No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Major phenolic compounds in olive oil: Metabolism and health effects
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.
... EVOO is renowned for its culinary virtues and its rich array of phenolic com which are garnering increasing attention for their potential therapeutic implication [30,33,34]. Central to this group of compounds are primary phenolics like OLE, tyrosol, which undergo dynamic changes during olive maturation and oil extrac fluencing EVOO's health properties [30,35,36]. OLE, a major phenolic in olive frui derivative OLG, and HT, known for its potent antioxidant capacity, possess criti roprotective effects [34,36,37]. ...
... EVOO is renowned for its culinary virtues and its rich array of phenolic compounds, which are garnering increasing attention for their potential therapeutic implications in AD [30,33,34]. Central to this group of compounds are primary phenolics like OLE, HT, and tyrosol, which undergo dynamic changes during olive maturation and oil extraction, influencing EVOO's health properties [30,35,36]. OLE, a major phenolic in olive fruit and its derivative OLG, and HT, known for its potent antioxidant capacity, possess critical neuroprotective effects [34,36,37]. ...
... Additionally, variants like deacetoxy OLE and ligstroside aglycone (Figure 1), along with other constituents like phenolic acids, flavonoids, and lignans (exemplified by pinoresinol and acetoxypinoresinol), contribute to EVOO's overall antioxidant capacity [34,37]. This intricate network of phenolic compounds plays a pivotal role in neutralizing reactive oxygen species (ROS) and protecting neuronal cells from oxidative damage, thereby impacting the progression of AD [35,36]. The diverse spectrum of EVOO's phenolic content underscores its potential as a natural therapeutic agent in the intricate pathology of AD, highlighting the need for continued research into its nuanced role in neuroprotection and disease mitigation [30,[33][34][35][36][37]. ...
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that is characterized by several pathological hallmarks, including the deposition of amyloid-β (Aβ) plaques, neurofibrillary tangles, blood–brain barrier (BBB) dysfunction, increased oxidative stress, and neuroinflammation. Current treatment options include monoclonal antibody drugs, acetylcholinesterase, and n-methyl-d-aspartate (NMDA) antagonists. Although those treatments provide some improvements in patients’ quality of life, they fail to prevent or cure AD. Current research aims to identify novel targets and tools for AD prevention and modification. In this context, several studies showed the beneficial effect of the Mediterranean diet in the prevention and treatment of AD. One integral component of the Mediterranean diet is olive oil and extra-virgin olive oil (EVOO), which is high in phenolic compounds. EVOO and other olive-related phenolic compounds have been shown to reduce the risk of developing mild cognitive impairment (MCI) and AD. In this review, we discuss the mechanisms by which EVOO and phenolic compounds exert neuroprotective effects, including modulation of AD pathologies and promotion of cognitive health. Findings indicate that EVOO and its phenolic constituents influence key pathological processes of AD, such as Aβ aggregation, tau phosphorylation, and neuroinflammation, while also enhancing BBB integrity and reducing oxidative stress. The human studies cited reveal a consistent trend where the consumption of olive oil is associated with cognitive benefits and a decreased risk of AD and related dementias. In conclusion, EVOO and its phenolic compounds hold promising potential for the prevention and treatment of AD, representing a significant shift towards more effective strategies against this complex neurodegenerative disorder.
... Obviously, olive oil primarily consists of triacylglycerols and approximately 0.5-1.0% non-glycerol constituents, including over 30 phenolic compounds [10]. Similarly to many other plants and edible oils made thereof, the phenolic composition of olive oil is influenced by the production and storage methods, with a higher total phenolic content in extra virgin olive oil compared to refined virgin olive oil. ...
... When olives mature, the concentration of OLE decreases, while that of HT increases due to the hydrolysis of OLE (Figure 1). The concentrations of HT and OLE in olive oil can vary, with reported ranges of 1.4-5.6 mg/kg and 2.3-9.0 mg/kg, respectively [10]. Other phenolic compounds from olive oil and olive products include luteolin 7-O-glucoside, apigenin 7-O-glucoside, rutin, tyrosol, and verbascoside [12]. ...
Non-communicable diseases (NCDs) cause 41 million deaths annually, accounting for 74% of global fatalities. The so-called Mediterranean diet, with its especially significant consumption of olive oil, has shown promising results in reducing the risk of developing NCDs, such as cardiovascular, liver, or bone diseases. In the context of the nutritional health benefits of foods, phenolic compounds such as olive oil’s main components, oleuropein (OLE) and hydroxytyrosol (HT), have been shown to possess different beneficial effects. However, no systematic review has evaluated the health-promoting effects of OLE and HT until now. Consequently, this systematic review analyzed 12 human randomized controlled trials (RCTs), involving 683 participants, to assess the effects of supplements, pure compounds, or enriched foods containing OLE and HT regarding systemic health outcomes, including CVD risk factors, liver parameters, and bone, joint, and cognitive health. The review found contrasting but encouraging results, with some studies reporting significant modulation of body weight, lipid profile, and glucose metabolism, and improvements in bone, joint, and cognitive functions. The studies described different dosages and forms of supplementation, ranging from 5 mg/d HT to 990 mL/d olive leaf infusion (320.8 mg OLE and 11.9 mg HT), highlighting the need for further research to determine the optimal dosing and duration. Despite the mixed outcomes, OLE and HT supplementation show potential for improving some of the cardiometabolic health outcomes and bone, joint, and cognitive health. However, further studies are necessary to understand their benefits better and address existing limitations.
... The major constituents in olive oil are lipids, which contain fatty acids [32]. Olive oil also contains a considerable amount of phenolic compounds, and their composition mainly depends on production and storage methods [33,34]. Thus, despite the clean-up step, we were able to detect high concentrations of endogenous compounds, mainly co-extracted fatty acids and lipids. ...
... in olive oil are lipids, which contain fatty acids [32]. Olive oil also contains a considerable amount of phenolic compounds, and their composition mainly depends on production and storage methods [33,34]. Thus, despite the clean-up step, we were able to detect high concentrations of endogenous compounds, mainly co-extracted fatty acids and lipids. ...
Oligomers are a particular category of non-intentionally added substances (NIAS) that may be present in food contact materials (FCMs), such as polyethylene terephthalate (PET), and consequently migrate into foods. Here, an ultra-high-pressure liquid chromatography quadruple time-of-flight mass spectrometry (UHPLC-qTOF-MS) method was developed for the analysis of 1st series cyclic PET oligomers in virgin olive oil (VOO) following a QuEChERS clean-up protocol. Oligomer migration was evaluated with two different migration experiments using bottles from virgin and recycled PET: one with VOO samples stored in household conditions for a year and one using the food simulant D2 (95% v/v ethanol in water) at 60 °C for 10 days. Calibration curves were constructed with fortified VOO samples, with the LOQs ranging from 10 to 50 µg L−1 and the recoveries ranging from 86.6 to 113.0%. Results showed no migration of PET oligomers in VOO. However, in the simulated study, significant amounts of all oligomers were detected, with the migration of cyclic PET trimers from recycled bottles being the most abundant. Additional substances were tentatively identified as linear derivatives of PET oligomers. Again, open trimer structures in recycled bottles gave the most significant signals.
... Other phenolic compounds in olives include tyrosol, glycoside oleuropein, oleocanthal, and oleacein. Both hydroxytyrosol and oleuropein have been shown to exhibit antimicrobial activity against ATTC bacterial strains and clinical bacterial isolates [29,33]. ...
This review describes the enhanced classification of polyphenols into flavonoids, lignans, phenolic acids, stilbenes, and tannins. Its focus is the natural sources of polyphenols and an in-depth discussion of their antibacterial, antifungal, and antiviral activity. Besides a broad literature overview, this paper contains authors’ experimental data according to some daily consumed vegetables such as tomatoes, different varieties of onion, garlic, parsley, and cayenne pepper and the probable relation of these activities to polyphenols. The isolation of polyphenols via conventional and ultrasonic, pressurized liquids and pulse-field extractions, as well as their methods for detection and determination, are interpreted as well. The main mechanisms by which polyphenols inhibit the growth of bacteria, fungi, and viruses, such as protein synthesis, cell membrane destabilization, and ROS production induction, are in focus. Data on polyphenol concentrations and their respective MIC or the inhibition zone diameters of different bacterial and fungal species and suppressing viral replication are depicted. The toxicity of polyphenols in vitro, ex vivo, and in vivo towards microorganisms and human/animal cells, and the safety of the polyphenols applied in clinical and industrial applications are expanded. This review also characterizes the antimicrobial effects of some chemically synthesized polyphenol derivatives. Biotechnological advances are also reported, especially the entrapment of polyphenols in biocompatible nanoparticles to enhance their bioavailability and efficacy. Polyphenols are promising for exploring molecules’ novel antimicrobial substances and paving the path for effective novel antimicrobial agents’ discovery, taking into consideration their positives and negatives.
... Thermal techniques like Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis have also been implemented, along with other methods such as Electrochemical Impedance Spectroscopy (EIS), Surface-enhanced Raman Spectroscopy (SERS), Photonics sensor, Electronic nose (E-nose), Electronic tongue (E-tongue), Voltammetric analysis, and DNA-based analysis (Apetrei & Apetrei 2014;Bernicker Fig. 1 Schematic overview of the health benefits of olive oil. Information collected from Jimenez-Lopez et al. (2020) and Tuck and Hayball (2002) Content courtesy of Springer Nature, terms of use apply. Rights reserved. ...
The present work investigates the adulteration of extra virgin olive oil (EVOO) using highly surface-sensitive SPR-enhanced ellipsometry (SPRE) technique, aiming to ensure food quality and consumer safety. Due to the elevated cost of EVOO, adulteration with cheaper, poor-quality refined or edible oils has become a common practice for economic profit. The EVOO is purposely adulterated by blending four different edible oils with transparent or similar colors and similar refractive indices to replicate realistic adulteration scenarios. An in-house-built SPRE setup was used to conduct the experiments using a reusable bimetallic Ag-Au SPR sensor chip. The quantification limit for EVOO adulteration was successfully obtained at a low level of 5% (v/v) at room temperature. This optical technique has strength in its convenience, simple instrumentation, ease of sample preparation, minimal solvent usage, non-destructive nature, and rapid real-time analysis. We believe that our experimental outcomes make a valuable contribution to the field, addressing the critical need for reliable methods to ensure the authenticity and quality of EVOO.
... 10 The pathogenesis of the cyclosporine-induced nephrotoxicity is not fully understood, but it is thought to be as result from the low-grade hypoxic injury to renal tubular cells and reactive oxygen species inducing apoptosis. 2,22 The development of cyclosporine nephrotoxicity in the present study was associated with a significant decrease in renal glutathione peroxidase, catalase, and SOD activity, indicating that oxidative stress plays a crucial role in the pathogenesis of cyclosporineinduced nephrotoxicity. In the present study, cotreatment with OLE prevented the depletion of renal glutathione peroxidase, catalase, and SOD associated with cyclosporine administration. ...
Introduction. Olive leaves are traditionally used in the Mediterranean basin in many medical conditions for its potent antioxidant activity. Cyclosporine A, a well-known immunosuppressant, can induce nephrotoxicity through oxidative stress. This study investigated the effect of olive leaf extract (OLE) on cyclosporine-induced nephrotoxicity in rats. Materials and Methods. Thirty Wistar rats (180 g to 200 g) were classified into 5 groups, each containing 6 rats. The first group received normal saline and served as control. The second group was treated with cyclosporine, 25 mg/kg for 21 days for nephrotoxicity induction. Groups 3 to 5 were treated with cyclosporine, 25 mg/ kg in addition to different doses of OLE (40 mg/kg, 80 mg/kg, and 120 mg/kg), respectively, for 21 days. After 21 days, the rats' body weights were recorded and the rats were sacrificed. Blood samples were collected and the animals were necropsied. Both kidneys were removed, one for histopathological and one for antioxidant activity evaluations. Results. Cyclosporine significantly reduced body weight and kidney weight; serum total protein, albumin, and sodium levels; and renal glutathione peroxidase, catalase, and superoxide dismutase. It also increased serum urea, creatinine, and calcium levels as compared to the control group. Groups 4 and 5 showed a significantly greater body weight and kidney weight; higher serum sodium, total protein, and albumin levels; greater glutathione peroxidase, catalase, and superoxide dismutase; and lower serum urea, creatinine, and calcium levels as compared to group 2. Conclusions. Treatment with OLE can alleviate cyclosporine-induced nephrotoxicity when used in a proper dose.
... The potential antihyperglycemic effects of these Olive-derived phenolics are believed to be mediated through several suggested mechanisms. These include enhancing glucose uptake in peripheral tissues, inhibiting carbohydrate-hydrolyzing enzymes such as α-amylase and α-glucosidase, and modulating insulin-related signaling pathways (6,18,23). ...
Background
Hyperglycemia and type 2 diabetes mellitus (T2DM) pose a significant risk for cardiovascular diseases and associated complications in individuals with hyperlipidemia. Statin therapy, effective in reducing cholesterol and cardiovascular risks, paradoxically increases incident T2DM risk due to its adverse impact on glucose homeostasis. Therefore, there is a pressing need for safe, and effective adjunctive or alternative therapies to manage hyperglycemia in hyperlipidemic individuals. There is growing body of pharmacological evidence suggesting that Amla and Olive extract supplementation can be beneficial in managing hyperglycemia in individuals with hyperlipidemia.
Objective
The present study aimed to assess for the first time the potential synergistic antihyperglycemic effects of a daily co-supplementation of 1,000 mg Amla fruit and 50 mg Olive fruit standardized extracts (Cholesfytol NG®) over a 2-months period in hyperlipidemic adults with T2DM or prediabetes.
Methods
This retrospective cross-sectional observational study analyzed treatment outcomes in 191 hyperlipidemic adults under the care of their physicians at 57 General Practitioner clinics in Belgium during real-life clinical practice between March 19, 2020, and January 31, 2022. These participants received Cholesfytol NG® as supplementary therapy to improve their metabolic health. The supplement was prescribed in an open-label, non-randomized manner, tailored to each participant’s need.
Results
After 2-months of Cholesfytol NG® supplementation, participants showed significant reductions in glycemia levels: in the T2DM group, levels decreased by 42.7 ± 17.9 mg/dL (27.9%, p < 0.0001), and in the prediabetic group, by 2.26 ± 11.5 mg/dL (4.7%, p = 0.0020). Conversely, no significant change was observed in participants with normal baseline glycemia (1.55 ± 10.3 mg/dL, p = 0.088). Overall, glycemia levels decreased from 96.4 ± 18.2 mg/dL to 94.0 ± 13.5 mg/dL (mean decrease of 2.4 ± 14.5 mg/dL, p < 0.0001). The supplement was well tolerated and no side-effects, serious adverse events, or treatment-emergent effects were reported.
Conclusion
The findings of this real-life clinical study highlight the potential synergistic antihyperglycemic effects of co-supplementation with Amla and Olive fruit extracts in managing hyperglycemia, particularly in individuals with hyperlipidemia. These results suggest that this botanical combination may help mitigate risks associated with hyperglycemia and cardiovascular disease in hyperlipidemic population.
Clinical trial registration
ClinicalTrials.gov, NCT06187298.
... Amongst the various olive-derived products, the tree is primarily cultivated for its oil and table olives, as well as for recreational and environmental purposes (Bartolini et al., 1998). Olive oil, one of the most economically important olive products, is rich in secondary metabolites with health-promoting properties, such as tyrosol, hydroxytyrosol, and oleuropein (Tuck & Hayball, 2002). Its consumption has been associated with preventing and treating several cardiovascular diseases and certain types of cancer (Pauwels, 2011). ...
Olive (Olea europea L.) is one of the most economically important tree crops worldwide, especially for the countries in the Mediterranean basin. Given the economic and nutritional importance of the crop for olive oil and drupe production, we generated transcriptional atlases for the Greek olive cultivars “Chondorlia Chalkidikis” and “Koroneiki,” which have contrasting characteristics in terms of fruit development, oil production properties, and use. Our analysis involved 14 different organs, tissue types, and developmental stages, including young and mature leaves, young and mature shoots, open and closed flowers, young and mature fruits (epicarp plus mesocarp), young and mature endocarps, stalks, as well as roots. The developed gene expression atlases and the associated resources offer a comprehensive insight into comparative gene expression patterns across several organs and tissue types between significant olive tree cultivars. The comparative analyses presented in this work between the “Koroneiki” cultivar, which performs better in olive oil production, and the “Chondorlia Chalkidikis,” which grows larger fruits, will be essential for understanding the molecular mechanisms underlying olive oil production and fruit shape and size development. The developed resource is also expected to support functional genomics and molecular breeding efforts to enhance crop quality and productivity in olive trees.
Outline of data resources generated
The transcriptome data were generated using paired-end Illumina Next-Generation Sequencing technologies. The sequencing yielded approximately 13 million reads per sample for "Chondrolia Chalkidikis" and around 24 million reads per sample for "Koroneiki." The transcriptomes were comparatively analyzed to reveal tissue-specific and differentially expressed genes and co-expression gene modules within and between cultivars.
Summary of key results
The comparative analysis unveiled tissue-specific and differentially expressed genes within and between cultivars. Hierarchical gene clustering revealed intra- and inter-cultivar expression patterns, particularly for the endocarp and fruit tissues relevant to olive oil production and fruit development. Additionally, genes associated with oil production and fruit size/shape development, including those in fatty acid metabolism and developmental regulation, were identified.
Broader utility of the resource
To facilitate accessibility, the GrOlivedb (www.GrOlivedb.com) database was developed, housing the comprehensive transcriptomic data for all of the analyzed organs and tissue types per cultivar. This resource will be a useful molecular tool for future breeding studies in olive oil production and fruit development and a valuable resource for crop improvement.
... Olive fruits and leaves contain the secoiridoid Oleuropein (OP) and very low amounts of its derivative Hydroxytyrosol (HT) (Scheme 1) [10]. Physico-chemical processes for olive oil refining result in HT degradation, therefore only the virgin olive oil (this is, obtained by just mechanical extraction), is rich in HT from olive fruits. ...
Oleuropein (OP) is an appreciated compound present not only in fruits but also in leaves of olive trees, which can be transformed into hydroxytyrosol (HT), a substance with high antioxidant activity. In this work, the transformation of an agricultural residue containing OP (olive leaves or wastewater from mills) to the high added value compound HT is accomplished through different enzymatic strategies. Different enzymes were used, immobilized on various supports by diverse binding forces: beta-glucosidase encapsulated in siliceous material, esterases and lipases immobilized on hydrophobic supports (octyl-functionalized amorphous silica and periodic mesoporous organosilica), and esterase immobilized on amine-functionalized ordered mesoporous silica. All these biocatalysts were tested for oleuropein hydrolysis through two different reaction approaches: a) split of glucosidic bond catalyzed by beta-glucosidase (β-glu), followed by hydrolysis of the aglycon and further ester hydrolysis. 5 mg·mL⁻¹ of β-glu fully hydrolyzed 5 mM OP at pH 7 and 50°C in 7 days, and further enzymatic hydrolysis of the aglycon yielded near to 0.5 mM HT in the best conditions tested. b) via direct hydrolysis of the ester bond to produce hydroxytyrosol in a one-step reaction using esterases or lipases. The latter reaction pathway catalyzed by lipase from Penicillium camemberti immobilized on octyl-silica (4 mg·mL⁻¹) at 35°C and pH 6 directly produced 6.8 mM HT (1 mg·mL⁻¹), transforming in 12 days near to 30% of the initial 25 mM OP from a commercial olive leaves extract.
... Olive leaves harbor a rich array of phenolic compounds, including iridoids, flavonoids, and simple phenols [3]. Notably, oleuropein, a major iridoid terpene, stands out for its high concentration and potent antioxidant properties due to its abundant catechol content [4,5]. Luteoloside is one of the key components of flavonoids, forming an oxidative heterocycle that exists in glycosylation form [6,7]. Additionally, hydroxytyrosol is classified as a simple phenolic compound and is an amphiphilic phenol with a phenylethanol structure [8]. ...
This study aims to extract phenolic-enriched compounds, specifically oleuropein, luteoloside, and hydroxytyrosol, from olive leaves using ball milling-assisted extraction (BMAE). Response surface methodology (RSM) and the Box–Behnken design (BBD) were used to evaluate the effects of the temperature, solvent-to-solid ratio, and milling speed on extraction recovery. The contents of the extract were determined by ultra-high-performance liquid chromatography–mass spectrometry (UPLC-MS) and converted to recoveries to evaluate the extraction efficiency. The optimal extraction conditions for oleuropein, luteoloside, and hydroxytyrosol were identified. Oleuropein had a recovery of 79.0% ± 0.9% at a temperature of 56.4 °C, a solvent-to-solid ratio of 39.1 mL/g, and a milling speed of 429 rpm. Luteoloside’s recovery was 74.6% ± 1.2% at 58.4 °C, 31.3 mL/g, and 328 rpm. Hydroxytyrosol achieved 43.1% ± 1.3% recovery at 51.5 °C, 32.7 mL/g, and 317 rpm. The reason for the high recoveries might be that high energy ball milling could reduce the sample size further, breaking down the cell walls of olive leaves, to enhance the mass transfer of these components from the cell to solvent. BMAE is displayed to be an efficient approach to extracting oleuropein, luteoloside, and hydroxytyrosol from olive leaves, which is easy to extend to industrial production.
... Hydroxytyrosol acts as a radical scavenger and induces apoptosis in cancer cells. Additionally, hydroxytyrosol exhibits antimicrobial properties [160]. The study conducted by Zoric et al. showed that hydroxytyrosol inhibits the transition of unicellular C. albicans yeast into filamentous forms and induces changes in the hydrophobicity of cell surfaces, factors affecting C. albicans adhesion to cell hosts [161]. ...
Inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, involves chronic inflammatory disorders of the digestive tract. Oxidative stress, associated with increased reactive oxygen species generation, is a major risk factor for IBD pathogenesis. Industrialized lifestyles expose us to a variety of factors that contribute to deteriorating gut health, especially for IBD patients. Many alternative therapeutic strategies have been developed against oxidative stress along with conventional therapy to alleviate IBD pathogenesis. Polyphenol-rich foods have attracted growing interest from scientists due to their antioxidant properties. Polyphenols are natural compounds found in plants, fruits, vegetables, and nuts that exhibit antioxidant properties and protect the body from oxidative damage. This review presents an overview of polyphenol benefits and describes the different types of polyphenols. It also discusses polyphenols’ role in inhibiting oxidative stress and fungal growth prevention. Overall, this review highlights how a healthy and balanced diet and avoiding the industrialized lifestyles of our modern society can minimize oxidative stress damage and protect against pathogen infections. It also highlights how polyphenol-rich foods play an important role in protecting against oxidative stress and fungal growth.
... This high thermal stability of OO can be largely attributed to the endogenous presence of polyphenolic compounds, such as hydroxytyrosol and oleuropein. 49,50 As the thermal behaviour was similar in both oils (OO and SO), four temperatures (25, 100, 180, and 220°C) were chosen from the TG curve for the study of improvement of the thermal stability of SO with additives 3b, 3c, 5b, and 5c. ...
Lipid oxidation is the major cause of the deterioration of fat-containing foods, especially those containing polyunsaturated fatty acids (PUFAs). Antioxidant additives of synthetic origin are added to matrices rich in PUFAs, such as sunflower oil (SO). However, there is controversy regarding their safety, and their low solubility in both water and fat has led to the search for new covalent modifications through lipophilicity. This work presents the synthesis of O-alkyl acid derivatives from ferulic and syringic acids and the study of their antioxidant capacity and effect on the thermoxidative degradation of SO. Antioxidant activities were evaluated by employing ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays in a concentration range of 10–100 µg mL⁻¹. The IC50 values for DPPH scavenging activity ranged from 15.61–90.43 µg mL⁻¹. The results of the FRAP assay for both O-alkyl ferulic (3a–f) and syringic (5a–f) series revealed a “cut-off” effect on antioxidant activity in carbon five (C5). Thermoxidation study of additives 3b–c and 5b–c showed a decrease in the slope of extinction coefficients K232 and K270 in comparison with SOcontrol. Furthermore, 3c presented higher antioxidant activity than 3b and 1, with a power to decrease the thiobarbituric acid reactive species (TBARS) 6 times higher than SOcontrol at 220 °C. Additives 5b–c exerted a protective effect on the thermoxidation of SO. The results suggest that increasing lipophilic and thermal properties of antioxidants through O-alkyl acid derivatization is an effective strategy for accessing lipophilic antioxidant additives with potential use in food matrices.
... Juniperus communis has been used in traditional medicine since ancient times and is recognized as an important medicinal plant (Dhaka & Mittal, 2021), which includes treating tumors, bronchitis, indigestion, diarrhea, and stomach pain (Mansouri et al., 2011), This is because it contains a sizable amount of phenolic chemicals, which have been demonstrated to have beneficial effects on a range of biological systems (Dhaka & Mittal, 2021). Additionally, these chemicals have the ability to modify the microbiota in the intestine by selectively promoting the growth of lactobacilli and bifidobacteria while inhibiting the growth of pathogenic bacteria like Clostridia (Tuck & Hayball, 2002). ...
The current study focuses on the effect of Juniperus communis extract on the probiotic properties of lactic acid bacteria isolated from camel milk in the region of El Oued (Algeria). Chromatographic analysis by HPLC was carried out to detect the most important compounds extracted from the plant. The total phenolic and flavonoid contents were determined using the colorimetric procedures Folin–Ciocalteu and aluminum chloride. The probiotic properties were studied and evaluated in vivo with Juniperus communis extracts after isolating strains from camel's milk and identifying them using 16S rRNA gene sequencing. Chromatographic profiles of the phenolic compounds revealed that Juniperus communis extract is rich in quercetin. After conducting chemical analyses of polyphenols and flavonoids, the results demonstrated a high content of phenolic compounds in Juniperus communis extracts (polyphenols: 103.80 ± 0.30 mg GAE/g E. flavonoids: 15.85 ± 0.80 mg QE/g E). Sequencing and phylogenetic analysis showed that the isolates belong to Bacillus pumilus and Bacillus safensis strains. The combination of Juniperus communis and Bacillus safensis restored the healthy intestine wall structure and returned the blood biochemical parameters to normal values. It was found that the mixture enhanced anti‐inflammatory effectiveness by reducing erythrocyte sedimentation rate and C‐reactive protein values. Juniperus communis has a high polyphenol and flavonoid content which can have a considerable impact on Bacillus safensis probiotic properties.
... Phenolic compounds present in olive oil are strong antioxidants and radical scavengers [26], helping to stabilize the product during its shelf life and providing sensory characteristics like bitterness and pungency [27]. The health benefits promoted by the consumption of olive oil are confirmed by EFSA [28]. ...
This study aimed to investigate the impact of Pulsed Electric Fields (PEF) technology in the extraction of olive oil on a pilot scale, using the “Galega Vulgar” olive variety as raw material. The extraction assisted by PEF had a malaxation time of 30 min and was compared with the traditional process of 45 min of malaxation. The main quality parameters of olive oil and the PEF’s cost-benefit assessment were performed. The incorporation of PEF in olive oil production reduced the malaxation stage by 33% without compromising the yield or extra-virgin classification. This efficiency leads to a potential 12.3% increase in annual olive oil production, with a 12.3% and 36.8% rise in revenue and gross profit, respectively. For small-scale production, the considerable upfront investment required for PEF equipment may be a challenge in terms of return on investment. In this scenario, opting for a renting scheme is the best economic solution, especially given the seasonal nature of olive oil production. In medium- to large-scale production, the investment in PEF is a sound investment since it is possible to achieve, with an equipment cost of EUR 450,000 and a production output of 5 tons per hour, an annual ROI of 20%.
... [10][11][12] Homovanillic acid, belonging to the class of phenolic acids, is a hydroxyphenyl acetic acid with potent radical scavenging properties. [13] Phloridzin, a flavonoid glucoside and member of the dihydro-chalcone family, is a natural antidiabetic component found abundantly in apple leaves, constituting more than 90 % of the soluble phenolic compounds. This flavonoid compound exhibits various biological activities primarily related to diabetes, obesity, stress, hyperglycemia, antioxidant activity, and cosmetic ingredients with life-prolonging effects. ...
Lactoperoxidase (LPO) is a crucial enzyme found in milk, tears, and saliva, protecting newborns from harmful microorganisms. This study examined the effects of phenolic substances (naringin, morin, esculin, homovanillic acid, and phloridzin) on purified LPO. LPO was purified from bovine milk using affinity chromatography, yielding 66.6 % with a purity of 387.5‐fold. Three methodologies were employed to assess inhibitory properties: spectrophotometric techniques, molecular docking, and MM‐GBSA. The compounds′ IC50 values were 0.0024 μM, 0.0315 μM, 0.0373 μM, 0.0506 μM, and 0.0221 μM, while their Ki values were 0.0059±0.0012 μM, 0.0672±0.0247 μM, 0.0973±0.0369 μM, 0.0664±0.0190 μM, and 0.0470±0.0159 μM, respectively. Naringin exhibited the most potent inhibitory effect, competitively inhibiting LPO. Therefore, naringin could serve as a novel reversible LPO inhibitor.
... Olive oil consumption has suffered an increase in the last two decades. The highest demand of this natural fat may be related to the use of olive oil as the main fat source in the so-called Mediterranean diet that has been proved to prevent the incidence of cardiovascular and neurodegenerative diseases in humans, and also some types of cancer (Tuck and Hayball 2002;Boudet 2007;Yang et al. 2007). ...
ABSTRACT
This study was designed to harness the environmentally friendly biological process which is economical in the treatment of industrial wastes. The study employed the effectiveness in the biodegradation and treatment of the olive mill wastewater (OMWW) by fungi, using standard procedures in the enzyme synthesis as well as data analysis. The result of the standard calibration curve showed that the OMWW have an optimum pH value in the range of 3 with phenolic degradation to laccase enzyme at 76.12% in 15minutes, allowing the OMWW to be degraded directly without adjustment in ph. It was also observed that an increased enzyme activity significantly increased the absorbance level with the most suitable temperature range found to be between 40.5°C to 41.5°C. The study has revealed the suitability of using fungi in remediation of industrial wastewater.
... Apart from the fatty acids in olive oil, extra virgin oil is quite nutritious, containing significant antioxidants and modest amounts of vitamins E and K. The antioxidants reduce the risk of chronic diseases [5,6], lower inflammation, and protect blood cholesterol from oxidation. The latter two benefits may lower the risk of heart diseases in several ways [7,8]. ...
... Oleuropein (OLE) and its hydrolysis product, hydroxytyrosol, are the main constituents of the leaves and unprocessed olive drupes of Olea europaea. Preclinical studies reported that these compounds display pleiotropic health benefits, mainly associated with their cardioprotective [33][34][35][36][37][38][39][40], anti-inflammatory [41], anti-diabetic [42] and anti-oxidant properties [43]. Current studies employing murine models of AD indicated that OLE also displays neuroprotective properties [44,45]. ...
Oleuropein (OLE), a main constituent of olives, displays a pleiotropic beneficial dynamic in health and disease; the effects are based mainly on its antioxidant and hypolipidemic properties, and its capacity to protect the myocardium during ischemia. Furthermore, OLE activates the peroxisome proliferator-activated receptor (PPARα) in neurons and astrocytes, providing neuroprotection against noxious biological reactions that are induced following cerebral ischemia. The current study investigated the effect of OLE in the regulation of various neural plasticity indices, emphasizing the role of PPARα. For this purpose, 129/Sv wild-type (WT) and Pparα-null mice were treated with OLE for three weeks. The findings revealed that chronic treatment with OLE up-regulated the brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the prefrontal cortex (PFC) of mice via activation of the ERK1/2, AKT and PKA/CREB signaling pathways. No similar effects were observed in the hippocampus. The OLE-induced effects on BDNF and TrkB appear to be mediated by PPARα, because no similar alterations were observed in the PFC of Pparα-null mice. Notably, OLE did not affect the neurotrophic factors NT3 and NT4/5 in both brain tissues. However, fenofibrate, a selective PPARα agonist, up-regulated BDNF and NT3 in the PFC of mice, whereas the drug induced NT4/5 in both brain sites tested. Interestingly, OLE provided neuroprotection in differentiated human SH-SY5Y cells against β-amyloid and H2O2 toxicity independently from PPARα activation. In conclusion, OLE and similar drugs, acting either as PPARα agonists or via PPARα independent mechanisms, could improve synaptic function/plasticity mainly in the PFC and to a lesser extent in the hippocampus, thus beneficially affecting cognitive functions.
... The olive is characterized by its low content of carbohydrates, fiber and protein, while its fruits have almost all essential amino acids. Moreover, olive oil contains many phenolic compounds, such as oleuropein, hydroxytyrosol, tyrosol, cinnamic acid, p-Coumaric acid and homovanillic acid [12], so olive fruits have many advantageous influences like antioxidant, antimicrobial and anti-inflammatory activities [13]. ...
Salinity currently affects more than 20% of agricultural land and is expected to pose potential challenges to land degradation and agricultural production in the future. It is a leading global abiotic stress that affects general plants and cultivated crops adversely. The utilization of biostimulants can enhance the efficiency of plant nutrition, facilitate the uptake of nutrients, boost crop yield, improve the quality characteristics of fruits and enhance plants' ability to withstand abiotic stresses. Biostimulants serve as a vital reservoir of macro-and microelements and plant hormones, such as auxins, cytokinins and gibberellins. Therefore, the current study was conducted to examine the effect of the foliar application of some biostimulants on relieving the side effects of salinity on olive trees (Olea europaea) cv. Kalamata. The olive trees were sprayed three times with moringa leaf aqueous extract (MLE) at 2, 4 and 6%, seaweed extract (SWE) at 1000, 2000 and 3000 ppm and their combinations: 2% MLE + 1000 ppm SWE (combination 1), 4% MLE + 2000 ppm SWE (combination 2) and 6% MLE + 3000 ppm SWE (combination 3). The results revealed that the application of biostimulants had a beneficial effect on the overall growth and development of olive trees, surpassing the performance of untreated trees. Spraying MLE and SWE, particularly at concentrations of 6% and 3000 ppm, respectively, significantly enhanced various aspects of olive tree performance. Notably, there were significant increases in leaf chlorophyll content, flower number, fruit set percentages, fruit yields, fruit oil content, fruit firmness, total soluble solid (TSS) percentage and leaf macro-and micronutrients. Furthermore, the combined application of MLE and SWE resulted in a greater effect when compared to using each one individually. In both seasons, combination 3 outperformed the other treatments that were applied.
... Oleuropein (OLE) and its hydrolysis product, hydroxytyrosol, are the main constituents of the leaves and unprocessed olive drupes of Olea europaea. Preclinical studies reported that these compounds display pleiotropic health benefits, mainly associated with their cardioprotective [33][34][35][36][37][38][39][40], anti-inflammatory [41], anti-diabetic [42] and anti-oxidant properties [43]. Current studies employing murine models of AD indicated that OLE also displays neuroprotective properties [44,45]. ...
Oleuropein (OLE), a main constituent of olive, displays a pleiotropic beneficial dynamic in health and disease, based mainly on its antioxidant and hypolipidemic properties, and its capacity to protect myocardium during ischemia. Furthermore, OLE activates peroxisome proliferator-activated receptor (PPARα) in neurons and astrocytes, providing neuroprotection against noxious biological reactions that are induced following cerebral ischemia. Current study investigated the effect of OLE in the regulation of various neural plasticity indices, emphasizing the role of PPARα. For this purpose, 129/Sv wild-type (WT) and Pparα-null mice were treated with OLE for three weeks. The present findings revealed that chronic treatment with OLE up-regulated the brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the prefrontal cortex (PFC) of mice via activation of ERK1/2, AKT and PKA/CREB signaling pathways. No similar effects were observed in the hippocampus. The OLE-induced effects on BDNF and TrkB appear to be mediated by PPARα, because no similar alterations were observed in the PFC of Pparα-null mice. Notably, OLE did not affect the neurotrophic factors NT3 and NT4/5 in both brain tissues. Fenofibrate though, a selective PPARα agonist, up-regulated BDNF and NT3 in the PFC of mice, whereas the drug induced NT4/5 in both brain sites tested. Interestingly, OLE provided neuroprotection in differentiated human SH-SY5Y cells against β-amyloid and H2O2 toxicity independently from PPARα activation. In conclusion, OLE and similar drugs acting either as PPARα agonists or via PPARα independent mechanisms could improve synaptic function/plasticity mainly in the PFC and to a lesser extent in the hippocampus, thus beneficially affecting cognitive functions.
... Numerous studies have been performed to assess and prove Mediterranean diet as the principal protective agent in the primary prevention of chronic diseases. Studies have pointed out that beneficial health effects of the Mediterranean diet are attributed to a large extent to olive oil (Jimenez-Lopez et al., 2020;Foscolou et al., 2018;Fernandes et al., 2020;Tuck et al., 2002). In addition, olive oil consumption was appointed to prevent from colorectal cancer, breast cancer, and skin cancer (Psaltopoulou et al., 2011;Owen et al., 2000). ...
Olive oil has received great research interest by many researchers due to its nutritional, organoleptic and therapeutic properties. The richness of olive oil with monounsaturated fatty acids, antioxidants, phenolic compounds, vitamin E and vitamin K contributes to the prevention of the risks of several chronic and acute metabolic disorders. When exposed to oxygen, light, moisture, and high temperature during storage, olive oil easily oxidized allowing in loss of biological functionality and producing an unpleasant odor and taste. Developing an easy process to produce a stabilized form of olive oil to enhance stability and prolong shelf life is essential for food industry. In addition, the diversification of olive oil products is required for a better competitivity in the market. In this context, microencapsulation processes could be a promising tool to preserve olive oil, increase its stability by masking the distinctive bitterness revoked by some consumers, and thus enhancing its shelf life. This chapter highlights important aspects of microencapsulation of olive oil, including the description of the most useful microencapsulation techniques and an overview of current research on applications of microencapsulation in food, pharmaceutical, and cosmetic industries.
... Tyrosol and hydroxytyrosol, antioxidative phenols found in olives [68], and ferulic acid, an antioxidant found in plant cell walls, exert protective effects against AβOs in vitro and in vivo [69][70][71][72][73] and also have been shown to enhance the Nrf2 pathway in other models [74][75][76]. ...
Recent studies have revealed that soluble amyloid-β oligomers (AβOs) play a pathogenetic role in Alzheimer’s disease (AD). Indeed, AβOs induce neurotoxic and synaptotoxic effects and are also critically involved in neuroinflammation. Oxidative stress appears to be a crucial event underlying these pathological effects of AβOs. From a therapeutic standpoint, new drugs for AD designed to remove AβOs or inhibit the formation of AβOs are currently being developed. However, it is also worth considering strategies for preventing AβO toxicity itself. In particular, small molecules with AβO toxicity-reducing activity have potential as drug candidates. Among such small molecules, those that can enhance Nrf2 and/or PPARγ activity can effectively inhibit AβO toxicity. In this review, I summarize studies on the small molecules that counteract AβO toxicity and are capable of activating Nrf2 and/or PPARγ. I also discuss how these interrelated pathways are involved in the mechanisms by which these small molecules prevent AβO-induced neurotoxicity and neuroinflammation. I propose that AβO toxicity-reducing therapy, designated ATR-T, could be a beneficial, complementary strategy for the prevention and treatment of AD.
... They have got a lot of attention in the fields of pharmaceutical and medical research because they appear to play a role in the prevention of many diseases and are involved in bioactivities applicable to human health. Phenolic acids exist in almost all edible plants, and the daily dietary consumption by humans is informed to be about 200 mg (Tuck and Hayball 2002;Heleno et al. 2015). Hydroxycinnamic acids form a main class of phenolic acids found in the plant kingdom. ...
Colorectal cancer is the third most lethal and fourth most commonly diagnosed cancer worldwide. Sinapic acid, a derivative of hydroxycinnamic acid, is a promising phytochemical exhibiting numerous pharmacological activities in various systems. It is a substantial chain-breaking antioxidant that operates as a radical scavenger. The aim of this research was to investigate the antiproliferative effect of sinapic acid on the HT-29 cell line besides the mechanisms underlying this activity. The effect of sinapic acid on the viability of HT-29 cell line was investigated using XTT assay. The levels of BCL-2, cleaved caspase 3, BAX, cleaved PARP, and 8-oxo-dG were measured using ELISA. Gamma-H2AX and cytochrome c expressions were assessed semiquantitatively using immunofluorescence staining. Sinapic acid at 200 µm and higher doses produced a significant antiproliferative effect on HT-29 cells. The IC50 value was found to be 317.5 µm for 24 h. Sinapic acid (317.5 µm) significantly elevated cleaved caspase 3, BAX, cleaved PARP, and 8-oxo-dG levels. The levels of gamma-H2AX foci are significantly higher, while the levels of cytochrome c are lower in sinapic acid-treated HT-29 cells. These results indicate that sinapic acid has antiproliferative, apoptotic, and genotoxic effects on colon cancer cells.
... On the contrary, oleuropein, another abundant olive polyphenol, in its free form, is less absorbed by the enterocyte because of its hydrophobic structure and greater molecular weight. This implies that it can be degraded to DOPET [25] because of biotransformation during digestion and absorption processes, thereby raising the bioavailable content of DOPET and, in part, reaching the large intestine, where it is degraded by colonic microflora [26]. ...
Current evidence supports the use of extra virgin olive oil (EVOO) and its minor components such as hydroxytyrosol or 3,4-dihydroxyphenyl ethanol (DOPET), to improve cardiovascular and metabolic health. Nevertheless, more intervention studies in humans are needed because some gaps remain in its bioavailability and metabolism. The aim of this study was to investigate the DOPET pharmacokinetics on 20 healthy volunteers by administering a hard enteric-coated capsule containing 7.5 mg of bioactive compound conveyed in EVOO. The treatment was preceded by a washout period with a polyphenol and an alcohol-free diet. Blood and urine samples were collected at baseline and different time points, and free DOPET and metabolites, as well as sulfo- and glucuro-conjugates, were quantified by LC-DAD-ESI-MS/MS analysis. The plasma concentration versus time profiles of free DOPET was analyzed by a non-compartmental approach, and several pharmacokinetic parameters (Cmax, Tmax, T1/2, AUC0–440 min, AUC0–∞, AUCt–∞, AUCextrap_pred, Clast and Kel) were calculated. Results showed that DOPET Cmax (5.5 ng/mL) was reached after 123 min (Tmax), with a T1/2 of 150.53 min. Comparing the data obtained with the literature, the bioavailability of this bioactive compound is about 2.5 times higher, confirming the hypothesis that the pharmaceutical formulation plays a pivotal role in the bioavailability and pharmacokinetics of hydroxytyrosol.
... The polyphenol composition in olive oil ranges from 50 to 1000 mg/kg [32] but is less saturated in extra virgin olive oil (EVOO) with 50 to 800 mg/kg [46]. However, the quantity of phenolic compounds in EVOO highly depends on the olive's maturation, the country's origin, climate, storage, extraction process, and so on [47]. ...
Pharmacologists have been emphasizing and applying plant and herbal-based treatments in vascular diseases for decades now. Olives, for example, are a traditional symbol of the Mediterranean diet. Hydroxytyrosol is an olive-derived compound known for its antioxidant and cardioprotective effects. Acknowledging the merit of antioxidants in maintaining endothelial function warrants the application of hydroxytyrosol in endothelial dysfunction salvage and recovery. Endothelial dysfunction (ED) is an impairment of endothelial cells that adversely affects vascular homeostasis. Disturbance in endothelial functioning is a known precursor for atherosclerosis and, subsequently, coronary and peripheral artery disease. However, the effects of hydroxytyrosol on endothelial functioning were not extensively studied, limiting its value either as a nutraceutical supplement or in clinical trials. The action of hydroxytyrosol in endothelial functioning at a cellular and molecular level is gathered and summarized in this review. The favorable effects of hydroxytyrosol in the improvement of endothelial functioning from in vitro and in vivo studies were scrutinized. We conclude that hydroxytyrosol is capable to counteract oxidative stress, inflammation, vascular aging, and arterial stiffness; thus, it is beneficial to preserve endothelial function both in vitro and in vivo. Although not specifically for endothelial dysfunction, hydroxytyrosol safety and efficacy had been demonstrated via in vivo and clinical trials for cardiovascular-related studies.
... 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. ...
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. ...
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). ...
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. ...
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.
Platelet-activating factor (PAF) is a potent lipid mediator, involved in thrombosis, inflammation, and atherosclerosis. The protective effect of wine and olive oil against atherosclerotic diseases is largely attributed to their phenolic compounds and mostly to resveratrol and tyrosol. Both compounds have been reported to inhibit PAF biosynthesis in interleukin-1β (IL-1β)-stimulated monocytes and also to attenuate PAF biosynthesis in cell lysates. The aim of this study was to investigate the effects of resveratrol, tyrosol, and their derivatives on unstimulated U937 cells and to explore the intracellular messaging pathways that participate in the activation of PAF biosynthesis in the same cell line. Tyrosol and its derivatives did not exert any substantial effect on PAF biosynthesis. Resveratrol (50 and 100 μM), as well as its methoxy derivative (5–20 μM), caused a reduction in the PAF biosynthetic enzymes’ activity by 20–43% after 24 h of incubation. On the other hand, lower resveratrol concentration (10 μM) and higher concentration of the methoxy derivative (50 μM) increased the Ca2+-dependent lyso–PAF acetyltransferase (LysoPAF-ATC) activity by 28–45% after half-hour incubation via p38 mitogen-activated protein kinase (p38-MAPK) action. IL-1β activated PAF biosynthetic pathways via different signaling pathways, with phospholipase C-β (PLC-β) being a key enzyme.
This review explores the potential health benefits and applications of phenolic secoiridoids derived from olive oil by-products in the prevention of Alzheimer’s disease (AD). As reviewed herein, polyphenols, such as epigallocatechin-3-gallate, epicatechin, and resveratrol, show in vitro and in vivo antioxidant, anti-inflammatory, and neuroprotective properties, and are particularly relevant in the context of AD, a leading cause of dementia globally. The olive oil industry, particularly in the Mediterranean region, produces significant amounts of waste, including leaves, pomace, and wastewater, which pose environmental challenges but also offer an untapped source of bioactive compounds. Despite promising in vitro and in vivo studies indicating that olive-derived polyphenols, such as oleuropein and hydroxytyrosol, may mitigate AD pathology, human clinical trials remain limited. The variability in extraction methods and the complex nature of AD further complicate research. Future studies should focus on standardizing the protocols and conducting robust clinical trials to fully assess the therapeutic potential of these compounds. This approach not only supports the development of new treatments for AD but also promotes environmental sustainability by valorizing olive oil industry waste.
Ozone serves as a potent oxidizing agent and a universal antiseptic, extensively employed in industries such as food, pharmaceuticals, and cosmetics due to its ability to dissolve in water and decompose into oxygen. This study aimed to treat virgin olive oil (VOO) with the ozonation process prior to its incorporation into a sunscreen product, and to discover any new potentially useful properties by comparing it with a sunscreen containing non-ozonated olive oil. The comparison was based on physicochemical properties, physical appearance, and sun protection factor (SPF)
value. VOO treated with 0.017 mole/L ozone was tested for various physicochemical properties such as color, viscosity, refractive index, acid value, iodine value, peroxide value, saponification value, and oxidative stability. The composition was analyzed using gas chromatography (GC) and gas chromatography – mass spectrometry (GC-MS). The properties of ozonated olive oil (OOO)
differed from VOO in terms of viscosity and flow behavior. An increase in shear rate significantly reduced the viscosity of OOO, while VOO maintained a constant viscosity and exhibited Newtonian flow behavior. When OOO was incorporated into sunscreen products, it enhanced the spreadability of the product on the skin, resulting in a significantly higher SPF value. The ability of a sunscreen to spread evenly on the skin and form a continuous thin film is crucial for effective protection against the sun’s rays. These findings highlight the potential of OOO in enhancing the photoprotection efficacy of sunscreen products by providing valuable data for its incorporation into formulations aiming to improve sun protection. Future research could focus on long-term stability and potential side effects of OOO in cosmetic formulations.
African horned melon (AHM) ( Cucumis metuliferus ), indigenous to Kenya. It contains high polyphenol and antioxidant content, yet remains underutilized in food products. This study sought to increase the utilization of AHM by developing a supplemented milk product and evaluating the effects of sundried AHM powder on the physicochemical and sensory properties of the fermented milk product. The fermented milk was supplemented with three different forms of AHM powder: whole fruit, peel, and seed, at concentrations of 0.5%, 0.7%, and 1% w/v. Physicochemical parameters such as pH, total titratable acidity (TTA), syneresis, texture, and viscosity were measured, alongside sensory acceptability assessments. Statistical analysis demonstrated significant differences ( p < 0.05) in physicochemical and sensory properties between the control (did not contain AHM) and supplemented samples, particularly at higher concentrations and extended storage periods. The inclusion of AHM powder markedly influenced the fermented milk's properties, with increased TTA and syneresis in samples with higher melon powder concentrations. TTA ranged between 0.32% and 0.46% among all samples during storage which were comparatively higher than the recommended values for fermented milk products at 0.3%. pH findings range was 4.22 and 4.58. The pH range between 4.2 and 4.6 is recommended by FDA for fermented milk. Syneresis were between 2% and 13%. Texture was between 1.24 and 3.95 N. Viscosity was between 1.67 and 3.87 cP. Sensory scores ranged from 8.00 to 2.67 during storage. Fruit seed powder (FSP1) recorded the lowest amount of pH. Control maintained a higher score in the sensory attributes.
An in-house validated ultra-high performance liquid chromatography (UHPLC) protocol for the purpose of supporting the health claim on “olive oil polyphenols” (EC Regulation 432/2012) is described. The method is based on the quantification of the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content in the polar fraction of olive oil prior to and after acidic hydrolysis of their bound forms. The chromatographic analysis requires ~about one-third of the time needed under high performance liquid chromatography (HPLC) conditions, and thus, the eluent consumption per sample is sixfold lower. In addition to being cost-effective, more samples can be analyzed on a daily basis, thus, reducing the environmental footprint. Two external curves (Htyr, Tyr), detection at 280 nm, and correction factors for molecular weight difference of the hydrolyzed bound forms are proposed. The method is selective, robust with satisfactory precision (%RSD values <11%), and provides for recoveries higher than 87.6% for the target analytes (Htyr, Tyr). Standard operational procedures can be easily adopted for routine quality control of olive oil. The in-house validated protocol presents certain pros that should be exploited by the interested parties.
Context
Olive oil is a vegetable oil that provides health benefits, including a reduction in free radicals and total cholesterol and prevention of chronic diseases. The escalating incidence of chronic diseases presents a substantial challenge to public health, prompting numerous studies to assess these health-related effects. Despite several systematic reviews and meta-analyses summarizing the association between olive oil consumption and specific health outcomes, there is no summary of the accumulated evidence from these reviews.
Objective
This umbrella review summarizes the evidence on olive oil consumption or intervention in adults and its association with multiple risk factors and diseases.
Data Sources
We retrieved systematic reviews of randomized trials or observational studies on oral interventions or the consumption of olive oil. The systematic search encompassed databases including MEDLINE, Embase, Scopus, Web of Science, LILACS, and CENTRAL from inception to February 6, 2023.
Data Extraction
Two independent reviewers conducted data extraction and assessed methodological quality using the Joanna Briggs Institute tool.
Data Analysis
Overall, 17 systematic reviews of randomized trials and observational studies, covering outcomes such as cardiovascular diseases, cancer, type 2 diabetes, glucose metabolism, inflammatory and oxidative markers, and all-cause mortality, were included. The evidence suggests a beneficial association between olive oil consumption and cardiovascular diseases, cancer, type 2 diabetes, and all-cause mortality. However, the evidence was less definitive for inflammatory markers, oxidative stress, glucose metabolism, and blood lipid outcomes. Several meta-analyses revealed high heterogeneity and wide confidence intervals, along with a limited number of randomized clinical trials.
Conclusion
Given the high heterogeneity and low quality of evidence, further studies involving randomized trials are imperative. Prioritizing an in-depth analysis of specific olive oil components and using a control group with distinct characteristics and different effects is strongly recommended.
Systematic Review Registration
PROSPERO registration no. CRD42022357290.
This book covers key areas of biological science. The contributions by the
authors include antioxidant properties, different antioxidant assays, thiobarbituric
acid reactive substances, malonic dialdehyde, lipid peroxidation, metabolomics,
nuclear magnetic resonance, mass spectrometry, time-of-flight, hydatid cyst
disease, echinococcosis, benzadazole, mebendazole, curcuma longa, traditional
medicine, bioavailability, piperine, liposomal encapsulation, microplastics,
polyamid content, breast milk, infant formula, ocean calcifiers, ocean
acidification, foraminifera, calcite compensation depth, climate change, carbon
sequestration, pteridophytes, natural habitats, in-vitro and ex-situ conservation,
economic importance, air purification, air pollution tolerance index, conservation
of environment, high efficiency particulate air filters, air pollution remedies, toxic
pollutants, continuously stirred tank reactor, non-gregarious locust pests,
predictive simulation, phytosanitary forecasting, species distribution models,
ecological niche models. This book contains various materials suitable for
students, researchers, and academicians in the fields of biological science.
It is not yet clear how adding silicon foliar fertilisation affects olive leaf (OL) phenolics and their potential to impact different cancer cells. Thus, we conducted a field trial to study the effect of foliar Si biostimulant fertilisation on the OL phenolic content of the ‘Leccino’ (LE) and ‘Istarska Bjelica’ (IB) cultivars. The experiment compared untreated Control (C) and three distinct levels of silicon (Si1, Si2, Si3) with Si concentrations of 0.55 g/L, 1.1 g/L, and 2.2 g/L, respectively. Si3 application resulted in the highest levels of oleuropein, apigenin-7-O-glucoside, luteolin-4-O-glucoside, rutin, and tyrosol compared to the C treatment. The polyphenols showed high cytotoxic activity in three cancer cell lines tested: cervical adenocarcinoma (HeLa), colon cancer (HCT116), and osteosarcoma (U2OS). The strongest inhibition of cell growth was observed in the HCT116 cell line. All cancer cells tested were more sensitive to treatment with polyphenols isolated from plants with added Si than those without added Si. The cytotoxic activity of the extracts on the healthy cell line RPE1 was similar to that on the cancer cell line HCT116 and U2OS.
Agri-food wastes generated by industrial food processing are valorized through the extraction of biomolecules to obtain value-added products useful for various industrial applications. In the present review, we describe the valuable by-products and bioactive molecules that can be obtained from agricultural wastes and propose extracellular vesicles (EVs) as innovative nutraceutical and therapeutic compounds that could be derived from agriculture residues. To support this idea, we described the general features and roles of EVs and focused on plant-derived extracellular vesicles (PDEVs) that are considered natural carriers of bioactive molecules and are involved in intercellular communication between diverse kingdoms of life. Consistently, PDEVs exert beneficial effects (anti-inflammatory, anti-tumor, and immune-modulatory) on mammalian cells. Although this research field is currently in its infancy, in the near future, the isolation of EVs and their use as nutraceutical tools could represent a new and innovative way to valorize waste from the agri-food industry in an ecofriendly way.
A renewed understanding of eco-friendly principles is moving the industrial sector toward a shift in the utilization of less harmful solvents as a main strategy to improve manufacturing. Green analytical chemistry (GAC) has definitely paved the way for this transition by presenting green solvents to a larger audience. Among the most promising, surely DESs (deep eutectic solvents), NaDESs (natural deep eutectic solvents), HDESs (hydrophobic deep eutectic solvents), and HNaDESs (hydrophobic natural deep eutectic solvents), with their unique features, manifest a wide-range of applications, including their use as a means for the extraction of small bioactive compounds. In examining recent advancements, in this review, we want to focus our attention on some of the most interesting and novel ‘solvent-free‘ extraction techniques, such as microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) in relation to the possibility of better exploiting DESs and NaDESs as plausible extracting solvents of the phenolic compounds (PCs) present in different matrices from olive oil components, such as virgin olive pomace, olive leaves and twigs, virgin and extra virgin olive oil (VOO and EVOO, respectively), and olive cake and olive mill wastewaters (OMWW). Therefore, the status of DESs and NaDESs is shown in terms of their nature, efficacy and selectivity in the extraction of bioactive phytochemicals such as secoiridoids, lignans, phenolic acids and alcohols. Related studies on experimental design and processes’ optimization of the most promising DESs/NaDESs are also reviewed. In this framework, an extensive list of relevant works found in the literature is described to consider DESs/NaDESs as a suitable alternative to petrochemicals in cosmetics, pharmaceutical, or food applications.
La dieta mediterránea (DiM) es un patrimonio cultural, histórico, social, territorial y medioambiental transmitido de generación en generación durante siglos, y ha formado parte, como sistema alimentario y de estilos de vida de los Pueblos del Mediterráneo a lo largo de su historia. En el año 2010, es reconocida como Patrimonio Cultural Inmaterial de la Humanidad por las Naciones Unidas para la Educación, la Ciencia y la Cultura. Fue el resultado de un proceso internacional, coordinado desde España, por la Fundación Dieta Mediterránea. Este reconocimiento ha favorecido un mejor entendimiento de la DiM en todo el mundo (UNESCO, 2010). La principal fuente de grasa en la DiM es el aceite de oliva. En las poblaciones mediterráneas se estima que el consumo por persona/día rondaría los 25 - 50 ml. Recientes estudios han desvelado que el consumo recomendado de aceite de oliva virgen extra (AOVE) estaría en aproximadamente 40 mL. Pocos fármacos son capaces de reducir un 30% la incidencia de complicaciones cardiovasculares mayores como lo ha conseguido una intervención con DiM. El aceite de oliva virgen extra es responsable de gran parte de los efectos cardiosaludables atribuidos a la DiM. No podemos renunciar a estos efectos, por lo que su concurso en nuestra alimentación debe ser atendido a diario. La agencia americana Food and Drugs Administration (FDA) autorizó la difusión de un mensaje en salud en relación con lo recomendable de una ingesta de 23 g de aceite de oliva al día, reemplazando la misma cantidad de grasa saturada, para prevenir el riesgo coronario (FDA, 2004). Y en 2013, la Autoridad Europea de Seguridad Alimentaria (EFSA), aprueba una declaración sobre la capacidad que confiere la ingesta de 5 mg/día de HT en la prevención de la oxidación de lipoproteínas de baja densidad. Resulta complicado, en ocasiones, atribuir los efectos cardiosaludables exclusivamente a un alimento. Por lo tanto, la recomendación debería estar basada en una dieta mediterránea, en la que la cantidad de aceite de oliva virgen extra no baje de 40-50 mL al día, sin olvidar la actividad física diaria (adecuada al perfil de cada individuo) y socializar la alimentación, lejos del estrés diario que obliga a deglutir más que a alimentarse.
Lipids have been little investigated as food for adult insects, considering the importance of these macronutrients for development and reproduction. Lipid reserves are essential for oogenesis and somatic functions. Through host‐feeding, parasitoid females obtain essential nutrients, including lipids used in reproduction. The present study determined the lipid profile of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae), a factitious host of Trichogramma parasitoid wasps, and evaluated whether the fertility of the parasitoid was increased by supplementing its diet with oils having a lipid profile similar to that of the host. Females of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) fed continuously with a diet composed of 90% honey and 10% vegetable oil, mixed in a water bath at 70 °C, parasitized significantly more eggs (11–18%) than did females fed only with pure honey. However, addition of the oil reduced the longevity of these wasps by 40% compared to the controls fed with pure honey. The oil‐enriched diet did not affect the flight performance and quality of the offspring. This information on the use and allocation of lipid reserves in T. pretiosum will help to increase the parasitism capacity of this important biocontrol agent, when produced by mass rearing.
Zeytinyağı, sağlıklı tekli doymamış yağlar ve antioksidanlar bakımından yüksek olduğundan sağlığımız için yararlıdır. Aynı zamanda anti-inflamatuar (iltihap giderici) özelliklere sahiptir. Katı yağların sağlık üzerindeki etkileri tartışmalı olmakla birlikte uzmanlar, zeytinyağının- özellikle sızma zeytinyağının – sağlığımız için faydalı olduğu konusunda hemfikirdirler.
Fibroblasts contribute to maintaining tissue integrity and homeostasis and are a key cell population in wound healing. This cell population can be stimulated by some bioactive compounds such as extra virgin olive oil (EVOO) polyphenols. The aim of this study was to determine the effects of hydroxytyrosol (htyr), tyrosol (tyr), and oleocanthal (ole) phenolic compounds present in EVOO on the proliferation, migration, cell cycle, and antigenic profile of cultured human fibroblasts. CCD-1064Sk human fibroblast cells were treated for 24 h with each polyphenol at doses ranging 10−5 to 10−9 M. Cell proliferation was evaluated using the MTT spectrophotometric technique, migration capacity by culture insert assay, and cell cycle and antigenic profile with flow cytometry. Cell proliferation was significantly increased by treatment with all compounds. The highest increases followed treatments with htyr or tyr at doses of 10−5 or 10−6 M and with ole at 10−6 and 10−7 M, and these compounds and doses were used for assays of antigenic profile, cell cycle, and migration. During the first few hours after treatment, increased fibronectin and α-actin expressions and greater cell migration were observed, with no cell cycle changes. In conclusion, these in vitro results suggest that phenolic compounds in EVOO might contribute to wound healing through action on fibroblasts related to tissue regeneration.
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.
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.
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.
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.
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.
Durch LiAlH4- Reduktion der literaturbekannten Carbonsäure (I) wird die Titelverbindung (II) erhalten.
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).
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.
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.
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.
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
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
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
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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
The 1978-1979 mortality rates for cancers of the breast, prostate, ovary, and colon in 26 to 30 countries were related to the average 1979-1981 food availability data published by the United Nations. The previously described relationship between breast cancer mortality rates and animal fat consumption continues to be evident, and applies also to the other three tumor types. The correlation with breast cancer was particularly strong in postmenopausal women. Since 1964, particularly notable increases in both breast cancer mortality rate and dietary fat intake have occurred in those countries with a relatively low breast cancer risk. The international comparisons support evidence from animal experiments that diets in which olive oil is a major source of fat are associated with reduced breast cancer risk. The excess in mortality rates for breast and ovarian cancer in Israel relative to the national animal fat consumption may be due to the mixed ethnic origin of the Israeli population. Positive correlations between foods and cancer mortality rates were particularly strong in the case of meats and milk for breast cancer, milk for prostate and ovarian cancer, and meats for colon cancer. All four tumor types showed a negative correlation with cereal intake, which was particularly strong in the case of prostate and ovarian cancer. Although, in general, there was a good positive correlation between prostate and breast cancer mortality rates and between prostate cancer and animal fat, discrepancies in national ranking indicate the operation of other etiologic factors that modify risk. The observed positive correlations between the four cancer mortality rates and caloric intake from animal sources, but negative correlations for vegetable-derived calories, suggest that, of the two, animal fat and not energy is the major dietary influence on cancer risk.
Oxidatively-modified low-density lipoproteins (LDL) contribute to the onset of the atherosclerotic disease. A recently discovered marker of lipid peroxidation in a series of prostaglandin F2-like compounds, the prostaglandin isomers isoprostanes, that are generated from arachidonic acid through cyclooxygenase-independent pathways following free radical injury and are endowed with potent biological activities. The incidence of cardiovascular disease in the Mediterranean area is low, possibly because of the type of fat (mainly olive oil) and other components (e.g. fruits and vegetables) of the diet. Natural antioxidants abound in this kind of diet and may also contribute to the observed protection from coronary heart disease (CHD) by retarding the formation of the atherosclerotic plaque. Olive oil, the major dietary fat in the Mediterranean countries, is rich in phenols with antioxidant properties. We thus investigated the formation of isoprostanes during in vitro LDL oxidation and tested the effect of an olive-oil-extracted phenol (i.e. hydroxytyrosol). Our data show that production of isoprostanes and other markers of lipid peroxidation occurs during LDL oxidation and is inhibited by hydroxytyrosol.
Oxidation of low density lipoproteins maybe a factor in the development of atherosclerosis. The Mediterranean diet rich in vegetables, grains, legumes, fruits, and oils, mainly olive oil, has been suggested to reduce the incidence of coronary heart disease, because of its low saturated and high monounsaturated fatty acids content. It is also possible that the natural antioxidants in the oil help to prevent lipid oxidation, e.g. that of low density lipoproteins, thus retarding the formation of atherosclerotic plaques. First-pressed, extra-virgin olive oil contains appreciable amounts of polyphenolic compounds that prevent its autoxidation and are responsible for its high stability. We tested these compounds on low density lipoprotein oxidation and found an inhibitory effect, at low concentrations, on various indexes of lipid oxidation (vitamin E content, formation of thiobarbituric acid-reacting substances, lipid peroxides, levels of polyunsaturated fatty acids, protein modification, conjugated diene formation). Our data suggest that natural antioxidants could play a role in inhibiting the formation of cytotoxic products such as lipid peroxides thus retarding the onset of the atherosclerotic damage.
Secoiridoides (oleuropein and derivatives), one of the major classes of polyphenol contained in olives and olive oil, have recently been shown to inhibit or delay the rate of growth of a range of bacteria and microfungi but there are no data in the literature concerning the possible employment of these secoiridoides as antimicrobial agents against pathogenic bacteria in man.
In this study five ATCC standard bacterial strains (Haemophilus influenzae ATCC 9006, Moraxella catarrhalis ATCC 8176, Salmonella typhi ATCC 6539, Vibrio parahaemolyticus ATCC 17802 and Staphylococcus aureus ATCC 25923) and 44 fresh clinical isolates (Haemophilus influenzae, eight strains, Moraxella catarrhalis, six strains, Salmonella species, 15 strains, Vibrio cholerae, one strain, Vibrio alginolyticus, two strains, Vibrio parahaemolyticus, one strain, Staphylococcus aureus, five penicillin-susceptible strains and six penicillin-resistant strains), causal agents of intestinal or respiratory tract infections in man, were tested for in-vitro susceptibility to two olive (Olea europaea) secoiridoides, oleuropein (the bitter principle of olives) and hydroxytyrosol (derived from oleuropein by enzymatic hydrolysis and responsible for the high stability of olive oil). The minimum inhibitory concentrations (MICs) calculated in our study are evidence of the broad antimicrobial activity of hydroxytyrosol against these bacterial strains (MIC values between 0.24 and 7.85 μg mL−1 for ATCC strains and between 0.97 and 31.25 μg mL−1 for clinically isolated strains). Furthermore oleuropein also inhibited (although to a much lesser extent) the growth of several bacterial strains (MIC values between 62.5 and 500 μg mL−1 for ATCC strains and between 31.25 and 250 μg mL−1 for clinical isolates); oleuropein was ineffective against Haemophilus influenzae and Moraxella catarrhalis.
These data indicate that in addition to the potential employment of its active principles as food additives or in integrated pest-management programs, Olea europaea can be considered a potential source of promising antimicrobial agents for treatment of intestinal or respiratory tract infections in man.
Phenolic compounds in Spanish virgin olive oils were characterized by HPLC. Simple phenols such as hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, and vanillin were found in most of the oils. The flavonoids apigenin and luteolin were also found in most of the oils. The dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol was also detected, as were oleuropein and ligstroside aglycons. The structure of a new compound was elucidated by MS and NMR as being that of 4-(acetoxyethyl)-1,2-dihydroxybenzene. Changes of phenolic compounds in virgin olive oils with maturation of fruits were also studied. Hydroxytyrosol, tyrosol, and luteolin increased their concentration in oils with maturation of fruits. On the contrary, glucoside aglycons diminished their concentration with maturation. No clear tendency was observed for the rest of the phenolic compounds identified.