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Major phenolic compounds in olive oil: Metabolism and health effects

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Abstract

It has been postulated that the components in olive oil in the Mediterranean diet, a diet which is largely vegetarian in nature, can contribute to the lower incidence of coronary heart disease and prostate and colon cancers. The Mediterranean diet includes the consumption of large amounts of olive oil. Olive oil is a source of at least 30 phenolic compounds. The major phenolic compounds in olive oil are oleuropein, hydroxytyrosol and tyrosol. Recently there has been a surge in the number of publications that has investigated their biological properties. The phenolic compounds present in olive oil are strong antioxidants and radical scavengers. Olive "waste water" also possesses compounds which are strong antioxidant and radical scavengers. Typically, hydroxytyrosol is a superior antioxidant and radical scavenger to oleuropein and tyrosol. Hydroxytyrosol and oleuropein have antimicrobial activity against ATTC bacterial strains and clinical bacterial strains. Recent syntheses of labeled and unlabelled hydroxytyrosol coupled with superior analytical techniques have enabled its absorption and metabolism to be studied. It has recently been found that hydroxytyosol is renally excreted unchanged and as the following metabolites as its glucuronide conjugate, sulfate conjugate, homovanillic acid, homovanillic alcohol, 3,4-dihydroxyphenylacetic acid and 3,4-dihydroxyphenylacetaldehyde. Studies with tyrosol have shown that it is excreted unchanged and as its conjugates. This review summarizes the antioxidant abilities; the scavenging abilities and the biological fates of hydroxytyrosol, oleuropein and tyrosol which have been published in recent years.

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... Previous studies have proposed different mechanisms by which OOC might reduce the risk of mortality. Olive oil is a rich source of MUFAs, vitamin E and several phenolic compounds including oleuropein, hydroxytyrosol and tyrosol, and it has been described biological properties of these compounds including vasodilator, hypoglycemic, antihypertensive, antioxidant and anti-inflammatory effects (29,30). Hydroxytyrosol has been shown to reduce the formation of atherosclerotic plaques, which increase the risk of coronary heart diseases (30). ...
... Olive oil is a rich source of MUFAs, vitamin E and several phenolic compounds including oleuropein, hydroxytyrosol and tyrosol, and it has been described biological properties of these compounds including vasodilator, hypoglycemic, antihypertensive, antioxidant and anti-inflammatory effects (29,30). Hydroxytyrosol has been shown to reduce the formation of atherosclerotic plaques, which increase the risk of coronary heart diseases (30). In addition, hydroxytyrosol promotes the induction of angiogenic genes in hypoxic MCF-7 cells which delays cancer progression (31). ...
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Objective We assessed the association between usual olive oil consumption (OOC) and all-cause, cardiovascular (CVD) and cancer mortality in an adult population in Spain. Materials and methods OOC was evaluated at baseline in 1,567 participants aged 20 years and older from the Valencia Nutrition Study in Spain using validated food frequency questionnaires. During an 18-year follow-up period, 317 died, 115 due to CVD and 82 due to cancer. Cox regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (95%CI). Results After adjusting for demographic and lifestyle factors, the OOC was associated with a lower risk of all-cause, CVD and cancer mortality. Compared to the less than once per month consumption, the consumption of up to one tablespoon per day was associated with a 9% lower risk of all-cause mortality (HR: 0.91; 95%CI: 0.68-1.22) and the consumption of 2 or more tablespoons with a 31% lower risk of all-cause mortality (HR: 0.69; 95%CI: 0.50–0.93; p-trend = 0.011). The consumption of 2 or more tablespoons per day was also associated with lower risk of mortality for CVD (HR: 0.54; 95%CI: 0.32–0.91; p-trend = 0.018) and cancer (HR: 0.49, 95%CI: 0.26–0.94; p-trend = 0.019). Conclusion Higher olive oil consumption was associated with lower long-term risk of all-cause, CVD and cancer mortality in an adult Mediterranean population. The maximum benefit was observed for the consumption of two or more tablespoons per day.
... Interestingly, this band was detected in BCs produced from OOMW, but not in BC produced from glucose ( Figure 2). The band at 1740 cm −1 may be related to the fatty acids [46], and this can be interpreted as tyrosol and hydroxytyrosol [47] naturally found in OOMW may be absorbed into the cellulose samples, although it was not clearly observed in only OOMW itself. ...
... It needs to be determined that it is suitable for food because of the ingredients from the OOMW. In addition, BC from OOMW can be a good candidate biomaterial for cosmetic and biomedical purposes [8,9,12,56] because OOMW contains natural bioactive compounds [23,47]. Alternatively, since it is a natural carbon source, it can be used in electrical/ electrochemical applications [10,11]. ...
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In this study, olive oil mill wastewater (OOMW), an important waste in the Mediterranean basin, was evaluated to produce bacterial cellulose (BC). For this purpose, the effects of different ratios of OOMW fractions (25-100%) and some additional nutrients (yeast extract, peptone and Hestrin-Schramm medium (HS) components) on BC productions were investigated. Unsupplemented OOMW medium (75% and 100%) yielded as much as BC obtained in HS medium (0.65 g/L), while enrichment of OOMW medium (%100) with yeast extract (5 g/L) and peptone (5 g/L) increased the amount of BC by 5.5 times, reaching to 5.33 g/L. In addition, produced BCs were characterized by FT-IR, TGA, XRD and SEM analyses. BC from OOMW medium (100% OOMW with supplementation) has a high thermal decomposition temperature (316.8°C), whereas it has lower crystallinity index (57%). According to the FT-IR analysis, it was observed that the components of OOMW might be absorbed by BCs. Thus, higher yield productions of BCs from OOMW media compared to BC obtained from HS medium indicate that olive oil industry wastes can be integrated into BC production for industrial applications. ARTICLE HISTORY
... It is widely distributed tree grown in many arid zones and native to all the countries around the Mediterranean region that provides 97% of olive production of the world. (Aragon and Palancar 2001;Tuck and Hayball, 2002;Aruoma, 2003). Olive oil industry generates large amount of oily waste designated raw olive pomace (lignocelluloses waste) and olive vegetable water (OVW) that contains a large amount of both organic and inorganic matter. ...
... The olive oils were obtained from Boundary Bend Olive Pty (Australia). ROO-, EVOOand OC-enriched diets were prepared based on the dietary intake of olive oil in the Greek population, that is 50 g/day [85], which resulted in a daily dose of 0.5 mg/kg body weight of total phenols (in EVOO) and OC. Mice were fed with ROO-, EVOO-and OC-enriched diet beginning at three months and continued for three months to end the treatment at six months. ...
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Alzheimer’s disease (AD) is characterized by several pathological hallmarks, including the deposition of amyloid-β (Aβ) plaques, neurofibrillary tangles, blood–brain barrier (BBB) dysfunction, and neuroinflammation. Growing evidence support the neuroprotective effects of extra-virgin olive oil (EVOO) and oleocanthal (OC). In this work, we aimed to evaluate and compare the beneficial effects of equivalent doses of OC-low EVOO (0.5 mg total phenolic content/kg) and OC (0.5 mg OC/kg) on Aβ and related pathology and to assess their effect on neuroinflammation in a 5xFAD mouse model with advanced pathology. Homozygous 5xFAD mice were fed with refined olive oil (ROO), OC-low EVOO, or OC for 3 months starting at the age of 3 months. Our findings demonstrated that a low dose of 0.5 mg/kg EVOO-phenols and OC reduced brain Aβ levels and neuroinflammation by suppressing the nuclear factor-κB (NF-κB) pathway and reducing the activation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes. On the other hand, only OC suppressed the receptor for advanced glycation endproducts/high-mobility group box 1 (RAGE/HMGB1) pathway. In conclusion, our results indicated that while OC-low EVOO demonstrated a beneficial effect against Aβ-related pathology in 5xFAD mice, EVOO rich with OC could provide a higher anti-inflammatory effect by targeting multiple mechanisms. Collectively, diet supplementation with EVOO or OC could prevent, halt progression, and treat AD.
... Phenolic derivatives entail antibacterial and phytotoxic activities suggesting that waste rich in phenolic compounds should be treated prior disposal (Mekki et al., 2007). However, polyphenols have gained growing interest for their antioxidant, antimicrobial, anti-inflammatory, anti-HIV, antiviral, antitumor, hypotensive, antiallergenic, cardio-protective and anti-thrombotic activities (Giada, 2013;Jeon and Choi, 2018;Tuck and Hayball, 2002). Thus, the recovery of phenolics from wastewater assists in minimizing the environmental impact of biowaste disposal, providing valuable molecules for human health. ...
Article
A biorefinery was developed employing olive pomace and table olive processing wastewater for the manufacture of polyphenols, lipids and algal biomass. Following extraction of pomace oil, olive pomace was subjected to dilute acid hydrolysis and enzyme hydrolysis under different conditions aiming to maximise the content of polyphenols and sugars formed in the hydrolysate produced for application in subsequent resin adsorption/desorption and microalgal fermentation processes. Hydrolysis of 100 kg exhausted olive pomace performed under the most efficient conditions yielded release of 54.5 kg of sugars and 3.2 kg of polyphenols. Polyphenols were recovered from olive pomace hydrolysates and table olive processing wastewater via adsorption/des-orption employing different polymeric resins. Application of XAD16N and PAD900 resins exhibited the highest overall polyphenols recovery, that reached 79.5% and 58.0% for table olive processing wastewater and exhausted olive pomace extracts respectively. The hydrolysates generated following polyphenols recovery were evaluated as feedstocks for lipids production by Scenedesmus obliquus and Isochrysis galbana, demonstrating maximum biomass and lipid productivity that reached 190 mg L −1 d −1 and 61.4 mg L −1 d −1 for S. obliquus, as well as 32 mg L −1 d −1 and 8.4 mg L −1 d −1 for I. galbana respectively. I. galbana accumulated high docosahexaenoic acid content that ranged between 8.4 and 9.5 mg g −1 of ash-free dry weight in fermentations of the hy-drolysates developed confirming that the strain could serve as an advanced bioproducer of polyunsaturated fatty acids in microalgal biorefineries. Abbreviations: BB Bold's Basal DA Dilute acid DW Dry weight EH Enzymatic hydrolysis EOP Exhausted olive pomace FS Fermentation step GAE Gallic acid equivalent OMW Olive mill wastewater
... Caffeine also worked effectively to suppress body weight gain through thermogenesis stimulus, compassionate stimuli, meal intakes, and adipose volume reduction (Kobayashi-Hattori et al. 2005). Furthermore, the threat of coronary artery disease and atherosclerosis by itself was reduced by hydroxytyrosol, one important phenolic ingredient in citrus water (Tuck and Hayball 2002). An amount of crops, including grapes, pistachio, peanuts and fruits, contain the resveratrol polyphenolic compound with strong antioxidant behavior and attract enhanced exposure because of its safety advantage, particularly unusual age-related diseases such as cancer, form 2, diabetes, cardiovascular disease, and neurological conditions (Marques et al. 2009). ...
Chapter
The phenolic compounds in plants can be used as antioxidants, functional polymers, attractants (flavonoids and carotenoids), ultraviolet light protectors (flavonoids), flash signals (salicylic acid), and phytoalexins, and protection chemicals. Phenolic compounds are important in defense reactions from a natural physiologic point of view, such as anti-aging, anti-inflammatory, antioxidant, and anti-proliferative operations. It is therefore useful to consume crop products which have elevated levels of antioxidants, thereby reducing the occurrence of certain acute illnesses, such as arthritis, tuberculosis, and cardiac illnesses, through oxidative stress management. Based on their impacts as allelopathic compounds and plant growth regulators, small molecular weight phenolics are of excellent concern and have traditionally been regarded protection molecules in plant pathogens. Recently, its function as signal molecules has become apparent in plant microbe structures. Specific molecules, such as Agrobacterium, can function as inducers or repressors for virulent mutations on plant–pathogen structures, Rhizobium-legume, and likely other symbiosis.
... This hyperlipidemia model was constructed by intraperitoneal injection of P407, as described in our previously published work [19]. In a previous study, the concentration of HT in olive oil varied from 1.55 to 14.42 mg/kg [20]. A crude count shows that a Mediterranean diet with 50 g olive oil intake should receive 0.7 mg HT at most per day. ...
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Hyperlipidemia results in endothelial dysfunction, which is intimately associated with disturbed mitochondrial homeostasis, and is a real risk factor for cardiovascular diseases (CVDs). Triphenylphosphonium (TPP+)-HT, constructed by linking a mitochondrial-targeting moiety TPP+ to hydroxytyrosol (HT), enters the cell and accumulates in mitochondria and is thus an important candidate drug for preventing hyperlipidemia-induced endothelial injury. In the present study, we found that TPP-HT has a better anti-inflammatory effect than HT. In vivo, TPP-HT significantly prevented hyperlipidemia-induced adverse changes in the serological lipid panel, as well as endothelial and mitochondrial dysfunction of the thoracic aorta. Similarly, in vitro, TPP-HT exhibited similar protective effects in palmitate (PA)-induced endothelial dysfunction, particularly enhanced expression of the mitochondrial ETC complex II, recovered FoxO1 expression in PA-injured human aorta endothelial cells (HAECs) and promoted FoxO1 nuclear translocation. We further demonstrated that FoxO1 plays a pivotal role in regulating ATP production in the presence of TPP-HT by using the siFoxO1 knockdown technique. Simultaneously, TPP-HT enhanced Nrf2 nuclear translocation, consistent with the in vivo findings of immunofluorescence, and the antioxidant effect of TPP-HT was almost entirely blocked by siNrf2. Concomitantly, TPP-HT’s anti-inflammatory effects in the current study were primarily mediated via the p38 MAPK/NF-κB signaling pathway in addition to the FoxO1 and Nrf2 pathways. In brief, our findings suggest that mitochondria-targeted TPP-HT prevents lipotoxicity induced endothelial dysfunction by enhancing mitochondrial function and redox balance by promoting FoxO1 and Nrf2 nuclear translocation.
... Clinical evidence related to HT metabolism is based primarily on human studies conducted with olive oils containing different concentrations of naturally present or added olive phenolic compounds [17][18][19][20][21][22][23][24][25][26][27][28]. Overall, these studies showed that HT can be rapidly absorbed from the intestine [19], metabolized in the gut and liver, distributed, and rapidly eliminated via the kidneys. ...
Article
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Table olives and olive oils are the main dietary sources of hydroxytyrosol (HT), a natural antioxidant compound that has emerged as a potential aid in protection against cardiovascular risk. Bioavailability studies with olive oils showed that HT is bioavailable from its free form and from conjugated forms such as oleuropein and its aglycone. Still, its low dietary intake, poor bioavailability, and high inter-individual variability after absorption through the gastrointestinal tract hamper its full benefits. In a randomized, controlled, blinded, cross-over study, we investigated the impact of HT metabolism and bioavailability by comparing two olive-derived watery supplements containing different doses of HT (30.58 and 61.48 mg of HT/dosage). Additionally, HT-fortified olive oil was used in the control group. To this aim, plasma and urine samples were evaluated in 12 healthy volunteers following the intake of a single dose of the supplements or fortified olive oil. Blood and urine samples were collected at baseline and at 0.5, 1, 1.5, 2, 4, and 12 h after intake. HT and its metabolites were analyzed using UHPLC-DAD-MS/MS. Pharmacokinetic results showed that dietary HT administered through the food supplements is bioavailable and bioavailability increases with the administered dose. After intake, homovanillic acid, HT-3-O-sulphate, and 3,4-dihydroxyphenylacetic acid are the main metabolites found both in plasma and urine. The maximum concentrations in plasma peaked 30 min after intake. As bioavailability of a compound is a fundamental prerequisite for its effect, these results promise a good potential of both food supplements for protection against oxidative stress and the consequent cardiovascular risk.
... The main classes of phenols in VOO are phenolic acids, phenolic alcohols, flavonoids, secoiridoids, hydroxy isocromans and lignans. Tuck and Hayball (2002) found that there are at least 30 phenolic compounds detected in olive oil belonging to the hydrophilic group. Oleuropein and ligstroside aglycon and their forms of dialdehyde were also detected as hydrophilic phenols from VOO (Owen et al., 2000 andCortesi, 2002). ...
Article
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In this study, the physicochemical properties and bioactive compounds of olive oils from cultivars koroneikiand “coratina, grown in Khatatba, Sadat city, Minufiya Governorate, Egypt, have been evaluated. Polyphenols are a large family of compounds found in fruits and vegetables, which exhibit strong antioxidant activity by scavenging different families of Reactive Oxygen Species (ROS). Polyphenols and secoiridoids found in EVOO, including oleocanthal (180.00 and 171.00 mg/kg), hydroxythyrosol (3.53 and 9.46 mg/ kg) and oleuropein aglycone (OLE) (575.76 and 664.91 mg/kg), in both Koroneiki and Coratina olive oils, respectively. In all oil samples analyzed the highest antioxidant capacity was attributed tokoroneiki olive oil (35.85% I of DPPH and 4.37% I of ABTS) compared tocoratina, (26.37% I of DPPH and 2.82% I of ABTS). The main characteristics of the koroneiki cultivar were a very high concentration of total phenols (530.00 mg/kg of gallic acid) and α-tocopherol (155.00 mg/kg).
... Many analytical techniques have been implemented to evaluate the phenolic content after the extraction process including spectrophotometric (Folin-Ciocalteu) and chromatographic techniques (Olmo-García et al. 2019). Highperformance liquid chromatography (HPLC) determination is characterized by its sensitivity, but the commercial availability of polyphenols standards restricted the HPLC application for a reliable quantification (Tuck and JHayball 2002;Cioffi et al. 2010;Capriotti et al. 2014;Ricciutelli et al. 2017;Siano et al. 2022;Romero and Brenes 2012). Paper spray tandem mass spectrometry (PS-MS/MS) and HPLC-MS/MS were used as more sophisticated chromatographic tools; however, these instruments are very expensive and not available in routine analysis laboratories (Bartella et al. 2018(Bartella et al. , 2020. ...
Article
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Phenolic compounds are responsible for healthy, nutritional, and sensory quality of olive oil. The present work deals with the optimization of a method for performing direct acid hydrolysis and extraction of the bound forms of hydroxytyrosol (Htyr) and tyrosol (Tyr) from olive oil. The proposed method was simpler and less time-consuming and required minimum sample pre-treatment steps, compared to liquid–liquid extraction and solid phase extraction (SPE) methods. The hydrolysis and extraction conditions were optimized in terms of extracting solvent, acid type and concentration, temperature, and mixing time. The maximum phenolic compound (Htyr and Tyr) contents were obtained when the olive oil sample was treated with 2.0 M H2SO4 and water as solvent for 4 h at 75 °C. The method showed satisfactory linearity (R² > 0.99), high precision (%RSD ˂ 3.0%), and high recovery (> 94.0%) for Tyr and Htyr. The limits of quantification (LOQ) were 0.56 and 0.69 mg/L for Tyr and Htyr, respectively. Some commercial olive oil samples from Jordanian olive cultivars such as Nabali Baladi, Nabali Mohasen, K18, and Rumi were analyzed using the developed method. The results obtained varied depending on the type of cultivar, and highest value of total phenolic compounds (421.70 mg/kg) was reported for K18 variety that harvested at early time. Furthermore, phenolic compounds including phenols, secoiridoids, flavones, and lignans were determined using SPE method. The results presented statistically significant differences (p < 0.05) between SPE and acid hydrolysis methods. Graphical Abstract
... Across all antioxidant assays, the vegetable material cooked in olive oil demonstrated relatively high antioxidant activity, in comparison to the other cooking and drying methods used. According to Tuck and Hayball [36], olive oil contains at least 30 phenolic compounds, hence considerable antioxidant activity. ...
Article
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In this study, Corchorus olitorius leaves were subjected to different thermal treatments (blanching, boiling, drying, frying, and steaming) and analyzed for proximate composition, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. Furthermore, Fourier transform infrared spectroscopy (FTIR) was used to identify functional groups, while metabolites were identified with LC-MC. The TPC and antioxidant activity of C. olitorius were significantly (p < 0.05) increased by cooking and drying. The steam-cooked sample had the highest TPC (18.89 mg GAE/g) and TFC (78.42 mg QE/g). With ABTS, FRAP, and DPPH assays, the steam-cooked sample exhibited the highest antioxidant activity of 119.58, 167.31, and 122.23 µM TE/g, respectively. LC-MS identified forty-two (42) metabolites in C. olitorius that included phenolic acid derivatives, flavonoid derivatives, and amino acid derivatives. Overall, steaming appears to be the best cooking method, with respect to the retention of phytochemical compounds and antioxidant activity.
... EVOO composition is primarily the glycerol fraction (~95%, rich in monounsaturated fatty acids) and the nonglycerol fraction, which contains phenolic compounds (~5%) [12]. Recent studies have shown that the phenolic compounds in EVOO are antioxidant molecules that can scavenge the toxic effects of oxygen metabolism, such as free radical formation, thus protecting cells against oxidative damage and contributing significantly to human health [13][14][15]. Our studies demonstrated that the addition of EVOO with variable levels of phenolic content (low to high range) to the diet of AD mouse models restored the BBB function and reduced brain Aβ-and tau-related pathologies, oxidative stress, and neuroinflammation, which collectively was associated with improved memory function [16][17][18][19][20]. ...
Article
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Mild cognitive impairment (MCI) and early Alzheimer’s disease (AD) are characterized by blood–brain barrier (BBB) breakdown leading to abnormal BBB permeability ahead of brain atrophy or dementia. Previous findings in AD mouse models have reported the beneficial effect of extra-virgin olive oil (EVOO) against AD, which improved BBB and memory functions and reduced brain amyloid-β (Aβ) and related pathology. This work aimed to translate these preclinical findings to humans in individuals with MCI. We examined the effect of daily consumption of refined olive oil (ROO) and EVOO for 6 months in MCI subjects on BBB permeability (assessed by contrast-enhanced MRI), and brain function (assessed using functional-MRI) as the primary outcomes. Cognitive function and AD blood biomarkers were also assessed as the secondary outcomes. Twenty-six participants with MCI were randomized with 25 participants completed the study. EVOO significantly improved clinical dementia rating (CDR) and behavioral scores. EVOO also reduced BBB permeability and enhanced functional connectivity. While ROO consumption did not alter BBB permeability or brain connectivity, it improved CDR scores and increased functional brain activation to a memory task in cortical regions involved in perception and cognition. Moreover, EVOO and ROO significantly reduced blood Aβ42/Aβ40 and p-tau/t-tau ratios, suggesting that both altered the processing and clearance of Aβ. In conclusion, EVOO and ROO improved CDR and behavioral scores; only EVOO enhanced brain connectivity and reduced BBB permeability, suggesting EVOO biophenols contributed to such an effect. This proof-of-concept study justifies further clinical trials to assess olive oil’s protective effects against AD and its potential role in preventing MCI conversion to AD and related dementias.
... Both hydroxytyrosol and oleuropein have been shown to possess anti-inflammatory, bactericidal and bacteriostatic activities [22] . Some in vivo studies on olive leaf have shown that its extract can decrease blood pressure and dilate the coronary arteries surrounding the heart [23] . Moreover, hydroxytyrosol has been shown to have anti-cancer effect on human colon adenocarcinoma HT-29 cells and human promyelocytic. ...
Article
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Nowadays viral disease like coronavirus is a significant threat and becomes dangerous all over the world. Currently, 1.1 million sixty-four thousand five hundred fifteen (1164515) people passed away from the infection of COVID-19 all over the world. Still, no data or vaccine was invented for coronavirus (COVID-19) treatment. The review study was conducted to evaluate and suggest the traditional and possible treatment immediately for the viral disease and COVID-19 (coronavirus). From the studies of different research data, it has been seen that black cumin seed and oil, olive fruit and oil, ajwa dates, ginger, clove, fig fruit, and leaf extract were effective traditional treatments for inflammation, flu, throat sore (pain), asthma as well as other viral diseases. Therefore, it may seem from the review data that black cumin seed and oil, olive fruit and oil, ajwa dates, ginger, clove, fig fruit, and leaf extract may be an effective treatment for COVID-19 (coronavirus) for the time being.
... There are also several lipophilic or amphiphilic microconstituents in virgin olive oil, including phytosterols, squalene, tocopherols, phenolic compounds and terpenic acid derivatives. Phenolic compounds, in turn, are present as phenolic acids or alcohols, oleuropein derivatives, lignans and flavonoids [2,3]. Polyphenols appear to reduce morbidity and/or slow down the progression of cardiovascular, neurodegenerative and cancer diseases. ...
... In dried fruit its content can reach up to 14%. [81] OL is responsible for the bitterness of fresh green olives. [82] Other secoiridoids of olive are demethyloleuropein and other derivatives of OL, oleocanthal, oleacein, ligstroside and its derivatives ( Table 2). ...
Article
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Iridoids are natural monoterpenoids, widely distributed in ornamental plants, herbs, and medicinal plants, but particularly in the green parts of plants. Their significance arises from diverse biological activities (anti-inflammatory, antioxidative, anti-cancer, anti-atherogenic, antidiabetic, neuroprotective, etc.) which have been well-documented and point out to the natural-origin, non-toxic compounds for the use in disease prevention and treatment. Nonetheless, iridoids are scarce in edible fruits and are not perceived as important phytocompounds of dietary fruits and food products. However, they do occur in some common edible fruits – olive, noni, berries, and a few less-common, but unique fruits – Japanese cornel, cornelian cherry, kousa dogwood, haskap berry, and guelder rose. In this review, we present the current state of knowledge regarding the identification and content of iridoids in edible fruits, their predominant activities, and above all, the possibilities and effects of iridoids’ application in foods, drinks, and pharmaceuticals. The consulted literature shows that iridoids or iridoid-rich fruits can be successfully applied to broaden the variety of foods, as functional additives, and possibly as future pharmaceuticals of natural origin. Therefore, iridoids deserve an important role in a healthy diet and disease prevention.
... 21,22 Due to the high concentration of phenolic compounds, of which most abundant is oleuropein, interest in olive leaf has increased recently. 23,24 The components of the olive leaves are known for their immunomodulatory, anti-inflammatory, antioxidant, hypoglycemic, antihypertensive, antimicrobial, and antiatherosclerotic effects. 25,26 Although its antiviral mechanism of action is not fully understood, several studies have been conducted on the antiviral effects of olive leaf extract. ...
Article
Objective: During the Coronavirus Disease-2019 (COVID-19) pandemic, in addition to the current measures, the healthy immune system plays an essential role and various natural agents have been recommended to boost innate immunity. The aim of this study was to investigate any association between the potential immunomodulatory activity and drinking olive leaf tea (OLT) in the COVID-19 pandemic. Design: The study was conducted among the workers in a tractor factory where OLT was served in routine. Drinking at least one cup of OLT per day for a minimum of 1 month was the inclusion criteria used in the study. The workers who had a history of vaccination and COVID-19 were excluded from the study, and lymphocyte subsets, interleukin (IL)-2, IFN-γ, COVID-19-specific IgM and IgG levels were analyzed in all the participants to determine the asymptomatic individuals among the participants and compare the immunological parameters. Results: The study was conducted among 336 workers, 183 of them were OLT drinkers and 153 were OLT nondrinkers. The results showed higher values of CD3-/CD16/56 (natural killer [NK]) cells, CD3+/CD16/56 (natural killer T [NKT]) cells, total NK (NK+NKT) cells, and serum IFN-γ, and IL-2 levels in OLT drinkers compared to the nondrinkers. Although all the OLT drinkers and nondrinkers included in the study reported no history of COVID-19, specific COVID-19 IgG levels were found positive in 60% of OLT drinkers and 38% OLT nondrinkers. Conclusions: Peripheral NK and NKT cell values and IL-2 and IFN-γ secretion levels were found higher in the OLT drinking group. There were positive correlations between the OLT drinking frequency and NK cell counts. Moreover, the number of individuals who had "asymptomatic" COVID-19 infection was higher in the OLT drinking group than in the nondrinking cohort. Clinical Trail: The trial has been registered in the ClinicalTrials.gov database (CTR NCT05222347).
... More specifically, the information concerning the bioavailability of most OBs is limited despite the intensive research that has been devoted the past two decades to the investigation of their biological properties. This fact is reflected in the number of review papers published from 2002 to 2022 [29,[47][48][49][50][51]. Regarding OBs' metabolism, sporadic reviews have been published focusing either on specific compounds [12] or specific approaches [52], or-in most cases due to the high variety of chemical categories and extremely high number of different compounds included in each olive product-they are investigated and discussed separately [34,50]. ...
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Consumption of olive products has been established as a health-promoting dietary pattern due to their high content in compounds with eminent pharmacological properties and well-described bioactivities. However, their metabolism has not yet been fully described. The present critical review aimed to gather all scientific data of the past two decades regarding the absorption and metabolism of the foremost olive compounds, specifically of the phenylalcohols hydroxytyrosol (HTyr) and tyrosol (Tyr) and the secoiridoids oleacein (Olea), oleocanthal (Oleo) and oleuropein (Oleu). A meticulous record of the in vitro assays and in vivo (animals and humans) studies of the characteristic olive compounds was cited, and a critical discussion on their bioavailability and metabolism was performed taking into account data from their gut microbial metabolism. The existing critical review summarizes the existing knowledge regarding the bioavailability and metabolism of olive-characteristic phenylalchohols and secoiridoids and spotlights the lack of data for specific chemical groups and compounds. Critical observations and conclusions were derived from correlating structure with bioavailability data, while results from in vitro, animal and human studies were compared and discussed, giving significant insight to the future design of research approaches for the total bioavailability and metabolism exploration thereof.
... It is necessity to find and develop new antimicrobial agents due to the increase in resistance to antibiotics, wide-spread use of immunesuppressing drugs and a rise in bacterial infections (15). An effective increase has been reported in the data from the last few years regarding the benefits of olive and its other products (16). Data has been shown that different types of cancer including intestine, prostate, breast, as well as other diseases neurological disorders, cardiovascular diseases and thrombotic diseases can be prevented by phenolic compounds of olive oil (17). ...
Article
Background and aim: The problem of drug-resistance developed by bacteria against antibiotics turned the attention of researchers to find out and develop such products which haven't such issues. For this purpose, this study was carried out by using walnut and olive oil against several gram negative and gram-positive bacteria. Methods: Different concentrations of oils were employed using disc diffusion method. They exhibited better antibacterial properties. Results: All the tested bacteria, viz.
... It is also present in olive fruits and virgin olive oil and is responsible for the characteristic bitter taste of unprocessed olives. OL exhibits numerous biological and pharmacological activities, including antioxidant [1], anti-inflammatory [2], anti-apoptotic functions [3], and so on [4]. In addition, OL was efficient in inhibiting hyperglycemia and oxidative stress induced by diabetes, suggesting that OL may help to prevent oxidative stress-related diabetes complications [5]. ...
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Compared to beta-cyclodextrins (beta-CD), hydroxypropyl-beta-cyclodextrins (HP-beta-CD) are a more popular material used to prepare inclusion complexes due to their superior solubility and intestinal absorption. In this study, oleuropein (OL) inclusion complexes with beta-CD (beta-CD:OL) and HP-beta-CD (HP-beta-CD:OL) were prepared and the formation of inclusion complexes was validated by IR, PXRD, and DSC. A phase solubility test showed that the lgK (25 °C) and binding energy of beta-CD:OL and HP-beta-CD:OL was 2.32 versus 1.98, and −6.1 versus −24.66 KJ/mol, respectively. Beta-CD:OL exhibited a more powerful effect than HP-beta-CD:OL in protecting OL from degradation upon exposure to light, high temperature and high humidity. Molecular docking, peak intensity of carbonyls in IR, and ferric reducing power revealed that beta-CD:OL formed more hydrogen bonds with the unstable groups of OL. Both inclusion complexes significantly enhanced the solubility, intestinal permeation and antioxidant activity of OL (p < 0.05). Though HP-beta-CD:OL had higher solubility and intestinal absorption over beta-CD:OL, the difference was not significant (p > 0.05). The study implies that lower binding energy is not always associated with the higher stability of a complex. Beta-CD can protect a multiple-hydroxyl compound more efficiently than HP-beta-CD with the intestinal permeation comparable to HP-beta-CD complex.
... We determined 29 individual phenols and five capsaicinoids in chili olive oil. The predominant phenolics in chili olive oil were secoiridoids, which were mainly oleuropein, tyrosol, and ligostride derivatives and aglycones, which has also been reported in studies by Cicerale et al. [26] and Tuck and Hayball [27]. The other phenolic groups were lignans, flavones, flavonols, and hydroxycinnamic acids, which accounted for only 0.2% of the determined phenolic content of chili olive oil. ...
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Chili olive oil is a popular addition to various foods in many countries. In a detailed study, the content of phenols and capsaicinoids in chili olive oil was determined using chili flakes and whole chilies. A total of 99.8% of the phenols in chili olive oil were secoiridoids, with elenolic acid, oleuropein aglycones, and ligostride aglycones being the most abundant. Chili olive oil with chili flakes contained higher levels of capsaicinoids (+21.6%) compared to whole chili olive oil. Capsaicin and dihydrocapsaicin accounted for about 95% of all capsaicinoids in the chili olive oil. The extrac-tion rate of dry “Cayenne” chili was 7.1% in whole chili olive oil and 9% in chili olive oil with flakes, confirming that chili flakes are better extracted in olive oil. With the determination of 29 individual phenols and five individual capsaicinoids, the study provided a detailed insight into the secondary metabolites of chili olive oil and confirmed that it is a health source.
... Furthermore, phenolic alcohols such as tyrosol and hydroxytyrosol are derived from secoiridoid compounds (Sánchez et al., 2019), which have even more antioxidant capacity than oleuropein (Giovannini et al., 1999;Gómez-Rico, 2008). In addition, hydroxytyrosol and oleuropein have antimicrobial activity (Tuck and Hayball, 2002). Flavonoids such as rutin, catechin, apigenin, and quercetin are recognized to remove free radicals, prevent coronary heart disease, and present antitumor properties (Yao et al., 2004). ...
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There are more than 2000 varieties of olives grown worldwide, of which only a few (2 %) are cultivated in Argentina. Mendoza is one of the main oil-producing provinces in the country due to its adequate agroecological conditions. In addition, Mendoza has an olive germplasm collection with over 70 accessions. This work aimed to characterize olive oil from 18 preselected varieties in the collection for qualitative characteristics that are important to the olive industry (i.e., industrial yield, acidity, oxidative stability, total phenolic compounds and phenolic profile). As a result, all evaluated characteristics were significantly different among varieties (p < 0.001) and allowed identifying excellent qualities in varieties not currently cultivated. Five scarcely cultivated varieties (‘Villalonga’, ‘Nebbio’, ‘Nevadillo Blanco’, ‘Canino’, and ‘Piangente’) were highlighted above the most widespread cultivars in Mendoza, Argentina. Featuring on average of 14 % of industrial yield, 15 h of oxidative stability and 373 mg kg⁻¹ of total phenolic compounds.
... Moreover, it is a healthy product which can prevent some cardiovascular diseases. Medical research has confirmed that regular consumption of olive oil contributes to lowering blood cholesterol, reducing the risk of certain kinds of cancer, and helping in calcium absorption (Owen et al., 2000;Sofi et al., 2008;Tuck and Hayball, 2002). The extensive dissemination of these findings supported by mass media has been a decisive help in creating an excellent image of olive oil as a healthy food product (Santosa et al., 2013;Xiong et al., 2014). ...
Article
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This paper focuses on tourists’ local olive oil purchasing behaviour in a tourist destination, providing evidence of consumer segments based on the importance of olive oil attributes for purchasing decisions. The research was conducted in Croatia, a famous tourist destination in the Mediterranean, recognised for its traditional food products, including olive oil. A survey conducted on 471 tourists shows that the main predictors of a tourist’s purchase of olive oil are the number of previous visits to the destination and the tourist’s country of origin. The relative importance of extrinsic and intrinsic olive oil attributes differed between tourists, and the present research identifies four market segments. The results of this study may help olive oil producers develop and implement more successful marketing strategies directed towards tourists in the destination.
... Besides, hydroxytyrosol and oleuropein have been shown to exhibit an antimicrobial effect against several bacterial strains. Indeed, although they were more effective against ATCC bacterials trains including Hemophilus influenzae ATCC 9006, Moraxella catarrhalis ATTC 8176, Salmonella typhi ATCC 6539 and Staphylococcus aureus ATTC 25923, these molecules induced a promising cytotoxic activity against a great number of bacterial strains such as Salmonella spp., Vibrio alginolyticus and Vibrio cholerae [90]. ...
Chapter
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Virgin olive oil is a highly appreciated edible oil, considered as a relevant component of the Mediterranean diet. The spread of this foodstuff all over the world is making, to a certain extent, that new markets and consumers are getting used to this "Mediterranean's golden treasure". Currently, there is great momentum in research relating virgin olive oil intake to healthiness, which has been mainly associated with its phenolics content. Phenolics are considered health-promoting compounds due to their multifaceted biochemical actions that can potentially reduce the risk of various health problems. Yet, since the health-promoting effects of various phenolic compounds have been widely attributed to their metabolic products rather than the naturally occurring forms, the assessment of virgin olive oil phenolics bioavailability is still gaining immense attention and considered a great hot topic among researchers. In the first section of this contribution, the main groups of phenolic compounds identified in virgin olive oil are described, their qualitative and quantitative variability is discussed while analytical approaches applied for their determination are highlighted. The second section reports the beneficial health properties of virgin olive oil consumption related to its phenolics content paying special attention to their bioavailability.
... O. europae is nearly all iconic species owing to its economical, ecological and cultural importance [2]. In fact the utilization of table olives as well as olive oil has been revealed to be connected with a diversity of physical condition and benefits, comprising a lesser frequency of heart ailment and firm types of cancer [3,4]. It is propagated by both sexual and asexual methods. ...
... They beneficially influence mitochondrial function, and have been increasingly used as prophylactic agents in controlling NAFLD in different animal models [6,11,12]. Hydroxytyrosol (HT) is a key component of extra virgin olive oil which exerts many beneficial biological activities such as scavenging free radicals and ameliorating fatty liver and diet-induced obesity [13,14]. Moreover, our previous study indicated that HT attenuated liver damage induced by high-fat diet [15]. ...
Article
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Emerging evidence suggests that mitochondrial dysfunction mediates the pathogenesis for non-alcoholic fatty liver disease (NAFLD). Hydroxytyrosol (HT) is a key component of extra virgin olive oil which can exert beneficial effects on NAFLD through modulating mitochondria. However, the mechanism of the impacts of HT still remains elusive. Thus, an in vivo and a series of in vitro experiments were carried out to examine the impacts of hydroxytyrosol (HT) on lipid metabolism and mitochondrial function in fish. For the in vivo experiment, two diets were produced to contain 10% and 16% fat as normal-fat and high-fat diets (NFD and HFD) and two additional diets were prepared by supplementing 200 mg/kg of HT to the NFD and HFD. The test diets were fed to triplicate groups of spotted seabass (Lateolabrax maculatus) juveniles for 8 weeks. The results showed that feeding HFD leads to increased fat deposition in the liver and induces oxidative stress, both of which were ameliorated by HT application. Furthermore, transmission electron microscopy revealed that HFD destroyed mitochondrial cristae and matrix and induced severe hydropic phenotype, while HT administration relieved these alterations. The results of in vitro studies using zebrafish liver cell line (ZFL) showed that HT promotes mitochondrial function and activates PINK1-mediated mitophagy. These beneficial effects of HT disappeared when the cells were treated with cyclosporin A (Csa) as a mitophagy inhibitor. Moreover, the PINK1-mediated mitophagy activation by HT was blocked when compound C (CC) was used as an AMPK inhibitor. In conclusion, our findings demonstrated that HT alleviates fat accumulation, oxidative stress and mitochondrial dysfunction, and its effects are deemed to be mediated via activating mitophagy through the AMPK/PINK1 pathway.
... They account for most of the antioxidant activity in plants. They have the ability to slow or prevent the oxidation of other molecules [17]. Phenols in particular are very important constituent of plant with the ability to scavenge free radicals owing to their methyoxy (-OCH3) and hydoroxyl (-OH) groups substituent [18,19]. ...
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Background: Kiwano, commonly called horned melon is a common fruit consumed in the tropics for its nutritional and therapeutic value. This study evaluated the composition of some bioactive compounds in the rind of the fruit as well as its antioxidant and anti-inflammatory effects using in vitro methods. Methods: The rind of the fruits of kiwano were peeled out, pulverized and extracted with 80% ethanol. The bioactive compounds evaluated were phenol, flavonoid, beta carotene, lycopene and ascorbic acid. The antioxidant properties were evaluated using DPPH, iron reducing power and inhibition of lipid peroxidation assays. Ascorbic acid served as the standard. The anti-inflammatory property was measured in-vitro using anti-proteinase activity, inhibition of albumin denaturation and membrane stabilization assay systems. Aspirin and diclofenac served as reference drugs Results: Phenol and flavonoids were the bioactive compounds found in higher concentration than the rest with concentrations of 261.73±13.54 and 130.86±9.66 mgGAE/ml of the dry matter respectively. In the antioxidant assay, the highest activity of more than 50% was recorded in DPPH assay. The maximum percentage radical scavenging activity of the extract was 76.74% at 800 µg/ml with a drop in activity at 1000 µg/ml (75.02%) and EC50 value of 230 µg/ml. Ascorbic acid exhibited 96.35% scavenging activity of radicals at 1000 µg/ml and EC50 value of 260 µg/ml. For the anti-inflammatory assay, the extract exhibited 16.43% anti-proteinase activity, 25.64% inhibition of heat-induced haemolysis activity and 47.14% inhibition of albumin denaturation activity at 1000 µg/ml. More than 50% activity was recorded for the reference drugs. Conclusion: We therefore conclude that the rind of the fruit of kiwano is rich in biologically active compounds and has antioxidant and anti-inflammatory properties. The rind is a potential source of therapeutic compounds.
... They account for most of the antioxidant activity in plants. They have the ability to slow or prevent the oxidation of other molecules [17]. Phenols in particular are very important constituent of plant with the ability to scavenge free radicals owing to their methyoxy (-OCH3) and hydoroxyl (-OH) groups substituent [18,19]. ...
Article
Full-text available
Background: Kiwano, commonly called horned melon is a common fruit consumed in the tropics for its nutritional and therapeutic value. This study evaluated the composition of some bioactive compounds in the rind of the fruit as well as its antioxidant and anti-inflammatory effects using in vitro methods. Methods: The rind of the fruits of kiwano were peeled out, pulverized and extracted with 80% ethanol. The bioactive compounds evaluated were phenol, flavonoid, beta carotene, lycopene and ascorbic acid. The antioxidant properties were evaluated using DPPH, iron reducing power and inhibition of lipid peroxidation assays. Ascorbic acid served as the standard. The anti-inflammatory property was measured in-vitro using anti-proteinase activity, inhibition of albumin denaturation and membrane stabilization assay systems. Aspirin and diclofenac served as reference drugs Results: Phenol and flavonoids were the bioactive compounds found in higher concentration than the rest with concentrations of 261.73±13.54 and 130.86±9.66 mgGAE/ml of the dry matter respectively. In the antioxidant assay, the highest activity of more than 50% was recorded in DPPH assay. The maximum percentage radical scavenging activity of the extract was 76.74% at 800 µg/ml with a drop in activity at 1000 µg/ml (75.02%) and EC 50 value of 230 µg/ml. Ascorbic acid exhibited 96.35% scavenging activity of radicals at 1000 µg/ml and EC 50 value of 260 µg/ml. For the Original Research Article Ani et al.; JALSI, 25(1): 48-58, 2022; Article no.JALSI.85819 49 anti-inflammatory assay, the extract exhibited 16.43% anti-proteinase activity, 25.64% inhibition of heat-induced haemolysis activity and 47.14% inhibition of albumin denaturation activity at 1000 µg/ml. More than 50% activity was recorded for the reference drugs. Conclusion: We therefore conclude that the rind of the fruit of kiwano is rich in biologically active compounds and has antioxidant and anti-inflammatory properties. The rind is a potential source of therapeutic compounds.
... Phenolic compounds are divided into seven categories: phenolic acids, simple phenols, flavonoids, secoiridoids, lignans, hydroxy-isochromans and pseudophenols. As polar compounds, they are mainly water soluble, slightly fat soluble and have a strong antioxidant activity [8]. The phenolic components present in olive oil are different from those of olives. ...
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The purpose of this study was to evaluate the key quality characteristics of olive oil with a main focus on the biophenolic content, its beneficial effects on health and the contribution of various quality characteristics to its health claims, as well as its influence from various parameters. Samples from different traditional oil-producing regions of Greece were initially examined for the most important quality parameters, such as the percentage of free acidity, the number of peroxides and the spectrophotometric investigation in the ultraviolet. The samples were then tested for their biophenolic content, expressed in milligrams of tyrosol, and its derivatives per 20 g of olive oil using the analytical technique high-performance liquid chromatography (HPLC). Then, the biophenol contents of the analyzed samples were compared based on the presented intensities in terms of the variety and the area of cultivation, the altitude, the type of cultivation, the extraction system in the mill and the time interval from olive harvest to oiling. Finally, according to the results, the content of biophenols in olive oil and its health claims were found to be influenced by the various parameters with which they were compared
... As OLE was spiked in olive oil, the dose was selected to resemble the dietary intake of olive oil in the Greek population (50 g/ day). 39 Mice were fed with an OLE-enriched diet, beginning at an age of 3 months and continuing for 3 months to end the treatment at 6 months. This age is characterized by aggravated pathology and memory impairment. ...
... In recent years, studies of hydroxytyrosol and similar phenols have increased because these chemicals may contribute to the avoidance of some abnormal situation including cardiovascular diseases and cancer. [3] The question remains as whether the dose ingested from food is high enough at the action site. ...
Article
Hepatotoma is the leading type of primary liver cancer in adults and third cause of death in the world. Hydroxytyrosol is a natural phenol existing in olive (Olea europaea L.). Hydroxytyrosol is the chief ingredient of olive oil, which was early deemed to be the most robust antioxidant in olive oil. Hydroxytyrosol is known to inhibit various types of cancer by different methods. This study was aimed to delineate the action of hydroxytyrosol on viability and [Ca2+]i in HepG2 hepatoma cells. Fura-2 was used to detect [Ca2+]i, and WST-1 assays were applied to explore cell cytotoxicity. Hydroxytyrosol elicited [Ca2+]i raises. Eliminating external Ca2+ diminished the Ca2+ signal by 30%. Hydroxytyrosol-evoked Ca2+ influx was diminished by 20% by three inhibitors of store-operated Ca2+ channels and by a protein kinase C activator and an inhibitor. In the absence of Ca2+, thapsigargin eradicated hydroxytyrosol-provoked [Ca2+]i raises. Suppression of phospholipase C (PLC) with U73122, a PLC inhibitor, did not inhibit hydroxytyrosol-elicited [Ca2+]i raises. Hydroxytyrosol reduced cell viability. This cytotoxic action was not reversed by preincubation with BAPTA/AM, a cytosolic Ca2+ binder. In sum, in HepG2 hepatoma cells, hydroxytyrosol elicited [Ca2+]i raises by provoking PLC-unrelated discharge of Ca2+ from ER and Ca2+ influx through PKC-sensitive store-operated Ca2+ entry. In addition, hydroxytyrosol elicited Ca2+-dissociated cytotoxicity.
... Brassica juncea seeds have been shown to possess antioxidant activity [11]. Olive oil is an example of edible oil and has been reported to contain high amount of phenolic compounds with antioxidant properties and other potent biological activities including anti-ulcer activity [8,[36][37][38][39][40], that could partially account for the observed effect. However, further studies will be required to identify other biological activities of edible oil and Brassica juncea seed and to confirm their possible roles in the gastroprotective activities of Mystomate4 ® as recorded in the present study. ...
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Background Ulcer remains a health challenge worldwide with antibiotics and proton pump inhibitors as major management therapy. The study investigated the acute, sub-chronic toxicity and gastrointestinal protective activity of a polyherbal formulation (Mystomate4®) used locally in Nigeria. Methods Oral LD50 and the sub-chronic toxicity test were determined in mice and rats. Mice were grouped into 8 groups of 8 mice each. They were dosed a graded concentration of the formulation (1.28, 2.56; 5.12; 10.24; 20.48; 40.96; 81.92; 163.84 g/kg body weight). The graded dose used was arrived at after an initial pilot study. Thereafter doses were chosen around the dose obtained from the pilot study. Animal were dosed orally and observed for sign of toxicity and number of death recorded after 24 h. The sub-chronic toxicity study was carried out for 3 months in rats at a dose of 2.5 and 5.0 g/kg body weight arrived at by titrating down the LD50 value after which some vital tissues were harvested and assessed for toxicity using relevant biomarkers. Anti-ulcer activity was evaluated in rats using ethanol, indomethacin and pylorus ligation induced ulcer models. Data were analysed with Graph Pad Prism version 5.0 using appropriate statistical method and significant level placed at p ≤ 0.05. Results The acute toxicity study showed an LD50 result of 22,837.21 g/kg. The sub-chronic toxicity study resulted in a significant reduction in body weight due to significant decrease (p ≤ 0.05) in feed consumption. Biochemical analyses of the blood samples showed a significant increase (p ≤ 0.05) in creatinine and albumin level in the 2.5 mg/kg female group. ALT was significantly increased in all the treated rats except in 2 mg/kg female rats. Alkaline phosphatase significantly increased in high dosed male (HM) group while blood urea:creatinine ratio was significantly lowered in all the treated groups. There was a significant increase in serum TGL in all rats while LDL was significantly increased and decreased in HM and high dosed female (HF) respectively. Conclusion Mystomate4® showed significant protection against ethanol and indomethacin-induced ulcer models but did not modify the gastric parameters in pylorus ligation-induced ulcer model. The polyherbal formulation is nontoxic with promising potentials for treating experimental peptic ulcer.
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تضم ليبيا عدد كبير من معاصر زيت الزيتون يقع اكثرها في المنطقة الغربية حيث تتركز زراعة اشجار الزيتون لغرض الحصول على الزيت، وينتج عن معاصر زيت الزيتون كميات كبيرة من المخلفات السائلة او المياه المرافقة التي تحتوي على كميات كبيرة من المواد العضوية والمركبات السامة، وتم في هذه الدراسة تجميع عينات من المياه الناتجة عن عمليات عصر الزيتون والمياه العادمة من عدد 17 معصرة منتشرة في المنطقة من القره بوللي الى الدافنية واجريت عليها بعض التحاليل لتقدير بعض الخصائص الكيميائية لها ومدى تأثيرها على البيئة حيث تمت دراسة كل من الاس الهيدروجيني والايصالية الكهربائية والمواد الصلبة الذائبة والعالقة والحمل العضوي والاكسجين الكيميائي المطلوب والفينولات واهم المغذيات كالنيتروجين والفوسفور، واظهرت النتائج وجود ارتفاع كبير في كميات وتراكيز هذه المواد في العينات التي تم تحليلها من المعاصر المختلفة مع وجود تفاوت كبير في كمية هذه المواد من معصرة لأخرى مع وجود فروق ملحوظة بين المياه الناتجة عن عصر حب الزيتون ومياه الصرف التي يتم تجميعها لغرض التخلص منها وبينت النتائج انه هناك تأثيرات سلبية كبيرة للطريقة التي يتم بها التخلص من هذه المخلفات السائلة لهذه المعاصر في منطقة الدراسة.
Chapter
Given the rising incidence of cognitive impairment in population, especially in elderly persons with or without Neurodegenerative diseases such as Alzheimer disease. Their prevention has become one the important and urgent action of public health, which conducts to the defiance of achieving optimal control and delaying its development. There is effort to assure a quality life of these vulnerable persons by non-pharmacological strategies. Therefore, adherence to a diet to prevent the development of cognitive disorders remains a desirable and cheaper solution. The importance of the Mediterranean diet (MD) and its benefits have received special attention. The MD is characterized by an elevated consumption of plant-based foods; legumes, fruits, seeds and nuts, bread and other forms of cereals. Also contains, moderate proportion of dairy products, medium amounts of poultry and fish, and lastly, small quantities of wine and red meat. The effect of the MD in the prevention of some chronic illness has stimulated the appetite of many researchers to study this diet in the last two decades. Previous studies have shown a significant relation between the adherence to MD and cognitive functions improvement in vulnerable patients especially patients with AD. Moreover, several findings from clinical and experimental studies have revealed evidences of some benefit of the MD on cognitive functions including working memory, reasoning, delayed recall, and processing speed. The possible mechanisms of the MD might be explained by a reduction of oxidative stress by enhancing the oxidative stress enzymes and reduce the Reactive oxygen species, improved inflammation and controlling metabolic factors.
Article
The prevalence of bone injuries is greatly increasing each year and the proper healing of fractures without any complications is very challenging. Self-setting calcium phosphate cements (CPCs) have attracted great attention as bioactive synthetic bone substitutes. Quercetin (QT) is a multipurposed drug with reported bone-conserving properties. The loading of QT and QT-phospholipid complex within nanostructured lipid carriers (NLC) was proposed to overcome the poor physical properties of the drug and to introduce the use of bioactive excipients as phospholipids and olive oil. The aim of this work was to formulate a regenerative scaffold loaded with nano-formulated QT for local treatment of orthopedic fractures. For the first time, scaffolds composed of brushite CPC were prepared and loaded with quercetin lipid nano-systems. In vitro tests proved that the addition of lipid nano-systems did not deteriorate the properties of CPC where QT-NLC/CPC showed an adequate setting time, appropriate compressive strength, and porosity. The scanning electron microscope confirmed maintenance of nanoparticles integrity within the cement. Using a rat femur bone defect animal model, the histological results showed that the QT-NLC/CPC had a superior bone healing potential compared to crude unformulated QT/CPC. In conclusion, QT-NLC /CPC are promising lipid nano-composite materials that could enhance bone regeneration.
Thesis
C. botulinum groupe I est la bactérie pathogène la plus résistante à la chaleur et son élimination nécessite de forts traitements thermiques qui peuvent nuire aux qualités des aliments. Pour limiter l'intensité des traitements thermiques, les industriels doivent associer d'autres moyens de contrôle comme l’acidification et le salage communément utilisés dans les produits à base d'olives. L’objectif de ce travail est d’étudier les effets combinés du pH et de la concentration en NaCl après un traitement thermique de faible intensité sur la croissance et la germination des spores de C. botulinum groupe I et de C. sporogenes qui est son substitut non-toxinogène et également reconnu comme espèce d’altération. Il apparait que le domaine de germination et de croissance des spores de C. sporogenes PA 3679 (limite à pH 4,8) est plus restreint que le domaine de croissance des cellules végétative (limite à pH 4,5). De plus, les traitements thermiques de faible intensité diminuent la gamme de pH et de concentration en NaCl où la germination et la croissance des spores est possible.La limite chute à 3% pour des spores traitées (5,2 min à 100 °C) alors qu’elle est de 7% de NaCl pour les cellules végétatives. Ces observations ont été étendues à plusieurs souches de C. sporogenes et C. botulinum groupe I sélectionnées en fonction de leurs caractéristiques physiologies et génétiques. Cette étude a également a mis en évidence une certaine hétérogénéité au sein des deux espèces vis-à-vis de leurs limites de croissance (pH/NaCl), de la thermorésistance de leurs spores et de leurs caractéristiques génétiques (séquençage du génome complet et création d’un arbre phylogénétique). Ces éléments permettent de confirmer la stabilité des produits à base d’olives traités thermiquement. L’association synergique du pH, du NaCl et du traitement thermique explique l’inhibition de la germination et/ou de la croissance de C. sporogenes et C. botulinum groupe I. Ces résultats ouvrent de nouvelles possibilités pour optimiser les processus de formulation/fabrication des aliments afin de gérer les risques d'altération liés à C. sporogenes et apporte des informations pour mieux gérer ceux liés à C. botulinum.
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Table olives and olive oils are the main dietary sources of hydroxytyrosol (HT), a natural antioxidant compound that has emerged as a potential aid in protection against cardiovascular risk. Bioavailability studies with olive oils showed that HT is bioavailable from its free form and from conjugated forms like oleuropein and its aglycone. Still, its low dietary intake, poor bioavailability, and high inter-individual variability after absorption through the gastrointestinal tract hamper its full benefits. In a randomized, controlled, blind, cross-over study, we investigated the impact of HT metabolism and bioavailability by comparing two olive-derived watery supplements containing different doses of HT (30.58 and 61.48 mg of HT/dosage, respectively); additionally, HT-fortified olive oil was used in the control group. To this aim, plasma and urine samples were evaluated in 12 healthy volunteers following the intake of a single dose of the supplements or fortified olive oil. Blood and urine samples were collected at baseline and at 0.5, 1, 1.5, 2, 4, and 12 hours after intake. HT and its metabolites were analyzed by UHPLC-DAD-MS/MS. Pharmacokinetic results showed that dietary HT administered through the food supplements is bioavailable and biovailability increases with the administered dose. After intake, homovanillic acid, HT-3- O -sulfate, and 3,4-dihydroxyphenylacetic acid are the main metabolites found both in plasma and urine. The maximum concentrations in plasma peaked 30 minutes after intake. Being the bioavailability of a compound a fundamental prerequisite for its effect, these results promise a good potential of both food supplements for the protection against oxidative stress and the consequent cardiovascular risk.
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ABSTRACT Current trials to the treatment of coronavirus disease 2019 should open new prospects in the search for novel drugs from medicinal plants and other natural products. This paper provides details of some nutraceuticals that inhibit human coronavirus entry into cells, general replication, and specific chymotrypsin-like protease (3CLpro)-mediated replication. Many non-pharmaceutical interventions were approved by countries worldwide in the fight against the COVID-19 pandemic with adverse socioeconomic side effects, which raises the question about their differential effectiveness. We estimate the effect of each intervention on the incidence of COVID-19. In recent years, there has been a growing interest in nutraceuticals, which are those nutrients in foods that have beneficial effects on health. There has been extensive interest in the antiviral properties of nutraceuticals, which are especially topical in the context of the ongoing COVID-19 pandemic. The Prophet Mohamed may God’s prayers and peace be upon him, came with the religion and assistance to the world as he urged what is in the benefit of the bodies and prohibited everything that spoils them, so he commanded and desired medication. Many quranic verses in the Book of God Almighty talk about the bliss of paradise and what God has prepared for his pious servants. Therefore, the aim of this review is to evaluate the main nutraceuticals to which antiviral roles have been attributed (either by direct action on viruses or by modulating the immune system), with a focus on what was mentioned in the Holy Quran and Sunnah. Furthermore, the possible use of these substances against SARS-CoV-2.
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The dietary inclusion of plant-based products in fish feeds formulation is required for the sustainable development of aquaculture. Moreover, considering functional diets, hydroxytyrosol, one of the major phenolic compounds found in olives (Olea europaea), has been identified as a potential candidate to be used in the aquafeeds industry due to its health promoting abilities. The aim of this study was to evaluate the effects of the inclusion of an olive juice extract rich in hydroxytyrosol as an additive (0.52 g HT/kg feed) in a high-fat (24% lipids) diet in gilthead sea bream (Sparus aurata) juveniles. Moreover, the experimental diets, with or without the extract, were administered daily at a standard (3% of total biomass in the tank) or restricted ration (40% reduction) for 8–9 weeks. Growth and biometric parameters, insulin-like growth factor 1 (IGF-1) plasma levels and growth hormone/IGF axis-, myogenic- and osteogenic-related genes expression in liver, white muscle and/or bone were analyzed. Moreover, in vitro cultures of vertebra bone-derived cells from fish fed the diets at a standard ration were performed at weeks 3 and 9 to explore the effects of hydroxytyrosol on osteoblasts development. Although neither body weight or any other biometric parameter were affected by diet composition after 4 or 8 weeks, the addition of the hydroxytyrosol-rich extract to the diet increased IGF-1 plasma levels, regardless of the ration regime, suggesting an anabolic condition. In muscle, the higher mRNA levels of the binding protein igfbp-5b and the myoblast fusion marker dock5 in fish fed with the hydroxytyrosol-rich diet suggested that this compound may have a role in muscle, inducing development and a better muscular condition. Furthermore in bone, increased osteogenic potential while delayed matrix mineralization after addition to the diet of the olive juice extract was supported by the upregulated expression of igf-1 and bmp4 and reduced transcript levels of osteopontin. Overall, this study provides new insights into the beneficial use of hydroxytyrosol as a dietary additive in gilthead sea bream functional diets to improve muscle-skeletal condition and, the aquaculture industry.
Article
The chemistry of the phenolic compounds found in virgin olive oil (VOO) is very complex due, not only to the different classes of polyphenols that can be found in it, but, above all, due to the existence of a very specific phenol class found only in oleaceae plants: the secoiridoids. Searching in the Scopus data base the keywords flavonoid, phenolic acid, lignin and secoiridoid, we can find a number of 148174, 79435, 11326 and 1392 research articles respectively, showing how little is devote to the latter class of compounds. Moreover, in contrast with other classes, that include only phenolic compounds, secoiridoids may include phenolic and non-phenolic compounds, being the articles concerning phenolic secoiridoids much less than the half of the abovementioned articles. Therefore, it is important to clarify the structures of these compounds and their chemistry, as this knowledge will help understand their bioactivity and metabolism studies, usually performed by researchers with a more health science's related background. In this review, all the structures found in many research articles concerning VOO phenolic compounds chemistry and metabolism was gathered, with a special attention devoted to the secoiridoids, the main phenolic compound class found in olives, VOO and olive leaf.
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Olea europaea L. Cv. Arbequina (OEA) (Oleaceae) is an olive variety species that has received little attention. Besides our previous work for the chemical profiling of OEA leaves using LC–HRESIMS, an additional 23 compounds are identified. An excision wound model is used to measure wound healing action. Wounds are provided with OEA (2% w/v) or MEBO® cream (marketed treatment). The wound closure rate related to vehicle-treated wounds is significantly increased by OEA. Comparing to vehicle wound tissues, significant levels of TGF-β in OEA and MEBO® (p < 0.05) are displayed by gene expression patterns, with the most significant levels in OEA-treated wounds. Proinflammatory TNF-α and IL-1β levels are substantially reduced in OEA-treated wounds. The capability of several lignan-related compounds to interact with MMP-1 is revealed by extensive in silico investigation of the major OEA compounds (i.e., inverse docking, molecular dynamics simulation, and ΔG calculation), and their role in the wound-healing process is also characterized. The potential of OEA as a potent MMP-1 inhibitor is shown in subsequent in vitro testing (IC50 = 88.0 ± 0.1 nM). In conclusion, OEA is introduced as an interesting therapeutic candidate that can effectively manage wound healing because of its anti-inflammatory and antioxidant properties.
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Among other factors, food intolerance is cardinal in triggering irritable bowel syndrome (IBS) symptoms in a significant percentage of patients. As a result, specific dietary patterns are the first-line therapeutic approach. The low-FODMAP diet (LFD) is gaining ground as the most well-documented diet intervention that significantly reduces IBS symptoms. Though the LFD improves symptoms, the diet’s impact on intestinal low-grade inflammation, one of the cardinal mechanisms contributing to symptom development, remains doubtful. On the other hand, the Mediterranean diet (MedDiet) is recommended for chronic low-grade inflammation-related diseases because of its anti-inflammatory properties, derived predominantly from olive oil and phenolic compounds. Thus far, the role of a modified LFD, enriched with the MedDiet’s anti-inflammatory components, has not been evaluated in IBS patients. This review aims to examine the hypothesis of a potential combination of the immunomodulatory effects of the MedDiet with the LFD to improve IBS symptoms.
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The prevention of pathologies by diet management is an important public health challenge. The Mediterranean diet (Med diet) is considered one of the healthiest dietary patterns. According to current scientific research, this dietary pattern is linked to a decreased prevalence and incidence of various chronic diseases, including cardiovascular disease, diabetes, cancer, and age-related cognitive decline, as well as a lower overall mortality rate. In the Mediterranean diet, a high consumption of Virgin Olive Oil (VOO), fruit, nuts, vegetables, and grains is linked to a decreased incidence of many diseases and a longer life expectancy. According to numerous studies, VOO is the major food responsible for the health and nutritional benefits of the Mediterranean diet. VOO chemical compounds have been shown in vitro and in vivo investigations to have potentially favorable health benefits as a result of their biological activities. VOO composition has been linked to a variety of biological activities, including antioxidant, anti-inflammatory, anti-diabetic, anti-cancer, and antiviral characteristics. As a result, increasing attention is being paid to the composition of VOO and the identification of its biologically active components. Because of their antioxidant, anti-inflammatory, and anti-thrombotic properties, phytochemicals, particularly phenolic compounds, have health-promoting effects, especially on cardiovascular and metabolic illnesses. These characteristics are even more important in light of the COVID-19 severe illness's heightened inflammatory and pro-thrombotic consequences. This overview collects and discusses the scattered data available in the literature concerning VOO compounds of biological interest and highlights their possible mechanisms of action and effects on human health. In vitro studies and in vivo intervention trials were selected and included in the study after conducting literature searches through "PubMed" and "Web of Science." In the majority of investigations, the ability of VOO phytochemicals to prevent the oxidation process at both the initiation and promotion/progression phases of several pathologies has been verified. The health benefits discussed in this article support the prospective health benefits acquired from VOO as a possible candidate in developing pharmaceutical preparations and nutraceutical or functional foods for a variety of pathological disorders. This idea could pave the way for future in vivo research and, eventually, clinical trials. In addition, greater research into the mechanisms of action and efficacy is needed to clarify the real biological potential of VOO phytochemicals on humans by performing intervention studies on populations at high disorder risk.
Thesis
Les insectes, comme les autres animaux, sont dotés d’un système gustatif qui leur permet d’analyser les molécules sapides présentes dans leurs aliments, comme des sucres (qui stimulent l’alimentation) ou bien des molécules amères (qui l’inhibent). L’amertume est généralement considérée comme permettant à l’animal d’éviter d’ingérer des substances toxiques. L’amertume d’un composé est testée la plupart du temps en mélangeant un composé potentiellement amer à un aliment et en mesurant la quantité consommée en conditions de choix ou de non-choix. Un tel type de protocole ne permet cependant pas de distinguer entre les effets liés à l’amertume proprement dite de ceux qui sont liés à la toxicité.Dans cette thèse, nous avons essayé d’évaluer si l’amertume était liée à la toxicité, en étudiant les réponses alimentaires et la survie de Drosophila melanogaster vis-à-vis de 7 molécules, choisies pour leur amertume et leur toxicité (quinine, berbérine, benzoate de dénatonium, paraquat, nicotine, escine, caféine). Afin de quantifier le comportement alimentaire, nous avons d’abord établi un protocole de mesure semi-automatique du volume de liquide ingéré par des mouches individuelles. Lorsque ces mouches ont le choix entre un liquide sucré et un liquide contenant une substance amère, nous avons pu observer que les mouches diminuaient leur consommation avec la concentration en molécule amère, et que cette réduction de consommation pouvait également impacter la consommation de solution sucrée. Nous avons également évalué l’impact de ces molécules sur la durée de vie des mouches, lorsqu’elles sont mélangées au milieu alimentaire (liquide ou agar), ou injectée dans l’abdomen de l’animal. Nous avons pu constater que la durée de vie des mouches était fortement corrélée à la quantité de molécules de sucre ingérées plus qu’à la quantité de molécules amères. L’ensemble de ces résultats suggère que l’amertume des molécules inhibe fortement l’alimentation des insectes, plus que la toxicité proprement dite. Par ailleurs, nous nous sommes intéressés à la possibilité de masquage de l’amertume d’une molécule modèle, l’oleuropéine qui est le principal composé de l’amertume de l’huile d’olive, par interaction avec une protéine laitière, la β-lactoglobuline. L’efficacité du masquage de l’amertume a été évaluée par consommation de mélange oleuropéine/β-lactoglobuline par les mouches. L’amertume de l’oleuropéine semble être masquée par la protéine pour des concentrations en oleuropéine inférieures ou égales à 0,1 mM.
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Advances in olive oil research have blossomed in recent years, and articles on olive oil have been widely recorded. However, a comprehensive and systematic bibliometric analysis of olive oil research has not been completed. Through a systematic literature search, we consolidated 7003 papers from the Web of Science Core Collection database. This bibliometric analysis was carried out to examine the article growth, geographical distribution, and analysis of journals/research areas/authors/keywords. The results revealed the following: (1) Exponential growth was shown in the annual number of publications (R2 = 0.9791). The geographical distribution is biased to a few countries, especially Spain, Italy, and Greece in the Mediterranean region, placing a larger focus on olive oil research. (2) Quality analysis‐related research acted as a link between keyword groups, the disease prevention and treatment‐related research of olive oil received decreasing interest, while authentication and quality analysis‐related research of olive oil showed the opposite trend, by‐products‐related research of olive oil got waving interests over the whole period. (3) Improvement is needed in the degree of olive oil with international collaboration. This is the first time that hotspots and trends in olive oil research have been shown. Research on olive oil.
Chapter
The major component in edible oils is triacylglycerol which consists of 95–98% while the remaining is made up of minor components such as sterols, tocopherols and tocotrienols, carotenoids, squalene, phenolic compounds, chlorophylls, phospholipids and trace metals. Although minor components possess a limited proportion in edible oils, their presence is significant due to the purported health benefits. These minor components are found in abundantly in crude oil but eventually removed during the oil refining process. As some of the minor components such as carotenoids, tocopherols and tocotrienols are beneficial to health, it is important not only to maximize their retention but also to optimize the recovery of these minor components. Other than health benefits, minor components in edible oils also provide a valuable markers for oils and fats authentication. This chapter highlights the properties of various minor components found in fats and oils as well as the recent techniques used for its recovery.KeywordsTocopherolTocotrienolSterolSqualeneCarotenoidPhenolic compoundsRecoveryAuthentication
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Purpose of Review The purpose of this review is to summarize the recently published scientific evidence on the effects of diet on diabetes and skeletal health. Recent Findings The impact of diet on overall health has been a growing topic of interest among researchers. An inappropriate eating habit is a relatively modified risk factor for diabetes in adults. Parallel with the significant increase in the incidence of diabetes mellitus worldwide, many studies have shown the benefits of lifestyle modifications, including diet and exercise for people with, or at risk of developing, diabetes. In the last years, accumulating evidence suggests that diabetes is a risk factor for bone fragility. As lifestyle intervention represents an effective option for diabetes management and treatment, there is potential for an effect on bone health. Summary Healthy lifestyle is critical to prevent bone fragility. However, more studies are needed to fully understand the impact of diet and weight loss on fracture risk in diabetics.
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A staple food for thousands of years for the inhabitants of the Mediterranean region, olive oil is now becoming popular among consumers all over the world. Olive oil differs from other vegetable oils because it is used in its natural form and has unique flavor and other characteristics. More and more research suggests its healthful benefits including reduced risk of coronary heart disease. Olive Oil is a compact and readable text on the most important aspects of chemistry, technology, quality, analysis and biological importance of olive oil. The topics selected have been developing rapidly in recent years, and will provide the reader with a background to address more specific problems that may arise in the future. Readers can expect more contributors and chapters in the 2nd edition, as well as a glossary.
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The total polar fraction and individual phenols present in virgin olive oil were tested for their antioxidant effect in refined olive oil. Hydroxytyrosol and caffeic acid showed protection factors greater than BHT. Protocatechuic and syringic acid were also found to have antioxidant activity. Tyrosol, p-hydroxyphenylacetic acid, o-coumaric acid, p-coumaric acid, p-hydroxybenzoic acid and vanillic acid had very little or no effect, and their contribution to the stability of the oil is negligible.
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From the seeds of Olea europaea , three known glucosides, salidroside (tyrosol-glucose), nüzhenide (glucose-elenolic acid-glucosetyrosol) and nüzhenide-oleoside have been isolated as well as two new secoiridoid glucosides with tyrosol, elenolic acid and glucose moieties in unknown sequence. Se han aislado de semillas de aceituna ( Olea europaea ) tres glucósidos secoiridoides ya conocidos: salidrósido (tirosol-glucosa), nuzhenida (glucosa-ácido elenólico-glucosa-tirosol) y nuzhenida-oleósido, así como otros dos glucósidos secoiridoides que también tienen en su molécula tirosol, ácido elenólico y glucosa cuyas secuencias no se han podido establecer.
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We investigated the injurious effects of reactive oxygen metabolites on the intestinal epithelium and the possible protective role played by two olive oil phenolic compounds, (3,4-dihydroxyphenyl)ethanol and (p-hydroxyphenyl)ethanol, using the Caco-2 human cell line. We induced oxidative stress in the apical compartment, either by the addition of 10 mmol/L H2O2 or by the action of 10 U/L xanthine oxidase in the presence of xanthine (250 micromol/L); after the incubation, we evaluated the cellular and molecular alterations. Both treatments produced significant decreases in Caco-2 viability as assessed by the neutral red assay. Furthermore, we observed a significant increase in malondialdehyde intracellular concentration and paracellular inulin transport, indicating the occurrence of lipid peroxidation and monolayer permeability changes, respectively. The H2O2-induced alterations were completely prevented by preincubating Caco-2 cells with (3,4-dihydroxyphenyl)ethanol (250 micromol/L); when the oxidative stress was induced by xanthine oxidase, complete protection was obtained at a concentration of polyphenol as small as 100 micromol/L. In contrast, (p-hydroxyphenyl)ethanol was ineffective up to a concentration of 500 micromol/L. Our data demonstrate that (3,4-dihydroxyphenyl)ethanol can act as a biological antioxidant in a cell culture experimental model and that the ortho-dihydroxy moiety of the molecule is essential for antioxidant activity. This study suggests that dietary intake of olive oil polyphenols may lower the risk of reactive oxygen metabolite-mediated diseases such as some gastrointestinal diseases and atherosclerosis.
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Hydroxytyrosol acetate was synthesized, and the antioxidant activity of this olive oil component was assessed in comparison with that of other olive oil components, namely hydroxytyrosol, oleuropein, 3,4-DHPEA-EA, and alpha-tocopherol in bulk oil and oil-in-water emulsions. The activity of the compounds was also assessed by scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Hydroxytyrosol acetate had a weaker DPPH radical scavenging activity than hydroxytyrosol, oleuropein, or 3,4-DHPEA-EA but it had a radical scavenging activity similar to that of alpha-tocopherol. In oil, the antioxidant activity of hydroxytyrosol acetate was much higher than that of alpha-tocopherol or oleuropein, but in an emulsion 3,4-DHPEA-EA and alpha-tocopherol were more effective as antioxidants than hydroxytyrosol acetate. The antioxidant activity of hydroxytyrosol acetate was rather similar to that of hydroxytyrosol in oil and emulsions despite the difference in DPPH radical scavenging activity.
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Durch LiAlH4- Reduktion der literaturbekannten Carbonsäure (I) wird die Titelverbindung (II) erhalten.
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The main reaction products obtainable by the hydrolysis of commercially available oleuropein by hyperthermophilic beta -glycosidase were purified and structurally characterized by UV and H-1 and C-13 NMR analyses. Their antioxidant activity, in particular their capacity to inhibit the fatty acid peroxidation rate, was studied. The molecular structures assigned revealed the presence of two elenolic acid forms presenting different antioxidant abilities closely correlated to their molecular structures, as well as an unstable elenolate which is a rearrangement product of the oleuropein aglycon. This molecule, under the reaction conditions (pH 7.0, 60 degreesC) required for beta -glycosidase activity, rapidly gives rise to 3,4-dihydroxy-phenylethanol (hydroxytyrosol).
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The effects of olive fruit extract on arachidonic acid lipoxygenase activities were investigated using rat platelets and rat polymorphonuclear leukocytes (PMNL). Olive extract strongly inhibited both 12-lipoxygenase (12-LO) and 5-lipoxygenase (5-LO) activities. One of the compounds responsible for this inhibition was purified and identified as 2-(3,4-dihydroxyphenyl)ethanol (DPE). DPE inhibited platelet 12-LO activity (IC50, 4.2 μμ) and PMNL 5-LO activity (IC50, 13 μμ) but not cyclooxygenase activity in cell-free conditions. It also inhibited 12-LO activity in intact platelets (IC50, 50 μμ) and reduced leukotriene B4 production in intact PMNL stimulated by A23187 (IC50, 26μμ). The inhibition by DPE of both lipoxygenase activities was stronger than that by oleuropein, caffeic acid, or 7 other related phenolic compounds, especially in intact cells. These results suggest that DPE is a potent specific inhibitor of lipoxygenase activities.
Article
Oleuropein and hydroxytyrosol, two phenolic compounds contained in olives and olive oil, are known to possess several biological properties, many of which may be related, partially at least, to their antioxidant and free radical-scavenger ability. Hence, together with their scavenging activity against the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test), we have investigated the antioxidative effect of oleuropein and hydroxytyrosol in a model system consisting of dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (DPPC/LA LUVs) and a water-soluble azo compound as a free radical generator (LP–LUV test). The results obtained were also interpreted in the light of biophenol interactions, studied by differential scanning calorimetry (DSC), with dimyristoylphosphatidylcholine (DMPC) vesicles as a biological membrane model. Our results obtained in the DPPH and LP–LUV tests confirm the good scavenger activity and antioxidant effect of oleuropein and hydroxytyrosol. However, while both compounds exhibit comparable effectiveness in the DPPH test (hydroxytyrosol being slightly more active than oleuropein), oleuropein seems, in the LP–LUV test, a better antioxidant than hydroxytyrosol. Besides oleuropein shows a better antioxidant activity in the membranous system than in homogenous solution. Furthermore, oleuropein, but not hydroxytyrosol, interacts with DMPC vesicles, causing shifts, toward lower values, of the calorimetric peak temperature (Tm), associated to the gel to liquid-crystal phase transition, typical for DMPC multilayers. The hypothesis will be discussed that hydroxytyrosol can serve as scavenger of aqueous peroxyl radicals near the membrane surface, while oleuropein acts also as a scavenger of chain-propagating lipid peroxyl radicals within the membranes.
Article
A simple procedure for the deuteriation of a large range of phenols has been developed using Amberlyst 15, a polymer supported acid catalyst. A number of phenols present in olive oil have been successfully deuteriated. The aromatic protons of hydroxytyrosol are 100% exchanged under the conditions used. This method is applicable for the tritiation of phenols. Copyright © 2000 John Wiley & Sons, Ltd.
Article
During olive oil production, large volumes of water are generated and subsequently discarded. Olives contain a variety of bioactive components, and some of them, according to their partition coefficients, end up in the water phase. The current investigation aimed at comparing different methods for the extraction of biologically active components of the olive mill waste waters (OMWW) and evaluating the in vitro antioxidant and anti-inflammatory activities of the resulting extracts. The results indicate that OMWW extracts are able to inhibit human LDL oxidation (a process involved in the pathogenesis of atherosclerosis) and to scavenge superoxide anions and hypochlorous acid at concentrations as low as 20 ppm. Finally, two of the three extracts also inhibited the production of leukotrienes by human neutrophils. The potency of the extracts depended on their degree of refinement:  extracts containing only low molecular weight phenols were the most effective. Keywords: Antioxidants; waste water; olive oil; free radicals; polyphenols
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2-(3,4-Dihydroxyphenyl)ethanol (DPE), the major phenolic compound in olive oil, may contribute the antioxidative activities and other beneficial effects to olive oil. However, the lack of commercial available DPE and procedures sensitive enough to quantitatively determine DPE in body fluids have limited the bioavailability and metabolism studies on this phenolic compound. In the present study, DPE was synthesized with high yield and high purity and administered orally to rats. DPE concentration in rat plasma, after absorption, was measured using a sensitive GC-MS-SIM method. The results indicated that the highest level of DPE in plasma was detected at 5−10 min after administration. During this period, the concentration of DPE fluctuated widely with the individual. Keywords: Hydroxytyrosol; dihydroxyphenylethanol (DPE); plasma; GC-MS; metabolism
Article
Olive oil is the fat of choice in the Mediterranean area, where the diet has been associated with a lower incidence of coronary heart disease and certain cancers. Phenols in extra virgin olive oil are responsible for its peculiar pungent taste and for its high stability. Recent findings demonstrate that olive oil phenolics inhibit oxidation of low-density lipoproteins (the most atherogenic ones) and possess other potent biological activities that if demonstrated in vivo, could partially account for the observed healthful effects of diets that include high-quality olive oil and other foods rich in flavonoids and phenols. Keywords: Olive oil; phenols; atherosclerosis; Mediterranean diet; antioxidants; free radicals
Article
The main phenolic compounds (oleuropein, verbascoside, rutin, luteolin 7-glucoside) were separated and determined by HPLC for three varieties (Picholine, Lucques, Salonenque) during the development and maturation of the fruit and for eight other varieties (Bouteillan, Verdale, Cailletier, Zrappola, Tanche, L11, L365, VP7) just during the maturation. Oleuropein content could reach 14% of the dry matter in young fruit and remains very important at harvest for green picked varieties. Furthermore, small-fruit varieties are characterized by high oleuropein and low verbascoside contents, while large-fruit varieties are characterized by low oleuropein and high verbascoside contents.
Article
Phenolic compounds have a fundamental importance in the nutritional and sensory characteristics of virgin olive oil. Problems regarding their qualitative and quantitative evaluation have not been completely solved; hence, in this paper the extractive and HPLC methods of analysis are examined and some modifications are presented. By means of these techniques, elenolic acid and four unknown compounds having phenolic behavior were separated from virgin olive oil. Four of them were correlated with total phenols evaluated by means of the Folin-Ciocalteu reagent, and two of them were correlated with olive oil autoxidation stability.
Article
Summary Qualitative and quantitative data are presented for the phenolic content of cvs Manzanillo and Cucco based on separation by high performance liquid chromatography, HPLC, with ultraviolet, fluorescence and mass spectrometric detection. Oleuropein is the principal phenolic compound in olive and its concentration changed significantly during fruit development. Changes in the content of tyrosol, ligstroside and verbascoside were also observed but these were relatively smaller.
Article
The levels of total polyphenols and o-diphenols were determined in virgin oils and in chloroform/methanol-extracted oils. The solventextracted oils were richer in polyphenols than the virgin oils. High polyphenol content was associated with a high resistance to oxidation of the oils. A linear relationship was found between polyphenol content and the oxidative stability of the virgin oils during storage at 60 C. After removal of the polyphenols, the oxidative stability of the oils decreased considerably and seemed to depend on polyunsaturated fatty acid concentration.
Article
A reinvestigation of the two known methods of preparation of the title compound 1 revealed that one of these leads to a mixture of 1 and 4-[2-(acetoxy)ethyl]-1,2-benzenediol (5). The other method yields only 2-methoxy-4-(2-phenylethyl)phenol (6). An unambiguous straightforward preparation of 1 by LiAlH4 reduction of 3,4-dihydroxy-1-benzeneacetic acid (8) is described. Eine neue Studie zur Darstellung von 3,4-Dihydroxy-1-benzolethanol Die zwei bekannten Darstellungsmethoden der Titelverbindung 1 sind erneut untersucht worden. Danach entsteht in einem Fall ein Gemisch von 1 und 4-[2-(Acetoxy)ethyl]-1,2-benzoldiol (5), im anderen nur 2-Methoxy-4-(2-phenylethyl)phenol (6). Im folgenden wird eine eindeutige und einfache Synthese für 1 durch Reduktion von 3,4-Dihydroxy-1-benzolessigsäure (8) mit LiAlH4 beschrieben.
Article
The stability of 24 samples of Greek virgin olive oil was examined in relation to total polyphenol content, and individual phenols were determined by reversed-phase HPLC. Tyrosol, the major olive-oil phenol, is not correlated with the shelf-life of the oil. Total polyphenol content and hydroxytyrosol-to-tyrosol ratio have a significant linear correlation with the resistance of the oil to autoxidation.
Article
Complex phenols, such as the glycoside oleuropein and hydroxytyrosol, are found in high concentrations in the typical components of the Mediterranean diet. We have previously reported that oleuropein inhibits androstenedione 6β-hydroxylase activity, a CYP3A marker in human liver microsomes (Stupans, I., Stretch, G., Hayball, P., 2000. Olive oil phenols inhibit human hepatic microsomal activity. Journal of Nutrition. 130 2367–2370). Oleuropein, but not the structurally similar compounds hydroxytyrosol and secologanin, was found to be a mechanism-based inhibitor of androstenedione 6β-hydroxylase activity. Preincubation with 100 μm oleuropein and NADPH resulted in a significantly lower androstenedione 6β-hydroxylase activity when compared to preincubation carried out with oleuropein without NADPH, 0.11±0.01 nmol/mg microsomal protein/min compared with 0.29±0.03 nmol/mg microsomal protein/min (P<0.05). The inactivation exhibited pseudo-first-order kinetics. The maximal rate constant for inactivation (kinactivation) was calculated to be 0.09 min−1 and the concentration of inactivator required for half maximal inactivation (Ki) was calculated to be 22.2 μm. Oleuropein was found to be a relatively weak inhibitor of CYP1A2-mediated 7-methoxyresorufin-O-deethylation (24% inhibition at 100 μm oleuropein), but not CYP2E1-mediated chlorzoxazone 6-hydroxylation. CYP1A2 did not undergo mechanism-based inactivation by oleuropein.
Article
Plants in the Mediterranean basin, such as vine and olive trees, have developed an array of antioxidant defences to protect themselves from environmental stress. Accordingly, the incidence of coronary heart disease and certain cancers is lower in the Mediterranean area, where olive oil is the dietary fat of choice. As opposed to other vegetable oils, extra virgin olive oil, which is obtained by physical pressure from a whole fruit, is rich in phenolic components that are responsible for the particular stability of the oil. We have investigated the scavenging actions of some olive oil phenolics, namely hydroxytyrosol and oleuropein, with respect to superoxide anion generation, neutrophils respiratory burst, and hypochlorous acid. The low EC50s indicate that both compounds are potent scavengers of superoxide radicals and inhibitors of neutrophils respiratory burst: whenever demonstratedin vivo,these properties may partially explain the observed lower incidence of CHD and cancer associated with the Mediterranean diet.
Article
We have evaluated the effects of hydroxytyrosol (HT), a potent antioxidant present in olive oil, on the formation of arachidonic acid 5-lipoxygenase metabolites by leukocytes in vitro. HT, a simple phenolic compound, extracted from first-pressure oil, was isolated by HPLC and characterized by gas chromatography/mass spectrometry. HT inhibited in a dose-related manner the production of leukotriene B4 (LTB4) by calcium ionophore-stimulated leukocytes. As expected, similar inhibition was observed for ω-oxidized metabolites of LTB4, namely 20-hydroxy and 20-carboxy-LTB4. The results disclose a new biological activity of olive oil-derived phenols on leukocyte eicosanoid production. © 1997 Elsevier Science Ltd
Article
The Mediterranean diet, rich in fruit, vegetables, grain, and vegetable oil (mainly olive oil) is correlated with a lower incidence of coronary heart disease (CHD). Natural antioxidants contained in the Mediterranean diet might also play a role in the prevention of cardiovascular diseases, through inhibition of LDL oxidation. We tested this hypothesis “in vitro” by inducing LDL oxidation with copper sulphate and preincubating the samples with oleuropein, the bitter principle of olive, that is one of the major components of the polyphenolic fraction of olive oil. Oleuropein 10−5 M effectively inhibited CuSO4-induced LDL oxidation, as assessed by various parameters. We demonstrate in this investigation that polyphenolic components of the Mediterranean diet interfere with biochemical events that are implicated in atherogenetic disease, thus proposing a new link between the Mediterranean diet and prevention of CHD.
Article
This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP- or collagen-induced PRP aggregations were 23 and 67 μM, respectively. At 400 μM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects on PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavonoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.
Article
Monolayers of a well differentiated human intestinal epithelial cell line, Caco-2, were used as a model to study passive drug absorption across the intestinal epithelium. Absorption rate constants (expressed as apparent permeability coefficients) were determined for 20 drugs and peptides with different structural properties. The permeability coefficients ranged from approximately 5 x 10(-8) to 5 x 10(-5) cm/s. A good correlation was obtained between data on oral absorption in humans and the results in the Caco-2 model. Drugs that are completely absorbed in humans had permeability coefficients greater than 1 x 10(-6) cm/s. Drugs that are absorbed to greater than 1% but less than 100% had permeability coefficients of 0.1-1.0 x 10(-6) cm/s while drugs and peptides that are absorbed to less than 1% had permeability coefficients of less than or equal to 1 x 10(-7) cm/s. The results indicate that Caco-2 monolayers can be used as a model for studies on intestinal drug absorption.
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