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result(s) for
"Ambra, Roberto"
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The Role of Bioactive Phenolic Compounds on the Impact of Beer on Health
by
Ambra, Roberto
,
Pastore, Gianni
,
Lucchetti, Sabrina
in
Acids
,
Alcohol
,
Alcoholic Beverages - analysis
2021
This review reports recent knowledge on the role of ingredients (barley, hop and yeasts), including genetic factors, on the final yield of phenolic compounds in beer, and how these molecules generally affect resulting beer attributes, focusing mainly on new attempts at the enrichment of beer phenols, with fruits or cereals other than barley. An entire section is dedicated to health-related effects, analyzing the degree up to which studies, investigating phenols-related health effects of beer, have appropriately considered the contribution of alcohol (pure or spirits) intake. For such purpose, we searched Scopus.com for any kind of experimental model (in vitro, animal, human observational or intervention) using beer and considering phenols. Overall, data reported so far support the existence of the somehow additive or synergistic effects of phenols and ethanol present in beer. However, findings are inconclusive and thus deserve further animal and human studies.
Journal Article
A Review of the Effects of Olive Oil-Cooking on Phenolic Compounds
by
Ambra, Roberto
,
Pastore, Gianni
,
Lucchetti, Sabrina
in
Antioxidants
,
bioaccessibility
,
Carbon
2022
The fate of phenolic compounds in oil and food during cooking vary according to the type of cooking. From a nutritional point of view, reviews largely suggest a preference for using extra-virgin olive oil at a low temperature for a short time, except for frying and microwaving, for which there appears to be no significant advantages compared to olive oil. However, due to the poorly pertinent use of terminology, the different protocols adopted in studies aimed at the same objective, the different type and quality of oils used in experiments, and the different quality and quantity of PC present in the used oils and in the studied vegetables, the evidence available is mainly contradictory. This review tries to reanalyse the main experimental reports on the fate, accessibility and bioavailability of phenolic compounds in cooking oils and cooked vegetables, by considering different cooking techniques and types of oil and foods, and distinguishing experimental findings obtained using oil alone from those in combination with vegetables. The re-analysis indicates that incomplete and contradictory observations have been published in the last few years and suggests that further research is necessary to clarify the impact of cooking techniques on the phenolic compounds in oil and vegetables during cooking, especially when considering their nutritional properties.
Journal Article
The Fate of Chlorophylls in Alkali-Treated Green Table Olives: A Review
2023
This paper reviews the current knowledge regarding modifications to chlorophylls during the processing of green table olives treated with alkali. Particular attention is given to the pheophytinization reactions (substitution of Mg2+ by 2H+ in the chlorophyll chromophore group) that can take place because of pH and/or temperature changes and the possible sequential substitution of the 2H+ with Cu2+ within the chlorophyll porphyrin ring. These reactions may have a direct impact on the commercial value of olive productions as some naturally forming Cu–chlorophylls complexes (i) are identical to strictly forbidden colorants for table olives (E141) and (ii) have been identified as responsible for the unwelcome appearance of the so-called green staining alteration (characterized by bluish-green zones distributed over the olive skin of the drupes).
Journal Article
Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies
2023
The purpose of this review is to systematically examine the scientific evidence investigating selenium’s relationship with COVID-19, aiming to support, or refute, the growing hypothesis that supplementation could prevent COVID-19 etiopathogenesis. In fact, immediately after the beginning of the COVID-19 pandemic, several speculative reviews suggested that selenium supplementation in the general population could act as a silver bullet to limit or even prevent the disease. Instead, a deep reading of the scientific reports on selenium and COVID-19 that are available to date supports neither the specific role of selenium in COVID-19 severity, nor the role of its supplementation in the prevention disease onset, nor its etiology.
Journal Article
Reply to Rayman et al. Comment on “Ambra et al. Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies. Molecules 2023, 28, 4130”
by
Ambra, Roberto
,
Venneria, Eugenia
,
Melloni, Sahara
in
COVID-19
,
COVID-19 - epidemiology
,
COVID-19 - prevention & control
2024
We thank the Authors of the Comment (AC) [...]
Journal Article
Botanical Origin, Phytochemical Profile, and Antioxidant Activity of Bee Pollen from the Mila Region, Algeria
by
Ambra, Roberto
,
Belattar, Hakima
,
Ghorab, Asma
in
Algeria
,
antioxidant activity
,
Antioxidants
2025
Bee pollen is a complex mixture of floral pollen, and nectar fused substances from bee saliva. It is well known for its high content of proteins, carbohydrates, lipids, vitamins, and phenolic compounds, among various other physiologically active components. Its composition varies significantly depending on its botanical sources and environmental conditions. This study investigates the relationship between the botanical origins, chemical compositions, and antioxidant activities of 15 bee pollen samples collected from different areas in the Mila region of northeastern Algeria. The botanical origins were identified using a palynological method, categorizing 11 samples as monofloral and the rest as polyfloral. The total phenolic and flavonoid contents were measured, and their antioxidant capacities were evaluated through DPPH radical scavenging assay, reducing power assay (FRAP), and total antioxidant capacity (TAC). HPLC analysis was conducted to measure 17 phenolic compounds. The data indicated that the total phenolic content (TPC) and flavonoid content (TFC) ranged from 7.72 ± 0.29 to 23.49 ± 1.48 mg GAE/g and from 1.48 ± 0.00 to 5.57 ± 0.27 mg QE/g of pollen, respectively. The variations in the concentration of bioactive compounds among samples led to significant differences in their antioxidant activities: DPPH (IC
: 1.12 ± 0.15 to 0.21 ± 0.00 mg/mL), FRAP (EC
: 0.06 ± 0.00 to 0.29 ± 0.00 mg/mL), and TAC (262.17 ± 3.41 to 677.14 ± 12.81 EAA mg/100 g of bee pollen), with the most active samples being monofloral types from
type and
type. A strong correlation was observed between TPC, TFC, and antioxidant activity. Among the 17 tested compounds, only coumaric acid, rutin, myricetin, naringenin, resveratrol, and kaempferol were detected. In conclusion, both monofloral and polyfloral bee pollen samples represent a rich source of polyphenols with significant antioxidant potential.
Journal Article
The Fate of the Chlorophyll Derivatives in Olives Preserved and/or Packaged in Presence of Exogenous Copper
by
Ambra, Roberto
,
Aguzzi, Altero
,
Pastore, Gianni
in
Analysis
,
Chlorophyll
,
Chlorophyll - analysis
2023
Chlorophyll pigments are thought to be responsible for the highly appreciated green color of unfermented Castelvetrano-style table olives, but no studies have considered the effects of a controlled addition of copper during storage or packaging at the industrial level. For this purpose, chlorophyll derivatives were analyzed in Nocellara cultivar table olives debittered industrially using the Castelvetrano method, via means of HPLC and MS analyses, following the addition of copper in alkaline brines stored at 4 °C for 3 months in 220 L barrels, and during the subsequent storage in acid brines in commercial 400 g packages at 4 °C for up to 18 months. The presence of copper in storage or in packaging brines both contributed significantly to maintaining the green color of the olives, which was associated with a specific pattern of chlorophyll derivatives, as evidenced by principal component analysis. Notably, re-greening was rapidly achievable also for olives that had yellowed for 18 months at a copper concentration below the limit of EU legislation. Finally, by means of PCA, we also demonstrated that a short-term thermic treatment can work as an accelerated predictive tool in determining the fate of chlorophyll derivatives.
Journal Article
Redox Role of Lactobacillus casei Shirota Against the Cellular Damage Induced by 2,2′-Azobis (2-Amidinopropane) Dihydrochloride-Induced Oxidative and Inflammatory Stress in Enterocytes-Like Epithelial Cells
by
Ambra, Roberto
,
Nobili, Fabio
,
Garaguso, Ivana
in
Antioxidants
,
Cardiovascular diseases
,
Cell culture
2018
In western societies where most of the day is spent in the postprandial state, the existence of oxidative and inflammatory stress conditions makes postprandial stress an important factor involved in the development of cardiovascular risk factors. A large body of evidence have been accumulated on the anti-inflammatory effects of probiotics, but no information is available on the mechanisms through which intestinal microbiota modulates redox unbalance associated with inflammatory stress. Here, we aimed to investigate the ability of
Shirota (LS) to induce an antioxidant response to counteract oxidative and inflammatory stress in an
model of enterocytes. Our results show that pretreatment of enterocytes with LS prevents membrane barrier disruption and cellular reactive oxygen species (ROS) accumulation inside the cells, modulates the expression of the gastro-intestinal glutathione peroxidase (GPX2) antioxidant enzyme, and reduces p65 phosphorylation, supporting the involvement of the Nfr2 and nuclear factor kappa B pathways in the activation of antioxidant cellular defenses by probiotics. These results suggest, for the first time, a redox mechanism by LS in protecting intestinal cells from AAPH-induced oxidative and inflammatory stress.
Journal Article
Tocotrienols: A Family of Molecules with Specific Biological Activities
by
Ambra, Roberto
,
Comitato, Raffaella
,
Virgili, Fabio
in
Antioxidants
,
Apoptosis
,
Biological activity
2017
Vitamin E is a generic term frequently used to group together eight different molecules, namely: α-, β-, γ- and δ-tocopherol and the corresponding tocotrienols. The term tocopherol and eventually Vitamin E and its related activity was originally based on the capacity of countering foetal re-absorption in deficient rodents or the development of encephalomalacia in chickens. In humans, Vitamin E activity is generally considered to be solely related to the antioxidant properties of the tocolic chemical structure. In recent years, several reports have shown that specific activities exist for each different tocotrienol form. In this short review, tocotrienol ability to inhibit cancer cell growth and induce apoptosis thanks to specific mechanisms, not shared by tocopherols, such as the binding to Estrogen Receptor-β (ERβ) and the triggering of endoplasmic reticulum (EndoR) stress will be described. The neuroprotective activity will also be presented and discussed. We propose that available studies strongly indicate that specific forms of tocotrienols have a distinct mechanism and biological activity, significantly different from tocopherol and more specifically from α-tocopherol. We therefore suggest not pooling them together within the broad term “Vitamin E” on solely the basis of their putative antioxidant properties. This option implies obvious consequences in the assessment of dietary Vitamin E adequacy and, probably more importantly, on the possibility of evaluating a separate biological variable, determinant in the relationship between diet and health.
Journal Article
Involvement of miR-190b in Xbp1 mRNA Splicing upon Tocotrienol Treatment
by
Ambra, Roberto
,
Guantario, Barbara
,
Comitato, Raffaella
in
Alternative Splicing
,
Antioxidants - pharmacology
,
Apoptosis
2020
We previously demonstrated that apoptosis induced by tocotrienols (γ and δT3) in HeLa cells is preceded by Ca2+ release from the endoplasmic reticulum. This event is eventually followed by the induction of specific calcium-dependent signals, leading to the expression and activation of the gene encoding for the IRE1α protein and, in turn, to the alternative splicing of the pro-apoptotic protein sXbp1 and other molecules involved in the unfolded protein response, the core pathway coping with EndoR stress. Here, we showed that treatment with T3s induces the expression of a specific set of miRNAs in HeLa cells. Data interrogation based on the intersection of this set of miRNAs with a set of genes previously differentially expressed after γT3 treatment provided a few miRNA candidates to be the effectors of EndoR-stress-induced apoptosis. To identify the best candidate to act as the effector of the Xbp1-mediated apoptotic response to γT3, we performed in silico analysis based on the evaluation of the highest ∆ in Gibbs energy of different mRNA–miRNA–Argonaute (AGO) protein complexes. The involvement of the best candidate identified in silico, miR-190b, in Xbp1 splicing was confirmed in vitro using T3-treated cells pre-incubated with the specific miRNA inhibitor, providing a preliminary indication of its role as an effector of EndoR-stress-induced apoptosis.
Journal Article