Добірка наукової літератури з теми "Oleocanthal"

The health benefits of extra-virgin olive oil (EVOO) are strictly linked to the presence of phenolic compounds, which exhibit numerous nutraceutical properties. In EVOO, the most important class of phenolic compounds is represented by secoiridoids (oleacein and oleocanthal). EVOO is constantly subjected to degradation processes, including hydrolytic and oxidative reactions that influence its phenolic composition. In particular, the hydrolytic reactions determine the transformation of oleocanthal and oleacein into the corresponding phenyl-alcohols, tyrosol, and hydroxytyrosol. Furthermore, oleocanthal by oxidation processes can be converted to oleocanthalic acid. In this study, we evaluated the phenolic composition of three EVOO samples kept at different storage conditions for 15 months, focusing on the variation of oleocanthalic acid content. Specifically, the samples were stored at 4 °C in darkness and at 25 °C with light exposure. The results of our analyses highlighted that in EVOOs exposed to light and maintained at 25 °C, the degradation was more marked than in EVOO stored in dark and at 4 °C, due to the greater influence of external factors on storage conditions. Although chemical–physical characteristics of EVOOs are slightly different depending on provenience and treatment time, the results of this study reveal that storage conditions are fundamental to controlling phenol concentration.

Background: Open heart surgery is performed with the aid of cardiopulmonary bypass (CPB) techniques that may cause neuronal injuries. Objective: This study investigated the potential protective effect of oleocanthal pre-treatment against CPB-induced cerebral injury. Methods: Oleocanthal 30 mg/kg i.p. was administered 3 h before CPB induction in the treated group. Behavioral neurological scores and cerebral injury were assessed to determine the effects of oleocanthal, based on oxidative stress and serum mediators of inflammation by enzyme-linked immunosorbent assay (ELISA). Quantitative Polymerase Chain Reaction (qRT-PCR) was used to estimate the mRNA expression of Toll-like receptor 4 (TLR4) and Interleukin 1 Receptor Associated Kinase 4 (IRAK4) proteins in the cerebral tissue of rats CPB-induced injury. Western blot assay and histopathology were also performed. Results: The findings suggest that pre-treatment with oleocanthal reduced neurological dysfunction and cerebral injury. Parameters of oxidative stress and cytokine levels were reduced in the serum of the oleocanthal treated group compared with the CPB-only group. Pre-treatment with oleocanthal ameliorated the expression of TLR-4, IRAK4, and Zonula occludens-1 (ZO-1) proteins in the cerebral tissue of the CPB-injured rats. Conclusions: The results revealed that treatment with oleocanthal protected against cerebral damage by controlling microglia inflammation through the TLR-4 pathway.

Neurodegenerative diseases represent a heterogeneous group of disorders that share common features like abnormal protein aggregation, perturbed Ca2+ homeostasis, excitotoxicity, impairment of mitochondrial functions, apoptosis, inflammation, and oxidative stress. Despite recent advances in the research of biomarkers, early diagnosis, and pharmacotherapy, there are no treatments that can halt the progression of these age-associated neurodegenerative diseases. Numerous epidemiological studies indicate that long-term intake of a Mediterranean diet, characterized by a high consumption of extra virgin olive oil, correlates with better cognition in aged populations. Olive oil phenolic compounds have been demonstrated to have different biological activities like antioxidant, antithrombotic, and anti-inflammatory activities. Oleocanthal, a phenolic component of extra virgin olive oil, is getting more and more scientific attention due to its interesting biological activities. The aim of this research was to characterize the neuroprotective effects of oleocanthal against H2O2-induced oxidative stress in neuron-like SH-SY5Y cells. Moreover, protein expression profiling, combined with pathways analyses, was used to investigate the molecular events related to the protective effects. Oleocanthal was demonstrated to counteract oxidative stress, increasing cell viability, reducing reactive oxygen species (ROS) production, and increasing reduced glutathione (GSH) intracellular level. Proteomic analysis revealed that oleocanthal significantly modulates 19 proteins in the presence of H2O2. In particular, oleocanthal up-regulated proteins related to the proteasome, the chaperone heat shock protein 90, the glycolytic enzyme pyruvate kinase, and the antioxidant enzyme peroxiredoxin 1. Moreover, oleocanthal protection seems to be mediated by Akt activation. These data offer new insights into the molecular mechanisms behind oleocanthal protection against oxidative stress.

A copper-(I)-catalyzed variation of the Huisgen 1,3-dipolar cycloaddition has been applied to lead the in living-cell mass-spectrometry based identification of protein targets of oleocanthal, a natural metabolite daily ingested by millions of people. Chemical proteomics revealed heat-shock proteins, HSP70 and HSP90, as main oleocanthal interactors in living systems. These two proteins are involved in cancer development and, thus, our findings could have important outcomes for a deep evaluation of the bio-pharmacological significance of oleocanthal.

Olive oil phenols (OOPs) are associated with the prevention of many human cancers. Some of these have been shown to inhibit cell proliferation and induce apoptosis. However, no systematic comparative study exists for all the investigated compounds under the same conditions, due to difficulties in their isolation or synthesis. Herein are presented innovative methods for large-scale selective extraction of six major secoiridoids from olive oil or leaves enabling their detailed investigation. The cytotoxic/antiproliferative bioactivity of these six compounds was evaluated on sixteen human cancer cell lines originating from eight different tissues. Cell viability with half-maximal effective concentrations (EC50) was evaluated after 72 h treatments. Antiproliferative and pro-apoptotic effects were also assessed for the most bioactive compounds (EC50 ≤ 50 μΜ). Oleocanthal (1) showed the strongest antiproliferative/cytotoxic activity in most cancer cell lines (EC50: 9–20 μΜ). The relative effectiveness of the six OOPs was: oleocanthal (1) > oleuropein aglycone (3a,b) > ligstroside aglycone (4a,b) > oleacein (2) > oleomissional (6a,b,c) > oleocanthalic acid (7). This is the first detailed study comparing the bioactivity of six OOPs in such a wide array of cancer cell lines, providing a reference for their relative antiproliferative/cytotoxic effect in the investigated cancers.

Oleocanthal and ligstroside aglycone are olive oil-derived polyphenols. The former interferes with tumor growth with minor or no cytotoxicity on non-tumorigenic primary cell lines. The information about the bioactivity of ligstroside aglycone are scanty, with the exception of a known antioxidant power. Hepatocellular carcinoma is a malignant tumor with high mortality rates. Systemic chemotherapy is only marginally effective and is frequently complicated by toxicity. Previous observations have shown that hepatocellular carcinoma cell lines become more sensitive to taxol when it is combined with Tumor Necrosis Factor α (TNFα). The present work aimed to assess the effects of a polyphenolic extract containing both oleocanthal and ligstroside aglycone on proliferation and/or death in three liver cancer cell lines (HepG2, Huh7 and Hep3B). The possibility to enhance such effect by the addition of TNFα was also investigated. Both cell proliferation and death were enhanced by the exposure to the polyphenolic extract. Such effect was associated with induction of autophagy and could be potentiated by TNFα. The presence of ligstroside aglycone in the extract lowered the oleocanthal concentration required for cytotoxicity. These results show for the first time that the effects of a polyphenol extract can be potentiated by TNFα and that modulation of autophagy likely account for these effects.

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.

Oxidative stress contributes to the development and progression of a broad range of syndromes and diseases, especially cancer and neurodegenerative processes. Malignant pleural mesothelioma (MPM) is a highly aggressive tumor originating from the mesothelial cells of the pleura, associated with asbestos exposure. Inhalation of long and thin asbestos fibers induces a chronic inflammatory response at sites of fibers deposition, with accumulation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) that over time may lead to malignant cell transformation. MPM is characterized by a long latency period, a poor prognosis, and limited effective therapies. Thus, there is a real need for improvement in prognostic and diagnostic tools for MPM. In recent years the focus in the field of biomarker discovery has moved from intracellular components to secreted factors. Cancer cell secretome provides an useful source in the search for proteins involved in tumor development and can be considered a potential tool to investigate tumor properties. Proteomic approaches are increasingly used for biomarker discovery as proteins produced by cancer cells or their microenvironment may eventually enter the circulation and their expression can be assessed for diagnostic purpose. In order to obtain an inclusive overview of MPM cell protein expression, we examined through a proteomic approach the proteome and secretome profiles of two MPM cell lines (NCI-H28 and NCI-2052) and compared to those of a non malignant mesothelial cell line (Met-5A). In this study, we identified mesothelioma cells-secreted proteins prosaposin (PSAP) and quiescin sulfhydryl oxidase 1 (QSOX1) as novel biomarker candidates for mesothelioma and validated their increase in serum of MPM patients by ELISA. Our results crearly show PSAP and QSOX1 serum levels are significantly increased in MPM patients in respect to asbestos-exposed healthy subjects. The informations gained from this investigation have increased our knowledge on MPM and identified two novel potential biomarkers. Neurodegenerative diseases represent a heterogeneous group of disorders that share common features like abnormal protein aggregation, perturbed Ca2+ homeostasis, excitotoxicity, impairment of mitochondrial functions, apoptosis, inflammation, and oxidative stress. Despite recent advances in the research of biomarkers, early diagnosis and pharmacotherapy, there are no treatments that can halt the progression of these age-associated neurodegenerative diseases. Numerous epidemiological studies indicate that long-term intake of a Mediterranean diet, characterized by a high consumption of extra virgin olive oil, correlates with better cognition in aged populations. Olive oil phenolic compounds have been demonstrated to have different biological activities such as antioxidant, antithrombotic, and anti-inflammatory properties. Oleocanthal, a phenolic component of extra-virgin olive oil, is getting more and more scientific attention due to its interesting biological activities. In this study, we aimed to characterize the neuroprotective effects of oleocanthal against H2O2-induced oxidative stress in neuron-like SH-SY5Y cells. Protein expression profiling, combined with pathways analyses, was used to investigate the molecular events related to the protective effects. Oleocanthal demonstrated to counteract oxidative stress increasing cell viability, reducing ROS production and increasing GSH intracellular level. Proteomic analysis revealed that oleocanthal significantly modulates 19 proteins in the presence of H2O2. In particular, oleocanthal up-regulated proteins related to the proteasome, the chaperone heat shock protein 90, the glycolytic enzyme pyruvate kinase and the antioxidant enzyme peroxiredoxin 1. These data offer new insights in the molecular mechanisms behind oleocanthal protection against oxidative stress.

O azeite é um dos principais componentes da dieta mediterrânica. A caracterização de azeites monovarietais permite identificar a singularidade das características de cada cultivar que lhe conferem propriedades únicas e valorizáveis, permitindo acrescentar valor ao azeite. Como tal, pretendeu-se com este estudo contribuir para o conhecimento da composição química de azeites monovarietais provenientes da região do Alentejo. Foram selecionadas sete variedades de azeitona Arbequina, Blanqueta, Cobrançosa, Cordovil, Galega, Picual e Verdeal de Serpa, por serem atualmente as que melhor representam a área plantada de olival na região Alentejo, principal região olivícola de Portugal. As amostras de azeitona foram recolhidas diretamente das explorações agrícolas, na época normal de colheita da campanha de 2017/2018, entre novembro e dezembro. A extração do azeite foi efetuada após a colheita através do método Abencor. As análises realizadas confirmaram a classificação das amostras como azeite virgem extra, obtendo-se valores de ácidos gordos livres ≤ 0,8%, valores de índice de peróxidos ≤20 meqO2/kg e índices espetrofotométricos na região do ultravioleta ≤ 0,22 (K270) e 2,50 (K232). Relativamente ao teor de compostos fenólicos totais, estes oscilaram entre 27±3 mg EAG/kg (Arbequina) e 262 mg EAG/kg (Verdeal). A actividade antioxidante variou entre 0,43 ± 0,05 mg EAA/kg(Galega) e 0,87 mg EAA/kg (Blanqueta). Os flavonóides entre 30±4 mg catequina/kg (Cordovil) e 62±17 mg catequina/kg (Verdeal de Serpa). O K225 relacionado com o atributo amargo variou entre 0,02 (Arbequina) e 0,45±0,05 (Verdeal de Serpa). A cor dos diferentes azeites localiza-se na zona dos verdes com um ângulo de Hue próximo de 178º, sendo o azeite da cv. Picual o mais verde e o azeite da cv. Galega vulgar o menos verde, o mais claro o da cv. Arbequina e o mais escuro o da cv. Blanqueta. Todos os azeites alcançaram os níveis padrão para as alegações de saúde estabelecidos pela União Europeia que prevê 5 mg de hidroxitirosol e seus derivados em 20 g de azeite que corresponde no mínimo a 250 mg de oleocantal e oleaceína por kg de azeite. O valor mais elevado foi observado nas cvs.Blanqueta, Cobrançosa e Cordovil (1000 mg/kg) e o valor mais reduzido na cv.Galega vulgar (250 mg/kg).

The Mediterranean Diet contains fruits, vegetables, nuts, whole grains, fish and virgin olive oil (VOO) as a key component. It is well explained that those consumption has a number of positive health effects. It has been accepted for a long time that the leading compound in olive was oleic acid as a monounsaturated fatty acid. However, the latter researches were figured out that VOO rich in natural phenolics have multifaceted influence on major diseases including cancer, diabetes, cardiovascular diseases, neurodegenerative disease, and metabolic disorders. Recent medical studies proved that oleocanthal and oleacein, characteristic bioactive biophenol-secoiridoids in VOO, success in the anti-inflammatory and in the antioxidant properties, respectively. It has more recently investigated that oleocanthal and hydroxytyrosol (HT) kills cancer cells (CCs). HT and oleuropein reduces breast cancer and cutaneous melanoma cancer cells both in number and aggressiveness, and inhibits CCs multiplying. It has been declared too many times that nutrition type is the strongest factor can be caused acute and chronic diseases. However, at the same time, nutrition can also prevent some of those heavy symptoms. The main purpose of presented chapter is to meet olive’s bioactive molecules and to examine how to improve our health with diet.

Liver cancer or hepatocellular carcinoma (HCC) is a malignant tumor in liver tissue and worldwide it is fourth leading death cause among all cancers. The most common causes of liver cancer are hepatitis B or C virus infections, alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH), smoking and obesity. The development and metastasis of liver cancer is a multistage and branched process of morphological and genetic traits. Various corresponding signaling pathways such as Yes-Associated Protein-Hippo Pathway (YAP-HIPPO), Wnt/β-catenin and inflammation by interleukin-6 (IL-6), tumor necrosis factor (TNF), nuclear factor-Κb (NF-κB), biological pathways including epithelial–mesenchymal transition (EMT), tumor microenvironment, tumor-stromal interactions and cancer stem cells and gut microbial dysbiosis are allied to both origination, progression and metastasis of liver cancer. Numerous therapeutic approaches are classified into different categories such as pharmacological therapy including sorafenib, lenvatinib and ramuciruma, surgery of HCC patients includes surgical resection, adjuvant therapy after surgical resection and liver transplantation. Loco-regional ablative therapy includes cryotherapy, ethanol injection and radiofrequency ablation, cytotoxic chemotherapy, natural compounds such as piperine, as curcumin and oleocanthal, oncolytic virus therapy, immunotherapies and nanotechnology.

The bottom line for olive oil is how it tastes. We present an overview of the tasting process and explain how the human sensory apparatus interacts with the chemicals in the oil. Phenolic compounds that give rise to the bitterness and the oleocanthol that gives rise to the “burn” are featured here.