New drugs from ancient natural foods. Oleocanthal, the natural occurring spicy compound of olive oil: a brief history

Neuroprotective Effects of Olive Oil: A Comprehensive Review of Antioxidant Properties

Neurodegenerative diseases are a significant challenge to global healthcare, and oxidative stress plays a crucial role in their development. This paper presents a comprehensive analysis of the neuroprotective potential of olive oil, with a primary focus on its antioxidant properties. The chemical composition of olive oil, including key antioxidants, such as oleuropein, hydroxytyrosol, and oleocanthal, is systematically examined. The mechanisms by which these compounds provide neuroprotection, including counteracting oxidative damage and modulating neuroprotective pathways, are explored. The neuroprotective efficacy of olive oil is evaluated by synthesizing findings from various sources, including in vitro studies, animal models, and clinical trials. The integration of olive oil into dietary patterns, particularly its role in the Mediterranean diet, and its broader implications in neurodegenerative disease prevention are also discussed. The challenges in translating preclinical findings to clinical applications are acknowledged and future research directions are proposed to better understand the potential of olive oil in mitigating the risk of neurodegenerative conditions. This review highlights olive oil not only as a dietary component, but also as a promising candidate in preventive neurology, advocating for further investigation in the context of neurodegenerative diseases.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

Bioactive compounds in Spanish extra virgin olive oils: Migration and stability according to the culinary technique used

Extra virgin olive oil (EVOO) is a basic food of the Mediterranean diet and an important source of bioactive compounds, especially phenolic substances. The culinary techniques to which the oil is subjected before consumption cause the migration of these compounds, hence the importance of studying their stability before and after culinary treatment. We determined the behaviour of the phenols present in EVOO and its total antioxidant capacity before and after the use of various culinary techniques such as deep frying, boiling (in a water/oil mixture (W/O) and sauteing, observing that the study parameters varied according to the variety of oil and the culinary technique used. Significant statistical differences were observed between the different varieties of EVOO according to the culinary technique used. But this was not the case with respect to polyphenol content, for which no statistically significant differences were observed among the different varieties of EVOO according to the culinary techniques employed (p > 0.05), except with the Arbequina variety (p < 0.05). With respect to the individual polyphenols - tyrosol, p-vainillin, vanillic acid, gallic acid, trans-caffeic acid, ferulic acid and luteolin - our analysis shows that although there were differences in content between raw EVOO and EVOO treated with each of the culinary techniques, these differences were not statistically significant (p > 0.05). There were significant losses of oleocanthal with the W/O boiling technique, but content increases were observed following sauteing and deep frying with respect to raw EVOO. Total antioxidant capacity presented a similar pattern in all samples, with increases after sauteing and decreases after W/O boiling and deep frying. ABTS was the most suitable technique for determining antioxidant capacity in EVOO. In short, the behaviour of the bioactive compounds in EVOO depends on the temperature and the cooking medium used.

Oleocanthal alleviated lipopolysaccharide-induced acute lung injury in chickens by inhibiting TLR4/NF-κB pathway activation

This study aimed to investigate the ameliorative effect of oleocanthal (OC) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in chickens and its possible mechanisms. In total, 20 chickens were randomly divided into 4 groups: control (CON) group, LPS group, LPS + OC group, and OC group. LPS + OC and OC groups were intragastrically administered a 5 mg/kg·d OC dose for 7 d. On d 8, the LPS group and LPS + OC group were intratracheally administered 2 mg/kg LPS for 12 h. It was found that OC ameliorated the pathological morphology and significantly suppressed apoptosis after OC treatment in LPS-induced ALI chicken (P < 0.01). Antioxidant capacity was higher in the LPS + OC group compared with the LPS group (P < 0.01). OC downregulated the related genes and proteins expression of toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) pathway in LPS group (P < 0.01). In conclusion, OC supplementation can alleviate LPS-induced ALI in chickens by suppressing apoptosis, enhancing lung antioxidant capacities and inhibiting TLR4/NF-κB pathway activation.

Phenolic Compounds from Virgin Olive Oil: Approaches for Their Synthesis and Analogues

Virgin olive oil (VOO) is the main fat consumed by populations in the Mediterranean basin, and phenolic compounds, minor components of this fat, are known to be responsible for diverse health benefits when consumed in a regular diet. According to numerous investigations, these benefits are mostly related to phenols such as tyrosol and hydroxytyrosol and secoiridoid derivatives such as ligstroside, oleuropein, oleocanthal and oleacein. These compounds are present in low concentrations, and for some of them, standards are not commercially available, hampering studies on the mechanisms underlying their biological activity. In order to contribute to a better knowledge of the bioactivity of these compounds and their metabolites, they must be available with high purity and in sufficient amounts for the assays. Chemical synthesis has been considered a convenient way to obtain these compounds. This Review will focus on the synthesis of representative VOO compounds, namely, ligstroside, oleuropein, oleocanthal, oleacein and analogues.

Biological effects of olive oil phenolic compounds on mitochondria

Phenolic compounds derived from olive oil have beneficial health properties against cancer, neurodegenerative, and metabolic diseases. Therefore, there are discrepancies in their impact on mitochondrial function that result in changes in oxidative capacity, mitochondrial respiration, and energetic demands. This review focuses on the versatile role of oleuropein, a potent antioxidant that regulates the AMPK/SIRT1/mTOR pathway to modulate autophagy/mitophagy and maintain metabolic homeostasis.

Synthesis of a Seco iso-Secologanin Aglycone Analogue of Interest toward Secoiridoids and Monoterpene Indole Alkaloids

We report the access to an acyclic iso-secologanin aglycone analogue relevant to secoiridoids and monoterpene indole alkaloids. Its synthesis involved the regioselective allylic alkylation of a linear dienyl carbonate with dimethyl malonate, which was catalyzed by an iridium complex, and an anti-Markovnikov Wacker-type oxidation of the terminal alkene of the branched product that was obtained. The thus-formed aldehyde was engaged in a Pictet-Spengler reaction with tryptamine toward monoterpene indole alkaloids.

Spontaneous In Vitro and In Vivo Interaction of (-)-Oleocanthal with Glycine in Biological Fluids: Novel Pharmacokinetic Markers

Since the first discovery of its ibuprofen-like anti-inflammatory activity in 2005, the olive phenolic (-)-oleocanthal gained great scientific interest and popularity due to its reported health benefits. (-)-Oleocanthal is a monophenolic secoiridoid exclusively occurring in extra-virgin olive oil (EVOO). While several groups have investigated oleocanthal pharmacokinetics (PK) and disposition, none was able to detect oleocanthal in biological fluids or identify its PK profile that is essential for translational research studies. Besides, oleocanthal could not be detected following its addition to any fluid containing amino acids or proteins such as plasma or culture media, which could be attributed to its unique structure with two highly reactive aldehyde groups. Here, we demonstrate that oleocanthal spontaneously reacts with amino acids, with high preferential reactivity to glycine compared to other amino acids or proteins, affording two products: an unusual glycine derivative with a tetrahydropyridinium skeleton that is named oleoglycine, and our collective data supported the plausible formation of tyrosol acetate as the second product. Extensive studies were performed to validate and confirm oleocanthal reactivity, which were followed by PK disposition studies in mice, as well as cell culture transport studies to determine the ability of the formed derivatives to cross physiological barriers such as the blood-brain barrier. To the best of our knowledge, we are showing for the first time that (-)-oleocanthal is biochemically transformed to novel products in amino acids/glycine-containing fluids, which were successfully monitored in vitro and in vivo, creating a completely new perspective to understand the well-documented bioactivities of oleocanthal in humans.

Optimization of Surfactant- and Cosurfactant-Aided Pine Oil Nanoemulsions by Isothermal Low-Energy Methods for Anticholinesterase Activity

Highly stable pine oil-loaded nanoemulsions were evaluated for nutraceutical and storage stability applications. Pine oil-loaded nanoemulsion preparation was done with pine oil as the oily phase and additionally with different ratios of the non-ionic surfactant (Tween 80) and cosurfactant (ethanol) in an aqueous solution using the isothermal low-energy or spontaneous emulsification method. A transparent and stable nanoemulsion was obtained with a combination of pine oil (5 wt %), surfactant mixture (35 wt %), and water quantity sufficient (qs) by the isothermal low-energy method. The mean droplet size and ζ-potential of the fabricated nanoemulsion were ≈14 nm and -3.4 mV, respectively. The size of the transparent nanoemulsion increased to ∼45 nm and showed turbidity at 60 °C. Microrheological investigation highlighted the gel-sol-gel conversion in the presence of applied angular frequency at 25 °C. The loss modulus shifted to lower frequency at 60 °C in comparison to other temperatures. The anticholinesterase (AChE) inhibition activity of the pine oil-loaded nanoemulsion suggested a possible therapeutic value, and at 0.10% concentration of the nanoemulsion, the AChE inhibition activity was ≈95.72 ± 5.59%. These studies have important implications in fabrication and optimization of a nanoemulsion as a delivery system for combating reminiscence in Alzheimer's disease and application in the nutraceutical-based industry. This isothermal low-energy method offers an advantage of preparing an edible oil delivery system using simple and rapid operational parameters.

Dual prophylactic/therapeutic potential of date seed, and nigella and olive oils-based nutraceutical formulation in rats with experimentally-induced Alzheimer's disease: A mechanistic insight

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a multifactorial etiology and significantly increasing incidence during the last decade. Hence, developing an effective therapy is crucial for public health. The current study aimed to examine the dual prophylactic/therapeutic potential of a nutraceutical formula based on aqueous extract of roasted date seeds, and nigella and virgin-olive oils against experimentally-induced Alzheimer's disease in rats. Alzheimer's disease-like pathology was induced in male Wistar rats using oral CuSO₄ (200 mg/Kg/day for two months). The nutraceutical formula was given orally to experimental animals (10 mL/kg/d) for 14 days before (as prophylaxis) and after Alzheimer's disease induction and its therapeutic effect in both cases is tested in comparison to donepezil (0.5 mg/kg/d). The nutraceutical formula was found to ameliorate the CuSO₄-induced neuronal damage and regenerate the affected hippocampus tissue and significantly improvemed in learning ability. The formula was also effective in decreasing brain amyloid-β, tau protein, TNF-α level, iNOS level in hippocampus, oxidative stress level, and inhibiting acetylcholinesterase activity and expression in brain and hippocampus, respectively. Further, an increase in GSH levels, activities of SOD, and GST and levels of hippocampus ADAM 17 and brain phospholipids was observed. In conclusion, the studied nutraceutical formula is proved to be effective in ameliorating Alzheimer's neurodegenerative progression with added-prophylactic potential.

Polyphenols from Food and Natural Products: Neuroprotection and Safety

Polyphenols are naturally occurring micronutrients that are present in many food sources. Besides being potent antioxidants, these molecules may also possess anti-inflammatory properties. Many studies have highlighted their potential role in the prevention and treatment of various pathological conditions connected to oxidative stress and inflammation (e.g., cancer, and cardiovascular and neurodegenerative disorders). Neurodegenerative diseases are globally one of the main causes of death and represent an enormous burden in terms of human suffering, social distress, and economic costs. Recent data expanded on the initial antioxidant-based mechanism of polyphenols’ action by showing that they are also able to modulate several cell-signaling pathways and mediators. The proposed benefits of polyphenols, either as protective/prophylactic substances or as therapeutic molecules, may be achieved by the consumption of a natural polyphenol-enriched diet, by their use as food supplements, or with formulations as pharmaceutical drugs/nutraceuticals. It has also been proved that the health effects of polyphenols depend on the consumed amount and their bioavailability. However, their overconsumption may raise safety concerns due to the accumulation of high levels of these molecules in the organism, particularly if we consider the loose regulatory legislation regarding the commercialization and use of food supplements. This review addresses the main beneficial effects of food polyphenols, and focuses on neuroprotection and the safety issues related to overconsumption.

Direct determination of phenolic secoiridoids in olive oil by ultra-high performance liquid chromatography-triple quadruple mass spectrometry analysis

In recent years, a large number of biological properties and an important role in the organoleptic characteristics of olive oil have been attributed to phenolic secoiridoids, such as oleacein, oleocanthal, oleuropein aglycone and ligstroside aglycone. Consequently, quantifying them is of great interest for the olive oil sector. Currently, there is no consensus in which analytical method must be use to accurately determine these compounds in olive oil, mainly owing to the lack of reference standards for calibration. In this work, analytical standards of phenolic secoiridoids have been used to develop a quantitative and rapid analytical method by UHPLC-MS/MS, in which sample extraction is not carried out. Simple dilutions of the sample with dry tetrahydrofuran and dry acetonitrile were performed before analysing them. It is worth noting that under these conditions the generation of artefacts such as acetals and hemiacetals of the aldehydic forms is highly reduced. The detection and quantification was performed with a Xevo TQS tandem quadrupole mass spectrometer. The method was validated at four concentration levels and finally applied to six samples of extra virgin olive oil.

Olive oil in pharmacological and cosmetic traditions

Among the numerous natural substances used in medical remedies, oil certainly plays an important role and, over the centuries, there have been many functions and properties attributed to it. We present the processes that have seen it as protagonist in the pharmacological field and in the cosmetic field.

Natural Molecules for Healthy Lifestyles: Oleocanthal from Extra Virgin Olive Oil

Extra virgin olive oil (EVOO) is the main source of fat in the Mediterranean diet. Phenolic compounds of EVOO, in particular, secoiridoids, are minor components that have generated special interest due to their positive effects on human health, supported by several clinical trials. This review summarizes the most recent findings on the pharmacological properties and action's mechanisms of secoiridoid oleocanthal, focusing attention on inflammation, oxidative stress, cancer, neurodegenerative processes, and rheumatic diseases. Being of relevance to the clinical effects of EVOO intake, the bioavailability and biotransformation of EVOO polyphenols are addressed. Moreover, this review summarizes the factors that may influence the oleocanthal concentration in EVOO. With the growing incidence of age- and lifestyle-related diseases, the current data indicated that the administration of EVOO rich in secoiridoids may be helpful in the prevention or treatment of different pathologies with an inflammatory component. Although promising, the future raises several questions and challenges, which are discussed here. The real beneficial effects of olive oil phenols on human health need to be clarified in new, well-designed clinical studies.

Novel liquid-liquid extraction and self-emulsion methods for simplified isolation of extra-virgin olive oil phenolics with emphasis on (-)-oleocanthal and its oral anti-breast cancer activity

Epidemiological and clinical studies compellingly documented the ability of Mediterranean diet rich in extra-virgin olive oil (EVOO) to reduce breast and colon cancers incidence, cardiovascular diseases, and aging cognitive functions decline. (-)-Oleocanthal (OC) and other EVOO phenolics gain progressive research attention due to their documented biological effects against cancer, inflammations, and Alzheimer’s disease. There is no simple, reliable, and cost-effective isolation protocol for EVOO phenolics, which hinder their therapeutic applications. This study develops novel methods to isolate OC and other EVOO phenolics. This includes the use of ultra-freezing to eliminate most EVOO fats and the successful water capacity to efficiently extract OC and EVOO phenolics as self-emulsified nano-emulsion. Subsequent resin entrapment and size exclusion chromatography afforded individual EVOO phenolics in high purity. OC in vitro and in vivo oral anti-breast cancer (BC) activities validated its lead candidacy. Effective isolation of EVOO phenolics provided in this study will facilitate future preclinical and clinical investigations and stimulate the therapeutic development of these important bioactive natural products.

Quantification of oleacein and oleuropein aglycone in olive oil using deuterated surrogates by normal-phase ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry

An analytical method for the analysis of relevant secoiridoid-based components in olive oil, oleacein and oleuropein aglycone, is described using for the first time deuterated surrogates. 0.2 g of sample was necessary to perform the analysis using liquid-liquid extraction and ultrasound-assisted extraction with a mixture of methanol/water (4:1, v/v). To avoid the formation of by-products, normal-phase ultra high performance liquid chromatography was chosen for the chromatographic separation. The selected mobile phase was a gradient mixture of tetrahydrofurane and hexane, and an ACE Excel 3 CN-ES column as stationary phase. The detection and quantification was performed with a SYNAPT G2-Si mass spectrometer. The calibration curves for oleacein and oleuropein aglycone were linear and quadratic, respectively. The validation was done at three levels of concentration. Relative errors from 0.1 to 10.5% and relative standard deviations lower than 9% were obtained. The method was applied to study different samples of olive oil.

Organic synthesis in the Smith Group: a personal selection of a dozen lessons learned at the University of Pennsylvania

The passionate study of the complex and ever-evolving discipline of organic synthesis over more than a four-decade span is certain to elucidate meaningful and significant lessons. Over this period, Amos B. Smith III, the Rhodes-Thompson Professor of Chemistry and Member of the Monell Chemical Senses Center at the University of Pennsylvania, has mentored well over 100 doctoral and masters students, more than 200 postdoctoral associates and numerous undergraduates, in addition to collaborating with a wide spectrum of internationally recognized scholars. His research interests, broadly stated, comprise complex molecule synthesis, the development of new, versatile and highly effective synthetic methods, bioorganic and medicinal chemistry, peptide mimicry chemistry and material science. Each area demands a high level of synthetic design and execution. United by a passion to unlock the secrets of organic synthesis, and perhaps of Nature itself, innumerable lessons have been, and continue to be, learned by the members of the Smith Group. This lead article in a Special Issue of the Journal of Antibiotics affords an opportunity to share some of those lessons learned, albeit a small selection of personal favorites.

Dietary and Policy Priorities for Cardiovascular Disease, Diabetes, and Obesity: A Comprehensive Review

Suboptimal nutrition is a leading cause of poor health. Nutrition and policy science have advanced rapidly, creating confusion yet also providing powerful opportunities to reduce the adverse health and economic impacts of poor diets. This review considers the history, new evidence, controversies, and corresponding lessons for modern dietary and policy priorities for cardiovascular diseases, obesity, and diabetes mellitus. Major identified themes include the importance of evaluating the full diversity of diet-related risk pathways, not only blood lipids or obesity; focusing on foods and overall diet patterns, rather than single isolated nutrients; recognizing the complex influences of different foods on long-term weight regulation, rather than simply counting calories; and characterizing and implementing evidence-based strategies, including policy approaches, for lifestyle change. Evidence-informed dietary priorities include increased fruits, nonstarchy vegetables, nuts, legumes, fish, vegetable oils, yogurt, and minimally processed whole grains; and fewer red meats, processed (eg, sodium-preserved) meats, and foods rich in refined grains, starch, added sugars, salt, and trans fat. More investigation is needed on the cardiometabolic effects of phenolics, dairy fat, probiotics, fermentation, coffee, tea, cocoa, eggs, specific vegetable and tropical oils, vitamin D, individual fatty acids, and diet-microbiome interactions. Little evidence to date supports the cardiometabolic relevance of other popular priorities: eg, local, organic, grass-fed, farmed/wild, or non-genetically modified. Evidence-based personalized nutrition appears to depend more on nongenetic characteristics (eg, physical activity, abdominal adiposity, gender, socioeconomic status, culture) than genetic factors. Food choices must be strongly supported by clinical behavior change efforts, health systems reforms, novel technologies, and robust policy strategies targeting economic incentives, schools and workplaces, neighborhood environments, and the food system. Scientific advances provide crucial new insights on optimal targets and best practices to reduce the burdens of diet-related cardiometabolic diseases.

Design, synthesis, and anticancer evaluation of long-chain alkoxylated mono-carbonyl analogues of curcumin

Curcumin is a nontoxic phenolic compound that modulates the activity of several cellular targets that have been linked with cancers and other chronic diseases. However, the efficacy of curcumin in the clinic has been limited by its poor bioavailability and rapid metabolism in vivo. We have previously reported the design and discovery of series of 5-carbon linker-containing mono-carbonyl analogues of curcumin (MACs) as anti-cancer agents. In continuation of our ongoing research, we designed and synthesized 37 novel long-chain alkoxylated MACs for anti-cancer evaluation here. The MTS assay was used to determine the cytotoxicity of compounds in gastrointestinal cancer cells. Compounds 5, 28, and 29 showed strongest inhibition against gastric cancer cell proliferation and were subjected to further analysis. The effects of 5, 28, and 29 on cell apoptosis were measured by flow cytometry. Expression levels of Bcl-2, cleaved poly ADP-ribose polymerase (PARP), and pro-caspase-3 were detected by western blotting. Compounds 5, 28, and 29 induced apoptosis in human gastric carcinoma cells, increased PARP cleavage, and decreased expression of Bcl-2 and pro-caspase-3 protein. We then showed that compound 28, which possessed the strongest activity among the test compounds in vitro, exhibited significant tumor inhibition in SGC7901-driven xenograft mouse model. Taken together, the novel compound 28 could be further explored as an effective anticancer agent for the treatment of human gastric cancer.