19 research outputs found

    Detection of adulterations in food products containing milk and/or milk proteins

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    A critical review of the most relevant analytical methodologies for quality and authenticity control of dairy products and foods containing milk proteins is presented. Chromatographic, electrophoretic and immunological methods are used for: detection of cow's milk in ewe and goat milks, detection of whey added to milk, detection of caseins and/or whey proteins in non-lactic foods and study compounds resulting from milk proteins degradation. Techniques based on polimerase chain reaction are also suitable for detection of cow's milk on cheeses of ewe and goat milks

    In-depth phenolic characterization of iron gall inks by deconstructing representative Iberian recipes

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    UIDB/50006/2020 PTDC / QUI-OUT / 29925/2017Iron-gall ink is one of the most important inks in the history of western civilization. The deep black colour results from Fe3+ complexes with phenolic compounds available in gall extracts. Unfortunately, it induces the degradation of both ink and support over time. Furthermore, our knowledge of these complex molecular structures is limited. This work aims to overcome this gap, revealing essential information about the complex structures of these pigments and dyes that will create a breakthrough in the next generation of conservation treatments. It presents the first in-depth phenolic identification and quantification of extracts and inks, prepared with and without gum arabic (an essential additive in medieval recipes). Five representative Iberian recipes were selected and prepared. Their phenolic profile was analysed by HPLC–DAD and HPLC–ESI–MS, which revealed that the phenolic compounds present in higher concentration, in the gall extracts, are pentagalloylglucose and hexagalloylglucose (0.15 ± 0.01–32 ± 3 mg/mL), except for one recipe, in which gallic acid is the main phenolic. The influence of the ingredients is also discussed by deconstructing the recipes: extracts of additives as pomegranate peel and solvents used in the extraction of the galls (vinegar and white wine) were characterized.publishersversionpublishe

    Polyphenol extraction by deep eutectic solvent for valorisation of portuguese green tea and their impact on chitosan-based films properties

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    The current demand for antioxidant active packaging, that is achieved by introducing antioxidants into food packaging material, is increasing due to both the unquestionable advantages compared to the addition of antioxidants directly to the food and the tendency to consume healthy and fresh products. When developing active packaging materials, research has been focused on natural and biodegradable polymers (such as polysaccharides like chitosan) containing polyphenol compounds (as bio preservative) in their formulation. Due to their rare solvation properties, the natural deep eutectic solvents (NADES), are considered good solvents to be used as an extraction medium of bioactive products. Moreover, the search for the use of ecological solvents for this field has intensified due to their acceptable toxicity profile and chemical diversity. The use of these inexpensive, non-volatile, and nonaqueous biodegradable solvents, complying with the Green Chemistry principles, could potentially improve the stability of the polyphenolic compounds allowing to retard food spoilage for packaging material, Catechins (components of green tea (GT)), a polyphenolic group known for its high value-added antioxidant properties, have been associated with health-promoting effects. In this sense, the incorporation of GT components for food application purposes and as active ingredient in packaging materials can be expected to improve food functionality and availability, while performing a dual role (antioxidant and antimicrobial agent) and possibly also having low-cost advantages. In this work, for the first time, a ternary deep eutectic solvent (ChCl/glycerol/lactic acid) was used as an environmentally friendly media for the extraction of polyphenolic compounds from green tea. The extraction solution was compared with traditional method and used to improve chitosan film properties. The casting method used to produce films with and without GT/NADES plasticizer. Transparent films were obtained and evaluated in terms of mechanical, water resistance, optical and microstructural properties. The results were compared with those obtained for chitosan films containing binary deep eutectic solvents (ChCl/glycerol and ChCl/lactic acid, with and without GT)) as plasticizers in their formulations.The work was supported through the project UIDB/50006/2020, funded by FCT/MCTES through national funds and by the AgriFood XXI I&D&I project (NORTE-01-0145-FEDER-000041 co-financed by European Regional Development Fund (ERDF), through the NORTE 2020. N Teixeira and Hiléia Souza thanks FCT for CEECIND/00025/2018/CP1545/CT0009 and PTDC/OCE-ETA/31250/2017 project respectively.info:eu-repo/semantics/publishedVersio

    Spatio-temporal expression patterns of anandamide-binding receptors in rat implantation sites: evidence for a role of the endocannabinoid system during the period of placental development

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    <p>Abstract</p> <p>Background</p> <p>Although there is growing evidence that endocannabinoids play a critical role in early pregnancy, there are no studies describing the possible targets for this system after implantation. The endometrial stroma, which undergoes extensive proliferation and differentiation giving rise to the decidua and the trophoblast cells that invade after the initial stages of implantation, are potential targets. Since high anandamide (AEA) levels, the main endocannabinoid, are detrimental to implantation and in order to gain insight into the role of the endocannabinoid system in the development of the fetoplacental unit, the spatio-temporal pattern of expression of the anandamide-binding receptors, CB1, CB2 and the vanilloid receptor (TRPV1), were investigated by quantitative RT-PCR, western blot and immunohistochemistry.</p> <p>Methods</p> <p>Rat uterine maternal tissues from different days of pregnancy were used to investigate the expression of CB1, CB2 and vanilloid receptors by quantitative RT-PCR, western blot and immunohistochemistry.</p> <p>Results</p> <p>The data indicate that all the three receptors were expressed in decidualized cells and placenta. Interestingly, CB1 and CB2 were also expressed in smooth muscle cells of maternal blood vessels and in endovascular trophoblast cells, whereas TRPV1 was mainly expressed in uterine natural killer (uNK) cells and in the longitudinal muscle layer throughout pregnancy. In all tissues, CB2 protein was present at a lower level than CB1.</p> <p>Conclusion</p> <p>These observations support a role for the endocannabinoid system during the period of decidualization and placental development.</p

    New steroidal aromatase inhibitors: Suppression of estrogen-dependent breast cancer cell proliferation and induction of cell death

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    <p>Abstract</p> <p>Background</p> <p>Aromatase, the cytochrome P-450 enzyme (CYP19) responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI), which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds <b>3a </b>and <b>4a</b>, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells.</p> <p>Results</p> <p>The new steroids inhibit hormone-dependent proliferation of MCF-7aro cells in a time and dose-dependent manner, causing cell cycle arrest in G<sub>0</sub>/G<sub>1 </sub>phase and inducing cell death with features of apoptosis and autophagic cell death.</p> <p>Conclusion</p> <p>Our <it>in vitro </it>studies showed that the two steroidal AIs, <b>3a </b>and <b>4a</b>, are potent inhibitors of breast cancer cell proliferation. Moreover, it was also shown that the antiproliferative effects of these two steroids on MCF-7aro cells are mediated by disrupting cell cycle progression, through cell cycle arrest in G<sub>0</sub>/G<sub>1 </sub>phase and induction of cell death, being the dominant mechanism autophagic cell death. Our results are important for the elucidation of the cellular effects of steroidal AIs on breast cancer.</p

    O Sistema Endocanabinóide – uma perspetiva terapêutica

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    Although the medicinal use of Cannabis sativa derivatives is well known since antiquity, the study of their properties expanded recently with the discovery of an endogenous cannabinoid system, which comprises the endogenous cannabis-like ligands (endocannabinoids), the cannabinoid receptors (CB1 and CB2) and the enzymes involved in their metabolism. Since the discovery of the endocannabinoid system (ECS), the scientific community focused on research of its clinical use and achieved important findings during the last decade. In some countries, cannabis derivatives are a pharmacological option for appetite stimulation and pain treatment. However, the first ECS-based drug rimonabant (a CB1 antagonist), approved for the treatment obesity with associated risk factors, was withdrawn due to safety concerns. Nowadays, based on the growing evidences resulting from preclinical and clinical studies of ECS modulators, these drugs are currently pointed out as novel therapeutic approaches for several pathophysiological conditions. Here, we review the potential role of (endo)cannabinoid system in therapeutics and the recent designed strategies for the development of drugs that target this system. A utilização terapêutica da Cannabis sativa ou seus derivados é conhecida há muitos anos, no entanto, o estudo das suas propriedades despontou recentemente com a descoberta de um sistema canabinóide endógeno (ECS). O ECS compreende os compostos endógenos similares ao tetrahidrocanabinol (endocanabinóides), os recetores canabinóides (CB1 e CB2) e as enzimas envolvidas no seu metabolismo. Desde a descoberta do ECS, a comunidade científica focou-se na investigação do seu potencial clínico com resultados encorajadores. Em alguns países, os derivados da cannabis constituem uma opção farmacológica na estimulação do apetite e tratamento da dor. O primeiro medicamento baseado no ECS, o rimonabant (um antagonista CB1), foi aprovado para o tratamento da obesidade associada a outros fatores de risco, no entanto foi retirado por questões de segurança. Atualmente, e baseadas nos estudos pré-clínicos e clínicos, existem várias evidências do seu interesse clínico na modulação de diversas condições fisiopatológicas. Neste artigo discutimos o papel potencial do sistema (endo)canabinóide na terapêutica e as recentes estratégias desenvolvidas na modulação do sistema.

    Sustainable chitosan packaging films: Green tea polyphenolic extraction strategies using deep eutectic solvents

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    In this work, an alternative approach towards the use of a ternary natural deep eutectic solvent (ChCl/glycerol/lactic acid: NADES-3) as an environmentally friendly medium for the extraction of polyphenolic compounds from green tea (GT) was investigated. The ternary NADES have a higher capacity of polyphenolic extraction in comparison with the other two binary NADES (NADES-1 and NADES-2, ChCl/glycerol and ChCl/Lactic acid, respectively). The extraction GT solutions were used to improve chitosan (Chit) film properties, using the casting method, to produce films with and without different GT/NADES (ternary and binary) plasticizers. Transparent, uniform, and homogeny films (without cracks or pores) were obtained and evaluated in terms of mechanical, water resistance, optical and microstructural properties. The results were compared with those obtained for chitosan films containing binary deep eutectic solvents (ChCl/glycerol and ChCl/lactic acid, with and without GT)) as plasticizers in their formulations. In this sense, the presence of GT polyphenolic compounds led to different surface structures, and the surface of the biofilms become rougher with the increase of GT content. FTIR spectra confirmed physical entanglements film components and suggested the existence of the interaction between the extract's polyphenols and the Chit matrix. Films with 10% of NADES (binary and ternary) showed good high water barrier properties. Regarding mechanical properties, they also showed higher resistance, being the NADES-2 (10%) the film with better resistance.The work was supported through the project UIDB/50006/2020, funded by FCT/MCTES through national funds and by the AgriFood XXI I&D&I project (NORTE-01-0145-FEDER-000041 co-financed by European Regional Development Fund (ERDF), through the NORTE 2020. Natércia Teixeira and Hiléia Souza thanks FCT for CEECIND/00025/2018/CP1545/CT0009, PTDC/OCE-ETA/31250/2017 and PTDC/BII-BIO/5626/2020 projects. The authors would like to thank Gorreana for proffering the green tea sample for this work. Sincere thanks to Professor Carlos M. Pereira from Department of Chemistry and Biochemistry, CIQUP, University of Porto, Portugal, for carrying out Karl Fischer analysis.info:eu-repo/semantics/publishedVersio

    Synthetic cannabinoids JWH-018, JWH-122, UR-144 and the phytocannabinoid THC activate apoptosis in placental cells

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    The increasing use of synthetic cannabinoids (SCBs) in recreational settings is becoming a new paradigm of drug abuse. Although SCBs effects mimic those of the Cannabis sativa plant, these drugs are frequently more potent and hazardous. It is known that endocannabinoid signalling plays a crucial role in diverse reproductive events such as placental development. Moreover, the negative impact of the phytocannabinoid Δ9-tetrahydrocannabinol (THC) in pregnancy outcome, leading to prematurity, intrauterine growth restriction and low birth weight is well recognized, which makes women of childbearing age a sensitive group to developmental adverse effects of cannabinoids. Placental trophoblast turnover relies on regulated processes of proliferation and apoptosis for normal placental development. Here, we explored the impact of the SCBs JWH-018, JWH-122 and UR-144 and of the phytocannabinoid THC in BeWo cell line, a human placental cytotrophoblast cell model. All the cannabinoids caused a significant decrease in cell viability without LDH release, though this effect was only detected for the highest concentrations of THC. Moreover, a cell cycle arrest at the G2/M phase was also observed. JWH-018 and JWH-122 increased reactive oxygen species (ROS) production and THC, UR-144 and JWH-122 caused loss of mitochondrial membrane potential. All the compounds were able to induce caspase-9 activation. The involvement of apoptotic pathways was further confirmed through the significant increase in caspase -3/-7 activities. For UR-144, this effect was reversed by the CB1 antagonist AM281, for JWH-018 and THC this effect was mediated by both cannabinoid receptors CB1 and CB2 while for JWH-122 it was cannabinoid receptor-independent. This work demonstrates that THC and SCBs are able to induce apoptotic cell death. Although they may act through different mechanisms and potencies, the studied cannabinoids have the potential to disrupt gestational fundamental events.info:eu-repo/semantics/publishedVersio
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