogenic activities required for granulation tissue formation and wound re-epithelialization. These results indicate the potential usefulness of EVOO phenolic compounds for wound treatment, either alone or in combination with other therapies. Human studies are warranted to verify this proposition.

Targeting Mitochondrial Biogenesis with Polyphenol Compounds

Appropriate mitochondrial physiology is an essential for health and survival. Cells have developed unique mechanisms to adapt to stress circumstances and changes in metabolic demands, by meditating mitochondrial function and number. In this context, sufficient mitochondrial biogenesis is necessary for efficient cell function and haemostasis, which is dependent on the regulation of ATP generation and maintenance of mitochondrial DNA (mtDNA). These procedures play a primary role in the processes of inflammation, aging, cancer, metabolic diseases, and neurodegeneration. Polyphenols have been considered as the main components of plants, fruits, and natural extracts with proven therapeutic effects during the time. These components regulate the intracellular pathways of mitochondrial biogenesis. Therefore, the current review is aimed at representing an updated review which determines the effects of different natural polyphenol compounds from various plant kingdoms on modulating signaling pathways of mitochondrial biogenesis that could be a promising alternative for the treatment of several disorders.

Anti-Inflammatory Activity of AF-13, an Antioxidant Compound Isolated from the Polar Fraction of Allomyrina dichotoma Larva, in Palmitate-Induced INS-1 Cells

This study was conducted to evaluate the fractions isolated from Allomyrina dichotoma larva extract (ADLE) that exhibited anti-apoptotic and anti-inflammatory effects. A total of 13 fractions were eluted from ADLE by centrifugal chromatography (CPC), and the polar AF-13 fraction was selected, which exerted a relatively protective effect against fat-induced toxicity in INS-1 cells. AF-13 treatment of palmitate-treated INS-1 cells decreased the expression level of apoptosis-related proteins and DNA fragmentation. AF-13 also significantly inhibited the production of nitric oxide and reactive oxygen species and the triglyceride content induced by palmitate, and the effect was found to be similar to that with ADLE treatment. Palmitate upregulated the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) through the activation of NF-κB p65; however, this effect was significantly attenuated by AF-13 treatment. In conclusion, AF-13 is one of the major components of ADLE responsible for anti-apoptotic and anti-inflammatory activities.

Angiogenic Properties of Concentrated Growth Factors (CGFs): The Role of Soluble Factors and Cellular Components

Blood-derived concentrated growth factors (CGFs) represent a novel autologous biomaterial with promising applications in regenerative medicine. Angiogenesis is a key factor in tissue regeneration, but the role played by CGFs in vessel formation is not clear. The purpose of this study was to characterize the angiogenic properties of CGFs by evaluating the effects of its soluble factors and cellular components on the neovascularization in an in vitro model of angiogenesis. CGF clots were cultured for 14 days in cell culture medium; after that, CGF-conditioned medium (CGF-CM) was collected, and soluble factors and cellular components were separated and characterized. CGF-soluble factors, such as growth factors (VEGF and TGF-β1) and matrix metalloproteinases (MMP-2 and -9), were assessed by ELISA. Angiogenic properties of CGF-soluble factors were analyzed by stimulating human cultured endothelial cells with increasing concentrations (1%, 5%, 10%, or 20%) of CGF-CM, and their effect on cell migration and tubule-like formation was assessed by wound healing and Matrigel assay, respectively. The expression of endothelial angiogenic mediators was determined using qRT-PCR and ELISA assays. CGF-derived cells were characterized by immunostaining, qRT-PCR and Matrigel assay. We found that CGF-CM, consisting of essential pro-angiogenic factors, such as VEGF, TGF-β1, MMP-9, and MMP-2, promoted endothelial cell migration; tubule structure formation; and endothelial expression of multiple angiogenic mediators, including growth factors, chemokines, and metalloproteinases. Moreover, we discovered that CGF-derived cells exhibited features such as endothelial progenitor cells, since they expressed the CD34 stem cell marker and endothelial markers and participated in the neo-angiogenic process. In conclusion, our results suggest that CGFs are able to promote endothelial angiogenesis through their soluble and cellular components and that CGFs can be used as a biomaterial for therapeutic vasculogenesis in the field of tissue regeneration.

Impact of hydroxytyrosol on stroke: tracking therapy response on neuroinflammation and cerebrovascular parameters using PET-MR imaging and on functional outcomes

Immune cells have been implicated in influencing stroke outcomes depending on their temporal dynamics, number, and spatial distribution after ischemia. Depending on their activation status, immune cells can have detrimental and beneficial properties on tissue outcome after stroke, highlighting the need to modulate inflammation towards beneficial and restorative immune responses. Novel dietary therapies may promote modulation of pro- and anti-inflammatory immune cell functions. Among the dietary interventions inspired by the Mediterranean diet, hydroxytyrosol (HT), the main phenolic component of the extra virgin olive oil (EVOO), has been suggested to have antioxidant and anti-inflammatory properties in vitro. However, immunomodulatory effects of HT have not yet been studied in vivo after stroke. The aim of this project is therefore to monitor the therapeutic effect of a HT-enriched diet in an experimental stroke model using non-invasive in vivo multimodal imaging, behavioural phenotyping and cross-correlation with ex vivo parameters. Methods: A total of N = 22 male C57BL/6 mice were fed with either a standard chow (n = 11) or a HT enriched diet (n = 11) for 35 days, following a 30 min transient middle cerebral artery occlusion (tMCAo). T₂-weighted (lesion) and perfusion (cerebral blood flow)-/diffusion (cellular density)-weighted MR images were acquired at days 1, 3, 7, 14, 21 and 30 post ischemia. [¹⁸F]DPA-714 (TSPO, neuroinflammation marker) PET-CT scans were acquired at days 7, 14, 21 and 30 post ischemia. Infarct volume (mm³), cerebral blood flow (mL/100g/min), apparent diffusion coefficient (10^-4·mm²/s) and percentage of injected tracer dose (%ID/mL) were assessed. Behavioural tests (grip test, rotarod, open field, pole test) were performed prior and after ischemia to access therapy effects on sensorimotor functions. Ex vivo analyses (IHC, IF, WB) were performed to quantify TSPO expression, immune cells including microglia/macrophages (Iba-1, F4/80), astrocytes (GFAP) and peripheral markers in serum such as thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) 35 days post ischemia. Additionally, gene expression of pro- and anti-inflammatory markers were assessed by rt-qPCR, including tspo, cd163, arg1, tnf and Il-1β. Results: No treatment effect was observed on temporal [¹⁸F]DPA-714 uptake within the ischemic and contralateral region (two-way RM ANOVA, p = 0.71). Quantification of the percentage of TSPO⁺ area by immunoreactivity indicated a slight 2-fold increase in TSPO expression within the infarct region in HT-fed mice at day 35 post ischemia (p = 0.011) correlating with a 2-3 fold increase in Iba-1⁺ cell population expressing CD163 as anti-inflammatory marker (R² = 0.80). Most of the GFAP⁺ cells were TSPO^-. Only few F4/80⁺ cells were observed at day 35 post ischemia in both groups. No significant treatment effect was observed on global ADC and CBF within the infarct and the contralateral region over time. Behavioural tests indicated improved strength of the forepaws at day 14 post ischemia (p = 0.031). Conclusion: An HT-enriched diet significantly increased the number of Iba-1⁺ microglia/macrophages in the post-ischemic area, inducing higher expression of anti-inflammatory markers while no clear-cut effect was observed. Also, HT did not affect recovery of the cerebrovascular parameters, including ADC and CBF. Altogether, our data indicated that a prolonged dietary intervention with HT, as a single component of the Mediterranean diet, induces molecular changes that may improve stroke outcomes. Therefore, we support the use of the Mediterranean diet as a multicomponent therapy approach after stroke.

Hydroxytyrosol enhances cisplatin-induced ototoxicity: Possible relation to the alteration in the activity of JNK and AIF pathways

Hydroxytyrosol (HT), a polyphenol widely contained as an ester in olive fruits and olive leaves, exhibits a broad spectrum of effectiveness. The present study was designed to investigate the effect of HT alone as well as in the combination with cisplatin on the House Ear Institute-Organ of Corti 1 cells (HEI-OC1) and C57BL/6 cochlear hair cells in vitro. The cell viability was measured by cell counting kit-8 (CCK8) assay. The levels of reactive oxygen species were evaluated by Dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining. The expression of phosphorylated Jun N-terminal kinase (p-JNK) and cleaved-caspase 3 was assessed by Western blotting. The apoptosis was detected by terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) staining. The distribution of apoptosis inducing factor (AIF) was determined by immunofluorescent staining. HT alleviated the levels of reactive oxygen species in both untreated state and after cisplatin stimulus. However, HT at concentration of 100 μM decreased the cell viability of HEI-OC1 from 100 ± 17.38% in control group to 50.17 ± 1.89% and increased the expression of p-JNK and c-caspase 3 from 0.62 ± 0.10, 0.20 ± 0.050 in the control group to 1.24 ± 0.18, 0.85 ± 0.18 in the group treated with 30 μM cisplatin, as well as to 1.64 ± 0.14, 1.44 ± 0.12 in the group with 30 μM cisplatin +100 μM HT, respectively. Meanwhile, HT triggered AIF transferring to nuclei and, also, led to cochlear HCs arranging disorderly and missing. Moreover, HT elevated the expression of p-JNK and c-caspase 3 from 1.00 ± 0.27, 1.00 ± 0.26 in the control group to 2.23 ± 0.24, 22.87 ± 3.80 in the group with 30 μM cisplatin, and to 2.75 ± 0.23, 31.56 ± 3.86 in the group with 30 μM cisplatin+100 μM HT correspondingly. Taken together, data from this work reveal that HT itself possesses toxic effect on HCs mainly thorough AIF-dependent apoptosis, while, it aggravates the ototoxicity-caused by cisplatin via both JNK and AIF pathways related apoptosis. Findings from this work offer clear evidence that that HT might not be recommended to utilize for preventing cisplatin-induced ototoxicity.

Hydroxytyrosol improves mitochondrial energetics of a cellular model of Alzheimer's disease

Mitochondrial energetic deficit is one of the hallmarks of neurodegenerative disorders, e.g. Alzheimer´s disease (AD). Adherence to a Mediterranean diet is associated with lower incidence of cognitive decline and AD and extra virgin olive oil's (poly)phenols such as oleuropein and hydroxytyrosol (HT) are being actively studied in this respect. In this study, we assessed the effects of HT on mitochondrial energetic dysfunction in the 7PA2 cells cellular model, i.e. one of the best cellular models of Aβ toxicity with a well-characterized mitochondrial dysfunction typically observed in AD. We report an increase of new mitochondria at 8 h post HT-treatment, which was followed by higher mitochondrial fusion. Further, ATP concentrations were significantly increased after 24 h of treatment with HT as compared with controls. Our data suggest that HT may revert the energetic deficit of a cellular model of AD by potentiating mitochondrial activity. Because HT is being proposed as dietary supplement or component of functional foods, future studies in appropriate animal models and - eventually - humans are warranted to further investigate its potential neuroprotective actions in AD.

Molecular Action of Hydroxytyrosol in Wound Healing: An In Vitro Evidence-Based Review

Hydroxytyrosol (HT) is an essential molecule isolated from the phenolic fraction of olive (Olea europaea). HT has been implicated for its health-stimulating effect mainly due to its antioxidative capacity. The current review summarises and discusses the available evidence, related to HT activities in wound healing enhancement. The literature search of related articles published within the year 2010 to 2020 was conducted using Medline via Ebscohost, Scopus, and Google Scholar databases. Studies were limited to in vitro research regarding the role of HT in wound closure, including anti-inflammation, antimicrobial, antioxidative, and its direct effect to the cells involved in wound healing. The literature search revealed 7136 potentially relevant records were obtained from the database search. Through the screening process, 13 relevant in vitro studies investigating the role of HT in wound repair were included. The included studies reported a proangiogenic, antioxidative, antiaging, anti-inflammatory and antimicrobial effect of HT. The current in vitro evidence-based review highlights the cellular and molecular action of HT in influencing positive outcomes toward wound healing. Based on this evidence, HT is a highly recommended bioactive compound to be used as a pharmaceutical product for wound care applications.

Dihydromyricetin Improves Endothelial Dysfunction in Diabetic Mice via Oxidative Stress Inhibition in a SIRT3-Dependent Manner

Dihydromyricetin (DHY), a flavonoid component isolated from Ampelopsis grossedentata, exerts versatile pharmacological activities. However, the possible effects of DHY on diabetic vascular endothelial dysfunction have not yet been fully elucidated. In the present study, male C57BL/6 mice, wild type (WT) 129S1/SvImJ mice and sirtuin 3 (SIRT3) knockout (SIRT3^-/-) mice were injected with streptozotocin (STZ, 60 mg/kg/day) for 5 consecutive days. Two weeks later, DHY were given at the doses of 250 mg/kg by gavage once daily for 12 weeks. Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) level, endothelium-dependent relaxation of thoracic aorta, reactive oxygen species (ROS) production, SIRT3, and superoxide dismutase 2 (SOD2) protein expressions, as well as mitochondrial Deoxyribonucleic Acid (mtDNA) copy number, in thoracic aorta were detected. Our study found that DHY treatment decreased FBG and HbA1c level, improved endothelium-dependent relaxation of thoracic aorta, inhibited oxidative stress and ROS production, and enhanced SIRT3 and SOD2 protein expression, as well as mtDNA copy number, in thoracic aorta of diabetic mice. However, above protective effects of DHY were unavailable in SIRT3^-/- mice. The study suggested DHY improved endothelial dysfunction in diabetic mice via oxidative stress inhibition in a SIRT3-dependent manner.

Wide Biological Role of Hydroxytyrosol: Possible Therapeutic and Preventive Properties in Cardiovascular Diseases

The growing incidence of cardiovascular disease (CVD) has promoted investigations of natural molecules that could prevent and treat CVD. Among these, hydroxytyrosol, a polyphenolic compound of olive oil, is well known for its antioxidant, anti-inflammatory, and anti-atherogenic effects. Its strong antioxidant properties are due to the scavenging of radicals and the stimulation of synthesis and activity of antioxidant enzymes (SOD, CAT, HO-1, NOS, COX-2, GSH), which also limit the lipid peroxidation of low-density lipoprotein (LDL) cholesterol, a hallmark of atherosclerosis. Lowered inflammation and oxidative stress and an improved lipid profile were also demonstrated in healthy subjects as well as in metabolic syndrome patients after hydroxytyrosol (HT) supplementation. These results might open a new therapeutic scenario through personalized supplementation of HT in CVDs. This review is the first attempt to collect together scientific literature on HT in both in vitro and in vivo models, as well as in human clinical studies, describing its potential biological effects for cardiovascular health.

Hydroxytyrosol as a Promising Ally in the Treatment of Fibromyalgia

Fibromyalgia (FM) is a chronic and highly disabling syndrome, which is still underdiagnosed, with controversial treatment. Although its aetiology is unknown, a number of studies have pointed to the involvement of altered mitochondrial metabolism, increased oxidative stress and inflammation. The intake of extra virgin olive oil, and particularly of one of its phenolic compounds, hydroxytyrosol (HT), has proven to be protective in terms of redox homeostatic balance and the reduction of inflammation. In this context, using a proteomic approach with nanoscale liquid chromatography coupled to tandem mass spectrometry, the present study analysed: (i) Changes in the proteome of dermal fibroblasts from a patient with FM versus a healthy control, and (ii) the effect of the treatment with a nutritional relevant dose of HT. Our results unveiled that fibroblast from FM show a differential expression in proteins involved in the turnover of extracellular matrix and oxidative metabolism that could explain the inflammatory status of these patients. Moreover, a number of these proteins results normalized by the treatment with HT. In conclusion, our results support that an HT-enriched diet could be highly beneficial in the management of FM.

Maternal Supplementation of Inositols, Fucoxanthin, and Hydroxytyrosol in Pregnant Murine Models of Hypertension

BACKGROUND

Myoinositol (M) and D-chiro-inositol (D) are insulin sensitizer compounds, while fucoxanthin (F) and hydroxytyrosol (H) are antioxidant substances. We aim to investigate if the combination of these compounds, will improve the vascular responses in pregnant mouse models of hypertension: a genetic model, transgenic heterozygous mice lacking endothelial nitric oxide synthase gene (eNOS-/+); and environmental, wild-type (WT) mice. Those mouse models will allow a better understanding of the genetic/environmental contribution to hypertension in pregnancy.

METHODS

eNOS-/+ and WT female were fed high fat diet for 4 weeks, then at 7-8 weeks of age were mated with WT male. On gestational day (GD) 1, they were randomly allocated to receive MDFH treatment or water as control: eNOS-/+ MDFH (n = 13), eNOS-/+ (n = 13), WT-MDFH (n = 14), and WT (n = 20). Systolic blood pressure (SBP) was obtained at GD 18, then dams were sacrificed; fetuses and placentas collected, and 2 mm segments of carotid arteries isolated for vascular responses using the wire-myograph system. Responses to phenylephrine (PE), with/without the NOS inhibitor (N-nitro-l-arginine methyl ester (l-NAME)), and to acetylcholine (Ach) and sodium nitroprussiate (SNP) were performed.

RESULTS

SBP decreased in eNOS-/+ and WT dams after MDFH supplementation. In eNOS-/+, MDFH lower the contractile response to PE and l-NAME and improved Ach vasorelaxation. In WT dams, MDFH treatment did not affect PE response; MDFH treatment lowered the vascular PE response after incubation with l-NAME. No differences were seen in SNP relaxation in both models.

CONCLUSIONS

MDFH decreased SBP in both genetically and environmentally hypertensive dams and improved vascular responses mostly in the eNOS-/+ dams.

Polyphenols as Caloric Restriction Mimetics Regulating Mitochondrial Biogenesis and Mitophagy

The tight coordination between mitochondrial biogenesis and mitophagy can be dysregulated during aging, critically influencing whole-body metabolism, health, and lifespan. To date, caloric restriction (CR) appears to be the most effective intervention strategy to improve mitochondrial turnover in aging organisms. The development of pharmacological mimetics of CR has gained attention as an attractive and potentially feasible approach to mimic the CR phenotype. Polyphenols, ubiquitously present in fruits and vegetables, have emerged as well-tolerated CR mimetics that target mitochondrial turnover. Here, we discuss the molecular mechanisms that orchestrate mitochondrial biogenesis and mitophagy, and we summarize the current knowledge of how CR promotes mitochondrial maintenance and to what extent different polyphenols may mimic CR and coordinate mitochondrial biogenesis and clearance.

Effects of Olive Oil on Blood Pressure: Epidemiological, Clinical, and Mechanistic Evidence

The increasing access to antihypertensive medications has improved longevity and quality of life in hypertensive patients. Nevertheless, hypertension still remains a major risk factor for stroke and myocardial infarction, suggesting the need to implement management of pre- and hypertensive patients. In addition to antihypertensive medications, lifestyle changes, including healthier dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to favorably affect blood pressure and are now recommended as integrative tools in hypertension management. An analysis of the effects of nutritional components of the Mediterranean diet(s) on blood pressure has therefore become mandatory. After a literature review of the impact of Mediterranean diet(s) on cardiovascular risk factors, we here analyze the effects of olive oil and its major components on blood pressure in healthy and cardiovascular disease individuals and examine underlying mechanisms of action. Both experimental and human studies agree in showing anti-hypertensive effects of olive oil. We conclude that due to its high oleic acid and antioxidant polyphenol content, the consumption of olive oil may be advised as the optimal fat choice in the management protocols for hypertension in both healthy and cardiovascular disease patients.

Carotenoids Inhibit Fructose-Induced Inflammatory Response in Human Endothelial Cells and Monocytes

Objective

This research is aimed at determining the vascular health characteristics of carotenoids by evaluating their effect on excessive inflammatory response in endothelial and monocyte cells, the main factors of atherosclerosis.

Methods

Human umbilical vein endothelial cells (HUVECs) or U937 monocytes were treated with escalating concentrations (0.1, 0.5, and 1 μM) of five most common carotenoids in human plasma, i.e., α-carotene, β-carotene, β-cryptoxanthin, lutein, and lycopene prior to stimulation with 2 mM fructose. We examined the monocyte adhesion to endothelial cells (ECs) and relevant endothelial adhesion molecules. Chemokine and proinflammatory cytokine production as well as intracellular oxidative stress were also assessed in fructose-stimulated ECs and monocytes.

Results

Carotenoids repressed monocyte adhesion to fructose-stimulated ECs dose dependently via decreasing primarily the expression of endothelial VCAM-1. In ECs and monocytes, three carotenoids, i.e., β-cryptoxanthin, lutein, and lycopene, suppressed the fructose-induced expression of chemokines MCP-1, M-CSF, and CXCL-10 and inflammatory cytokines TNF-α and IL-1β, with CXCL-10 being the most repressed inflammatory mediator. β-Cryptoxanthin, lutein, and lycopene dramatically downregulated the fructose-induced CXCL-10 expression in vascular cells. The reduction in the inflammatory response was associated with a slight but significant decrease of intracellular oxidative stress.

Conclusions

Our results show that carotenoids have a variety of anti-inflammatory and antiatherosclerosis activities, which can help prevent or reduce fructose-induced inflammatory vascular diseases.

Is Extra Virgin Olive Oil an Ally for Women's and Men's Cardiovascular Health?

Noncommunicable diseases are long-lasting and slowly progressive and are the leading causes of death and disability. They include cardiovascular diseases (CVD) and diabetes mellitus (DM) that are rising worldwide, with CVD being the leading cause of death in developed countries. Thus, there is a need to find new preventive and therapeutic approaches. Polyphenols seem to have cardioprotective properties; among them, polyphenols and/or minor polar compounds of extra virgin olive oil (EVOO) are attracting special interest. In consideration of numerous sex differences present in CVD and DM, in this narrative review, we applied "gender glasses." Globally, it emerges that olive oil and its derivatives exert some anti-inflammatory and antioxidant effects, modulate glucose metabolism, and ameliorate endothelial dysfunction. However, as in prescription drugs, also in this case there is an important gender bias because the majority of the preclinical studies are performed on male animals, and the sex of donors of cells is not often known; thus a sex/gender bias characterizes preclinical research. There are numerous clinical studies that seem to suggest the benefits of EVOO and its derivatives in CVD; however, these studies have numerous limitations, presenting also a considerable heterogeneity across the interventions. Among limitations, one of the most relevant in the era of personalized medicine, is the non-attention versus women that are few and, also when they are enrolled, sex analysis is lacking. Therefore, in our opinion, it is time to perform more long, extensive and lessheterogeneous trials enrolling both women and men.

Stope M. Gas Plasma-Treated Prostate Cancer Cells Augment Myeloid Cell Activity and Cytotoxicity

Despite recent improvements in cancer treatment, with many of them being related to foster antitumor immunity, tumor-related deaths continue to be high. Novel avenues are needed to complement existing therapeutic strategies in oncology. Medical gas plasma technology recently gained attention due to its antitumor activity. Gas plasmas act via the local deposition of a plethora of reactive oxygen species (ROS) that promote the oxidative cancer cell death. The immunological consequences of plasma-mediated tumor cell death are only poorly understood, however. To this end, we exposed two prostate cancer cell lines (LNCaP, PC3) to gas plasma in vitro, and investigated the immunomodulatory effects of the supernatants in as well as of direct co-culturing with two human myeloid cell lines (THP-1, HL-60). After identifying the cytotoxic action of the kINPen plasma jet, the supernatants of plasma-treated prostate cancer cells modulated myeloid cell-related mitochondrial ROS production and their metabolic activity, proliferation, surface marker expression, and cytokine release. Direct co-culture amplified differentiation-like surface marker expression in myeloid cells and promoted their antitumor-toxicity in the gas plasma over the untreated control conditions. The results suggest that gas plasma-derived ROS not only promote prostate cancer cell death but also augment myeloid cell activity and cytotoxicity.

Purified oleocanthal and ligstroside protect against mitochondrial dysfunction in models of early Alzheimer's disease and brain ageing

As components of the Mediterranean diet (MedDiet) olive polyphenols may play a crucial role for the prevention of Alzheimer's disease (AD). Since mitochondrial dysfunction is involved in both, brain ageing and early AD, effects of 10 different purified phenolic secoiridoids (hydroxytyrosol, tyrosol, oleacein, oleuroside, oleuroside aglycon, oleuropein, oleocanthal, ligstroside, ligstroside aglycone and ligustaloside B) and two metabolites (the plant metabolite elenolic acid and the mammalian metabolite homovanillic acid) were tested in very low doses on mitochondrial function in SH-SY5Y-APP₆₉₅ cells - a cellular model of early AD. All tested secoiridoids significantly increased basal adenosine triphosphate (ATP) levels in SY5Y-APP₆₉₅ cells. Oleacein, oleuroside, oleocanthal and ligstroside showed the highest effect on ATP levels and were additionally tested on mitochondrial respiration. Only oleocanthal and ligstroside were able to enhance the capacity of respiratory chain complexes. To investigate their underlying molecular mechanisms, the expression of genes associated with mitochondrial biogenesis, respiration and antioxidative capacity (PGC-1α, SIRT1, CREB1, NRF1, TFAM, complex I, IV and V, GPx1, SOD2, CAT) were determined using qRT-PCR. Exclusively ligstroside increased mRNA expression of SIRT1, CREB1, complex I, and GPx1. Furthermore, oleocanthal but not ligstroside decreased Aβ 1-40 levels in SH-SY5Y-APP₆₉₅ cells. To investigate the in vivo effects of purified secoiridoids, the two most promising compounds (oleocanthal and ligstroside) were tested in a mouse model of ageing. Female NMRI mice, aged 12 months, received a diet supplemented with 50 mg/kg oleocanthal or ligstroside for 6 months (equivalent to 6.25 mg/kg b.w.). Young (3 months) and aged (18 months) mice served as controls. Ligstroside fed mice showed improved spatial working memory. Furthermore, ligstroside restored brain ATP levels in aged mice and led to a significant life extension compared to aged control animals. Our findings indicate that purified ligstroside has outstanding performance on mitochondrial bioenergetics in models of early AD and brain ageing by mechanisms that may not interfere with Aβ production. Additionally, ligstroside expanded the lifespan in aged mice and enhanced cognitive function.

Therapeutic prospects of hydroxytyrosol on experimentally induced diabetic testicular damage: potential interplay with AMPK expression

Male reproductive dysfunction represents one of the overlooked consequences of diabetes that still deserve more scientific attention. We designed this study to explore the therapeutic potential of hydroxytyrosol (HT) on diabetic testicular damage and to investigate its relationship with adenosine monophosphate-activated protein kinase (AMPK) expression. In this context, 30 adult male Wistar rats were utilized and subdivided into control, diabetic and HT-treated diabetic groups. Testicular sections were prepared for histopathological examination and immunohistochemical detection of 8-hydroxy-2'-deoxyguanosine, Sertoli cell vimentin, myoid cell α-SMA, androgen receptors and caspase-3. We also assessed oxidative enzymatic and lipid peroxidation biochemical profiles, sperm count, morphology and motility. Real-time PCR of AMPK expression in tissue homogenate was performed. We observed that HT restored testicular histopathological structure and significantly reduced oxidative DNA damage and the apoptotic index. The HT-treated group also exhibited significantly higher Sertoli cell vimentin, myoid cell α-SMA and androgen receptor immune expression than the diabetic group. A rescue of the oxidative enzymatic activity, lipid peroxidation profiles, sperm count, morphology and motility to control levels was also evident in the HT-treated group. Significant upregulation of AMPK mRNA expression in the HT-treated group clarified the role of AMPK as an underlying molecular interface of the ameliorative effects of HT. We concluded that HT exhibited tangible antioxidant and antiapoptotic impacts on the testicular cytomorphological and immunohistochemical effects of experimentally induced diabetes. Furthermore, AMPK has an impactful role in the molecular machinery of these effects.

Phenolic extracts from whole wheat biofortified bread dampen overwhelming inflammatory response in human endothelial cells and monocytes: major role of VCAM-1 and CXCL-10

PURPOSE

The aim of the study was to evaluate the vascular health properties of extracts from biofortified bread, obtained by adding different durum wheat milling by-products rich in phenolic compounds, by analyzing their effects on overwhelming inflammatory response in endothelial cells and monocytes, two main players of atherogenesis.

METHODS

Human umbilical vein endothelial cells or U937 monocytes were incubated with increasing concentrations (1, 5, 10 μg/mL) of biofortified bread polyphenol extracts or corresponding pure phenolic acids before stimulation with lipopolysaccharide (LPS). We analyzed the endothelial-monocyte adhesion and related endothelial adhesion molecules. The expression of chemokines and pro-inflammatory cytokines was also measured in LPS-stimulated endothelial cells and monocytes as well as intracellular oxidative stress.

RESULTS

Biofortified bread extracts inhibited monocyte adhesion to LPS-stimulated endothelial cells, in a concentration-dependent manner by reducing mainly endothelial VCAM-1 expression. Phenolic acid extracts contained in 10 mg biofortified bread downregulated the LPS-induced expression of chemokines MCP-1, M-CSF, and CXCL-10 as well as pro-inflammatory cytokines TNF-α and IL-1β, in endothelial cells and monocytes, with CXCL-10 as the most reduced inflammatory mediator. Among phenolic acids of biofortified bread, ferulic, sinapic, and p-coumaric acids significantly inhibited the LPS-stimulated CXCL-10 expression in vascular cells. The reduced pro-inflammatory response was related to a slightly but significant reduction of intracellular oxidative stress.

CONCLUSIONS

Our findings suggest the bread biofortified with selected durum wheat milling by-products as a source of phenolic acids with multiple anti-inflammatory and anti-atherosclerotic properties, which could help to counteract or prevent inflammatory vascular diseases.

The Nutraceutical Value of Olive Oil and Its Bioactive Constituents on the Cardiovascular System. Focusing on Main Strategies to Slow Down Its Quality Decay during Production and Storage

Cardiovascular diseases represent the principal cause of morbidity and mortality worldwide. It is well-known that oxidative stress and inflammatory processes are strongly implicated in their pathogenesis; therefore, anti-oxidant and anti-inflammatory agents can represent effective tools. In recent years a large number of scientific reports have pointed out the nutraceutical and nutritional value of extra virgin olive oils (EVOO), strongholds of the Mediterranean diet, endowed with a high nutritional quality and defined as functional foods. In regard to EVOO, it is a food composed of a major saponifiable fraction, represented by oleic acid, and a minor unsaponifiable fraction, including a high number of vitamins, polyphenols, and squalene. Several reports suggest that the beneficial effects of EVOO are linked to the minor components, but recently, further studies have shed light on the health effects of the fatty fraction and the other constituents of the unsaponifiable fraction. In the first part of this review, an analysis of the clinical and preclinical evidence of the cardiovascular beneficial effects of each constituent is carried out. The second part of this review is dedicated to the main operating conditions during production and/or storage that can directly influence the shelf life of olive oil in terms of both nutraceutical properties and sensory quality.

Mediterranean diet and health status: Active ingredients and pharmacological mechanisms

The Mediterranean diet (MedDiet) is one of the most widely described and evaluated dietary patterns in scientific literature. It is characterized by high intakes of vegetables, legumes, fruits, nuts, grains, fish, seafood, extra virgin olive oil, and a moderate intake of red wine. A large body of observational and experimental evidence suggests that higher adherence to the MedDiet is associated with lower risk of mortality, cardiovascular disease, metabolic disease, and cancer. Current mechanisms underlying the beneficial effects of the MedDiet include reduction of blood lipids, inflammatory and oxidative stress markers, improvement of insulin sensitivity, enhancement of endothelial function, and antithrombotic function. Most likely, these effects are attributable to bioactive ingredients such as polyphenols, monounsaturated and polyunsaturated fatty acids, or fibre. This review will focus on both established and less established mechanisms of action of biochemical compounds contained in a MedDiet. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Hydroxytyrosol, Tyrosol and Derivatives and Their Potential Effects on Human Health

The Mediterranean diet and olive oil as its quintessential part are almost synonymous with a healthy way of eating and living nowadays. This kind of diet has been highly appreciated and is widely recognized for being associated with many favorable effects, such as reduced incidence of different chronic diseases and prolonged longevity. Although olive oil polyphenols present a minor fraction in the composition of olive oil, they seem to be of great importance when it comes to the health benefits, and interest in their biological and potential therapeutic effects is huge. There is a growing body of in vitro and in vivo studies, as well as intervention-based clinical trials, revealing new aspects of already known and many new, previously unknown activities and health effects of these compounds. This review summarizes recent findings regarding biological activities, metabolism and bioavailability of the major olive oil phenolic compounds—hydroxytyrosol, tyrosol, oleuropein, oleocanthal and oleacein—the most important being their antiatherogenic, cardioprotective, anticancer, neuroprotective and endocrine effects. The evidence presented in the review concludes that these phenolic compounds have great pharmacological potential, however, further studies are still required.

The Use of Nutraceuticals to Counteract Atherosclerosis: The Role of the Notch Pathway

Despite the currently available pharmacotherapies, today, thirty percent of worldwide deaths are due to cardiovascular diseases (CVDs), whose primary cause is atherosclerosis, an inflammatory disorder characterized by the buildup of lipid deposits on the inside of arteries. Multiple cellular signaling pathways have been shown to be involved in the processes underlying atherosclerosis, and evidence has been accumulating for the crucial role of Notch receptors in regulating the functions of the diverse cell types involved in atherosclerosis onset and progression. Several classes of nutraceuticals have potential benefits for the prevention and treatment of atherosclerosis and CVDs, some of which could in part be due to their ability to modulate the Notch pathway. In this review, we summarize the current state of knowledge on the role of Notch in vascular health and its modulation by nutraceuticals for the prevention of atherosclerosis and/or treatment of related CVDs.

Secoiridoids of olive and derivatives as potential coadjuvant drugs in cancer: A critical analysis of experimental studies

Phenolic secoiridoids from olive, including oleocanthal, oleuropein and related derivatives, are bioactive natural products with documented anticancer activities, that have mainly been attributed to their antioxidant, anti-inflammatory and antiproliferative effects. This review summarizes the results of the preclinical studies on the natural secoiridoids of olive used as single agents or in combination with other chemotherapeutics against cancer cells. The molecular targets of their action are described. A critical analysis of the importance of the experimental studies in view of the possible use in humans is also discussed.

Effects of Polyphenols on Thermogenesis and Mitochondrial Biogenesis

Obesity is a health problem worldwide, and energy imbalance has been pointed out as one of the main factors responsible for its development. As mitochondria are a key element in energy homeostasis, the development of obesity has been strongly associated with mitochondrial imbalance. Polyphenols are the largest group of phytochemicals, widely distributed in the plant kingdom, abundant in fruits and vegetables, and have been classically described as antioxidants owing to their well-established ability to eliminate free radicals and reactive oxygen species (ROS). During the last decade, however, growing evidence reports the ability of polyphenols to perform several important biological activities in addition to their antioxidant activity. Special attention has been given to the ability of polyphenols to modulate mitochondrial processes. Thus, some polyphenols are now recognized as molecules capable of modulating pathways that regulate mitochondrial biogenesis, ATP synthesis, and thermogenesis, among others. The present review reports the main benefits of polyphenols in modulating mitochondrial processes that favor the regulation of energy expenditure and offer benefits in the management of obesity, especially thermogenesis and mitochondrial biogenesis.