Publications

Abstract Several therapeutic properties have been attributed to epigallocatechin gallate (EGCG), a phytopharmaceutical polyphenol with antioxidant and antiproliferative activity. EGCG is, however, very prone to oxidation in aqueous solutions which changes its bioactive properties. Its loading in nanoparticles has been proposed to reduce its degradation while increasing its in vivo efficacy. The aim of this study was to compare the antiproliferative effect of EGCG before and after its loading in solid lipid nanoparticles (SLNs), against five different cell lines (Caco-2, HepG2, MCF-7, SV-80 and Y-79). EGCG produced concentration- and time-dependent antiproliferative effect, with efficacy dependent on the cell line. The order of potency was: MCF-7>SV-80>HepG2>Y-79>Caco-2, for 24 h exposure (MCF-7 IC50=58.60 +/- 3.29 mu g/mL; Caco-2 IC50>500.00 mu g/mL). To the best of our knowledge this is the first study reporting EGCG antiproliferative effect in SV-80 and Y-79 cells. DDAB-SLN physicochemical properties (size similar to 134 nm; PI similar to 0.179; ZP similar to+28mV) were only slightly modified with EGCG loading (EGCG-DDAB-SLN: similar to 144 nm; PI similar to 0.160; ZP similar to+26mV). EGCG loading in SLN, only slightly increases the EGCG antiproliferative effect in MCF-7 and SV-80 cells. SLN exhibited intrinsic toxicity, attributed to the surfactant used in its production. From the obtained results, the biocompatibility of blank SLN must be also considered when testing the efficacy of loaded phytopharmaceutics.

Abstract Herein Ho3+/Yb3+ doped GdF3 phosphor was prepared by chemical coprecipitation method. Further, during sample preparation, Ag+ ions were incorporated into the GdF3 lattice to enhance the upconversion emission. Using 980 nm excitation intense emission bands were observed at 543 nm and 650 nm corresponding to the E-5(4) -> I-5(8) and F-5(5) -> I-5(8) transitions. Incorporation of Ag+ ions has resulted in enhancement in the emission and maximum intensity was obtained for the Ag+ concentration of 10 mol %. It was supposed that Ag+ ions change the crystal field around the Ho3+ ions that result in emission enhancement. The Ag+ incorporation was also confirmed through UV-vis absorption and down-conversion analysis. The effect of the magnetic field was studied on the emission intensity and an optical hysteresis loop was observed in the plot of emission intensity vs the magnetic field. The CIE color coordinate variation based temperature sensing ability of the optimized sample is also demonstrated. (C) 2018 Published by Elsevier B.V.

Abstract Consensus scoring has become a commonly used strategy within structure-based virtual screening (VS) workflows with improved performance compared to those based in a single scoring function. However, no research has been devoted to analyze the worth of docking scoring functions components in consensus scoring. We implemented and tested a method that incorporates docking scoring functions components into the setting of high performance VS workflows. This method uses genetic algorithms for finding the combination of scoring components that maximizes the VS enrichment for any target. Our methodology was validated using a data set including ligands and decoys for 102 targets that have been widely used in VS validation studies. Results show that our approach outperforms other methods for all targets. It also boosts the initial enrichment performance of the traditional use of whole scoring functions in consensus scoring by an average of 45%. Our methodology showed to be outstandingly predictive when challenged to restore external (previously unseen) data. Remarkably, CompScore was able not only to retain its performance after redocking with a different software, but also proved that the enrichment obtained was not artificial.

Abstract Mitochondria are cytoplasmic double-membraned organelles that are involved in a myriad of key cellular regulatory processes. The loss of mitochondrial function is related to the pathogenesis of several human diseases. Over the last decades, an increasing number of studies have shown that dietary polyphenols can regulate mitochondrial redox status, and in some cases, prevent or delay disease progression. This paper aims to review the role of four dietary polyphenols - resveratrol, curcumin, epigallocatechin-3-gallate nd quercetin - in molecular pathways regulated by mitochondria and their potential impact on human health. Cumulative evidence showed that the aforementioned polyphenols improve mitochondrial functions in different in vitro and in vivo experiments. The mechanisms underlying the polyphenols' beneficial effects include, among others, the attenuation of oxidative stress, the regulation of mitochondrial metabolism and biogenesis and the modulation of cell-death signaling cascades, among other mitochondrial-independent effects. The understanding of the chemical-biological interactions of dietary polyphenols, namely with mitochondria, may have a huge impact on the treatment of mitochondrial dysfunction-related disorders.

Abstract We report the synthesis of 4-thioferulic acid (TFA), a new ferulic acid (FA) derivative, and highlight the differences between the two compounds concerning rate and mechanism of radical scavenging activity, redox potential, acidity of the phenol/thiophenol moieties, cytotoxicity in differentiated SH-SY5Y cells, and neuroprotection against hydrogen peroxide (H2O2) and tert-butyl hydroperoxide (t-BHP) in the same cellular model.

Abstract A simple, fast, and laboratory efficient doped P carbon nanoparticles synthesis is developed for fingerprint imaging, using 1,3-dihydroxyacetone and di-phosphorous pentoxide. Fluorescence nanoparticles, with an average size of 230 nm were obtained, without additional energy input or external heating. ATR, solid NMR, XPS and fluorescence spectroscopy revealed their surface functionalization; a reaction mechanism is proposed. Fluorescence measurements exhibited a maximum emission band at ca. 495 nm, when excited at 385 nm. The images obtained, on different surfaces such as mobile telephone screen, magnetic band and metallic surface of a credit card and a Euro banknote treated with the obtained nano-powders allows us to record positive matches, confirming that the experimental results illustrate the effectiveness of proposed method.

Abstract We report a study on the energetics and structural properties of gallic (1) and ellagic (2) acids. The experimental values of standard enthalpy of formation in solid state at 298.15 K, Delta H-f(m)0 (cd) of 1 as (-985.0 +/- 2.9 kJ.mol(-1)) and 2 as (-1377.9 +/- 4.7 kJ.mol(-1)) have been determined. The vapour pressure of 1 have been measure by Knudsen effusion methodology and the derived enthalpy of sublimation, Delta H-g(cd)m(0). was combined with the Delta H-f(m)0 (cd) in order to derive its gas-phase enthalpy of formation, Delta(f) H-m(0)(1,g) = -835.7 +/- 4.0 kJ.mol(-1). Quantum chemical calculations, at DFT (M05-2X) and composite ab initio Gn (n = 3, 4) levels of theory, provided the consistency of the experimental results and a plausible estimation of Delta H-f(m)0 (g) of 2 as (-1128.6 +/- 6.4 kJ.mol(-1)), which was deduced from the isodesmic-reactions methodology. (C) 2018 Published by Elsevier Ltd.