1,721,002 research outputs found
Role of Dietary Polyphenols in the Activity and Expression of Nitric Oxide Synthases: A Review
Full text linkNitric oxide (NO) plays several key roles in the functionality of an organism, and it is usually released in numerous organs and tissues. There are mainly three isoforms of the enzyme that produce NO starting from the metabolism of arginine, namely endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and neuronal nitric oxide synthase (nNOS). The expression and activity of these isoforms depends on the activation/deactivation of different signaling pathways at an intracellular level following different physiological and pathological stimuli. Compounds of natural origin such as polyphenols, which are obtainable through diet, have been widely studied in recent years in in vivo and in vitro investigations for their ability to induce or inhibit NO release, depending on the tissue. In this review, we aim to disclose the scientific evidence relating to the activity of the main dietary polyphenols in the modulation of the intracellular pathways involved in the expression and/or functionality of the NOS isoforms
Biological relevance of extra virgin olive oil polyphenols metabolites
Full text linkExtra virgin olive oil (EVOO) polyphenols beneficial effects have widely been debated throughout the last three decades, with greater attention to hydroxytyrosol and tyrosol, which are by far the most studied. The main concern about the evaluation of EVOO phenols activities in vitro and in vivo is that the absorption and metabolism of these compounds once ingested lead to the production of different metabolites in the human body. EVOO phenols in the ingested forms are less concentrated in human tissues than their glucuronide, sulfate and methyl metabolites; on the other hand, metabolites may undergo deconjugation before entering the cells and thus act as free forms or may be reformed inside the cells so acting as conjugated forms. In most in vitro studies the presence of methyl/sulfate/glucuronide functional groups does not seem to inhibit biological activity. Parent compounds and metabolites have been shown to reach tissue concentrations useful to exert beneficial effects others than antioxidant and scavenging properties, by modulating intracellular signaling and improving cellular response to oxidative stress and pro-inflammatory stimuli. This review aims to give an overview on the reported evidence of the positive effects exerted by the main EVOO polyphenols metabolites in comparison with the parent compounds
formed metabolites of polyphenols and their biological efficacy
No full textIt is well known that plant-derived polyphenols are biologically relevant for human health both for their direct antioxidant activity and for their effects in the modulation of intracellular signals. Experts in this field have become aware of the need to carefully evaluate the effectiveness of these compounds in vivo, because of their absorption and metabolism kinetics once ingested. Indeed, it has been established that phenolic compounds are exposed to extensive metabolism in the human body, and their bioavailability is poor with respect to their metabolites. Thus, considering the biological activity of parent compounds, instead of that of their metabolites, is the major concern in relation to the studies on these molecules, especially in vitro. Recently, the main metabolites of polyphenols have become the subject of manifold research studies, which have revealed their beneficial effects particularly as antioxidant, anti-inflammatory and anticancer agents. They have also been investigated for their role in the prevention of cardiovascular and neurodegenerative diseases. The goal of this review is to emphasize the importance of the main in vivo formed metabolites of polyphenols for their potential benefits in relation to human health, showing the most significant outcomes of in vivo and in vitro studies carried out in the last few decades
Modulation of LPS-induced nitric oxide production in intestinal cells by hydroxytyrosol and tyrosol metabolites: Insight into the mechanism of action
Full text linkAt intestinal level, after acute or chronic exposure to iNOS-derived NO, a toxic mechanism of action leads to inflammation and degenerative diseases. The aim of this study was to investigate the effect of glucuronide and sulfate metabolites of the extra virgin olive oil phenols tyrosol (Tyr) and hydroxytyrosol (HT), in comparison with their parent compounds, on the release of NO following exposure to a pro-inflammatory stimulus, the bacterial lipopolysaccharide (LPS). Human colon adenocarcinoma cells (Caco-2), differentiated as normal enterocytes, were treated with pathological concentrations of LPS, in order to stimulate iNOS pathway, which involves NF-ĸB activation through IĸBα phosphorylation and subsequent degradation induced by Akt or MAPKs. All the tested metabolites inhibited NO release induced by LPS, acting as inhibitors of iNOS expression, with an efficacy comparable to that of the parent compounds. HT and Tyr metabolites were effective in the inhibition of IĸBα degradation. No one of the compounds was able to inhibit Akt activation, whereas they modulated p38 and ERK1/2 MAPK. Obtained data show that HT and Tyr metabolites are able to prevent a pathological NO overproduction at intestinal level, where they concentrate, thus significantly contributing to the protective activity exerted by their parent compounds against inflammation
Determination of dansylated amino acids and biogenic amines in Cannonau and Vermentino wines by HPLC-FLD
No full textFree amino acids (AA) and biogenic amines (BA) were quantified for the first time in Cannonau and Vermentino wines, the two most popular "Controlled Designation of Origin" wines from Sardinia (Italy). An analytical method for the simultaneous determination of AA and BA was developed, using selective derivatization with dansyl chloride followed by HPLC with fluorescence detection. Thirty-two compounds were identified in the wines analysed. High levels of AA were found, with proline being the most abundant with average levels of 1244 ± 398 and 1008 ± 281 mg/L in Cannonau and Vermentino wines, respectively. BA were detected at average concentrations <10 mg/L, except putrescine which reached 20.5 ± 10.2 mg/L in Cannonau wines. Histamine was never detected in any Vermentino wines. γ-Aminobutyric acid, 4-hydroxyproline, glycine, leucine + isoleucine and putrescine proved to be useful for differentiating Cannonau wines from Vermentino wines
Phenolic compounds, antioxidant activity, and other characteristics of extra virgin olive oils from italian autochthonous varieties Tonda di Villacidro, Tonda di Cagliari, Semidana, and Bosana
Full text linkExtra virgin olive oils (EVOOs) from the fruits of Italian autochthonous varieties Tonda di Villacidro, Tonda di Cagliari, Semidana, and Bosana were investigated to promote their quality aspects. All the analyzed EVOOs showed low values of acidity (≤0.45%) and of peroxide value (≤6.22 mEq O2/kg). There were no relevant differences in fatty acids and triacylglycerols composition among the four EVOOs. Tocopherols determined by HPLC-FL revealed that Bosana oil was characterized by the highest α -tocopherol level (213.3 ± 55.4 mg/kg). Chlorophylls, carotenoids, and total phenol (TP) contents as well as antioxidant activity (FRAP, DPPH, and ABTS+ assays) of the oils hydrophilic fractions (HFs) were assessed by spectrophotometric methods. Some differences concerning the antioxidant activity and the TP content were observed: Bosana oil HF activity was the most pronounced (1.17 ± 0.37 mmol TEAC/kg) and it contained the highest TPs amount (335.20 ± 121.34 mg/kg). HFs phenolic composition was determined by HPLC-DAD. The main identified phenols were secoiridoids, dominating in Bosana oil, such as decarboxymethyl ligstroside aglycone (p-HPEA-EDA, 35.8 ± 19.9 mg/kg) and oleuropein aglycone (3,4-HPEA-EA up to 84.7 mg/kg). In summary, all the four varieties showed good characteristics for the use as quality EVO
Insight into the Chemical Diversity of Late/Ice Harvest Gewürztraminer Wine
No full textLate harvest (LHW) and ice harvest (IHW) Gewürztraminer wine samples from Croatia (Ilok) were investigated. Their technological parameters, chromaticity coordinates, total phenols content, and antioxidant capacity were determined. 5-(Hydroxymethyl)furfural, xanthine, and trans-caftaric acid were analyzed in the samples by high performance liquid chromatography (HPLC-DAD). Headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC/MS) analysis revealed isoamyl alcohol as predominant compound (21.25 – 60.30%). Diethyl succinate, 2-phenylethanol, and benzaldehyde were also abundant. Ethyl octanoate (1.48 – 5.70%) and ethyl caprate (0.48 – 4.83%) decreased significantly in LHW, being the lowest in IHW. Two solvents were applied for the samples extraction (solvent A – pentane/diethyl ether 1:2 (v/v) and solvent B – dichloromethane), and the extracts were analyzed by GC/MS. Ethyl hydrogen succinate (solvent A: 27.30 – 52.04%; solvent B: 28.04 – 46.69%) and diethyl succinate (solvent A: 5.21 – 18.2%; solvent B: 2.66 – 7.72%) were predominant in IHW and LHW. Aromatic alcohols were also found: 2-phenylethanol (solvent A: 7.07 – 21.09%; solvent B: 5.50 – 11.82%), 4-hydroxybenzyl alcohol (solvent A: 1.45 – 6.68%; solvent B: 2.47 – 12.16%) and benzyl alcohol (solvent A: 0.10 – 0.77%). The obtained results complement a previous study on IHW (Gewürztraminer) from Croatia providing new features and indicating great chemical diversity among the samples
Characterization, phenolic profile, nitrogen compounds and antioxidant activity of Carignano wines
No full textThe aim of this study was to perform a preliminary chemical and physical characterization of the Carignano wine, an Italian monovarietal red wine mainly produced in the south-west of Sardinia (Italy). Technological parameters (alcohol, reducing sugars, total and volatile acidity, and pH), organic acid content, CIE L*C*abh°ab chromaticity coordinates, phenolic compound contents (with spectrophotometric assays and HPLC-DAD), nitrogen compounds (with HPLC-FLD) and antioxidant capacity assessed by FRAP and DPPH assays were evaluated in 14 samples (vintage 2013) and compared with 3 aged samples. Carignano wines showed a significant level of phenolic compounds (2023 ± 435 mg GAE/L) and a good in vitro antioxidant capacity (31.6 ± 5.2 mmol Fe2+/L and 10.0 ± 1.4 mmol TEAC/L, respectively). The content of total polyphenols correlated significantly (p < 0.001) with the total reducing power and radical scavenging capacity. The nitrogen compounds found in samples were mainly amino acids, and among these, the content of essential amino acids was of 61.4 ± 22.5 mg/L. A relatively low amount of undesirable biogenic amines was also found (17.2 ± 6.9 mg/L). Xanthine was detected in all the samples in the range 48.0–101.4 mg/L. These data may help wineries improve their consumer safety procedures for Carignano wine productio
Diagnosi di Laboratorio per Infezione nel Distretto Parodontale, dalla PCR al “Molecular Beacon Array”
No full textI dati forniti dall’ Organizzazione Mondiale della Sanità (OMS) riportano che a fronte del 30% della popolazione italiana che presenta salute parodontale, il restante 70 % è affetta da una forma di patologia che può essere lieve (80%) e grave (5-20%). Si tratta dunque di una patologia che ha un forte impatto sociale, e quindi una notevole incidenza nei costi della spesa sanitaria. Si impone pertanto un corretto approccio in termini di: prevenzione della diagnosi clinica e di laboratorio, delle strategie terapeutiche. L ‘eziologia della malattia parodontale e di tipo infettivo ma rispetto ad altre patologie causate da microorganismi la parodontite presenta notevoli peculiarità, peculiarità che vanno ricercate nelle caratteristiche dei patogeni parodontali, in particolare : (a) sono descritte almeno 300 specie differenti ( la maggior parte non ancora identificate), (b) La maggior parte sono anaerobi, (c) difficoltà nella coltura, (d) crescita molto lenta ( anche 2 settimane), (e) presentano un' organizzazione a ” biofim complesso”. Attualmente, un aiuto importante alla diagnostica di laboratorio in parodontologia, viene dalla biologia molecolare. Le tecniche più efficaci e moderne attualmente in uso sono la Polymerase Chain Reaction (PCR), e la sua versione quantitativa : la PCR real-Time. Queste metodiche hanno come principio lo specifico riconoscimento di una sequenza di DNA/RNA appartenente al microorganismo patogeno. I vantaggi principali vengono rilevati nella sensibilita’ ( un incremento di 10-100 volte) e nel tempo del risultato (1- 6 ore ). Nonostante questi vantaggi notevoli , i metodi citati possono presentare una bassa specificità , dovuta a sequenze di DNA molto simili appartenenti a specie microbiche affini.
2 Recentemente un ulteriore passo nella diagnostica microbiologica molecolare e’ stato raggiunto con i “Molecular Beacon”MB, (Tyagi et al., 1996). I MB, ,rappresentano sonde fluorescenti a DNA con struttura circolare (Fig.1). La sonda presenta una sequenza nucleotidica che si apre (ed emette fluorescenza),solo se trova una regione complementare perfettamente identica nel DNA bersaglio del patogeno parodontale, questo determina il massimo grado di specificità possibile nella diagnostica molecolare, di conseguenza vengono ridotti i possibili falsi positivi della PCR tradizionale. L’utilizzo dei MB in un pannello analitico contenente tutte le specie rappresentative della malattia parodontale “molecular beacon array”, dispone per il clinico elementi più oggettivi e, soprattutto scientificamente/tecnologicamente più significativi, su cui basare la diagnosi di infezione per malattia parodontale
Probiotic lactobacilli attenuate oxysterols-induced alteration of intestinal epithelial cell monolayer permeability: Focus on tight junction modulation
Full text link© 2022, Elsevier Ltd. The attached document (embargoed until 15/12/2023) is an author produced version of a paper published in FOOD AND CHEMICAL TOXICOLOGY uploaded in accordance with the publisher’s self-archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it
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