Academic literature on the topic 'Olive Leaves Extract (OLE)'

(1) Background: Nowadays, the health-promoting properties of extra virgin olive oil (EVOO), including the antioxidant and anti-inflammatory actions, are well recognized and mainly attributed to the different polyphenols, such as oleocanthal and oleacein. In EVOO production, olive leaves represent a high value by-product, showing a wide spectrum of beneficial effects due to the presence of polyphenols, especially oleuropein. Here we report the study of olive leaf extract (OLE)-enriched EVOO extracts, obtained by adding different percentages of OLE to EVOO in order to ameliorate their nutraceutical activities. (2) Methods: The polyphenolic content of the EVOO/OLE extracts was analyzed by HPLC and the Folin-Ciocalteau assay. For further biological testing, an 8% OLE-enriched EVOO extract was chosen. Therefore, antioxidant effects were evaluated by three different methods (DPPH, ABTS, and FRAP), and the anti-inflammatory properties were assessed in terms of cyclooxygenase activity inhibition. (3) Results: The antioxidant and anti-inflammatory profiles of the new EVOO/OLE extract are significantly improved compared to those of EVOO extract; (4) Conclusions: The combination of OLE and EVOO extract can lead to an extract enriched in terms of bioactive polyphenols and endowed with better biological properties than the singular EVOO extract. Therefore, it may represent a new complement in the nutraceutical field.

The aim of this study was to evaluate fig (Ficus carica L.) leaves’ extract (FLE), olive (Olea europaea L.) leaves’ extract (OLE), and their mixture (MLE), to extend the shelf life of pasteurized milk. OLE, FLE, and their mixture MLE (1:1) were added to the pasteurized milk in different concentrations (0.2%, 0.4%, and 0.6%). Several tests were then conducted to determine the activity of these extracts. The antioxidant activity as IC50 was determined by using DPPH radical assay. FLE showed higher IC50 (30.21 µg/mL) compared to the IC50 of OLE (22.43 µg/mL). Phenolic compounds were identified by using high-performance liquid chromatography (HPLC). The highest antimicrobial activity was obtained with 0.6% concentration. Organoleptic properties indicated that the addition of these extracts did not affect the sensory properties of pasteurized milk. Pasteurized milk treated with 0.6% of FLE, OLE, and MLE has significantly decreased (p ≤ 0.05) lipase and protease activity during the storage period, at 5 °C. The results indicated that extending the shelf life of pasteurized milk from 5 to 16 days was successfully achieved through using 0.6% of FLE, OLE, and MLE. The combination of the two extracts (MLE) provides an efficient and safe method to prolong the shelf life of pasteurized milk, without altering the properties of pasteurized buffalo milk.

This research was done to investigate the effectiveness of the presence of olive leaf extract in vacuum packaging in maintaining the physicochemical properties of fresh-cut snake fruit under ambient temperature. The snake fruits were vacuum packaged in the presence of 3% (v/w) olive leave extract (OLE) and stored in room temperature for 8 days of storage. The physicochemical properties including color changes, firmness, and total dissolved solid (TDS) were observed. The results indicated that addition olive leaves extract in vacuum packaging gave the best result by inhibiting color changes by declining in total color difference by 10.88, BI 5.08, absorbance 2.750 Ǻ declining in hardness by 14.61% and lowest TDS level. As an alternative method of storing fresh-cut snake fruit under ambient conditions, vacuum packaging containing olive leave extract can be used.

Olive leaf extract (OLE), prepared from the fresh or dried leaves of Olea europaea L., is generating interest as a cardiovascular and metabolic disease risk modifier. Positive effects for the leaf extract and its key phytochemical constituents have been reported on blood pressure, respiratory infections, inflammation, and insulin resistance. A variety of OLE products are available both over-the-counter and for professional dispensing. The aim of this research was to quantitatively explore the phytochemical profile of different OLE products on the Australian market. Ten OLE products available on the Australian market (five over-the-counter products and five products for professional compounding and dispensing) were quantitatively analyzed for oleuropein, hydroxytyrosol, oleacein, oleocanthal, total biophenols, maslinic acid, and oleanolic acid, using high-performance liquid chromatography (HPLC). Substantial variation in oleuropein and hydroxytyrosol levels was noted between extracts, with a trend towards higher oleuropein and lower hydroxytyrosol levels being noted in products produced using the fresh olive leaf as opposed to dry olive leaf. These results suggest that OLE products on the Australian market vary substantially in their phytochemical profiles. Products for professional compounding and dispensing in many cases contained less oleuropein than over-the-counter products, but more hydroxytyrosol and comparable total biophenol levels.

Olive tree leaves have been widely used in traditional remedies in European and Mediterranean countries and in the human diet as extracts, herbal teas, and powder, which contain several potential bioactive compounds that may have antihypertensive, antiatherogenic, anti-inflammatory, hypoglycemic, hypocholesterolemic, antidiabetic and antioxidant activities. The present study was carried out to evaluate the role of olive leaves extracts (OLE) in ameliorating the metabolic changes in rats treated with carbon tetrachloride (CCl4). Forty-eight male rats were classified into six groups; the first group was the control which received 1 ml distilled water, the second group was treated daily with oral dose of cold OLE (1 ml/kg) for one month, the third group was treated daily with oral dose of boiled OLE (1 ml/kg) for one month, the fourth group was treated daily with oral dose of CCl4 (1 ml/kg) for one month, the fifth group was treated with both cold OLE and CCl4 (1 ml/kg for each) for one month and the sixth group was treated with both boiled OLE and CCl4 (1 ml/kg for each) for one month. Serum levels of thiobarbituric acid reactive substance (TBARS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), urea, creatinine, insulin and glutathione (GSH), catalase (CAT), albumin, total protein, free triiodothyronine (FT3) , free thyroxin (FT4) were measured in serum. Histological examination of hepatic tissue was examined. The results showed that administration of CCl4 to rats induced significant increase (P<0.05) in serum levels of thiobarbituric acid reactive substance (TBARS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma- glutamyl transferase (GGT), lactate dehydrogenase (LDH), urea, creatinine, insulin and significant decrease (P<0.05) in glutathione (GSH), catalase (CAT), albumin, total protein, free triiodothyronine (FT3) and free thyroxin (FT4). The histological examination of hepatic tissue showed some degenerative changes while significant improvement in biochemical and histological changes was observed either in CCl4 + cold OLE or CCl4 + boiled OLE groups. It could be concluded that the protective effect of olive leaves extract either cold or boiling may be attributed to its antioxidant properties. The obtained results indicated that both cold and boiled olive leaves extract has potent effect to restore the antioxidant status, hepato-renal function, insulin and thyroid hormones near to the control levels.

Leaves of Olea europaea are a by-product of the olive oil industry and a dietary supplement with acknowledged antioxidant and anti-inflammatory activity but underestimated photoprotective potential. We investigated the protective effects of the LC-PDA-MS/MS standardized ethanol-water extract of olive leaves (OLE), containing 26.2% total phenols and 22.2% oleuropein, with underlying mechanisms against the UVA-induced oxidative damage in human dermal fibroblasts. Hs68 cells were pre-treated (24 h) with OLE (2.5–25 μg/mL) or the reference antioxidants, quercetin and ascorbic acid (25 μg/mL), followed by irradiation (8 J/cm2). OLE significantly reduced the UVA-induced DNA damage and reactive oxygen species (ROS) overproduction and increased the thioredoxin reductase (TrxR) expression and post-radiation viability of fibroblasts by inhibiting their apoptosis. Both intrinsic and extrinsic apoptotic signaling pathways appeared to be inhibited by OLE, but the activity of caspase 9 was the most reduced. We hypothesized that the TrxR up-regulation by OLE could have prevented the UVA-induced apoptosis of Hs68 cells. In addition, a significant decrease in UVA-induced secretion levels of tumor necrosis factor (TNF-α) and interleukin-2 (IL-2) was shown in human lymphocyte culture in response to OLE treatment. In summary, our results support the beneficial effect of OLE in an in vitro model and indicate its great potential for use in the cosmetic and pharmaceutical industry as a topical photoprotective, antioxidant, and anti-inflammatory agent.

The awareness of the large amount of waste produced along the food chain, starting in the agricultural sector and continuing across industrial transformation to the domestic context, has in recent years also aroused strong concern amongst the public, who are ing about the possible consequences that this could have on environmental sustainability, resource waste and human health. The aim of the present research is the recovery of substances with high added value from waste and by-products typical of the Mediterranean area, such as the residue from the industrial processing of red oranges, called pastazzo (peels, pulps and seeds), which is particularly rich in anthocyanins, flavanones and hydroxycinnamic acids, and has numerous nutraceutical properties, as well as the olive leaves coming from olive-tree pruning, which are rich in substances such as oleuropein, elenolic acid, hydroxytyrosol, tyrosol and rutin. The effect of Red Orange Extract (ROE) and Olive Leaf Extract (OLE) on HepG2 fatty storage capacity was assessed performing Oil Red O’ staining, and antioxidant properties of the extracts were evaluated following the steatosis model onset. Based on the results obtained, the preparation of natural extracts that are derived from these waste products can be useful for preventing, counteracting or delaying the onset of the complications of fatty liver disease, such as hepatic steatosis.

Olive leaf extract (OLE) can be obtained as biowaste and is extensively used a food supplement and an over-the-counter drug for its beneficial effects. New studies have investigated OLE concerning the role of oxidative stress in the pathogenesis of vascular disease. This in vitro study aims to evaluate if OLE extracted from the Tuscan Olea europaea protects endothelial cells against oxidative stress generated by reactive oxygen species (ROS). Methods: OLE total polyphenols (TPs) were characterized by the Folin–Ciocalteu method. Endothelial cells were grown in conventional cultures (i.e., two-dimensional, 2D) and on a biomaterial scaffold (i.e., three-dimensional, 3D) fabricated via electrospinning. Cell viability and ROS measurement after H2O2 insults were performed. Results: OLE TP content was 23.29 mg GAE/g, and oleuropein was the principal compound. The dose-dependent viability curve highlighted the absence of significant cytotoxic effects at OLE concentrations below 250 µg/mL TPs. By using OLE preconditioning at 100 µg/mL, cell viability decrease was observed, being in 3D lower than in the 2D model. OLE was protective against ROS in both models. Conclusions: OLE represents a high-value antioxidant source obtained by biowaste that is interesting for biomedical products. Using a 3D scaffold could be the best predictive model to mimic the physiological conditions of vascular tissue reaction.

The current study was aimed to synthesized zinc oxide nanoparticles (ZnONPs) using aqueous extract of olive leaves (OLE), which is very simple and eco-friendly method. ZnONPs were formed by dissolving of OLE in zinc oxide solution with adjusted pH to 12. Zinc acetate dehydrate reduced to ZnONPs during mixing with OLE associated with change of the color solution from white to pale yellow color within a few minutes. The synthesized OLEZnONPs were separated by centrifugation (4000rpm/ 5min) , then characterized by Fourier Transmission Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and Field emission-Scanning Electron Microscopy (FE-SEM) methods. The results of FT-IR showed that the functional group related to Zn-O at (433.98 to 416.67 cm_1), whereas X-RD at 2 theta diagnose the type of oxide formation as ZnO and determined particle size in range (20 – 30 nm). Besides, SEM image was showed the presence of hexagonal shape of ZnO nanoparticles (42.87nm). Therefore, the biogenic synthesis of zinc oxide nanoparticles using Olea Europaea leaves was simple, low coast, can be an alternative to chemical synthesis and the possibility of using in biomedicine field

Chitosan films with olive leaf extract (OLE) incorporated at different concentrations were characterized regarding their antimicrobial, antioxidant and some relevant physical properties (i.e., solubility, water vapor permeability, and tensile properties). Results indicate that the active films have substantial antimicrobial activity against Listeria monocytogenes and Campylobacter jejuni mostly extending the microorganisms lag phase. A lower level of inhibition was found in the case of Escherichia coli. However, the OLE seems not to improve the intrinsic antimicrobial properties of the chitosan itself, except for C. jejuni. These results were confirmed with in situ testing using chicken. The chitosan films with OLE exhibited antioxidant activity, increasing with the OLE concentration, from 0.04 to 0.15 g/L ascorbic acid equivalents, corresponding to films with 10%–30% OLE relative to the chitosan. Chitosan films loaded with OLE exhibited a higher solubility in food simulants and a reduced permeability against water vapor. Overall, the combination of OLE and chitosan allows to obtain a promising active bio-based packaging solution for addressing safety and quality issues.

Introduzione. L'Olea europaea è uno degli alberi più antichi della regione mediterranea. Gli estratti di foglie di olivo (Olive Leaf Extracts, OLE) hanno suscitato interesse nei ricercatori di diverse discipline scientifiche principalmente a causa della particolare composizione fenolica, presumibilmente correlata alla sua potente attività biologica. Obiettivi. Lo scopo di questo studio è stato valutare: a) le proprietà degli OLE di Olea europaea Toscana per proteggere le cellule endoteliali dallo stress ossidativo generato dalle specie reattive dell'ossigeno (ROS), sia in coltura 2D sia in innovativi scaffold 3D (P (VDF-TrFE)); b) studiare l'effetto antimicrobico di OLE rispetto alla tecnologia Cold Atmospheric Plasma (CAP), o la loro combinazione, contro agenti patogeni, ad esempio Escherichia coli, Staphylococcus aureus e Listeria innocua, cresciuti a livello esponenziale o in fase stazionaria; c) caratterizzare fibre composite elettrofilate a base di PHBHV caricate con OLE per applicazioni nella guarigione delle ferite; d) valutare la capacità di OLE incorporato nelle fibre di poliidrossialcanoati (PHA) di modulare il rilascio di citochine da cheratinociti umani sani (HaCaT). Metodi: I polifenoli totali (total polyphenols, TP) di OLE sono stati caratterizzati con il metodo di Folin-Ciocalteu. Le cellule endoteliali sono state coltivate in colture convenzionali (cioè bidimensionali, 2D) e su impalcature tridimensionali fabbricate tramite elettrofilatura. La vitalità cellulare e la misurazione dei ROS dopo lo stress indotto da H2O2 sono state eseguite tramite WST-1, alamar Blue e la sonda CM-H2DCFDA per ROS. La crescita di E. coli, S. aureus e L. innocua è stata valutata mediante il test di unità (CFU) formanti colonie (espressa in CFU/ml) e CAP. È stata eseguita la reazione a catena della polimerasi in tempo reale (real-time PCR) per valutare le proprietà immunomodulatorie; analisi di spettroscopia infrarossa in trasformata di Fourier (FT-IR), per discriminare la composizione chimica in entrambe le fibre elettrofilate; cromatografia a permeazione su gel (GPC) per consentire l'analisi della biodegradazione; microscopia SEM per lo studio della morfologia delle fibre ed in fine, HPLC per eseguire lo studio di rilascio. Risultati: il contenuto in TP di OLE era 23,29 mg di acido gallico equivalente (GAE)/g e l'oleuropeina era il composto principale. La curva di vitalità dose-dipendente ha evidenziato l'assenza di effetti citotossici significativi a concentrazioni di OLE inferiori a 250 μg GAE/ml di TP. Il pretrattamento di 100 μg GAE/ml di TP di OLE ha avuto effetti protettivi sullo stress ossidativo indotto da H2O2 in entrambi i modelli (2D e 3D). La combinazione di CAP e OLE ha determinato una sostanziale inattivazione microbica contro tutti i ceppi in fase esponenziale mostrando una completa inattivazione. OLE ha dimostrato una significativa attività antinfiammatoria, sottoregolando l'espressione di tutte le citochine proinfiammatorie e sovraregolando IL-8, IL-1α e TNF-α nel modello HaCaT. Conclusione: OLE possiede una significativa attività antiossidante e antinfiammatoria; la fibra a base di PHBHV + OLE preserva gli effetti benefici di OLE e rappresenta uno scaffold 3D di alto valore con un grande potenziale nella rigenerazione dei tessuti. CAP e OLE possiedono un'attività antibatterica sinergica; pertanto, la tecnologia CAP in combinazione con OLE può essere utilizzata per una decontaminazione efficace, ad esempio nella guarigione delle ferite ed in dispositivi biomedicali.
Background. Olea europaea is one of the most ancient trees of the Mediterranean region. Olive leaf extracts (OLE) have aroused interest in researchers from different scientific disciplines mainly due to the distinctive phenolic composition allegedly related to potent biological activities. Objectives. The aim of the present s study was to evaluate: A) the properties of OLE extracted from the Tuscan Olea europaea to protect endothelial cells against oxidative stress generated by reactive oxygen species (ROS) in 2D culture and innovative 3D scaffold (P(VDF-TrFE)); B) to investigate the antimicrobial effect of OLE versus Cold Atmospheric Plasma (CAP) technology or their combination against pathogens, i.e., Escherichia coli, Staphylococcus aureus and Listeria innocua, grown to exponential (24h) or stationary (6h) phase; C) to characterize electrospun OLE-loaded PHBHV based composite fibers for wound healing applications; D) to evaluate the ability of OLE incorporated in Polyhydroxyalkanoates (PHAs) fibers to modulate the release of cytokines from healthy Human Keratinocytes (HaCaT). Methods: OLE total polyphenols (TPs) were characterized by the Folin–Ciocalteu method. Endothelial cells were grown in conventional cultures (two-dimensional, 2D) and on three-dimensional scaffold fabricated via electrospinning. Cell viability and ROS production after H2O2 insults were evaluated by WST-1, AlamarBlue and Probe CM-H2DCFDA assays. The E.coli, S.aureus and L.innocua growth were assessed by CFU/mL and CAP methods; Real-time polymer chain reaction (PCR) was carried out to evaluate the immunomodulatory properties; Fourier Transform Infrared Spectroscopy (FT-IR) Analysis was performed to discriminate the chemical composition in both electrospun fibers. Moreover, Gel Permeation Chromatography (GPC) to allow biodegradation analysis, SEM microscopy to study fiber morphology and HPLC to carry out the release study, were performed. Results: OLE TP content was 23.29 mg of gallic acid equivalent (GAE)/g, and oleuropein was the principal compound. The dose-dependent viability curve highlighted the absence of significant cytotoxic effects at OLE concentrations below 250 μg GAE/ml TPs. OLE preconditioning at 100 μg GAE/ml was protective against ROS in both models. The combination of CAP and OLE resulted in substantial microbial inactivation against all strains at exponential phase showing a complete inactivation. OLE possess a significant anti-inflammatory activity, downregulating the expression of all proinflammatory cytokines, upregulating IL-8, IL- 1α and TNF-α in HaCaT model. Conclusion. OLE possess a significant antioxidant and anti-inflammatory activities; PHBHV+OLE retains OLE beneficial effects and represents a high-value 3D scaffold with great potential in tissue regeneration. CAP and OLE have synergistic antibacterial activity; therefore, CAP technology in combination with OLE can be utilized for effective decontamination when required for example in wound healing and biomedical devices.

L’olio extravergine d’oliva (Extra-Virgin Olive Oil, EVOO) e l’estratto di foglie d’ulivo (Olive Leaves Extract, OLE) rappresentano un'importante fonte di composti nutraceutici, tra cui si annoverano composti a struttura fenolica e polifenolica come i fenil alcoli, gli acidi fenolici, i lignani, i flavoni, i flavonoli ed i secoiridoidi, una classe di composti esclusivi della famiglia delle Oleaceae. I secoiridoidi principalmente presenti nell’EVOO sono l’oleaceina e l’oleocantale, mentre nelle foglie si ritrova l’oleuropeina. Questi composti possiedono proprietà nutraceutiche, quali quelle antiproliferative, cardioprotettive, antiossidanti ed antinfiammatorie. Il progetto di ricerca della mia tesi di dottorato è stato focalizzato sullo studio dei composti fenolici e polifenolici presenti nell’EVOO e nell’OLE e si è articolato in varie direttrici:  Sviluppo di metodi efficienti per l'estrazione e la purificazione di oleocantale ed oleaceina da EVOOs Durante il dottorato sono state messe a punto delle procedure che hanno permesso di ottimizzare le precedenti metodiche di estrazione e purificazione ottenendo quantità significative di oleaceina ed oleocantale con buona purezza, partendo da EVOO fresco.  Studio delle proprietà nutraceutiche di oleocantale ed oleaceina L’oleocantale e l’oleaceina estratti e purificati dagli EVOOs sono stati sottoposti a studi farmacologici al fine di investigare le loro proprietà nutraceutiche. Questi studi hanno evidenziato il ruolo dei due secoiridoidi nell'infiammazione degli adipociti associata all'obesità e nella via di segnale NF-κB. È stato possibile evidenziare la capacità dell'oleaceina di inibire la proliferazione delle cellule di melanoma cutaneo in vitro (cellule 501Mel). Inoltre, è stato provato che l'oleocantale esercita un effetto anti-fibrotico, sia su modelli in vitro che in vivo di fibrosi epatica.  Studio delle variazioni della composizione fenolica e polifenolica degli EVOOs nel tempo Queste ricerche sono state condotte analizzando differenti EVOOs mediante metodiche HPLC sviluppate in questo dottorato. I risultati di queste analisi hanno confermato che i composti fenolici presenti nell’EVOO subiscono nel tempo un processo idrolitico, che differisce in ciascun campione di EVOO ed è fortemente correlato alle condizioni di conservazione.  Studio di nuovi componenti negli EVOOs e delle loro potenziali proprietà nutraceutiche Tra i pochi studi relativi ai processi ossidativi subiti dai composti fenolici e polifenolici presenti nell’EVOO, recentemente è stato individuato un nuovo prodotto di ossidazione dell’oleocantale, l’acido oleocantalico, che da studi preliminari è risultato essere particolarmente interessante per le sue potenziali proprietà neuroprotettive. La mia attenzione si è quindi focalizzata sull’acido oleocantalico al fine di ottenerlo ad alto grado di purezza, per poterlo poi sottoporre ad ulteriori studi per investigare le sue proprietà nutraceutiche. È stata valutata per la prima volta la sua attività antiossidante, dimostrando che l’acido oleocantalico possiede un’attività radical scavenging di specie reattive dell’ossigeno.  Studio della composizione di EVOOs toscani per la determinazione della loro tracciabilità geografica Questa parte della mia attività è stata svolta nell’ambito di un progetto che si propone di sviluppare un modello che permetta di verificare e garantire l’origine dell’olio, legandolo indissolubilmente al suo territorio di produzione. In particolare, mi sono dedicata allo studio delle caratteristiche di quaranta EVOOs toscani (acidità totale, contenuto dei composti fenolici e dei principali acidi grassi) al fine di correlarle con dati relativi ad altri parametri, quali la concentrazione di macroelementi, microelementi, elementi in traccia essenziali e non essenziali, nonché terre rare, presenti sia nei campioni di EVOOs che in quelli di suolo dove gli ulivi sono stati coltivati.  Sviluppo di device utili nel campo della rigenerazione tissutale a partire da fitoestratti di foglie d’ulivo (OLEs) ottenute da ulivi di Cultivar autoctone toscane Questa parte dell’attività di ricerca è stata svolta nell’ambito di un progetto che ha come obiettivo quello di studiare fibre biocompatibili che incorporano OLEs per lo sviluppo di dispositivi biomedicali utili nel processo di rigenerazione tissutale. Nell’ambito di questo progetto mi sono dedicata all’analisi di diversi OLEs al fine di selezionare quello più appropriato in termini di composizione fenolica e polifenolica, che è stato quindi incorporato nei biopolimeri. Ho quindi confermato l’avvenuta incorporazione dell’OLE nei biopolimeri e verificato che questi fossero in grado di rilasciare i fenoli ed i polifenoli dell’OLE. Inoltre, è stato dimostrato che i biopolimeri che incorporano l’OLE possiedono promettenti proprietà anti-infiammatorie ed immunomodulatorie, utili per il possibile sviluppo dei device.
Extra-virgin olive oil (EVOO) and olive leaves extract (OLE) represent an important source of nutraceutical compounds, including phenolic and polyphenolic compounds such as phenyl alcohols, phenolic acids, lignans, flavones, flavonols and secoiridoids. Secoiridoids are a class of compounds exclusive of Oleaceae family. Oleocanthal and oleacein are the most important secoiridoids present in EVOO, while oleuropein is the main representative in OLE. These compounds possess nutraceutical properties, such as antiproliferative, cardioprotective, antioxidant and anti-inflammatory properties. My PhD project was focused on the study of the phenolic and polyphenolic compounds in EVOO and in OLE and it was aimed to several parallel objectives:  Development of efficient methods for the extraction and the purification of oleocanthal and oleacein from EVOOs During this PhD, new procedures were developed by improving previous extraction and purification methods, obtaining significant quantities of oleacein and oleocanthal from fresh EVOO, with good purity.  Study of the nutraceutical properties of oleocanthal and oleacein Oleocanthal and oleacein extracted and purified from EVOOs were then submitted to pharmacological studies to investigate their nutraceutical properties. The results of these studies highlighted the role of the two secoiridoids in obesity-associated adipocytes inflammation and in the NF-κB pathway. The ability of oleacein to inhibit the proliferation of skin melanoma cells in vitro (501Mel cells) was demonstrated. Moreover, the antifibrotic effect of oleocanthal, in both in vitro an in vivo models of liver fibrosis, was proved.  Study of the variations in the phenolic and polyphenolic composition of EVOOs during storage This study was conducted by analysing several EVOOs using HPLC methods developed during this PhD thesis. The results of these analyses confirmed that the phenolic compounds present in EVOO underwent a hydrolytic process during storage. However, the evolution of this pathway differs in each EVOO sample, and it is strongly related to storage condition.  Study of novel components in EVOOs and their potential nutraceutical properties The oxidative process involving phenolic and polyphenolic compounds in EVOO are poorly investigated. A new oleocanthal oxidation product, named oleocanthalic acid, has been recently identified and preliminary studies showed the potential neuroprotective properties of this compound. My attention was therefore focused on obtaining oleocanthalic acid with high purity in order to submit it to further studies for its nutraceutical properties investigation. A detailed assessment of its in vitro radicals quenching activity was performed for the first time, demonstrating its scavenging capacity against reactive oxygen species.  Study of composition of Tuscan EVOOs for the determination of their geographical traceability This part of my PhD work was carried out as a part of a project aimed to develop a model that would allow to verify and guarantee the origin of the oil, indissolubly linking it to its production area. In particular, I studied the characteristics of forty Tuscan EVOOs (free acidity, phenolic compounds content and main fatty acids content). The results of these analyses will be correlated with other parameters studied, such as the concentration of macro-elements, micro-elements, essential and non-essential trace elements, as well as rare earth elements, present both in the samples of EVOOs and in those of soil where the olive trees were cultivated.  Development of devices useful in tissue regeneration fields from olive leaves phytoextracts (OLEs) obtained from autochthonous Tuscan olive trees Cultivars This part of my research was carried out under a project that aims to study biocompatible fibers incorporating OLEs for the development of biomedical devices useful in the tissue regeneration field. In particular, I analysed the phenolic and polyphenolic composition of several OLEs in order to select the most appropriate one to incorporate into the biopolymers. I therefore confirmed the incorporation of the OLE into the biopolymers and their capability to release the OLE phenols and polyphenols. Furthermore, the biopolymers incorporating OLE showed promising anti-inflammatory and immunomodulatory properties, useful for the development of devices.

Neoparamoebae perurans is a marine protozoan parasite that infects gills of cultured Atlantic salmon, Salmo salar, causing amoebic gill disease (AGD) which is currently reported in most salmon producing countries. In Tasmania, the management of AGD in Atlantic salmon accounts for 20% of production costs. As a result, several studies have been done to explore alternative treatment methods. However, previous studies other than freshwater bathing focused solely on testing chemotherapeutants against AGD. With the exception of garlic Allium sativum and AQUI-S\(^®\) (product based on clove oil), no other plant products have been tested against AGD. In the first study, the effects of clove oil and its derivative AQUI-S\(^®\) against N. perurans were studied. N. perurans trophozoites were exposed to clove oil at 10, 20, 40 and 80 μL L\(^{-1}\) for 10 min and 5, 10, 20 and 40 μL L\(^{-1}\) for 120 min; AQUI-S\(^®\) at 5, 10, 20 and 40 μL L\(^{-1}\) for 10 min and 2.5, 5, 10 and 20 μL L\(^{-1}\) for 120 min. There were no significant differences in viability and survival of trophozoites after exposure to the anaesthetics. When trophozoites were exposed to clove oil at 80 μL L\(^{-1}\) for 10 min there was significantly (P < 0.05) more detachment from a plastic surface compared to the control. Continued use of clove oil and AQUI-S\(^®\) at 40 μL L\(^{-1}\) or at lower concentrations for up to 120 min is unlikely to have a detrimental impact on amoebae that are isolated and collected from salmon with AGD to be used for AGD research. In the second study, viability estimations using viability assays were compared to manual counting using trypan blue and neutral red vital dyes. The four viability assays examined were CellTiter-Blue\(^®\), CellTiter-Glo\(^®\), CellTiter-Fluor™ and CytoTox-ONE™. A stock solution comprising of 50% live cells and 50% dead cells (25% heat inactivated, 25% formaldehyde inactivated) was used. All viability assays and manual counting using neutral red estimated viability of cells in stock solution to be approximately 50%, except trypan blue which overestimated cell viability. A positive linear relationship between the signal generated and the number of live cells was observed when the maximum number of viable cells did not exceed 1500. However, positive linear relationship between signal generated and the number of live cells was only observed in CellTiter-Glo\(^®\) and CellTiter-Fluor™ when the maximum number of viable cells did not exceed 10000. CellTiter-Glo\(^®\) was determined to be the most suitable viability assay due to the ease of use and the ability to maintain linearity over a wide range of viable cells. In the third study, efficacy of GTE (green tea extract) and OLE (olive leaf extract) against N. perurans was examined in vitro using gill isolated amoebae and exposing them to GTE at 9, 19, 38, 75, 150 and 300 mg L\(^{-1}\) and OLE at 12500, 6250, 1562, 780 and 390 mg L\(^{-1}\) . OLE and GTE were found to be effective against N. perurans at 780 mg L\(^{-1}\) and 150 mg L\(^{-1}\) respectively. Safety of GTE and OLE to Atlantic salmon were examined using bath treatment of either 1500 mg L\(^{-1}\) OLE or 75, 150 & 300 mg L\(^{-1}\) GTE in seawater; only OLE was considered safe. Subsequently in the fourth study, efficacy of OLE as bath treatment for AGD was studied by bathing AGD affected salmon at 780 mg L\(^{-1}\) for 1 h. OLE significantly reduced the prevalence of fish affected by AGD both immediately after and seven days after bath treatment. This thesis identified OLE as a potential therapeutic compound against AGD caused by N. perurans. This finding serves as a proof of concept that plant products such as OLE could have therapeutic effects against AGD. This indicates that OLE could be worth examining against other ectoparasitic diseases and OLE warrants further investigations as a potential in-feed treatment for AGD in Atlantic salmon.

This work is composed of a bibliographic survey and an experimental part. The bibliographic part consists of a study on the epidemiological situation of Campylobacter spp. in Europe, advances in research on natural solutions for the conservation of chicken, studies aimed at reducing contamination by Campylobacter spp., the use of olive leaf extract (OLE) for the conservation of food, and other new alternatives for food preservation. The experimental part consists of a laboratory study on the effectiveness of OLE against Campylobacter spp. and its application in an active packaging for the conservation of chicken. The epidemiological situation related to Campylobacter infections in the EU is not homogeneous between countries and its related to the consumption of foods contaminated with these bacteria. Some seasonality has also been observed for infections. In recent years many studies have been carried out to develop new natural solutions for the conservation of chicken, due to the need to increase the shelf life of food. In these studies, new natural plants have been found as well as very effective minerals to lengthen the shelf life of food. OLE is a by-product of the olive industry that is widely used in phytotherapy, but in recent years it has been shown that it has a potential to increase the shelf life of food mainly due to its antioxidant and antibacterial effects. In microbiological studies it has been demonstrated its effectiveness against Campylobacter spp., however, there are no studies in the literature that have the objective of reducing or eliminating Campylobacter spp. in chicken with the use of OLE. For this reason, OLE was chosen to carry out an experimental study. In the experimental work, results from in vitro and in situ tests were in agreement. OLE has been effective as a growth inhibitor at the optimal growth conditions of Campylobacter spp., that is, at 41.5 oC and in microaerophilia. Nevertheless, once samples were removed from contact with OLE growth was observed, this means that the extract has not killed all the bacteria. The experimental design was not able to prove the efficacy of OLE in reducing the viable cell count at low temperatures.
Este trabalho e composto por uma parte de pesquisa bibliográfica e uma parte experimental. A parte bibliográfica consiste num estudo sobre a situação epidemiológica de Campylobacter spp. na UE, avanços na investigação de soluções naturais para a conservação de frangos, estudos destinados a reduzir a contaminação por Campylobacter spp., a utilização do extrato de folha de Oliveira (OLE) para a conservação de alimentos, e outras novas alternativas para a conservação de alimentos. A parte experimental consiste num estudo laboratorial sobre a eficácia da OLE contra Campylobacter spp. e a sua aplicação numa embalagem ativa para a conservação de frango. A situação epidemiológica relacionada com as infeções por Campylobacter spp. na UE não é homogénea entre os países da união e esta relacionada com o consumo de alimentos contaminados com estas bactérias. Também tem sido observada alguma sazonalidade nas infeções. Nos últimos anos tem sido realizados muitos estudos para desenvolver novas soluções naturais para a conservação de frango, devido a necessidade de aumentar o tempo de conservação dos alimentos, nestes estudos foram abordadas novas soluções naturais, bem como minerais eficazes para prolongar o tempo de conservação dos alimentos. O OLE e um subproduto da indústria do azeite amplamente utilizado na fitoterapia, mas nos últimos anos tem sido demonstrado que tem potencial para aumentar o prazo de validade dos alimentos, principalmente devido aos seus efeitos antioxidante e antibacteriano. Em estudos microbiológicos foi demonstrada a sua eficácia contra Campylobacter spp., contudo, não existem estudos na literatura que tenham como objetivo reduzir ou eliminar Campylobacter spp. em frangos com o uso de OLE. Por esta razão, OLE foi escolhido para realizar um estudo experimental. No trabalho experimental, os resultados dos testes in vitro e in situ foram concordantes. O OLE revelou-se eficaz como inibidor de crescimento nas condições ótimas de crescimento de Campylobacter spp., ou seja, a 41.5 °C e em microaerofilia. Contudo, uma vez que após remoção das amostras do contacto com o OLE, observou-se crescimento, indicando que haviam ainda células estavam viáveis, o que significa que o extrato não matou todas as bactérias. Não foi possível, com o design experimental seguido, provar a eficácia do OLE na redução do número de células viáveis a baixas temperaturas.

Hypertension (HTN) is one of the most common disorders and increases the risk of cardiovascular diseases (CVD), which are one of the main causes of death in the world. The Mediterranean diet has the efficacy to modulate CVD risk factors such as HTN, mainly because of olive tree products, which are the most pivotal ingredients in this diet. Among the olive tree products, olive leaf consists of many sorts of phenolic compounds and has several beneficial effects on human body, such as antioxidant, anti-atherosclerotic, anti-inflammatory and especially anti-hypertensive effects. So, we conducted a new systematic review and meta-analysis on anti-hypertensive effect of OLE in adults. The meta-analysis showed a significant reduction effect of OLE on systolic blood pressure. The anti-hypertensive effect of OLE is mainly considered due to its principal phenolic compound known as oleuropein (OL), which reduces blood pressure by a number of particular mechanisms associated with its specific chemical characteristics.

Abstract Chapter One discusses the ‘prehistory’ of Athenian ostracism by studying both the attested cases of ostracism outside Athens (in Megara, Argos, Tauric Chersonesos, Cyrene, Thourioi, the Sicilian Naxos and possibly in Miletus, as well as the petalismos, or vote using olive leaves, in Syracuse) and conceivable traces of ostracism-like institutions or procedures in Athens of the archaic period. Here, on the one hand, both the famous late Byzantine testimony of the so-called ‘bouleutic ostracism’ (the manuscript Vaticanus Graecus 1144) and that of the archaic ostraca, from the Athenian Agora and the Acropolis, are discounted as unreliable witnesses to the alleged ‘ostracism before ostracism’ in Athens. On the other hand, all extra-Athenian ostracisms seem to post-date the Athenian institution by at least two decades, which bespeaks against the widely held hypothesis that ostracism in Athens was just one local elaboration of a more general Greek practice. More probably, all those institutions in the wider Greek world followed the Athenian model. Additionally, the hypothesis of the ritual origins of ostracism is reassessed and rejected. All in all, it turns out that Athenian ostracism (properly speaking) was an unprecedented Athenian invention.

Olive leaves (OL) are considered a potential source of bioactive compounds mainly due to its high content of polyphenols, widely known as natural antioxidants. The objective of this study was to optimize supercritical fluid extraction conditions from OL in order to obtain natural extracts with high antioxidant activity. OL (belong to the Arbequina cultivar) were collected from a local producer (Uruguay) and subjected to a drying and milling (1 mm particle size) pre-treatment. Supercritical fluid extractions were carried out using a laboratory-built system equipped with a 25 mL stainless steel vessel filled with 10 g of OL. A total of 10 extractions were carried out following a Central Composite Design in which the two independent variables considered were: extraction temperature (40–60 °C) and extraction pressure (150-350 bar). In all cases, extraction solvent was CO2 with 10% of ethanol as modifier. A constant flow rate of 0.5 L/min CO2 was set and each run was finished when 100 L of CO2 were measured in the flow totalizer. Extraction yield (% wt), total phenolic content (Folin-Ciocalteau) and antioxidant activity (ABTS+. assay) of the extracts were considered as response variables. Extraction yield was positively correlated with temperature and pressure, while total phenolic content and antioxidant activity were negatively correlated with temperature. Phenolic content of the extracts varied from 22.9 to 53.6 mg GAE/g. For the extract obtained at optimal conditions, the identification of individual polyphenols was performed by RP/HPLC-Q-TOF MS/MS, being phenolic acids, simple phenols and secoiridoids the most abundant compounds. Finally, oxidative stability of canola oil with or without the incorporation of 250 ppm of some extracts was assessed during five weeks of storage at 60°C. Peroxide, K232, K270, and Rancimat values, besides tocopherol content were determined. Results obtained reinforce the use of supercritical fluid technology to obtain antioxidants compounds from natural sources.

Worldwide, around 50 million people have dementia with nearly 10 million new cases every year. Alzheimer’s Disease (AD) is the most common form of dementia, and it may contribute to 60–70 % of these cases. This multifactorial pathophysiology has been widely characterized by neuroinflammation, extensive oxidative damage, synaptic loss and neuronal cell death. However, only a few drugs have been approved for the therapeutic treatment of AD (with unpleasant side effects), and many studies have suggested that diet and/or food components can prevent the onset of AD. Among these constituents, terpenoids and carotenoids from diverse natural sources have been investigated, and based on a Foodomics approach, our group has demonstrated that an olive leaves extract enriched in triterpenoids and a carotenoids-enriched extract from Dunaliella salina microalgae have neuroprotective potential using in vitro assays. In addition, the neuroprotective and anti-inflammatory potential of these extracts have been confirmed in a neuronal in vitro cell culture model and in vivo using a transgenic Caenorhabditis elegans model. Moreover, different lipidomics studies were performed using advanced analytical methodologies, namely, charged-surface hybrid chromatography-quadrupole-time of flight mass spectrometry (CSH-Q-TOF MS/MS). This technology allowed the annotation of more than 250 intracellular lipids, and among them, a number of phosphatidylcholines, phosphatidylethanolamines and triacylglycerols were significantly altered, suggesting triterpenoids from olive leaves and carotenoids from microalgae as good neuroprotective candidates.