1,143 research outputs found

    An Exogenous Pre-Storage Melatonin Alleviates Chilling Injury in Some Mango Fruit Cultivars, by Acting on the Enzymatic and Non-Enzymatic Antioxidant System

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    Melatonin (MT) treatment (100 M, 2 h) was applied to four mango fruit cultivars (‘Langra’, ‘Chaunsa’, ‘Dashehari’, and ‘Gulab Jamun’), before being stored at 5 1 C for 28 d, in order to alleviate chilling injury (CI). Maximum CI reduction was observed in ‘Langra’ mangoes, and minimum in ‘Gulab Jamun’ mangoes. This positive effect on quality preservation was associated with an increased concentration of endogenous MT, which prevented the accumulation of reactive oxygen species (H2O2 and O2 ) and stimulated non-enzymatic antioxidants (total phenolic compounds and total flavonoids), possibly due to higher activity of phenylalanine ammonia lyase and tyrosine ammonia lyase. Increased antioxidant activity was also documented in MT-treated ‘Langra’ mangoes, according to four different assays (DPPH, TEAC, FRAP, and CUPRAC) and higher activity of six antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase). In contrast, ‘Gulab Jamun’ mangoes showed minimal or no positive effects on the aforementioned variables in response to the exogenous MT application. ‘Chaunsa’ and ‘Dashehari’ mangoes had some intermediate effects on their antioxidant system (enzymatic and non-enzymatic) and alleviation of CI, when treated with exogenous MT.We conclude that exogenous MT exerts a cultivar-dependent stimulating effect on the antioxidant system of mangoes, which results in an increase in the fruits’ resistance to low temperature

    In vitro studies on the relationship between the antioxidant activities of some berry extracts and their binding properties to serum albumin

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    The aim of this study was to investigate the possibility to use the bioactive components from cape gooseberry (Physalis peruviana), blueberry (Vaccinium corymbosum), and cranberry (Vaccinium macrocarpon) extracts as a novel source against oxidation in food supplementation. The quantitative analysis of bioactive compounds (polyphenols, flavonoids, flavanols, carotenoids, and chlorophyll) was based on radical scavenging spectrophometric assays and mass spectrometry. The total phenolic content was the highest (P < 0.05) in water extract of blueberries (46.6 ± 4.2 mg GAE/g DW). The highest antioxidant activities by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and Cupric reducing antioxidant capacity were in water extracts of blueberries, showing 108.1 ± 7.2 and 131.1 ± 9.6 μMTE/g DW with correlation coefficients of 0.9918 and 0.9925, and by β-carotene linoleate assay at 80.1 ± 6.6 % with correlation coefficient of 0.9909, respectively. The water extracts of berries exhibited high binding properties with human serum albumin in comparison with quercetin. In conclusion, the bioactive compounds from a relatively new source of gooseberries in comparison with blueberries and cranberries have the potential as food supplementation for human health. The antioxidant and binding activities of berries depend on their bioactive compounds

    The Extrusion Process as an Alternative for Improving the Biological Potential of Sorghum Bran: Phenolic Compounds and Antiradical and Anti-Inflammatory Capacity

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    Approximately 80% of sorghum phenolic compounds are linked to arabinoxylans by ester bonds, which are capable of resisting the digestion process in the upper gastrointestinal tract, compromising their bioaccessibility and biological potential. The aim of this study was to evaluate the effect of the extrusion process on the content of phenolic compounds in sorghum bran and its impact on phenolic compounds and antiradical and anti-inflammatory capacity. Results revealed that the extrusion process increased total phenol content in sorghum bran compared to nonextruded sorghum, particularly for extrusion at 180°C with 20% moisture content (2.0222±0.0157 versus 3.0729±0.0187 mg GAE/g +52%), which positively affected antiradical capacity measured by the DPPH and TEAC assays. The percentage of inhibition of nitric oxide (NO) production by RAW cells due to the presence of extruded sorghum bran extract was significantly higher than that of nonextruded sorghum bran extract (90.2±1.9% versus 76.2±1.3%). The results suggest that extruded sorghum bran could be used as a functional ingredient and provide advantages to consumers by reducing diseases related to oxidative stress and inflammation

    In vitro Inhibition of Pancreatic Lipase by Polyphenols: A Kinetic, Fluorescence Spectroscopy and Molecular Docking Study

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    Svrha je ovog istraživanja bila ispitati molekulsko uklapanje i inhibicijski učinak četiri fenolna spoja pronađena u ljutim papričicama, i to: kavene kiseline, p-kumarne kiseline, kvercetina i kapsaicina, na aktivnost lipaze izolirane iz svinjske gušterače. Najjači inhibicijski učinak imao je kvercetin (IC50=(6.1±2.4) μM), zatim p-kumarna (170.2±20.6) μM) i kavena kiselina (401.5±32.1) μM), dok su kapsaicin i ekstrakt ljute papričice imali iznimno slab učinak. Svi polifenolni spojevi imali su inhibicijski učinak miješanog tipa. Mjerenjem fluorescencije utvrđeno je da su polifenolni spojevi ugasili prirođenu fluorescenciju lipaze izolirane iz gušterače, i to pomoću statičkog mehanizma. Sekvencija Stern-Volmerove konstante bila je: kvercetin, kavena kiselina, te p-kumarna kiselina. Rezultati ispitivanja molekulskih uklapanja pokazali su da se kavena kiselina, kvercetin i p-kumarna kiselina vežu blizu, za razliku od kapsaicina koji se veže daleko od aktivnog mjesta. Vodikove veze i hidrofobne pi-interakcije glavni su načini međusobnog povezivanja polifenolnih spojeva u lipazi izoliranoj iz gušterače.The inhibitory activity and binding characteristics of caffeic acid, p-coumaric acid, quercetin and capsaicin, four phenolic compounds found in hot pepper, against porcine pancreatic lipase activity were studied and compared to hot pepper extract. Quercetin was the strongest inhibitor (IC50=(6.1±2.4) μM), followed by p-coumaric acid ((170.2±20.6) μM) and caffeic acid ((401.5±32.1) μM), while capsaicin and a hot pepper extract had very low inhibitory activity. All polyphenolic compounds showed a mixed-type inhibition. Fluorescence spectroscopy studies showed that polyphenolic compounds had the ability to quench the intrinsic fluorescence of pancreatic lipase by a static mechanism. The sequence of Stern-Volmer constant was quercetin, followed by caffeic and p-coumaric acids. Molecular docking studies showed that caffeic acid, quercetin and p-coumaric acid bound near the active site, while capsaicin bound far away from the active site. Hydrogen bonds and π-stacking hydrophobic interactions are the main pancreatic lipase-polyphenolic compound interactions observed

    Antimicrobial and antioxidant properties of byproduct extracts of mango fruit

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    Byproducts of fruit processing could have higher content of phenolic compounds that can act as antimicrobial and antioxidant agents. In this context, the main objective of this study was to obtain extracts from peel, seed, and unused flesh of Haden, Ataulfo and Tommy Atkins mango varieties, in order to measure their antioxidant and antimicrobial properties. The extraction was performed using different methods, such as methanolic-polar, methanolic-non-polar, ethanolic-polar, ethanolic-non-polar and water infusion. The total phenolic content of the ethanolic-non-polar extract from seed of mango Haden showed 875.06 mg/g, DPPH EC50: 0.04 mg/mL, cau-sing a 100 % inhibition of bacteria pathogens applying 25 mg/mL and inhibition of 89.78 % against Alternaria applying 6.25 mg/mL. The flesh always showed the lowest content and bioactivity of the tested parameters. These results demonstrate the antimicrobial and antioxidant potential uses of fruit byproducts as sources of bioactive compounds

    Antioxidant and Antimicrobial Capacity of Phenolic Compounds of Mango (Mangifera indica L.) Seed depending upon the Extraction Process

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    The extraction method is critical for the recovery of phenolic compounds. The main goal was to evaluate the effect of an extraction process from mango seed on their phenolic profile, antioxidant and antimicrobial capacities. Phenolic extraction was performed in different steps: maceration, alkaline hydrolysis, acid/alkaline hydrolysis, polar and non-polar fraction of an ethyl acetate separation.The macerated extract showed a higher variety of polyphenols from mango seed:gallic (138.36 µg/g dry weight), coumaric (65.36 µg/g), ferulic (1376.67 µg/g) , chlorogenic (57.75 µg/g) anddicaffeoylquinic (219.29 µg/g) acids, catechin (16.78 µg/g) and rutin (6678.62µg/g). In alkaline hydrolyzed extract most of these compounds were lost, ferulic acid decreased 1356.77 µg/g dw and gallic acid increased 1383.89 µg/g dw. Gallic and chlorogenic acids increased 165 and 969. 45 µg/g dw respectively in acid/alkaline hydrolyzed, 109.57 and 841.38 µg/g dw respectively in non-polar and 277.15 and 77.88 µg/g dw respectively in polar extracts related to the macerated extract. Rutin was found only in acid/hydrolyzed and non-polar extract in lesser amount (87.62 and 78.51 µg/g dw) compared to macerated extract. The content of phenolic compounds was higher for the macerated extract (phenols=484.42 mg GAE/g and flavonoids=86.59 mg QE/g) than for the other steps. Acid/alkaline hydrolysis increased the antioxidant activity (1787.67 μmol TE/g for DPPH and 3692.86 μmol TE/g for TEAC); while the alkaline hydrolysis increased the antimicrobial effectivity (MIC=2.5 mg/mL for bacteria and 0.5 mg/mL for yeast). Results indicate that the acid or alkaline hydrolysis yields a stronger antioxidant and antimicrobial extract

    La investigación biomédica en España (II). Evaluación del Fondo de Investigación Sanitaria (FIS) a través de los proyectos de investigación financiados en el período 1988-1995 a centros de investigación, facultades y escuelas

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    En un trabajo previo, publicado en esta misma revista, los autores han estudiado los resultados generados por los proyectos de investigación financiados por el Fondo de Investigación Sanitaria (FIS) a las Instituciones Sanitarias Asistenciales (hospitales) y los procedentes de los cuestionarios de encuestas remitidos a los investigadores responsables de tales proyectos y a los directores gerentes de los hospitales en los que se realizaron los mismos. En el presente trabajo, se continúa el proceso de evaluación del FIS, centrándose la atención en la distribución de los proyectos de investigación concedidos a los centros de investigación, facultades y escuelas, y en los resultados obtenidos a través de los cuestionarios de encuesta cumplimentados por los investigadores principales pertenecientes a estas instituciones o entidades.La realización de este trabajo ha sido posible gracias a la financiación otorgada por el FIS al proyecto de investigación 96/1803.Peer reviewe

    Leptonic CP Violation and Neutrino Mass Models

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    We discuss leptonic mixing and CP violation at low and high energies, emphasizing possible connections between leptogenesis and CP violation at low energies, in the context of lepton flavour models. Furthermore we analyse weak basis invariants relevant for leptogenesis and for CP violation at low energies. These invariants have the advantage of providing a simple test of the CP properties of any lepton flavour model.Comment: 26 pages, no figures, submitted to the Focus Issue on `Neutrino Physics` edited by F. Halzen, M. Lindner and A. Suzuki, to be published in New Journal of Physic

    Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data

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    The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic scattering of reactor antineutrinos with silicon nuclei using charge-coupled devices (CCDs). In 2019 the experiment operated with a hardware binning applied to the readout stage, leading to lower levels of readout noise and improving the detection threshold down to 50 eV. The results of the analysis of 2019 data are reported here, corresponding to the detector array of 8 CCDs with a fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference between the reactor-on and reactor-off spectra shows no excess at low energies and yields upper limits at 95% confidence level for the neutrino interaction rates. In the lowest-energy range, 50-180 eV, the expected limit stands at 34 (39) times the standard model prediction, while the observed limit is 66 (75) times the standard model prediction with Sarkis (Chavarria) quenching factors.Comment: 23 pages, 14 figure

    CyberKnife Robotic-Assisted Stereotactic Radiosurgery for Advanced Stages of Ciliochoroidal Uveal Melanoma. Preliminary Results in Mexico

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    Objective: The objective of this study was to report the early results of CyberKnife® (CK®) stereotactic radiosurgery in advanced stages of ciliochoroidal (CBCh) melanoma in Mexican patients. Methods: A retrospective review of charts was performed to analyze the outcomes of patients who underwent CK® (Accuray Inc, Sunnyvale, CA, United States). Results: Four patients with CBCh melanoma were treated under this protocol. The mean age was 53.2 ± 5.3 years (range, 47-60). Median of follow-up was 9.5 ± 3.1 months (range, 5-12). Mean tumor diameter was 13.49 mm, mean thickness, 11.74 mm, and mean gross tumor volume was 1251.97 mm3. Tumors were dome- (50%) and mushroom-shaped (50%) in medium-to-large sizes. Three patients had T3b tumors, and one had a T4d tumor at the early tumor staging according to the American Joint Committee on Cancer. A mean dose of 2763 ± 181.3 cGy was prescribed to the 90% isodose line. All patients achieved local tumor control after single-session radiosurgery at the latest follow-up. One patient presented with acute toxicity (extensive serous retinal detachment associated with radiation induced tumor vasculopathy) that was promptly managed. None of the patients required secondary enucleation. Conclusions: CK® appears to be an effective therapy for medium to large-sized CBCh melanoma. A prospective comparative study with longer follow-up is needed to confirm these findings and to evaluate long-term morbidity
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