Metabolite Profiling, through LC-ESI/LTQOrbitrap/MS Analysis, of Antioxidant Extracts from Physalis alkekengi L

Due to the increasing use of Physalis alkekengi L. as a food supplement and starting material for tea preparation, a comprehensive analysis of green extracts was performed. Two different extraction methods were applied to yellow Physalis alkekengi L. fruit and calyx and compared: hydroalcoholic extraction and decoction. Characterization of the metabolome of the calyx and fruit of yellow Physalis alkekengi L. was performed by LC-ESI/LTQOrbitrap/MS followed by LC-ESI/LTQOrbitrap/MS/MS to identify 58 phytocompounds using the two different extraction techniques. Subsequently, through preliminary spectrophotometric assays followed by cell studies, the antioxidant activity of the different Physalis alkekengi L. extracts were evaluated. It was found that Physalis alkekengi L. extracts are a good source of metabolites such as flavonoids, organic acids, phenylpropanoids, physalins and carotenoids, with various biological activities, in particular, antioxidant activity capable of reducing the production of free radicals in intestinal Caco-2 cells. For the first time, an integrated approach (metabolomics approach and antioxidant evaluation) was applied to the study of Physalis alkekengi green extracts and decoctions, the green extraction method mostly used in herbal preparations. An interesting finding was the high antioxidant activity shown by these extracts.

Olive Oil Phenolic Compounds' Activity against Age-Associated Cognitive Decline: Clinical and Experimental Evidence

Epidemiological studies have shown that consuming olive oil rich in phenolic bioactive compounds is associated with a lower risk of neurodegenerative diseases and better cognitive performance in aged populations. Since oxidative stress is a common hallmark of age-related cognitive decline, incorporating exogenous antioxidants could have beneficial effects on brain aging. In this review, we firstly summarize and critically discuss the current preclinical evidence and the potential neuroprotective mechanisms. Existing studies indicate that olive oil phenolic compounds can modulate and counteract oxidative stress and neuroinflammation, two relevant pathways linked to the onset and progression of neurodegenerative processes. Secondly, we summarize the current clinical evidence. In contrast to preclinical studies, there is no direct evidence in humans of the bioactivity of olive oil phenolic compounds. Instead, we have summarized current findings regarding nutritional interventions supplemented with olive oil on cognition. A growing body of research indicates that high consumption of olive oil phenolic compounds is associated with better preservation of cognitive performance, conferring an additional benefit, independent of the dietary pattern. In conclusion, the consumption of olive oil rich in phenolic bioactive compounds has potential neuroprotective effects. Further research is needed to understand the underlying mechanisms and potential clinical applications.

Antioxidant Activity and Inhibition of Digestive Enzymes of New Strawberry Tree Fruit/Apple Smoothies

In this study, original smoothies obtained with strawberry tree fruit puree and apple juice enriched with Diospyros kaki fruits, Myrtus communis purple berry extract, Acca sellowiana, and Crocus sativus petal juice were evaluated for their antioxidant activity and inhibition of targeted digestive enzymes. Values of CUPRAC, FRAP, ORAC, DPPH•, and ABTS•+ assays generally increased with plant enrichment, particularly for A. sellowiana addition (ABTS•+ 2.51 ± 0.01 mmol Trolox/100 g fw). The same trend was observed regarding the ability to scavenge reactive oxygen species (ROS) tested in Caco-2 cell cultures. Inhibitory activity on α-amylase and α-glucosidase was increased by D. kaki, M. communis, and A. sellowiana. Total polyphenols evaluated by UPLC-PDA analysis ranged between 535.75 ± 3.11 and 635.96 ± 5.21 mg/100 g fw, and A. sellowiana provided the higher amount. Flavan-3-ols accounted for more than 70% of phenolic compounds, and only smoothies enriched with C. sativus showed a high amount of anthocyanins (25.12 ± 0.18 mg/100 g fw). The outcome of this study indicates these original smoothies as a possible ally in counteracting oxidative stress, as established by their favourable antioxidant compound profile, thus suggesting an interesting future application as nutraceuticals.

Design, Synthesis, and Antiviral Activities of New Benzotriazole-Based Derivatives

Several human diseases are caused by enteroviruses and are currently clinically untreatable, pushing the research to identify new antivirals. A notable number of benzo[d][1,2,3]triazol-1(2)-yl derivatives were designed, synthesized, and in vitro evaluated for cytotoxicity and antiviral activity against a wide spectrum of RNA positive- and negative-sense viruses. Five of them (11b, 18e, 41a, 43a, 99b) emerged for their selective antiviral activity against Coxsackievirus B5, a human enteroviruses member among the Picornaviridae family. The EC50 values ranged between 6 and 18.5 μM. Among all derivatives, compounds 18e and 43a were interestingly active against CVB5 and were selected to better define the safety profile on cell monolayers by transepithelial resistance test (TEER). Results indicated compound 18e as the hit compound to investigate the potential mechanism of action by apoptosis assay, virucidal activity test, and the time of addition assay. CVB5 is known to be cytotoxic by inducing apoptosis in infected cells; in this study, compound 18e was proved to protect cells from viral infection. Notably, cells were mostly protected when pre-treated with derivative 18e, which had, however, no virucidal activity. From the performed biological assays, compound 18e turned out to be non-cytotoxic as well as cell protective against CVB5 infection, with a mechanism of action ascribable to an interaction on the early phase of infection, by hijacking the viral attachment process.

Probiotic lactobacilli attenuate oxysterols-induced alteration of intestinal epithelial cell monolayer permeability: Focus on tight junction modulation

Oxidative stress and inflammation lead by dietary oxidised lipids, as oxysterols, have been linked to the loss of intestinal barrier integrity, a crucial event in the initiation and progression of intestinal disorders. In the last decade, probiotic lactobacilli have emerged as an interesting tool to improve intestinal health, thanks to their antioxidant and anti-inflammatory properties. The aim of the present study was to evaluate the ability of two commercial probiotic strains of lactobacilli (Lactiplantibacillus plantarum 299v® (DMS 9843) and Lacticaseibacillus casei DG® (CNCMI-1572)), both as live bacteria and intracellular content, to attenuate the oxysterols-induced alteration of intestinal epithelial Caco-2 cell monolayer permeability. Our investigation was focused on the modulation of tight junctions (TJs) proteins, occludin, ZO-1 and JAM-A, in relation to redox-sensitive MAPK p38 activation. Obtained results provided evidence on the ability of the two probiotics to counteract the alteration of monolayer permeability and loss of TJs proteins, at least in part, through the modulation of p38 pathway. The protective action was exerted by live bacteria, whose adhesion to Caco-2 cells was not altered by oxysterols, and bacterial intracellular components equally able to interact with the signaling pathway.

Role of Dietary Polyphenols in the Activity and Expression of Nitric Oxide Synthases: A Review

Nitric 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.

Synthesis and Antiproliferative Effect of Halogenated Coumarin Derivatives

A series of 6- and 6,8-halocoumarin derivatives have been investigated as potential antiproliferative compounds against a panel of tumor and normal cell lines. Cytotoxic effects were determined by the MTT method. To investigate the potential molecular mechanism involved in the cytotoxic effect, apoptosis assay, cell cycle analysis, reactive oxygen species (ROS), and reduced glutathione analysis were performed. Among the screened compounds, coumarins 6,8-dibromo-2-oxo-2H-chromene-3-carbonitrile 2h and 6,8-diiodo-2-oxo-2H-chromene-3-carbonitrile 2k exhibited the most antiproliferative effect in thyroid cancer-derived cells TPC-1. The apoptosis assay showed that both 2h and 2k induced apoptosis in TPC-1 thyroid cancer cells. According to these experiments, both coumarins induced a slight increase in TPC-1 cells in the G2/M phase and a decrease in the S phase. A significant increase in ROS levels was observed in TPC-1 treated with diiodocoumarin 2k, while the dibromocoumarin 2h induced a decrease in ROS in a dose and time-dependent manner.

Bichromonol, a dimeric coumarin with anti-HIV activity from the stem bark of Hypericum roeperianum

Infectious diseases caused by viruses like HIV and SARS-COV-2 (COVID-19) pose serious public health threats. In search for new antiviral small molecules from chemically underexplored Hypericum species, a previously undescribed atropisomeric C8-C8' linked dimeric coumarin named bichromonol (1) was isolated from the stem bark of Hypericum roeperianum. The structure was elucidated by MS data and NMR spectroscopy. The absolute configuration at the biaryl axis was determined by comparing the experimental ECD spectrum with those calculated for the respective atropisomers. Bichromonol was tested in cell-based assays for cytotoxicity against MT-4 (CC₅₀ = 54 µM) cells and anti-HIV activity in infected MT-4 cells. It exhibits significant activity at EC₅₀ = 6.6-12.0 µM against HIV-1 wild type and its clinically relevant mutant strains. Especially, against the resistant variants A17 and EFV^R, bichromonol is more effective than the commercial drug nevirapine and might thus have potential to serve as a new anti-HIV lead.

Conjugated Metabolites of Hydroxytyrosol and Tyrosol Contribute to the Maintenance of Nitric Oxide Balance in Human Aortic Endothelial Cells at Physiologically Relevant Concentrations

Nitric oxide (NO) is an important signaling molecule involved in many pathophysiological processes. NO mediates vasodilation and blood flow in the arteries, and its action contributes to maintaining vascular homeostasis by inhibiting vascular smooth muscle contraction and growth, platelet aggregation, and leukocyte adhesion to the endothelium. Dietary antioxidants and their metabolites have been found to be directly and/or indirectly involved in the modulation of the intracellular signals that lead to the production of NO. The purpose of this study was to investigate the contribution of conjugated metabolites of hydroxytyrosol (HT) and tyrosol (TYR) to the release of NO at the vascular level, and the related mechanism of action, in comparison to their parental forms. Experiments were performed in human aortic endothelial cells (HAEC) to evaluate the superoxide production, the release of NO and production of cyclic guanosine monophosphate (cGMP), the activation of serine/threonine-protein kinase 1 (Akt1), and the activation state of endothelial nitric oxide synthase (eNOS). It was observed that the tested phenolic compounds enhanced NO and cGMP concentration, inhibiting its depletion caused by superoxide overproduction. Moreover, some of them enhanced the activation of Akt (TYR, HT metabolites) and eNOS (HT, HVA, TYR-S, HT-3S). Overall, the obtained data showed that these compounds promote NO production and availability, suggesting that HT and TYR conjugated metabolites may contribute to the effects of parental extra virgin olive oil (EVOO) phenolics in the prevention of cardiovascular diseases.

Ferulic Acid Metabolites Attenuate LPS-Induced Inflammatory Response in Enterocyte-like Cells

Ferulic acid (FA) is a polyphenol pertaining to the class of hydroxycinnamic acids present in numerous foods of a plant origin. Its dietary consumption leads to the formation of several phase I and II metabolites in vivo, which represent the largest amount of ferulates in the circulation and in the intestine in comparison with FA itself. In this work, we evaluated their efficacy against the proinflammatory effects induced by lipopolysaccharide (LPS) in intestinal Caco-2 cell monolayers, as well as the mechanisms underlying their protective action. LPS-induced overexpression of proinflammatory enzymes such as inducible nitric oxide synthase (iNOS) and the consequent hyperproduction of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) were limited by physiological relevant concentrations (1 µM) of FA, its derivatives isoferulic acid (IFA) and dihydroferulic acid (DHFA), and their glucuronidated and sulfated metabolites, which acted upstream by limiting the activation of MAPK p38 and ERK and of Akt kinase, thus decreasing the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) translocation into the nucleus. Furthermore, the compounds were found to promote the expression of Nrf2, which may have contributed to the downregulation of NF-ĸB activity. The overall data show that phase I/II metabolites retain the efficacy of their dietary free form in contrasting inflammatory response.

Contribution of Biotransformations Carried Out by the Microbiota, Drug-Metabolizing Enzymes, and Transport Proteins to the Biological Activities of Phytochemicals Found in the Diet

The consumption of dietary phytochemicals has been associated with several health benefits and relevant biological activities. It is postulated that biotransformations of these compounds regulated by the microbiota, Phase I/II reactions, transport proteins, and deconjugating enzymes contribute not only to their metabolic clearance but also, in some cases, to their bioactivation. A number of factors (age, genetics, sex, physiopathological conditions, and the interplay with other dietary phytochemicals) modulating metabolic activities are important sources and contributors to the interindividual variability observed in clinical studies evaluating the biological activities of phytochemicals. In this review, we discuss all the processes that can affect the bioaccessibility and beneficial effects of these bioactive compounds. Herein, we argue that the role of these factors must be further studied to correctly understand and predict the effects observed following the intake of phytochemicals. This is, in particular, with regard to in vitro investigations, which have shown great inconsistency with preclinical and clinical studies. The complexity of in vivo metabolic activity and biotransformation should therefore be considered in the interpretation of results in vitro and their translation to human physiopathology.

Antiviral effect of Hornstedtia bella Škorničk essential oil from the whole plant against vaccinia virus (VV)

In the prevention of epidemic and pandemic emerging and neglected viral infections, natural products are an important source of lead compounds. Hornstedtia bella Škorničkis is a rhizomatous herb growing in the forest of central Vietnam. Hornstedtia bella essential oil (Hb EO) was recently characterised by our group as endowed of antimicrobial activity against Staphylococcus aureus Methicillin-Resistant strains. Here, we describe for the first time the evaluation of Hb EO against a spectrum of viruses responsible for important human diseases. Hb EO resulted active against Vaccinia virus (VV) (EC₅₀ values 80 μg/mL), closely related to variola virus, causative agent of smallpox. Hb EO was able to strongly reduce the viral VV titer in cell-based assay at not cytotoxic concentration and its potential mode of action was characterised by virucidal activity evaluation followed by time-of-addition assay. Furthermore, Hb EO antiviral activity was implemented in a combination study with the mycophenolic acid.

Altered paracellular permeability in intestinal cell monolayer challenged with lipopolysaccharide: Modulatory effects of pterostilbene metabolites

Epithelial barrier alteration is a central event in the pathogenesis of inflammatory bowel diseases. Lipopolysaccharide, correlated to the pathogenesis of such pathologies, has been demonstrated to cause altered membrane permeability, through the disruption and/or relocation of tight junction proteins, following redox-sensitive mitogen-activated protein kinases (MAPKs) modulation. Pterostilbene and its metabolite pinostilbene are natural stilbenoids which may reach relevant concentrations at intestinal level, together with their glucuronide and sulfate metabolites. The aim of our study was to evaluate the ability of these compounds to inhibit lipopolysaccharide-induced toxic effects on intestinal cell monolayer integrity and to explore the mechanism of action. Caco-2 cells, differentiated as enterocytes, were treated with lipopolysaccharide following pretreatment with the phenolic compounds at 1 μM physiological concentration. Caco-2 monolayer's permeability was monitored with time, measuring the transepithelial electrical resistance. Tight junction proteins were assessed by western blotting and immunofluorescence in lipopolysaccharide-treated cells, in relation to MAPK p38 and ERK1/2 activation. Pretreatment with all the phenolic compounds significantly slowed lipopolysaccharide-induced transepithelial electrical resistance decrease, preserved tight junction proteins levels and reduced MAPKs phosphorylation. The reported findings indicate that pterostilbene and its metabolites may counteract lipopolysaccharide-induced alteration of epithelial permeability, one of the initial events in the intestinal inflammatory process.

Antioxidant, Antimicrobial, and Other Biological Properties of Pompia Juice

Pompia is a Citrus species belonging to Sardinian endemic biodiversity. Health benefits were attributed to its flavedo rind extracts and essential oils while the juice qualities have never been investigated. In this paper, the antioxidant, antimicrobial, and other biological properties of Pompia juice were studied. A combined LCMS/electrochemical/biological approach was used to clarify a still debated phylogeny of this species and to explain the role of its juice phenolic compounds. A closer phylogenetic relationship with lemon and citron, rather than oranges was suggested. Sensors-based electrochemical measures, together with LCMS qualitative and quantitative analyses, revealed a high contribution of ascorbic acid and phenolics with low redox potential, isorhamnetin 3-O-rutinoside, diosmin, and diosmetin 6,8-diglucoside, to antioxidant capacity. The biological assays demonstrated a marked effect of low concentration of Pompia juice against reactive oxygen species (ROS) starting from 50 µg mL⁻¹, and a moderate capacity to reduce ROS damages on cell membrane. Treatments with Pompia juice also resulted in a significant reduction (20%) of the metabolic activity of SW48 colon cancer cells. Lastly, MIC, MBC, and MBIC antimicrobial assays demonstrated that Pompia and lemon juices have inhibitory and antibiofilm effects against the pathogenic bacteria Pseudomonas aeruginosa, Streptococcus aureus, and Enterococcus faecalis.

Potent and Selective Activity against Human Immunodeficiency Virus 1 (HIV-1) of Thymelaea hirsuta Extracts

Historically, natural products have been the most successful source of inspiration for the development of new drugs. Members of the Thymelaeaceae family have been of interest owing to their excellent medicinal value. Given the successful history of natural product-based drug discovery, extracts from the aerial parts of Thymelaea hirsuta were evaluated for their potential anti-human immunodeficiency virus type 1 (HIV-1) activity. Ethyl acetate extracts from leaves (71B) and branches (72B) of Thymelaea hirsuta showed potent and selective activity against HIV-1 wt (EC₅₀ = 0.8 µg/mL) at non-cytotoxic concentrations (CC₅₀ > 100 µg/mL). They proved to be active against HIV-1 variants carrying clinically relevant NNRTI and NRTI mutations at low concentration (0.3–4 µg/mL range) and against the M-tropic strain HIV-1 BaL. The 72B extract, chosen as a lead, was not able to inhibit the RT and protease enzymatic functions. Furthermore, it was not virucidal, since exposure of HIV to high concentration did not affect virus infectivity. The pre-clinical safety profile of this extract showed no adverse effect on the growth of Lactobacilli, and non-toxic concentration of the extract did not influence the Caco-2 epithelial cells monolayer integrity. Additionally, extract 72B prevented syncytia formation at low concentration (0.4 µg/mL). The potent inhibitory effect on the syncytia formation in co-cultures showed that 72B inhibits an early event in the replication cycle of HIV. All of these findings prompt us to carry on new studies on Thymelaea hirsuta extracts.

Human Herpesvirus 8 infection may contribute to oxidative stress in diabetes type 2 patients

OBJECTIVE

To investigate the link between Human Herpesvirus 8 (HHV8) infection and plasma oxidative stress in patients with diabetes mellitus type 2 (DM2).

RESULTS

Blood samples collected from DM2 and control subjects were screened for the presence of antibodies against HHV8 and for biomarkers of oxidative stress. We determined the products of radical damage on the plasma lipid fraction, such as malondialdehyde (MDA), fatty acid hydroperoxides (HP) and 7-ketocholesterol (7-keto), the oxidation products of unsaturated fatty acids (UFA) and cholesterol, respectively. The level of plasma antioxidant α-tocopherol (α-toc) was also assessed. Relevant differences were observed in the redox status in DM2 and either HHV8-positive or -negative control subjects. The level of α-toc significantly decreased in both DM2 and HHV8-positive subjects. Levels of MDA, HP and 7-keto were much higher in HHV8-positive and DM2 subjects, indicating that plasma oxidative stress is a common feature in both DM2 and HHV8-infection. In addition, 7-keto was further increased in HHV8-positive DM2 patients. We hypothesized that the HHV8-infection may contribute to the production of ROS, and hence to the oxidative stress closely related to the pathogenesis and development of DM2.

In vivoformed metabolites of polyphenols and their biological efficacy

The metabolites of polyphenols are antioxidant, anti-inflammatory and anticancer agents. Being bioavailable, they may play an important role in preventing degenerative diseases.

Insight into the Chemical Diversity of Late/Ice Harvest Gewürztraminer Wine

Late 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.

Biogenic amines and other polar compounds in long aged oxidized Vernaccia di Oristano white wines

Oxidized white wines are produced by techniques that provide a barrel ageing which can range from a few years to some decades. This step, characterized by the metabolic activity of peculiar strains of Saccharomyces cerevisiae yeast, can affect the chemical composition of these wines and the production of unwanted substances such as biogenic amines. In this study, Vernaccia di Oristano wines from different vintages have been analysed for the first time regarding the content of biogenic amines and amino acids (by HPLC-FLD), and polar compounds (by HPLC-DAD and LC-MS). Furthermore, colour and technological parameters (contents of alcohol, reducing sugars, total and volatile acidities, pH and organic acids) of the wines were also evaluated. Older samples showed dark shades, which may have derived from polyphenols' oxidation while ageing. Some typical ageing products, such as 5-(hydroxymethyl)furfural and hydroxycinnamic acid derivatives were found in larger quantities in these samples, as well as the purinic compound xanthine, which was also detected in relevant concentrations. Additionally, as expected, the average of the main biogenic amines quantified in Vernaccia di Oristano was higher compared to non-oxidized white wines, especially in the older samples. Thus, though this content does not exceed values which spoil the quality of the wine, the monitoring of the winemaking conditions is suggested, to further limit the presence of these undesirable compounds.

Evaluation of natural occurring bioactive compounds and antioxidant activity in Nuragus white wines

The aim of the present study is to highlight volatile and targeted non-volatile bioactive compounds in Nuragus wines, as a part of Italian DOC (Controlled Origin Designation) white wines. So far there has not been any systematic study of the chemical compositions and antioxidant activity of this monovarietal wine. Phenolic compounds, volatiles and organic acids were analysed and antioxidant capacity was assessed by spectrophotometric assays. Chromaticity coordinates and technological parameters (alcohol, reducing sugars, pH, total and volatile acidity) were also evaluated. Gallic acid (128±87mg/L), trans-caftaric acid (81±27mg/L) and tyrosol (25±8mg/L) were the most abundant phenolic compounds. The major headspace volatiles were isoamyl alcohol (35.8-76.6%) and 2-phenylethanol (5.9-24.9%). In the wine extracts, the most abundant were 2-phenylethanol (12.3-40.0%), 4-hydroxy-2-phenylethanol (12.5-33.3%), diethyl succinate (5.8-30.3%), (Z)-octadec-9-en-1-ol (5.9-18.3%) and tryptophol (2.8-15.6%). Nuragus wines exhibited an excellent antioxidant capacity. The data obtained may help Nuragus wine producers to promote this monovarietal wine as a valid complement associated with the Mediterranean diet.

Phenolic Compounds, Volatiles and Antioxidant Capacity of White Myrtle Berry Liqueurs

The aim of this research was to evaluate the antioxidant capacity and physical-chemical characteristics of commercial white myrtle berry (Myrtus communis L. var. leucocarpa DC) liqueur (WMBL). The total phenolic (TP) content was measured spectrophotometrically, applying a modified Folin-Ciocalteu's method, and phenolic compounds were identified by high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry, and quantified by HPLC coupled with ultraviolet/visible detection. The antioxidant capacities were evaluated by FRAP, CUPRAC, DPPH^•, and ABTS^•+ assays. The volatiles were assessed by gas chromatography and mass spectrometry (GC-MS/FID) after headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE). WMBL showed lower TP levels (636.3 ± 39.2 mg GAE/L) than in purple myrtle berry liqueur (PMBL). Nevertheless, WMBL exhibited better antioxidant capacities, potentially due to high concentrations of gallic acid (294.2 ± 14.2 mg/L) and its derivatives (58.3 ± 2.1 mg/L). Other phenolic compounds detected by HPLC-DAD and LC-MS/MS were flavonols like myricetin and its derivatives (myricetin-3-O-galactoside and myricetin-3-O-rhamnoside) with concentrations similar to those found in PMBL. GC-MS/FID analysis revealed 44 compounds (terpenes, higher aliphatic compounds and shikimic acid pathway derivatives). 1,8-Cineole was the most abundant terpene in the liqueur (26.5% (HS-SPME) and 9.6% (LLE)).

Antioxidant Effect of Natural Table Olives Phenolic Extract Against Oxidative Stress and Membrane Damage in Enterocyte-Like Cells

The phenolic fraction of a naturally fermented cultivar of table olives, "Tonda di Cagliari," was investigated for the ability to protect Caco-2 cells against oxidative stress and membrane damage induced by tert-butyl hydroperoxyde (TBH). TBH exposure resulted in an alteration of cellular redox status, with an increase in reactive oxygen species (ROS) and a decrease in reduced glutathione (GSH) level. A loss of the epithelial integrity, as indicated by the decrease of the transepithelial electrical resistance value, was also observed over time, together with an intense lipid peroxidation process. The olives phenolic extract significantly counteracted ROS generation and subsequent alteration of monolayer integrity and membrane oxidative damage. The protective action of the extract is likely due to the scavenging ability of its main components, as hydroxytyrosol, oleuropein, and verbascoside among the secoiridoids and derivatives. Since olives phenolic compounds concentrate in the intestinal lumen, they may be a useful tool in the prevention of intestinal disorders related to oxidative damage.

Determination of dansylated amino acids and biogenic amines in Cannonau and Vermentino wines by HPLC-FLD

Free 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 <10mg/L, except putrescine which reached 20.5 ± 10.2mg/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.