Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial

The leaves of the olive plant (Olea europaea) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced (P < 0.05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8-24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo, adding to growing evidence that olive phenolics could be beneficial for health.

Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers

Background and aims: Virgin olive oil (VOO) and nuts are basic components of the Mediterranean diet, a heart-healthy dietary pattern. Nuts have well known cholesterol lowering effects, while evidence is unclear for VOO. We designed a study in hypercholesterolemic patients to assess the effects on serum lipids and other intermediate markers of cardiovascular risk of replacing 40% of the fat in the background diet with VOO, walnuts or almonds. Methods and Results: After a 4 week run-in period with a healthy diet, eligible candidates were randomized into three diet sequences in a crossover design, with a common background diet enriched with VOO, walnuts or almonds, lasting 4 weeks each. Outcomes were changes of serum lipids and oxidation and inflammation markers, measured by standard methods. Plasma fatty acids were determined by gas chromatography to assess compliance. In 18 participants completing the study (9 women, mean age 56 y, BMI 25.7 kg/m(2)), LDL-cholesterol was reduced from baseline by 7.3%, 10.8% and 13.4% after the VOO, walnut and almond diets, respectively (P = 0.001, Friedman test). Total cholesterol and LDL/HDL ratios decreased in parallel. LDL-cholesterol decreases were greater than predicted from dietary fatty acid and cholesterol exchanges among diets. No changes of other lipid fractions, oxidation analytes or inflammatory biomarkers were observed. Plasma fatty acid changes after each diet sequence supported good compliance.

Effect of olive oil-based emulsion on human lymphocyte and neutrophil death

Background The incorporation of lipid emulsions in parenteral diets is a requirement for energy and essential fatty acid supply to critically ill patients. The most frequently used IV lipid emulsions (LE) are composed with long-chain triacylglycerols rich in omega-6 polyunsaturated fatty acids (PUFA) from soybean oil, but these LE promote lymphocyte and neutrophil death. A new emulsion containing 20% soybean oil and 80% olive oil rich in (omega-9 monounsaturated fatty acids (MUFA) has been hypothesized not to cause impairment of immune function. In this study, the toxicity of an olive oil-based emulsion (OOE) on lymphocytes and neutrophils from healthy volunteers was investigated. Methods: Twenty volunteers were recruited and blood was. collected before a 6-hour infusion of an OOE, immediately after infusion, and again 18 hours postinfusion. Lymphocytes and neutrophils were isolated by gradient density. The cells were studied immediately after isolation and after 24 hours or 48 hours in culture. The following determinations were carried out: triacylglycerol levels and fatty acid composition and levels in plasma, lymphocyte proliferation, production of reactive oxygen species, and parameters of lymphocyte and neutrophil death (viability, DNA fragmentation, phosphatidylserine externalization, mitochondrial depolarization, and neutral lipid accumulation). Results: OOE decreased lymphocyte proliferation, provoked lymphocyte necrosis, and had no effect on the proportion of viable neutrophils. The mechanism of cell death induced by OOE involved neutral lipid accumulation but had no effect on mitochondrial membrane depolarization. Conclusions: The OOE given as a single dose of 500 mL induced low toxicity to lymphocytes from healthy volunteers, probably by necrosis.

Flavour as an analytical tool : an anti-inflammatory compound in olive oil

The chemical senses have been underutilised as analytical instruments, although as detectors of chemicals our senses are highly specialised biological machines. This paper reviews the current state of knowledge of the chemical senses. A novel technique was used to isolate and identify a flavour-active non-steroidal antiinflammatory compound in virgin olive oil.

Programming your - objects (turtles, textboxes, sliders and buttons) in microworlds

This article outlines some new-object commands of Logo Microworlds and includes the use of buttons, sliders and programmable colours. The ability to assign object properties including font, colour and frames are discussed. As is assigning object-instructions and commands such as click on and clickoff, launch and cancel. Programming the turtle, making a new turtle, running simultaneous turtles, programming graphic colours and sliders as well as understanding dotimes are explored.

Sensory characterization of the irritant properties of oleocanthal, a natural anti-inflammatory agent in extra virgin olive oils

Oleocanthal is an olive oil phenolic possessing anti-inflammatory activity. Anecdotal evidence suggests that oleocanthal elicits a stinging sensation felt only at the back of the throat (oropharynx). Due to this compound possessing potentially health-benefiting properties, investigation into the sensory aspects of oleocanthal is warranted to aid in future research. The important link between the perceptual aspects of oleocanthal and health benefits is the notion that variation in sensitivity to oleocanthal irritation may relate to potential differences in sensitivity to the pharmacologic action of this compound. The current study assessed the unique irritant attributes of oleocanthal including its location of irritation, temporal profile, and individual differences in the perceived irritation. We show that the irritation elicited by oleocanthal was localized to the oropharynx (P < 0.001) with little or no irritation in the anterior oral cavity. Peak irritation was perceived 15 s postexposure and lasted over 180 s. Oleocanthal irritation was more variable among individuals compared with the irritation elicited by CO₂ and the sweetness of sucrose. There was no correlation between intensity ratings of oleocanthal and CO₂ and oleocanthal and sucrose (r = –0.15, n = 50, P = 0.92 and r = 0.17, n = 84, P = 0.12, respectively), suggesting that independent mechanisms underlie the irritation of CO₂ and oleocanthal. The unusual spatial localization and independence of acid (CO₂) sensations suggest that distinct nociceptors for oleocanthal are located in the oropharyngeal region of the oral cavity.

Influence of heat on biological activity and concentration of oleocanthal : a natural anti-inflammatory agent in virgin olive oil

The olive oil phenolic oleocanthal is a natural nonsteroidal anti-inflammatory compound that irritates the oral pharynx in a dose-dependent manner. It has been proposed that the biological activity of oleocanthal is partially responsible for the beneficial health effects of the Mediterranean diet. Virgin
olive oil containing oleocanthal is often added as an ingredient in a number of cooked dishes, and therefore it is of great importance to understand how best to preserve the putative health-promoting benefits of this compound, as olive oil phenolics are subject to degradation upon heating in general. One extra virgin olive oil containing 53.9 mg/kg oleocanthal was heated at various temperatures (100, 170, and 240 °C) for set time periods (0, 1, 5, 20, 60, and 90 min). Oleocanthal concentrations were quantified using HPLC, and its biological activity was determined with a taste bioassay measuring the intensity of throat irritation. Results demonstrated that oleocanthal was heat stable compared with other olive oil phenolics, with a maximum loss of 16% as determined by HPLC analysis. However, there was a significant decrease of up to 31% (p < 0.05) in the biological activity of oleocanthal as determined by the taste bioassay. Although there was minimal degradation of leocanthal concentration, there was a significant decrease in the biological activity of oleocanthal upon extended heating time, indicating a possible loss of the putative health -benefiting properties of oleocanthal. Alternatively, the difference in the concentration and biological activity of oleocanthal after heat treatment could be a result of an oleocanthal antagonist forming, decreasing or masking the biological activity of oleocanthal.

Chemistry and health of olive oil phenolics

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, and certain types of cancer. The apparent health benefits have been partially attributed to the dietary consumption of virgin olive oil by Mediterranean populations. Most recent interest has focused on the biologically active phenolic compounds naturally present in virgin olive oils. Studies (human, animal, in vivo and in vitro) have shown that olive oil phenolics have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, and antimicrobial activity. Presumably, regular dietary consumption of virgin olive oil containing phenolic compounds manifests in health benefits associated with a Mediterranean diet. This paper summarizes current knowledge on the physiological effects of olive oil phenolics. Moreover, a number of factors have the ability to affect phenolic concentrations in virgin olive oil, so it is of great importance to understand these factors in order to preserve the essential health promoting benefits of olive oil phenolic compounds.

Biological activities of phenolic compounds present in virgin olive oil

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro) have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

Children's knowledge and attitudes towards sea turtles in Colola, Michoacan, Mexico

Food as a medicine : healthful oleocanthal in Australian olive oil

Oleocanthal has gained much interest as a natural anti-inflammatory phenolic component in olive oil. The studies conducted as part of this thesis demonstrate that oleocanthal is a stable olive oil phenolic with potential to be a prime health benefiting compound.

Oleocanthal, a natural anti-Inflammatory compound in extra virgin olive oil

Recent research on the olive oil phenolic, oleo canthal has led to speculation that it may confer some of the health benefits associated with a traditional Mediterranean diet. Oleocanthal produces a peppery, stinging sensation at the back of the throat similar to that of the non-steroidal anti-inflammatory drug (NSAID), ibuprofen. This led to the hypothesis that the perceptual similarity between oleocanthal and ibuprofen may indicate similar pharmacological properties. Subsequent studies have proved the hypothesis and oleocanthal was shown not only to inhibit inflammation in the same way as ibuprofen does, but it was found to be substantially more potent than this NSAID. It is important to note that inflammation has been demonstrated to playa significant role in the development of a number of chronic diseases, such as cardiovascular disease (CVD) and certain types of cancers. Therefore, as a result of dietary feeding with olive oil as a part of the traditional Mediterranean diet, a reduction in inflammation produced by oleocanthal is speculated to be the potential mechanism that is partially responsible for the health benefits associated with this dietary pattern. This review summarizes the current knowledge on oleocanthal, in tenns of its physiological and sensory properties, as well as a discussion on the factors that have the ability to affect oleocanthal concentrations in extra virgin olive oils (EVOOs).