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1.
Sensors (Basel) ; 24(10)2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38793901

RESUMEN

The main purpose of the paper is to show how a magnetoresistive (MR) element can work as a current sensor instead of using a Wheatstone bridge composed by four MR elements, defining the concept of a magnetoresistive shunt (MR-shunt). This concept is reached by considering that once the MR element is biased at a constant current, the voltage drop between its terminals offers information, by the MR effect, of the current to be measured, as happens in a conventional shunt resistor. However, an MR-shunt has the advantage of being a non-dissipative shunt since the current of interest does not circulate through the material, preventing its self-heating. Moreover, it provides galvanic isolation. First, we propose an electronic circuitry enabling the utilization of the available MR sensors integrated into a Wheatstone bridge as sensing elements (MR-shunt). This circuitry allows independent characterization of each of the four elements of the bridge. An independently implemented MR element is also analyzed. Secondly, we propose an electronic conditioning circuit for the MR-shunt, which allows both the bridge-integrated element and the single element to function as current sensors in a similar way to the sensing bridge. Third, the thermal variation in the sensitivity of the MR-shunt, and its temperature coefficient, are obtained. An electronic interface is proposed and analyzed for thermal drift compensation of the MR-shunt current sensitivity. With this hardware compensation, temperature coefficients are experimentally reduced from 0.348%/°C without compensation to -0.008%/°C with compensation for an element integrated in a sensor bridge and from 0.474%/°C to -0.0007%/°C for the single element.

2.
Cell Mol Life Sci ; 79(4): 213, 2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35344105

RESUMEN

Endoplasmic reticulum (ER) stress and mitochondrial dysfunction, which are key events in the initiation and/or progression of several diseases, are correlated with alterations at ER-mitochondria contact sites, the so-called "Mitochondria-Associated Membranes" (MAMs). These intracellular structures are also implicated in NLRP3 inflammasome activation which is an important driver of sterile inflammation, however, the underlying molecular basis remains unclear. This work aimed to investigate the role of ER-mitochondria communication during ER stress-induced NLRP3 inflammasome activation in both peripheral and central innate immune systems, by using THP-1 human monocytes and BV2 microglia cells, respectively, as in vitro models. Markers of ER stress, mitochondrial dynamics and mass, as well as NLRP3 inflammasome activation were evaluated by Western Blot, IL-1ß secretion was measured by ELISA, and ER-mitochondria contacts were quantified by transmission electron microscopy. Mitochondrial Ca2+ uptake and polarization were analyzed with fluorescent probes, and measurement of aconitase and SOD2 activities monitored mitochondrial ROS accumulation. ER stress was demonstrated to activate the NLRP3 inflammasome in both peripheral and central immune cells. Studies in monocytes indicate that ER stress-induced NLRP3 inflammasome activation occurs by a Ca2+-dependent and ROS-independent mechanism, which is coupled with upregulation of MAMs-resident chaperones, closer ER-mitochondria contacts, as well as mitochondrial depolarization and impaired dynamics. Moreover, enhanced ER stress-induced NLRP3 inflammasome activation in the immune system was found associated with pathological conditions since it was observed in monocytes derived from bipolar disorder (BD) patients, supporting a pro-inflammatory status in BD. In conclusion, by demonstrating that ER-mitochondria communication plays a key role in the response of the innate immune cells to ER stress, this work contributes to elucidate the molecular mechanisms underlying NLRP3 inflammasome activation under stress conditions, and to disclose novel potential therapeutic targets for diseases associated with sterile inflammation.


Asunto(s)
Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Estrés del Retículo Endoplásmico , Humanos , Sistema Inmunológico , Mitocondrias
3.
Mar Drugs ; 21(3)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36976221

RESUMEN

Sargassum is one of the largest and most diverse genus of brown seaweeds, comprising of around 400 taxonomically accepted species. Many species of this genus have long been a part of human culture with applications as food, feed, and remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of natural antioxidant compounds of great interest, including polyphenols, carotenoids, meroterpenoids, phytosterols, and several others. Such compounds provide a valuable contribution to innovation that can translate, for instance, into the development of new ingredients for preventing product deterioration, particularly in food products, cosmetics or biostimulants to boost crops production and tolerance to abiotic stress. This manuscript revises the chemical composition of Sargassum seaweeds, highlighting their antioxidant secondary metabolites, their mechanism of action, and multiple applications in fields, including agriculture, food, and health.


Asunto(s)
Sargassum , Algas Marinas , Humanos , Antioxidantes/farmacología , Antioxidantes/química , Sargassum/química , Algas Marinas/química , Polifenoles/farmacología , Carotenoides
4.
Sensors (Basel) ; 23(3)2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36772254

RESUMEN

The sensitivity of tunneling magnetoresistance sensors is an important performance parameter. It depends on the derivative of resistance versus magnetic field (transfer curve) and the current and is expressed as the product of the two factors. Previous research has demonstrated that the bias voltage has a significant impact on the sensitivity. However, no research has been conducted into the dependence of current and the derivative on bias voltage magnitude and polarity, and their contribution to the sensitivity. Thus, this paper investigates the dependence of sensitivity, derivative of resistance versus magnetic field curve and current on bias voltage magnitude and polarity in CoFeB/MgO/CoFeB-based tunneling magnetoresistance sensors with weak, strong and no voltage-controlled perpendicular magnetic anisotropy modification. It demonstrates that the sensitivity dependence on bias voltage for sensors with voltage controlled magnetic anisotropy modification showed no saturation up to 1 V. Moreover, the sensitivity asymmetry with respect to bias polarity changed significantly with bias, reaching a ratio of 6.7. Importantly, the contribution of current and the derivative of resistance versus magnetic field curve to the sensitivity showed a crossover. The current dominated the bias dependence of sensitivity below the crossover voltage and the derivative above the voltage. Furthermore, the crossover voltage in sensors without voltage controlled magnetic anisotropy modification did not depend on polarity, whereas in sensors with voltage controlled magnetic anisotropy modification, it appeared at significantly higher voltage under positive than negative polarity.

5.
Molecules ; 28(12)2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37375400

RESUMEN

Propolis is a natural product produced by bees that contains a complex mixture of compounds, including phenolic compounds and flavonoids. These compounds contribute to its biological activities, such as antioxidant capacity. This study analysed the pollen profile, total phenolic content (TPC), antioxidant properties, and phenolic compound profile of four propolis samples from Portugal. The total phenolic compounds in the samples were determined by six different techniques: four different Folin-Ciocalteu (F-C) methods, spectrophotometry (SPECT), and voltammetry (SWV). Of the six methods, SPECT allowed the highest quantification, while SWV achieved the lowest. The mean TPC values for these methods were 422 ± 98 and 47 ± 11 mg GAE/g sample, respectively. Antioxidant capacity was determined by four different methods: DPPH, FRAP, original ferrocyanide (OFec), and modified ferrocyanide (MFec). The MFec method gave the highest antioxidant capacity for all samples, followed by the DPPH method. The study also investigated the correlation between TPC and antioxidant capacity with the presence of hydroxybenzoic acid (HBA), hydroxycinnamic acid (HCA), and flavonoids (FLAV) in propolis samples. The results showed that the concentrations of specific compounds in propolis samples can significantly impact their antioxidant capacity and TPC quantification. Analysis of the profile of phenolic compounds by the UHPLC-DAD-ESI-MS technique identified chrysin, caffeic acid isoprenyl ester, pinocembrin, galangin, pinobanksin-3-O-acetate, and caffeic acid phenyl ester as the major compounds in the four propolis samples. In conclusion, this study shows the importance of the choice of method for determining TPC and antioxidant activity in samples and the contribution of HBA and HCA content to their quantification.


Asunto(s)
Antioxidantes , Própolis , Antioxidantes/química , Própolis/química , Ferrocianuros , Flavonoides/análisis , Fenoles/química
6.
Molecules ; 28(22)2023 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-38005268

RESUMEN

In this study, the anti-cancer, anti-tyrosinase, and antioxidant activities of essential oils (EOs) of berries and leaves of Juniperus phoenicea grown wild in North of Tunisia were investigated. The EO yields from leaves and berries were 1.69% and 0.45%, respectively. GC-MS analysis revealed that α-pinene is the predominant component in both EOs (44.17 and 83.56%, respectively). Leaves essential oil presented high levels of ß-phellandrene (18%) and camphene (15%). The EOs displayed cytotoxic effects against MCF-7 breast cancer cell, HT-29 colon cancer, and the normal cells H9C2 cardiomyoblasts. Leaves oil strongly inhibited colon cell line proliferation (IC50 of 38 µg/mL), while berries essential oil was more potent against breast cancerous cells MCF-7 (IC50 of 60 µg/mL). Interestingly, berries essential oil exhibited high ability to inhibit melanin synthesis by inhibiting enzyme mono and diphenolase activities. Overall, the results suggested that the two oils are significant sources of healthy natural chemicals.


Asunto(s)
Juniperus , Aceites Volátiles , Aceites Volátiles/farmacología , Antioxidantes/farmacología , Antioxidantes/análisis , Monofenol Monooxigenasa , Cromatografía de Gases y Espectrometría de Masas
7.
Molecules ; 28(7)2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-37049869

RESUMEN

Melanoma is the deadliest type of skin cancer, with about 61,000 deaths annually worldwide. Late diagnosis increases mortality rates due to melanoma's capacity to metastasise rapidly and patients' resistance to the available conventional therapies. Consequently, the interest in natural products as a strategy for drug discovery has been emerging. Propolis, a natural product produced by bees, has several biological properties, including anticancer effects. Propolis from Gerês is one of the most studied Portuguese propolis. Our group has previously demonstrated that an ethanol extract of Gerês propolis collected in 2018 (G18.EE) and its fractions (n-hexane, ethyl acetate, and n-butanol) decrease melanoma cell viability. Out of all the fractions, G18.EE-n-BuOH showed the highest potential as a melanoma pharmacological therapy. Thus, in this work, G18.EE-n-BuOH was fractioned into 17 subfractions whose effect was evaluated in A375 BRAF-mutated melanoma cells. The subfractions with the highest cytotoxic activity were analysed by UPLC-DAD-ESI/MSn in an attempt to understand which phenolic compounds could account for the anti-melanoma activity. The compounds identified are typical of the Gerês propolis, and some of them have already been linked with antitumor effectiveness. These results reaffirm that propolis compounds can be a source of new drugs and the isolation of compounds could allow its use in traditional medicine.


Asunto(s)
Antineoplásicos , Melanoma , Própolis , Neoplasias Cutáneas , Humanos , Própolis/farmacología , Portugal , Melanoma/tratamiento farmacológico , Antineoplásicos/farmacología , Fenoles/farmacología
8.
Anal Bioanal Chem ; 414(10): 3243-3255, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34936009

RESUMEN

The present paper describes a compact point of care (POC) optical device for therapeutic drug monitoring (TDM). The core of the device is a disposable plastic chip where an immunoassay for the determination of immunosuppressants takes place. The chip is designed in order to have ten parallel microchannels allowing the simultaneous detection of more than one analyte with replicate measurements. The device is equipped with a microfluidic system, which provides sample mixing with the necessary chemicals and pumping samples, reagents and buffers into the measurement chip, and with integrated thin film amorphous silicon photodiodes for the fluorescence detection. Submicrometric fluorescent magnetic particles are used as support in the immunoassay in order to improve the efficiency of the assay. In particular, the magnetic feature is used to concentrate the antibody onto the sensing layer leading to a much faster implementation of the assay, while the fluorescent feature is used to increase the optical signal leading to a larger optical dynamic change and consequently a better sensitivity and a lower limit of detection. The design and development of the whole integrated optical device are here illustrated. In addition, detection of mycophenolic acid and cyclosporine A in spiked solutions and in microdialysate samples from patient blood with the implemented device are reported.


Asunto(s)
Inmunosupresores , Dispositivos Ópticos , Humanos , Inmunoensayo , Microfluídica , Silicio
9.
J Phycol ; 58(2): 219-233, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35133645

RESUMEN

The Synechococcales is a large cyanobacterial order comprising both unicellular and filamentous forms, with parietal thylakoid arrangement. Previously, this order has been the subject of taxonomic revisions with new families being erected. During studies of the phototrophic communities on the limestone walls of the Old Cathedral of Coimbra (UNESCO monument), a coccoid Aphanocapsa-like cyanobacterium was isolated. It was characterized using a polyphasic approach, based on morphology, 16S rRNA phylogenetic and phylogenomic analyses, internal transcribed spacer (ITS) secondary structure, and ecology. The 16S rRNA phylogenetic analyses showed that this strain is placed in a separate and highly supported family-level clade, as part of a large group comprising the families Prochlorococcaceae and Prochlorotrichaceae, with Lagosinema as the closest (although quite distant) taxon. Additionally, the phylogenomic analysis also placed this strain in a separate lineage, situated distantly apart from the family Thermosynechococcaceae, but with strains assigned to Acaryochloris marina MBIC 11017 and Aphanocapsa montana BDHKU210001 as the closest taxa. Based on these data, as well as on the results from the secondary ITS structure, morphology, and ecology, we here propose the establishment of Petrachlorosaceae fam. nov., along with the description of Petrachloros gen. nov. and Petrachloros mirabilis sp. nov. We also address additional considerations regarding some cyanobacterial taxa within the order Synechococcales, which we believe deserve further revisions.


Asunto(s)
Cianobacterias , Mirabilis , Técnicas de Tipificación Bacteriana , Cianobacterias/genética , ADN Bacteriano/genética , Ácidos Grasos , Humanos , Mirabilis/genética , Filogenia , Portugal , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , UNESCO
10.
Adv Exp Med Biol ; 1379: 413-444, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35761002

RESUMEN

Flow cytometers are well-established tools with fundamental importance in biology and medicine to examine and identify cell populations, density, size distributions, compositions, and disease diagnosis and monitoring. Still, these devices are expensive with a low level of integration for sample preparation. Miniaturized microfluidic cytometers, i.e., microcytometers, for monitoring cells in a wide range of biological samples are currently being developed, providing more affordable and integrated solutions. Several detection methods have been developed and applied in microcytometers such as electrical, optical, and magnetic sensing techniques, which are integrated with microfluidic technology. Magnetic microcytometers present several advantages when compared to optical systems such as the fact that these devices provide more stable labeling by using magnetic nanoparticles (MNPs) or beads (MBs) instead of fluorophores. In this chapter, we explore the evolution of the automation of whole cell detection and enumeration that led to the development of microcytometers and particularly examine the anatomy of magnetic microcytometers applied to cancer research. We then give an overview of the challenges of Circulating Tumor Cells enrichment and enumeration, and the progress of magnetic microcytometers in this field.


Asunto(s)
Microfluídica , Células Neoplásicas Circulantes , Citometría de Flujo/métodos , Humanos , Fenómenos Magnéticos , Magnetismo , Microfluídica/métodos , Células Neoplásicas Circulantes/patología
11.
Mar Drugs ; 20(12)2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36547901

RESUMEN

Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.


Asunto(s)
Phaeophyceae , Algas Marinas , Humanos , Taninos/farmacología , Taninos/química , Phaeophyceae/química , Algas Marinas/química , Fenoles/química , Antioxidantes/química
12.
Molecules ; 27(23)2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36500595

RESUMEN

Hepatocellular carcinoma (HCC) is a poor-prognosis type of cancer with high resistance to chemotherapy, making the search for safe drugs a mandatory issue. Plant-derived products have potential to reduce negative side effects of cancer treatments. In this work, ability of a defatted methanolic extract of Alocasia gigantea leaves to fight HCC was evaluated in an animal model. Overall, treatment of HCC-induced mice with the methanolic extract at 150 mg/kg body weight for four consecutive weeks caused induction of autophagy through silencing of the relative expression of autophagy suppressor (mTOR) and inducement of autophagy markers (AMPK, Beclin-1, and LC-3). Moreover, it improved preservation of the hepatic histological architecture of the animals, with minor hepatocytic changes but scattered foci of hepatocytic apoptosis. Chemical profiling of the methanolic extract via ultra-high-performance liquid chromatography coupled to a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI-MS/MS) allowed identification of di-C-glycosyl flavones, mostly represented by 6-C-hexosyl-8-C-pentosyl apigenin isomers, which may possibly be associated with inducement of the autophagy pathway in HCC. Overall, these outcomes gave an initial visualization of the operative effect of some compounds in A. gigantea leaves that are potential treatment for HCC.


Asunto(s)
Alocasia , Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratones , Animales , Espectrometría de Masas en Tándem , Carcinoma Hepatocelular/tratamiento farmacológico , Espectrometría de Masa por Ionización de Electrospray/métodos , Neoplasias Hepáticas/tratamiento farmacológico , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Metanol/química , Autofagia
13.
Molecules ; 27(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36364353

RESUMEN

Propolis, a natural product made by bees with resins and balsams, is known for its complex chemical composition and remarkable bioactivities. In this study, propolis extraction was studied seeking extracts with strong bioactivities using less orthodox solvents, with some derived from apiary products. For that, a propolis sample collected from Gerês apiary in 2018 (G18) was extracted by maceration with six different solvents: absolute ethanol, ethanol/water (7:3), honey brandy, mead, propylene glycol and water. The solvent influence on the chemical composition and antioxidant and antimicrobial activities of the extracts was investigated. Antioxidant potential was assessed by the DPPH free-radical-scavenging assay and the antimicrobial activity by the agar dilution method. Chemical composition of the extracts was determined in vitro by three colorimetric assays: total ortho-diphenols, phenolics and flavonoids contents and the LC-MS technique. To our knowledge, this is the first time that solvents such as honey brandy and mead have been studied. Honey brandy showed considerable potential to extract propolis active compounds able to inhibit the growth of bacteria such as the methicillin-sensitive Staphylococcus aureus and Propionibacterium acnes (MIC values of 100 and 200 µg/mL, respectively) and the fungi Candida albicans and Saccharomyces cerevisiae (MIC = 500 µg/mL, for both). Mead extracts displayed high antioxidant capacity (EC50 = 1.63 ± 0.27 µg/mL) and great activity against resistant bacteria such as the methicillin-resistant Staphylococcus aureus and Escherichia coli (MIC = 750 µg/mL, for both). The production of such solvents made from beehive products further promotes a diversification of apiary products and the exploration of new applications using eco-friendly solutions.


Asunto(s)
Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Própolis , Própolis/farmacología , Própolis/química , Solventes , Antioxidantes/farmacología , Antioxidantes/química , Pruebas de Sensibilidad Microbiana , Candida albicans , Etanol/química , Escherichia coli , Antiinfecciosos/farmacología , Antiinfecciosos/química , Agua
14.
Molecules ; 27(11)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35684471

RESUMEN

Melanoma is the most aggressive and life-threatening skin cancer type. The melanoma genome is the most frequently mutated, with the BRAF mutation present in 40-60% of melanoma cases. BRAF-mutated melanomas are characterized by a higher aggressiveness and progression. Adjuvant targeted treatments, such as BRAF and MEK inhibitors, are added to surgical excision in BRAF-mutated metastatic melanomas to maximize treatment effectiveness. However, resistance remains the major therapeutic problem. Interest in natural products, like propolis, for therapeutic applications, has increased in the last years. Propolis healing proprieties offer great potential for the development of novel cancer drugs. As the activity of Portuguese propolis has never been studied in melanoma, we evaluated the antitumoral activity of propolis from Gerês (G18.EE) and its fractions (n-hexane, ethyl acetate (EtOAc), and n-butanol) in A375 and WM9 melanoma cell lines. Results from DPPH•/ABTS• radical scavenging assays indicated that the samples had relevant antioxidant activity, however, this was not confirmed in the cell models. G18.EE and its fractions decreased cell viability (SRB assay) and promoted ROS production (DHE/Mitotracker probes by flow cytometry), leading to activation of apoptotic signaling (expression of apoptosis markers). Our results suggest that the n-BuOH fraction has the potential to be explored in the pharmacological therapy of melanoma.


Asunto(s)
Melanoma , Própolis , Apoptosis , Línea Celular Tumoral , Humanos , Melanoma/patología , Portugal , Própolis/farmacología , Própolis/uso terapéutico , Proteínas Proto-Oncogénicas B-raf , Especies Reactivas de Oxígeno
15.
Molecules ; 27(13)2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35807247

RESUMEN

Renal cell carcinoma is the most lethal cancer of the urological system due to late diagnosis and treatment resistance. Propolis, a beehive product, is a valuable natural source of compounds with bioactivities and may be a beneficial addition to current anticancer treatments. A Portuguese propolis sample, its fractions (n-hexane, ethyl acetate, n-butanol and water) and three subfractions (P1-P3), were tested for their toxicity on A498, 786-O and Caki-2 renal cell carcinoma cell lines and the non-neoplastic HK2 kidney cells. The ethyl acetate fraction showed the strongest toxicity against A498 (IC50 = 0.162 µg mL-1) and 786-O (IC50 = 0.271 µg mL-1) cells. With similar toxicity against 786-O, P1 (IC50 = 3.8 µg mL-1) and P3 (IC50 = 3.1 µg mL-1) exhibited greater effect when combined (IC50 = 2.5 µg mL-1). Results support the potential of propolis and its constituents as promising coadjuvants in renal cell carcinoma treatment.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Própolis , Acetatos , Carcinoma de Células Renales/tratamiento farmacológico , Humanos , Riñón , Neoplasias Renales/tratamiento farmacológico , Extractos Vegetales , Portugal , Própolis/farmacología
16.
Molecules ; 27(5)2022 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-35268666

RESUMEN

Myrtus communis L. essential oil (EO), mainly composed of myrtenyl acetate (30.6%), linalool (14.9%), α-pinene (11.10%) and 1,8-cineole or eucalyptol (9.9%), was microencapsulated with maltodextrin by emulsification and spray-drying, reaching a yield and efficiency of 43.7 and 48.7%, respectively. The microencapsulated myrtle EO (MMEO) was then evaluated regarding its gastroprotective activity in a model of ethanol/HCl-induced acute gastric ulcer in Wistar rats. Pretreatment with MMEO induced a remarkable inhibition of gastric lesions and acidity, correlated to high healing and protection percentages. Moreover, it exerted a potent anti-inflammatory effect on the gastric mucosa, counteracting EtOH-induced gastric lipoperoxidation and preventing the depletion of the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Taken together, the gastroprotective action of encapsulated MMEO may be multi-factorial, and ascribable, at least in parts, to its anti-inflammatory and antioxidant properties.


Asunto(s)
Antiulcerosos , Myrtus , Aceites Volátiles , Úlcera Gástrica , Animales , Antiulcerosos/farmacología , Etanol/efectos adversos , Mucosa Gástrica , Aceites Volátiles/uso terapéutico , Extractos Vegetales/farmacología , Ratas , Ratas Wistar , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/tratamiento farmacológico , Úlcera Gástrica/patología
17.
Molecules ; 27(24)2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36557791

RESUMEN

In the present study, two extracts from the aerial parts of the endemic species Satureja hispidula were analyzed for the first time by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS) method in order to identify and quantify their phenolic compounds. These extracts' antioxidant, α-glucosidase and α-amylase inhibitory activities were also evaluated. UHPLC-DAD-ESI/MS allowed the identification of 28 and 20 compounds in the ethanolic and aqueous extracts, respectively; among them, 5-O-caffeoylquinic acid was the most abundant in both extracts. The biological assay results indicate that the species S. hispidula, besides its high antioxidant power, is also potentially useful for inhibiting the α-glucosidase enzyme. In both antioxidant and α-glucosidase inhibitory assays, the aqueous extract exhibited the most promising results, significantly better than the standards used as positive controls.


Asunto(s)
Hiperglucemia , Satureja , Antioxidantes/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , alfa-Glucosidasas/metabolismo , Argelia , Cromatografía Líquida de Alta Presión
18.
Cancer Cell Int ; 21(1): 318, 2021 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-34167552

RESUMEN

The study describes the current state of knowledge on nanotechnology and its utilization in medicine. The focus in this manuscript was on the properties, usage safety, and potentially valuable applications of chitosan-based nanomaterials. Chitosan nanoparticles have high importance in nanomedicine, biomedical engineering, discovery and development of new drugs. The manuscript reviewed the new studies regarding the use of chitosan-based nanoparticles for creating new release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity of drugs. Nowadays, effective cancer treatment is a global problem, and recent advances in nanomedicine are of great importance. Special attention was put on the application of chitosan nanoparticles in developing new system for anticancer drug delivery. Pre-clinical and clinical studies support the use of chitosan-based nanoparticles in nanomedicine. This manuscript overviews the last progresses regarding the utilization, stability, and bioavailability of drug nanoencapsulation with chitosan and their safety.

19.
Biotechnol Bioeng ; 118(8): 3164-3174, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34037981

RESUMEN

Nosocomial or hospital-acquired infections (HAIs) have a major impact on mortality worldwide. Enterococcus and Staphylococcus are among the leading causes of HAIs and thus are important pathogens to control mainly due to their increased antibiotic resistance. The gold-standard diagnostic methods for HAIs are time-consuming, which hinders timely and adequate treatment. Therefore, the development of fast and accurate diagnostic tools is an urgent demand. In this study, we combined the sensitivity of magnetoresistive (MR) sensors, the portability of a lab-on-chip platform, and the specificity of phage receptor binding proteins (RBPs) as probes for the rapid and multiplex detection of Enterococcus and Staphylococcus. For this, bacterial cells were firstly labelled with magnetic nanoparticles (MNPs) functionalized with RBPs and then measured on the MR sensors. The results indicate that the RBP-MNPS provided a specific individual and simultaneous capture of more than 70% of Enterococcus and Staphylococcus cells. Moreover, high signals from the MR sensors were obtained for these samples, providing the detection of both pathogens at low concentrations (10 CFU/ml) in less than 2 h. Overall, the lab-on-chip MR platform herein presented holds great potential to be used as a point-of-care for the rapid, sensitive and specific multiplex diagnosis of bacterial infections.


Asunto(s)
Bacteriófagos/química , Técnicas Biosensibles , Enterococcus , Dispositivos Laboratorio en un Chip , Sistemas de Atención de Punto , Infecciones Estafilocócicas/diagnóstico , Staphylococcus , Humanos
20.
Mar Drugs ; 19(7)2021 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-34209623

RESUMEN

Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds' phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition.


Asunto(s)
Fucus , Microbioma Gastrointestinal/efectos de los fármacos , Extractos Vegetales/farmacología , Taninos/farmacología , Animales , Humanos , Fitoterapia
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