An extra-virgin olive oil rich in polyphenolic compounds has antioxidant effects in OF1 mice

Exploring the Impact of Extra Virgin Olive Oil on Maternal Immune System and Breast Milk Composition in Rats

Maternal breast milk plays a key role in providing newborns with passive immunity and stimulating the maturation of an infant's immune system, protecting them from many diseases. It is known that diet can influence the immune system of lactating mothers and the composition of their breast milk. The aim of this study was to establish if a supplementation during the gestation and lactation of Lewis rats with extra virgin olive oil (EVOO), due to the high proportion of antioxidant components in its composition, has an impact on the mother's immune system and on the breast milk's immune composition. For this, 10 mL/kg of either EVOO, refined oil (control oil) or water (REF group) were orally administered once a day to rats during gestation and lactation periods. Immunoglobulin (Ig) concentrations and gene expressions of immune molecules were quantified in several compartments of the mothers. The EVOO group showed higher IgA levels in both the breast milk and the mammary glands than the REF group. In addition, the gene expression of IgA in mammary glands was also boosted by EVOO consumption. Overall, EVOO supplementation during gestation and lactation is safe and does not negatively affect the mother's immune system while improving breast milk immune composition by increasing the presence of IgA, which could be critical for an offspring's immune health.

Olive oil increases the LIPC expression when associated with an Eastern pattern diet: An experimental study with Wistar rats

Some nutrigenomic effects of extra virgin olive oil (EVOO) are described in the literature; however, it is unknown whether its interaction with lipid-related genes is independent of the combined diet. In this sense, our objective was to investigate whether EVOO consumption associated with Western or Eastern human-based chow modulates the expression of APOE, APOB, and LIPC genes in rats. In view of this, the hypothesis is that the consumption of olive oil may not have the same nutrigenomic effects, depending on the diet consumed. For this study, 56 female rats were randomly divided into four groups: Western diet with EVOO (WS), Western-diet control (WC), Eastern-diet with EVOO (ES), and Eastern-diet control (EC). After 15 weeks, the animals were anesthetized with an intraperitoneal injection of chloral hydrate 15% (1.5 mL/kg) and euthanized by guillotining, and adipose tissue, liver, and blood were extracted. Triglycerides, cholesterol, and glucose levels were obtained following standard protocols, and relative gene expressions were calculated using the ΔΔCt method after quantitative PCR. The EVOO consumption was associated with LIPC gene expression increase in the liver only in animals fed the Eastern diet, compared to EC and WS animals. The EVOO consumption, combined with the Eastern diet, was associated with decreased triglyceride levels compared to WC. Although final weight and weight gain were similar between groups, WS animals had lower daily energy consumption. Conclusion: Given these results, the authors suggested that the EVOO nutrigenomic effects were restricted to an Eastern human-based diet.

Anti-Inflammatory Effects of Nutritionally Relevant Concentrations of Oleuropein and Hydroxytyrosol on Peripheral Blood Mononuclear Cells: An Age-Related Analysis

Immunosenescence and inflammaging facilitate the insurgence of chronic diseases. The Mediterranean diet is a non-invasive intervention to improve the chronic low-grade inflammatory status associated with aging. Olive oil oleuropein (OLE) and hydroxytyrosol (HT) demonstrated a controversial modulatory action on inflammation in vitro when tested at concentrations exceeding those detectable in human plasma. We studied the potential anti-inflammatory effects of OLE and HT at nutritionally relevant concentrations on peripheral blood mononuclear cells (PBMCs) as regards cell viability, frequency of leukocyte subsets, and cytokine release, performing an age-focused analysis on two groups of subjects: Adult (age 18-64 years) and Senior (age ≥ 65 years). OLE and HT were used alone or as a pre-treatment before challenging PBMCs with lipopolysaccharide (LPS). Both polyphenols had no effect on cell viability irrespective of LPS, but 5 µM HT had an LPS-like effect on monocytes, reducing the intermediate subset in Adult subjects. OLE and HT had no effect on LPS-triggered release of TNF-α, IL-6 and IL-8, but 5 µM HT reduced IL-10 secretion by PBMCs from Adult vs. Senior group. In summary, nutritionally relevant concentrations of OLE and HT elicit no anti-inflammatory effect and influence the frequency of immune cell subsets with age-related different outcomes.

Polyphenols from Olive-Mill Wastewater and Biological Activity: Focus on Irritable Bowel Syndrome

Waste represents a cost for companies, in particular for agro-food companies, which can become a resource as a secondary material. In this work, we examine three products of olive-oil waste water, named MOMAST® (Plus30, PW25, and HY100). Based on the chemical composition, obtained with different methods, we hypothesized a possible application as food supplements in irritable bowel syndrome (IBS). We therefore studied MOMASTs on some targets linked to this pathology: antioxidant action and spontaneous and induced intestinal contractility of the ileum and colon. Plus30, which showed a more promising biological of activity also for its oleuropein content, was characterized by an interesting action against some microorganisms. The results highlighted the ability of Plus30 to modulate spontaneous and induced contractility, to exert a good antioxidant action, and to significantly act on various microorganisms. These effects are synergistic in the presence of antibiotics. In conclusion, we can confirm that Plus30 could be a great candidate as a food supplement in patients with IBS.

Extra Virgin Olive Oil Protects the Testis and Blood from the Toxicity of Paracetamol (Overdose) in Adult Male Rats

Extra virgin olive oil (EVOO) is important in people's daily diets. Paracetamol is a widely used analgesic and antipyretic drug. The aim of this study is to investigate the protective effect of EVOO against hematotoxicity and testicular toxicity induced by paracetamol overdose in rats. Forty rats were divided into four groups. Group 1 rats were given water (control), Group 2 rats were given oral EVOO daily (2 mL/kg b.wt.), Group 3 rats were given oral paracetamol daily (650 mg/kg b.wt.), and Group 4 rats were given paracetamol and EVOO daily. After 15 days, blood and testis samples were collected for biochemical, histological, and ultrastructural studies. The results show that paracetamol decreased the PCV, Hb, and RBC counts relative to the control, and significantly increased the WBC counts and stab cells in Group 3. A significant decrease in blood testosterone was found in Group 3 compared to the control, while a significant increase in testosterone levels was observed in Group 4 compared to Group 3. Light and electron microscopy showed disorganized seminiferous tubules in Group 3. The testis in Group 4 appeared in normal shape. In conclusion, the results indicate that EVOO protects the testis and blood from paracetamol toxicity and may also increase fertility in male rats.

Effect of extra virgin olive oil consumption on glycemic control: A systematic review and meta-analysis

AIMS

Several health benefits are contributed to extra virgin olive oil (EVOO). The polyphenol fraction of EVOO may be responsible for its cardioprotective impacts. This systematic review and meta-analysis aimed to investigate the effect of EVOO intake on glycemic parameters. Electronic literature searched through 1 September 2020 across MEDLINE/PubMed, Web of Science, and SCOPUS databases to find all clinical trials that reported the effect of EVOO intake on glycemic parameters [FBS(fasting blood glucose), insulin, HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) and HbA1c (glycated hemoglobin A1c)] vs. control.

DATA SYNTHESIS

We pooled standardized mean differences (SMD) and 95% confidence intervals (CIs) from randomized clinical trials (RCTs) using random-effects models. Heterogeneity was assessed by Cochran Q-statistic and quantified (I²). We found 13 related trials comprising a total of 633 subjects. In pooled analysis, EVOO intake had no effect on FBS (SMD: -0.07; 95% CI: -0.20, 0.07; I² = 0.0%), insulin (SMD: -0.32; 95% CI: -0.70, 0.06; I² = 38.0%), and HOMA-IR (SMD: -0.32; 95% CI: -0.75, 0.10; I² = 51.0%). However, a decreasing trend was observed in these effects. Subgroup analysis based on age, health status, dose, and EVOO intake duration also did not significantly change results.

CONCLUSION

Although EVOO seems a promising hypoglycemic effects, we did not find any significant evidence that EVOO consumption impacts glucose homeostasis. Furthermore, well-designed RCTs with longer durations are still needed to evaluate the EVOO's efficacy on glycemic parameters.

Does the use of different oil sources in quail diets impact their productive and reproductive performance, egg quality, and blood constituents?

The present study investigated the impact of dietary oil sources (soybean, corn, peanut, flaxseed, olive, and sunflower oils as sources of omega 3, 6, and 9 fatty acids) on productive and reproductive traits, egg quality, hematological and biochemical blood parameters of laying Japanese quail. A total of 360 eight-week mature Japanese quail were randomly divided into 6 groups fed for 8 wk on a basal diet included with 1.5% of different oil sources. Results showed that the highest egg weights and the best feed conversion ratio (P < 0.01) were recorded for quail fed diets supplemented with 1.5% soybean and peanut oil. The highest hatchability percentages (P < 0.05) were recorded for quail fed diets supplemented with corn oil as compared to the other oils. Furthermore, diets enriched with corn, olive, or sunflower oils had higher values of blood lymphocytes (%) compared to the other treated groups. Blood total cholesterol significantly decreased in quail fed on corn, peanut, flaxseed, or olive oil sources as compared to soybean or sunflower oil groups. Immunologically, the highest levels (P < 0.001) of immunoglobulins (G and M) were recorded for quail fed on corn or olive oil sources compared to other oil sources. Quail consuming olive oil–included diets showed a significant increase in superoxide dismutase and glutathione S-transferase activities and a significant decrease on malondialdehyde level compared with those consumed the other oil sources. It could be concluded that varying the oil source can affect productive, reproductive, and health aspects of Japanese quail. Soybean oil showed good results regarding production aspects; however, olive oil was the best regarding health aspects.

Effect of crocin on antioxidant gene expression, fibrinolytic parameters, redox status and blood biochemistry in nicotinamide-streptozotocin-induced diabetic rats

Background

Diabetes is regarded as an epidemiological threat for the twenty-first century. Phytochemicals with known pharmaceutical properties have gained interest in the field of alleviating secondary complications of diseases. Such a substance is crocin, a basic constituent of saffron (Crocus sativus). The present study aimed at examining the beneficial effects of per os crocin administration on the antioxidant status, blood biochemical profile, hepatic gene expression and plasminogen activator inhibitor-1 activity (PAI-1) in the liver, kidney and plasma (an important marker of pre-diabetic status and major factor of thrombosis in diabetes) of healthy rats, as well as of rats with nicotinamide-streptozotocin-induced diabetes.

Results

Diabetes disrupted the oxidation-antioxidation balance, while crocin improved the antioxidant state in the liver by significantly affecting SOD1 gene expression and/or by restoring SOD and total antioxidant capacity (TAC) levels. In the kidney, crocin improved hydrogen peroxide decomposing activity and TAC. In blood, hepatic transaminases ALT and AST decreased significantly, while there was a trend of decrease regarding blood urea nitrogen (BUN) levels. The expression of PAI-1 gene was affected in the liver by the dose of 50 mg kg⁻¹.

Conclusions

Crocin treatment contributed in restoring some parameters after diabetes induction, primarily by affecting significantly hepatic transaminases ALT and AST, SOD1 and PAI-1 gene expression and nephric H₂O₂ decomposing activity. In conclusion, crocin did contribute to the alleviation of some complications of diabetes.

Extra Virgin Olive Oil Polyphenols: Modulation of Cellular Pathways Related to Oxidant Species and Inflammation in Aging

The olive-oil-centered Mediterranean diet has been associated with extended life expectancy and a reduction in the risk of age-related degenerative diseases. Extra virgin olive oil (EVOO) itself has been proposed to promote a "successful aging", being able to virtually modulate all the features of the aging process, because of its great monounsaturated fatty acids content and its minor bioactive compounds, the polyphenols above all. Polyphenols are mostly antioxidant and anti-inflammatory compounds, able to modulate abnormal cellular signaling induced by pro-inflammatory stimuli and oxidative stress, as that related to NF-E2-related factor 2 (Nrf-2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), which have been identified as important modulators of age-related disorders and aging itself. This review summarizes existing literature about the interaction between EVOO polyphenols and NF-κB and Nrf-2 signaling pathways. Reported studies show the ability of EVOO phenolics, mainly hydroxytyrosol and tyrosol, to activate Nrf-2 signaling, inducing a cellular defense response and to prevent NF-κB activation, thus suppressing the induction of a pro-inflammatory phenotype. Literature data, although not exhaustive, indicate as a whole that EVOO polyphenols may significantly help to modulate the aging process, so tightly connected to oxidative stress and chronic inflammation.

Effects of Antarctic krill oil on lipid and glucose metabolism in C57BL/6J mice fed with high fat diet

Background

Obesity and other metabolic diseases have become epidemic which greatly affect human health. Diets with healthy nutrition are efficient means to prevent this epidemic occurrence. Novel food resources and process technology were needed for these purpose. In this study, Antarctic krill oil (KO) extracted from a dry krill by a procedure of hot pump dehydration in combined with freezing-drying was used to investigate health effect in animals including the growth, lipid and glucose metabolism.

Methods

C57BL/6J mice were fed with a lard based high fat (HF) diet and substituted with KO for a period of 12 weeks in comparison with low fat normal control (NC) diet. Mice body weight and food consumption were recorded. Serum lipid metabolism - of C57BL/6J mice serum was measured. A glucose tolerance tests (GTTs) and pathology analysis of mice were performed at the end of the experiment.

Results

The KO fed mice had less body weight gain, less fat accumulation in tissue such as adipose and liver. Dyslipidemia induced by high fat diet was partially improved by KO feeding with significant reduction of serum low density lipoprotein-cholesterol (LDL-C) content. Furthermore, KO feeding also improved glucose metabolism in C57BL/6J mice including a glucose tolerance of about 22% vs. 32% of AUC (area under the curve) for KO vs HF diet and the fast blood glucose level of 8.5 mmol/L, 9.8 mmol/L and 9.3 mmol/L for NC, HF and KO diet groups, respectively. In addition, KO feeding also reduced oxidative damage in liver with a decrease of malondialdehyde (MDA) content and increase of superoxide dismutase (SOD) content.

Conclusion

This study provided evidence of the beneficial effects of KO on animal health from the processed technology, particularly on lipid and glucose metabolism. This study confirmed that as the Antarctic krill was extracted with a procedure of efficient energy, it might make it possible for Krill oil to be available for food industry.

Pathomechanisms of Oxidative Stress in Inflammatory Bowel Disease and Potential Antioxidant Therapies

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease whose incidence has risen worldwide in recent years. Accumulating evidence shows that oxidative stress plays an essential role in the pathogenesis and progression of IBD. This review highlights the generation of reactive oxygen species (ROS) and antioxidant defense mechanisms in the gastrointestinal (GI) tract, the involvement of oxidative stress signaling in the initiation and progression of IBD and its relationships with genetic susceptibility and the mucosal immune response. In addition, potential therapeutic strategies for IBD that target oxidative stress signaling are reviewed and discussed. Though substantial progress has been made in understanding the role of oxidative stress in IBD in humans and experimental animals, the underlying mechanisms are still not well defined. Thus, further studies are needed to validate how oxidative stress signaling is involved in and contributes to the development of IBD.

An extra-virgin olive oil rich in polyphenolic compounds has antioxidant effects in meat-type broiler chickens

The aim of this study was to extend the knowledge on the antioxidant effect of extra-virgin olive oil (EVOO) in the liver of broiler chickens not subjected to any form of insult. A total of 120 male broiler chickens (Hubbard strain) were divided into three groups and fed ad libitum with three isoenergetic diets from hatching until slaughter age (49 days) on a completely randomized design. The dietary treatments consisted of 2.5% added oil or fat from three sources as follows: diet containing sunflower oil (SFO); diet containing lard (LRD), and diet containing extra-virgin olive oil (EVOO). The activity of the main antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GS-Px) and glutathione S-transferase (GST), and lipid peroxidation as thiobarbituric acid-reactive substances (TBARS) content, was measured in the liver of chickens. The susceptibility to undergo lipid peroxidation was assessed by exposing liver homogenate to 30 °C or to an ascorbate/iron mixture as pro-oxidant system. Dietary oil or fat type improved significantly (P < 0.05) the body weight and gain as well as feed efficiency in birds fed EVOO compared to those fed with the other treatments. Supplementing EVOO in the diet significantly (P < 0.05) reduced lipid peroxidation by increasing antioxidant defense system. These findings, besides adding more results on the antioxidant effect of extra-virgin olive oil on liver of other experimental model other than rats and humans, could be significant for animal welfare, with consequent benefits for both producers and consumers.

Effects of dietary extra virgin olive oil and its fractions on antioxidant status and DNA damage in the heart of rats co-exposed to aluminum and acrylamide

Oxidative stress generated by an excessive production of free radicals has been linked to the development of several health problems such as cardiovascular diseases. We investigated the protective efficacy of Extra Virgin Olive Oil (EVOO) and its lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) against the cardiotoxicity and DNA damage induced by co-exposure to aluminum (AlCl3) and acrylamide (ACR). Rats were divided into eight groups of six each: controls, AlCl3 (50 mg per kg body weight) administered via drinking water and ACR (20 mg per kg body weight) given by gavage, combined group plus EVOO (300 μl); combined group plus the hydrophilic fraction (1 ml); combined group plus the lipophilic fraction (300 μl); extra virgin olive oil (EVOO) and its fractions were administered daily by gavage for 21 days. Three other groups, considered as positive controls, received either EVOO, OOLF or OOLH. Exposure of rats to both AlCl3 and ACR provoked oxidative stress objectified by an increase in MDA, AOPP and a decrease in GSH, NPSH and vitamin C levels. The activities of CAT, GPx and SOD were also decreased. EVOO and its OOLF fraction exhibited a pronounced enhancement of antioxidant status while a partial recovery in the antioxidant status was obtained with the OOHF fraction. Plasma LDH and CK activities, TC, LDL-C levels, TC/HDL-C and LDL-C/HDL-C ratios were increased, while HDL-C and TG decreased in rats treated with both AlCl3 and ACR. Co-administration of EVOO, OOLF or OOHF to treated rats restored cardiac biomarkers and lipid profile to near-normal values. Histological studies and DNA damage confirmed the biochemical parameters and the beneficial role of EVOO and its two fractions. Our results suggest that extra virgin olive oil and its two fractions can decrease the frequency of cardiac complications and genotoxicity.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.

Changes in LDL Oxidative Status and Oxidative and Inflammatory Gene Expression after Red Wine Intake in Healthy People: A Randomized Trial

Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. Micronutrients modulate immune system and exert a protective action by reducing low density lipoproteins (LDL) oxidation via induction of antioxidant enzymes. We evaluated the gene expression of oxidative stress (HOSp), inflammasome (HIp), and human drug metabolism pathways (HDM) and ox-LDL level at baseline and after the intake of red wine naturally enriched with resveratrol (NPVRW), in association with or without a McDonald's meal (McDM). The ox-LDL levels significantly increase comparing baseline (B) versus McDM and decreased comparing McDM versus McDM + NPVRW (P ≤ 0.05). Percentages of significant genes expressed after each nutritional intervention were the following: (1) B versus McDM, 2.88% HOSp, 2.40% of HIp, and 3.37% of HDMp; (2) B versus McDM + NPVRW, 1.44% of HOSp, 4.81% of HIp, and 0.96% of HDMp; (3) McDM versus McDM + NPVRW, 2.40% of HOSp, 2.40% of HIp, and 5.77% of HDMp; (4) B versus NPVRW, 4.80% HOSp, 3.85% HIp, and 3.85% HDMp. NPVRW intake reduced postprandial ox-LDL and the expression of inflammation and oxidative stress related genes. Chronic studies on larger population are necessary before definitive conclusions.

Dietary high-polyphenols extra-virgin olive oil is effective in reducing cholesterol content in eggs

BACKGROUND

Extra-virgin olive oil (EVOO) represents an important food in Mediterranean diet due to its favorable effects on human and animal health derived from the consumption of polyphenols. We studied the effects of dietary EVOO differing in polyphenols levels on egg quality.

METHODS

A total of 150 laying hens were allotted into three groups over 10 weeks of the experimental period. The three diets were based on wheat-soybean meal with added oils at 2.5%. Hens were fed the following diets: (1) commercial diet containing sunflower oil (Control), (2) diet EVOO from Cima di Bitonto variety (low-polyphenols content; Low-P), and (3) diet EVOO from Coratina variety (high-polyphenols content; High-P). The performance of the hen, the qualitative traits of eggs, and the fatty acid composition and cholesterol content of egg-yolk were measured.

RESULTS

None of the egg productive parameters studied were influenced by dietary treatment, except for yolk color score that was enhanced in hens fed the both EVOO diets (P<0.05). Feeding high-polyphenols EVOO reduced serum cholesterol level in hens (P<0.01) and egg-yolk cholesterol levels (as per egg; P<0.05). The dietary supplementation of high-polyphenols EVOO raised the polyunsaturated fatty acids (PUFAs) composition and increased the content of oleic and linolenic acids in egg-yolk. Moreover, the atherogenic index in egg-yolk decreased linearly in accordance with increasing levels of dietary polyphenols (P<0.01).

CONCLUSION

In conclusion, a diet for hens consisting of high-polyphenols level from extra-virgin olive oil can improve the fatty acid quality of egg-yolk while lowering the egg-yolk cholesterol level, which could be a beneficial functional food for human health.

Intake of red wine in different meals modulates oxidized LDL level, oxidative and inflammatory gene expression in healthy people: a randomized crossover trial

Several studies have found that adherence to the Mediterranean Diet, including consumption of red wine, is associated with beneficial effects on oxidative and inflammatory conditions. We evaluate the outcome of consumption of a McDonald's Meal (McD) and a Mediterranean Meal (MM), with and without the additive effect of red wine, in order to ascertain whether the addition of the latter has a positive impact on oxidized (ox-) LDL and on expression of oxidative and inflammatory genes. A total of 24 subjects were analyzed for ox-LDL, CAT, GPX1, SOD2, SIRT2, and CCL5 gene expression levels, before and after consumption of the 4 different meal combinations with washout intervals between each meal. When red wine is associated with McD or MM, values of ox-LDL are lowered (P < 0.05) and expression of antioxidant genes is increased, while CCL5 expression is decreased (P < 0.05). SIRT2 expression after MM and fasting with red wine is significantly correlated with downregulation of CCL5 and upregulation of CAT (P < 0.001). GPX1 increased significantly in the comparison between baseline and all conditions with red wine. We highlighted for the first time the positive effect of red wine intake combined with different but widely consumed meal types on ox-LDL and gene expression. Trial Registration. This trial is registered with ClinicalTrials.gov NCT01890070.

Hydroxytyrosol and its potential therapeutic effects

As olive oil is the main source of calories in the Mediterranean diet, a large number of studies have been carried out to characterize its role in various diseases and exploitation for the prevention and treatment of hypertension, carcinogenesis, diabetes, atherosclerosis, and other diseases. As one of the major polyphenols present in virgin olive oil, hydroxytyrosol shows a variety of pharmacological activities such as antioxidant properties, anticancer, anti-inflammatory, and neuroprotective activities, and beneficial effects on the cardiovascular system, which show its potentiality for the development of dietary supplements. In the future, more attention should be paid to its action mechanism in vivo and synergistic effect. Further research will be performed to provide the theoretical basis for hydroxytyrosol and its derivatives use as health supplements.

Mechanisms of action of brain insulin against neurodegenerative diseases

Insulin, a pancreatic hormone, is best known for its peripheral effects on the metabolism of glucose, fats and proteins. There is a growing body of evidence linking insulin action in the brain to neurodegenerative diseases. Insulin present in central nervous system is a regulator of central glucose metabolism nevertheless this glucoregulation is not the main function of insulin in the brain. Brain is known to be specifically vulnerable to oxidative products relative to other organs and altered brain insulin signaling may cause or promote neurodegenerative diseases which invalidates and reduces the quality of life. Insulin located within the brain is mostly of pancreatic origin or is produced in the brain itself crosses the blood-brain barrier and enters the brain via a receptor-mediated active transport system. Brain Insulin, insulin receptor and insulin receptor substrate-mediated signaling pathways play important roles in the regulation of peripheral metabolism, feeding behavior, memory and maintenance of neural functions such as neuronal growth and differentiation, neuromodulation and neuroprotection. In the present review, we would like to summarize the novel biological and pathophysiological roles of neuronal insulin in neurodegenerative diseases and describe the main signaling pathways in use for therapeutic strategies in the use of insulin to the cerebral tissues and their biological applications to neurodegenerative diseases.

Extra virgin olive oil (EVOO) consumption and antioxidant status in healthy institutionalized elderly humans

Recent studies show that the elderly have increased oxidative stress and impaired antioxidant defense systems. Our study aims to evaluate the effects of daily consumption of EVOO in the healthy institutionalized elderly. We studied anthropometric, biochemical and antioxidant parameters in 62 subjects aged 65-96 years after a 6-week daily intake of polyphenol-rich EVOO with high oleuropein derivative contents. Subjects were divided into a control group (CG) who maintained their dietary habits (n=39) and an olive group (OG) who consumed EVOO as the only added fat, plus a daily dose of 50ml (n=23). We found a significant reduction of total cholesterol (TC), HDL, LDL and TGs in OG subjects and a significant increase of HDL levels. There was no significant variation in the CG parameters. In OG the total antioxidant capacity (TAC) in plasma increased with significant differences over CG. Plasma hydroxytyrosol (OH-Tyr) concentration showed a significant increase after EVOO intervention. Daily consumption of EVOO was found to have positive effects on lipid profiles, OH-Tyr levels and TAC. The results also show a significant increase of catalase (CAT) in erythrocytes and a decrease (p<0.05) in superoxide dismutase (SOD) and glutathione peroxidase (GH-PX) activity after EVOO intake. To our knowledge, no other study has examined the effects of EVOO consumption on biochemical parameters, antioxidant capacity and antioxidant enzyme activity in healthy elderly subjects. In conclusion, our results show that nutritional intervention with EVOO improves antioxidant status in healthy elderly people.

Beneficial influence of topical extra virgin olive oil application on an experimental model of penile fracture in rats

Penile fracture (PF) is known as a traumatic rupture of the tunica albuginea of corpus cavernosum. In this study, we aimed to investigate the healing influence of topical extra virgin olive oil (EVOO) on PF through evaluating levels of some oxidative stress biomarkers for the first time. Histopathological evaluation was also realized. A total of 18 male Sprague-Dawley albino rats were divided into three groups of six rats each as control group, in PF (alone) group, and PF + EVOO group. Experimental PF was formed via incising from the proximal dorsal side of the penis in the rats of all groups except control. While in PF (alone) group, fracture was formed and the incision was primarily closed, in PF + EVOO group in addition to foregoing processes, EVOO was also administrated topically twice a day for 3 weeks. At the end of the experiment, all rats were killed and penectomy was carried out. While malondialdehyde, myeloperoxidase, lipid hyroperoxide, and total oxidant status significantly (p < 0.05) increased, reduced glutathione and total free sulfhydryl groups markedly (p < 0.05) decreased in PF (alone) group when compared with PF + EVOO group. Levels of these parameters were reversed to nearly normal values by topical EVOO application. Protection by EVOO is further substantiated via the improved histological findings in PF + EVOO group as against degenerative changes in the rats of PF (alone) group. Our data revealed that EVOO has protective effect in penile cavernosal tissue through probably its antioxidant, free radical defusing, anti-inflammatory, and antimicrobial effects.

Automated method for determination of olive oil phenols and metabolites in human plasma and application in intervention studies

The interest for olive oil phenols (OOPs) is a growing trend thanks to their contribution to prevent or improve diseases associated to oxidative damage. OOPs ingested in the diet are found at low concentrations in blood either as free forms (e.g. hydroxytyrosol, tyrosol, vanillin, ferulic acid, coumaric acid) or conjugated as sulfate and glucuronide derivatives. Therefore, the identification/quantitation of OOPs in plasma to study their biological effects and elucidate their metabolism requires selective and sensitive methods. The present research describes the development, validation and application of an automated method based on on-line coupling of solid-phase extraction and liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for quantitation of conjugated and free OOPs in human plasma. This approach minimizes sample handling-thus reducing analyte losses and degradation by contact with the atmosphere-and increases analysis throughput, which is crucial in intervention studies dealing with cohorts formed by numerous individuals. The fundamental of the approach is the retention of OOPs and metabolites in an SPE anionic cartridge with subsequent on-line elution to an LC-MS/MS system. Quantitative analysis of OOPs (relative quantitation for conjugated OOPs) was carried out by selected reaction monitoring mode that reported relative limits of detection and quantitation between 0.02-0.28 ng/mL (16.6-232 pg on-column) and 0.05-0.83 ng/mL (41.5-689 pg on-column), respectively. The accuracy of the method, estimated as recovery factor, ranged from 84.2 to 99.4%, and precision, expressed as relative standard deviation, was below 3.8%. The resulting method has been applied to the determination of OOPs and metabolites in plasma samples from individuals who ingested a breakfast prepared with virgin olive oil. The proposed method has an excellent potential for high-throughput use in both clinical and research laboratories.

Polyphenolic extracts from Olea europea L. protect against cytokine-induced β-cell damage through maintenance of redox homeostasis

Various pancreatic β-cell stressors, including cytokines, are known to induce oxidative stress, resulting in apoptotic/necrotic cell death and inhibition of insulin secretion. Traditionally, olive leaves or fruits are used for treating diabetes, but the cellular mechanism(s) of their effects are not known. We examined the effects of Olea europea L. (olive) leaf and fruit extracts and their component oleuropein on cytokine-induced β-cell toxicity. INS-1, an insulin-producing β-cell line, was preincubated with or without increasing concentrations of olive leaf or fruit extract or oleuropein for 24 hr followed by exposure to a cytokine cocktail containing 0.15 ng/mL interleukin-1β (IL-1β), 1 ng/mL interferon-γ (IFN-γ), and 1 ng/mL tumor necrosis factor-α (TNF-α) for 6 hr. The cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. Apoptosis was quantified by detecting acridine orange/ethidium bromide-stained condensed nuclei under a fluorescent microscope. The cells exposed to cytokines had a higher apoptotic rate, a decreased viability (MTT), and an increased caspase 3/7 activity. Both extracts and oleuropein partially increased the proportion of living cells and improved the viability of cells after cytokines. The protective effects of extracts on live cell viability were mediated through the suppression of caspase 3/7 activity. Oleuropein did not decrease the amount of both apoptotic and necrotic cells, whereas extracts significantly protected cells against cytokine-induced death. Cytokines led to an increase in reactive oxygen species (ROS) generation and inhibited glutathione level, superoxide dismutase activity, and insulin secretion in INS-1. Insulin secretion was almost completely protected by leaf extract, but was partially affected by fruit extract or oleuropein. Neither cytokines nor olive derivatives had a significant effect on cellular cytochrome c release and catalase activity. Moreover, the cells incubated with each extract or oleuropein showed a significant reduction in cytokine-induced ROS production and ameliorated abnormal antioxidant defense. The molecular mechanism by which olive polyphenols inhibit cytokine-mediated β-cell toxicity appears to be involving the maintenance of redox homeostasis.

Gene expression changes in mononuclear cells in patients with metabolic syndrome after acute intake of phenol-rich virgin olive oil

Background

Previous studies have shown that acute intake of high-phenol virgin olive oil reduces pro-inflammatory, pro-oxidant and pro-thrombotic markers compared with low phenols virgin olive oil, but it still remains unclear whether effects attributed to its phenolic fraction are exerted at transcriptional level in vivo. To achieve this goal, we aimed at identifying expression changes in genes which could be mediated by virgin olive oil phenol compounds in the human.

Results

Postprandial gene expression microarray analysis was performed on peripheral blood mononuclear cells during postprandial period. Two virgin olive oil-based breakfasts with high (398 ppm) and low (70 ppm) content of phenolic compounds were administered to 20 patients suffering from metabolic syndrome following a double-blinded, randomized, crossover design. To eliminate the potential effect that might exist in their usual dietary habits, all subjects followed a similar low-fat, carbohydrate rich diet during the study period. Microarray analysis identified 98 differentially expressed genes (79 underexpressed and 19 overexpressed) when comparing the intake of phenol-rich olive oil with low-phenol olive oil. Many of these genes seem linked to obesity, dyslipemia and type 2 diabetes mellitus. Among these, several genes seem involved in inflammatory processes mediated by transcription factor NF-κB, activator protein-1 transcription factor complex AP-1, cytokines, mitogen-activated protein kinases MAPKs or arachidonic acid pathways.

Conclusion

This study shows that intake of virgin olive oil based breakfast, which is rich in phenol compounds is able to repress in vivo expression of several pro-inflammatory genes, thereby switching activity of peripheral blood mononuclear cells to a less deleterious inflammatory profile. These results provide at least a partial molecular basis for reduced risk of cardiovascular disease observed in Mediterranean countries, where virgin olive oil represents a main source of dietary fat. Admittedly, other lifestyle factors are also likely to contribute to lowered risk of cardiovascular disease in this region.

Changes in antioxidant endogenous enzymes (activity and gene expression levels) after repeated red wine intake

The antioxidant properties of wine have been largely related to the reactive oxygen species (ROS) scavenging ability of phenolic compounds. Polyphenolic compounds are hardly absorbed and quickly transformed into metabolites. Their antioxidant activities just as radical scavenging properties are therefore limited, but it is worth looking to other mechanisms. This study intended to test whether wine consumption affects antioxidant enzyme activity and gene expression. For this purpose, eight subjects drank 300 mL of red wine every day for a week and ate a low phenolic diet (LPD + W) specifically designed to avoid interferences from other polyphenols in the diet. The control period was a week with this diet, and volunteers refrained from drinking wine (LPD). Blood samples were taken at 0, 1, and 7 days. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities were determined in erythrocytes (SOD), plasma (CAT and GR), and blood (GPx). Gene expression was determined in macrophages. Oxidative stress caused by LPD reduced SOD, CAT, and GR activities. After wine consumption, these activities significantly increased (P < 0.05), and this overcame the effect of oxidative stress on enzyme activity. The modulation of CAT activity may be independent of changes in their gene expression, which significantly increased after LPD. However, SOD gene expression increased only during the LPD + W week. Enzyme activities are not all regulated in the same way. The results show that subacute moderate wine ingestion modulated antioxidant enzyme expression and activity, which is important for the prevention of ROS-associated diseases.