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Stefania D'Angelo

Bio: Stefania D'Angelo is an academic researcher from University of Naples Federico II. The author has contributed to research in topics: Medicine & Membrane protein. The author has an hindex of 20, co-authored 41 publications receiving 1546 citations. Previous affiliations of Stefania D'Angelo include Parthenope University of Naples & Seconda Università degli Studi di Napoli.


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TL;DR: The pharmacokinetic analysis indicates a fast and extensive uptake of the molecule by the organs and tissues investigated, with a preferential renal uptake, and an intracellular metabolic pathway of exogenously administered DOPET, implying the involvement of catechol-O-methyltransferase, alcohol dehydrogenase, aldehyde dehydrogen enzyme, and phenolsulfotransferase has been proposed.
Abstract: 3,4-Dihydroxyphenylethanol (DOPET) is the major o-diphenol detectable in extra virgin olive oil, either in free or esterified form. Despite its relevant biological effects, mainly related to its antioxidant properties, little data have been reported so far on its toxicity and metabolism. The aim of the present work is to evaluate DOPET toxicity and to investigate its molecular pharmacokinetics by using the (14)C-labeled diphenol. When orally administered to rats, the molecule does not show appreciable toxicity up to 2 g/kg b.wt. To identify and quantify its metabolites, [(14)C]DOPET has been synthesized and intravenously injected in rats. The pharmacokinetic analysis indicates a fast and extensive uptake of the molecule by the organs and tissues investigated, with a preferential renal uptake. Moreover, 90% of the administered radioactivity is excreted in urine collected up to 5 h after injection, and about 5% is detectable in feces and gastrointestinal content. The characterization of the labeled metabolites, extracted from the organs and urine, has been performed by high-pressure liquid chromatography analysis. In all the investigated tissues, DOPET is enzymatically converted in four oxidized and/or methylated derivatives. Moreover, a significant fraction of total radioactivity is associated with the sulfo-conjugated forms, which also represent the major urinary excretion products. On the basis of the reported results, an intracellular metabolic pathway of exogenously administered DOPET, implying the involvement of catechol-O-methyltransferase, alcohol dehydrogenase, aldehyde dehydrogenase, and phenolsulfotransferase, has been proposed.

243 citations

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TL;DR: The kinetic data demonstrate that [14C]DPE transport occurs via a passive diffusion mechanism and is bidirectional; the calculated apparent permeability coefficient indicates that the molecule is quantitatively absorbed at the intestinal level.

213 citations

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TL;DR: In this paper, the effects of hydroxytyrosol (DOPET), the major antioxidant compound present in olive oil, on UVA-induced cell damages were investigated, using a human melanoma cell line (M14) as a model system.

156 citations

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TL;DR: The linear relationship demonstrated between biological effects and antioxidant capacity measured by the FRAP assay allows the use of this rapid colorimetric method in assessing and certifying the antioxidant power of extra virgin olive oil to be proposed.
Abstract: This paper reports the protective effect of the phenolic fraction extracted from extra virgin olive oils (OOPEs) against the cytotoxic effects of reactive oxygen species in human erythrocytes and Caco-2 cells, employed as model systems. Pretreatment of cells with various OOPEs, indeed, provides a remarkable protection against oxidative damages: this effect was strictly dependent on the o-diphenolic content of the extracts. Moreover, the protective effects observable in cellular systems were compared with in vitro antioxidant properties, measured by using the FRAP (ferric reducing/antioxidant power) assay; the reducing ability of OOPEs strictly parallels their o-phenolic content. The linear relationship demonstrated between biological effects and antioxidant capacity measured by the FRAP assay allows us to propose the use of this rapid colorimetric method in assessing and certifying the antioxidant power of extra virgin olive oil.

146 citations

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TL;DR: The association between polyphenols (resveratrol, quercetin, curcumin, and some polyphenolic extracts) and obesity is considered, focusing on human trials, and the data so far obtained encourage the setting of new trials, necessary to validate benefic role ofpolyphenols in obese individuals.
Abstract: The prevalence of obesity has steadily increased worldwide over the past three decades. The conventional approaches to prevent or treat this syndrome and its associated complications include a balanced diet, an increase energy expenditure, and lifestyle modification. Multiple pharmacological and non-pharmacological interventions have been developed with the aim of improving obesity complications. Recently, the use of functional foods and their bioactive components is considered a new approach in the prevention and management of this disease. Due to their biological properties, polyphenols may be considered as nutraceuticals and food supplement recommended for different syndromes. Polyphenols are a class of naturally-occurring phytochemicals, some of which have been shown to modulate physiological and molecular pathways involved in energy metabolism. Polyphenols could act in the stimulation of β-oxidation, adipocyte differentiation inhibition, counteract oxidative stress, etc. In this narrative review, we considered the association between polyphenols (resveratrol, quercetin, curcumin, and some polyphenolic extracts) and obesity, focusing on human trials. The health effects of polyphenols depend on the amount consumed and their bioavailability. Some results are contrasting, probably due to the various study designs and lengths, variation among subjects (age, gender, ethnicity), and chemical forms of the dietary polyphenols used. But, in conclusion, the data so far obtained encourage the setting of new trials, necessary to validate benefic role of polyphenols in obese individuals.

100 citations


Cited by
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TL;DR: The antioxidant abilities; the scavenging abilities and the biological fates of hydroxytyrosol, oleuropein and tyrosol which have been published in recent years are summarized.
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.

659 citations

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TL;DR: In an older population, a Mediterranean diet supplemented with olive oil or nuts is associated with improved cognitive function, and this work is likely to be a first step towards addressing the underlying cause of dementia in patients at high cardiovascular risk.
Abstract: Importance Oxidative stress and vascular impairment are believed to partly mediate age-related cognitive decline, a strong risk factor for development of dementia. Epidemiologic studies suggest that a Mediterranean diet, an antioxidant-rich cardioprotective dietary pattern, delays cognitive decline, but clinical trial evidence is lacking. Objective To investigate whether a Mediterranean diet supplemented with antioxidant-rich foods influences cognitive function compared with a control diet. Design, Setting, and Participants Parallel-group randomized clinical trial of 447 cognitively healthy volunteers from Barcelona, Spain (233 women [52.1%]; mean age, 66.9 years), at high cardiovascular risk were enrolled into the Prevencion con Dieta Mediterranea nutrition intervention trial from October 1, 2003, through December 31, 2009. All patients underwent neuropsychological assessment at inclusion and were offered retesting at the end of the study. Interventions Participants were randomly assigned to a Mediterranean diet supplemented with extravirgin olive oil (1 L/wk), a Mediterranean diet supplemented with mixed nuts (30 g/d), or a control diet (advice to reduce dietary fat). Main Outcomes and Measures Rates of cognitive change over time based on a neuropsychological test battery: Mini-Mental State Examination, Rey Auditory Verbal Learning Test (RAVLT), Animals Semantic Fluency, Digit Span subtest from the Wechsler Adult Intelligence Scale, Verbal Paired Associates from the Wechsler Memory Scale, and the Color Trail Test. We used mean z scores of change in each test to construct 3 cognitive composites: memory, frontal (attention and executive function), and global. Results Follow-up cognitive tests were available in 334 participants after intervention (median, 4.1 years). In multivariate analyses adjusted for confounders, participants allocated to a Mediterranean diet plus olive oil scored better on the RAVLT ( P = .049) and Color Trail Test part 2 ( P = .04) compared with controls; no between-group differences were observed for the other cognitive tests. Similarly adjusted cognitive composites (mean z scores with 95% CIs) for changes above baseline of the memory composite were 0.04 (−0.09 to 0.18) for the Mediterranean diet plus olive oil, 0.09 (−0.05 to 0.23; P = .04 vs controls) for the Mediterranean diet plus nuts, and −0.17 (−0.32 to −0.01) for the control diet. Respective changes from baseline of the frontal cognition composite were 0.23 (0.03 to 0.43; P = .003 vs controls), 0.03 (−0.25 to 0.31), and −0.33 (−0.57 to −0.09). Changes from baseline of the global cognition composite were 0.05 (−0.11 to 0.21; P = .005 vs controls) for the Mediterranean diet plus olive oil, −0.05 (−0.27 to 0.18) for the Mediterranean diet plus nuts, and −0.38 (−0.57 to −0.18) for the control diet. All cognitive composites significantly ( P Conclusions and Relevance In an older population, a Mediterranean diet supplemented with olive oil or nuts is associated with improved cognitive function. Trial Registration isrctn.org Identifier:ISRCTN35739639

610 citations

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TL;DR: Recent evidence suggests ROS are also important as second messengers in the regulation of intracellular signaling pathways and, ultimately, gene expression in diabetes.
Abstract: The morbidity and mortality associated with diabetes is the result of the myriad complications related to the disease One of the most explored hypotheses to explain the onset of complications is a hyperglycemia-induced increase in oxidative stress Reactive oxygen species (ROS) are produced by oxidative phosphorylation, nicotinamide adenine dinucleotide phosphate oxidase (NADPH), xanthine oxidase, the uncoupling of lipoxygenases, cytochrome P450 monooxygenases, and glucose autoxidation Once formed, ROS deplete antioxidant defenses, rendering the affected cells and tissues more susceptible to oxidative damage Lipid, DNA, and protein are the cellular targets for oxidation, leading to changes in cellular structure and function Recent evidence suggests ROS are also important as second messengers in the regulation of intracellular signaling pathways and, ultimately, gene expression This review explores the production of ROS and the propagation and consequences of oxidative stress in diabetes

584 citations

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TL;DR: This review focuses on recent works analysing the relationship between the structure of olive oil polyphenolic compounds and their antioxidant activity, which is related to the development of atherosclerosis and cancer, and to anti-inflammatory and antimicrobial activity.
Abstract: The Mediterranean diet is rich in vegetables, cereals, fruit, fish, milk, wine and olive oil and has salutary biological functions. Epidemiological studies have shown a lower incidence of atherosclerosis, cardiovascular diseases and certain kinds of cancer in the Mediterranean area. Olive oil is the main source of fat, and the Mediterranean diet's healthy effects can in particular be attributed not only to the high relationship between unsaturated and saturated fatty acids in olive oil but also to the antioxidant property of its phenolic compounds. The main phenolic compounds, hydroxytyrosol and oleuropein, which give extra-virgin olive oil its bitter, pungent taste, have powerful antioxidant activity both in vivo and in vitro. The present review focuses on recent works analysing the relationship between the structure of olive oil polyphenolic compounds and their antioxidant activity. These compounds' possible beneficial effects are due to their antioxidant activity, which is related to the development of atherosclerosis and cancer, and to anti-inflammatory and antimicrobial activity.

571 citations

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TL;DR: A review of the state-of-the-art on biodegradable polymers can be found in this paper, where the salient features of the design and properties of these polymers are discussed.
Abstract: Recent trends in biodegradable polymers indicate significant developments in terms of novel design strategies and engineering to provide advanced polymers with comparably good performance. However, there are several inadequacies in terms of either technology or cost of production especially in the case of applications in environmental pollution. So, there is a need to have a fresh perspective on the design, properties and functions of these polymers with a view to developing strategies for future developments. The paper reviews the present state-of-art on biodegradable polymers and discusses the salient features of the design and properties of biodegradable polymers. Special emphasis is given to the problems and prospects of (1) approaches adopted to make non-biodegradable synthetic polymers such as polyethylene biodegradable and (2) biodegradable polymers and copolymers made from renewable resources especially poly(lactic acid) based polymers and copolymers which are emerging as the candidate biodegradable materials for the future.

559 citations