In vitro antimicrobial activity, total polyphenols and flavonoids contents of Nopalea cochenillifera (L.) Salm-Dyck (Cactaceae)

This study evaluated the antimicrobial activity in vitro qualitative and quantitative methods, and made the determination of total polyphenols and flavonoids in the ethanol extract of Nopalea cochenillifera. The assessment determined the antimicrobial minimum inhibitory concentration (MIC) against Escherichia coli, Salmonella typhi, Micrococcus, Klebsiella pneumoniae, Staphylococcus aureus, Candida albicans, Candida glabrata, Prototheca zopffi, Cryptococcus neoformans, Saccharomyces cervisiae e Malassezia furfur. The determination of total polyphenols and flavonoids were significant when compared respectively to the standards of gallic acid and rutin

Paracrine effect of carbon monoxide - astrocytes promote neuroprotection through purinergic signaling in mice

© 2016. Published by The Company of Biologists Ltd.The neuroprotective role of carbon monoxide (CO) has been studied in a cell-autonomous mode. Herein, a new concept is disclosed - CO affects astrocyte-neuron communication in a paracrine manner to promote neuroprotection. Neuronal survival was assessed when co-cultured with astrocytes that had been pre-treated or not with CO. The CO-pre-treated astrocytes reduced neuronal cell death, and the cellular mechanisms were investigated, focusing on purinergic signaling. CO modulates astrocytic metabolism and extracellular ATP content in the co-culture medium. Moreover, several antagonists of P1 adenosine and P2 ATP receptors partially reverted CO-induced neuroprotection through astrocytes. Likewise, knocking down expression of the neuronal P1 adenosine receptor A2A-R (encoded by Adora2a) reverted the neuroprotective effects of CO-exposed astrocytes. The neuroprotection of CO-treated astrocytes also decreased following prevention of ATP or adenosine release from astrocytic cells and inhibition of extracellular ATP metabolism into adenosine. Finally, the neuronal downstream event involves TrkB (also known as NTRK2) receptors and BDNF. Pharmacological and genetic inhibition of TrkB receptors reverts neuroprotection triggered by CO-treated astrocytes. Furthermore, the neuronal ratio of BDNF to pro-BDNF increased in the presence of CO-treated astrocytes and decreased whenever A2A-R expression was silenced. In summary, CO prevents neuronal cell death in a paracrine manner by targeting astrocytic metabolism through purinergic signaling.publishersversionpublishe

Addressing the challenges of influenza virus-like particles purification

Virus-like particles (VLPs) have been widely used in vaccine development over the last decades [1]. In fact, there are already several approved human vaccines against viruses that use recombinant VLPs as antigen, e.g. for hepatitis B virus and human papillomavirus [2]. Vaccination remains the most effective way to prevent infection with influenza viruses. However, their constant antigenic drift requires an annual update of the seasonal vaccine to prevent influenza epidemics [3-4]. To use the full potential of VLPs as vaccines efficient upstream processing as well as downstream processing (DSP) trains need to be established. The latter is of particular importance as it often accounts for the major biomanufacturing costs. Here we describe the establishment of an improved DSP unit train platform, adapted from virus particles to influenza VLPs, using pseudo-affinity sulfated cellulose membrane adsorbers (SCMA) [5]. An initial clarification step prepares the bulk for the subsequent purification steps. SCMA performance was optimized using a design of experiments (DoE) approach. More than 80% of the product was recovered with removal of host cell protein and DNA above 89% and 80%, respectively. This represents a significant improvement in performance compared to the traditional use of ion exchangers commercially available. Using this SCMA platform for influenza virus particles purification we were able to speed up the process by decreasing the number of DSP steps, to improve the scale-up and to reduce costs due to the removal of other chromatographic steps. References [1] L. Lua, et al., Biotechnology and Bioengineering, 111(3): p. 425-440 (2014). [2] Q. Zhao, et al., Trends in Biotechnology, 31(11): p. 654-663 (2013). [3] D. Smith, et al., Science, 305(5682): p. 371-376 (2004). [4] C. Thompson, et al., Virology Journal, 10 (2013). [5]M. Wolff, and U. Reichl, Expert Review of Vaccines, 10(10): p. 1451-1475 (2011)

Liprobe, a vital dye for lipid aggregates detection in imaging and high-content screens

Pathological lipid accumulation is a hallmark of several metabolic disorders, and detection of lipid aggregates is an essential step for initial diagnosis and drug screening purposes. However, low-cost, simple, and reliable detection fluorescent probes are not widely available. Here, six push-pull-push dyes were studied, and proved to be highly sensitive to the polarity of the medium, presenting potential to distinguish structures with different hydrophobic indexes. Importantly, in the presence of lipid aggregates their staining specificity highly increased and the fluorescence wavelength blue shifted. One of the compounds, named Liprobe, was physiologically inert in cells, as witnessed by mass-spectrometry and metabolic assays. Liprobe was not toxic to living zebrafish embryos, and differentially stained the muscle and bone tissues. In triglyceride solutions, a high correlation was observed between Liprobe’s 558 and 592 nm emissions and the 0–2.5 mg dl−1 triglyceride range. Confocal and cell-based high content screens revealed that this fluorophore was able to selectively detect lipid droplets and ceramide loads in normal and Farber’s disease human fibroblasts, respectively. Our results demonstrate that Liprobe is a suitable fluorescing probe for vital staining of lipid aggregates, compatible with a rapid and cheap high content screening assays for preliminary diagnosis of Farber’s disease and, potentially, of other lipidosis.publishe

Expanding the potential of self-assembled silk fibroin as aerogel particles for tissue regeneration

A newly produced silk fibroin (SF) aerogel particulate system using a supercritical carbon dioxide (scCO2)-assisted drying technology is herein proposed for biomedical applications. Different concentrations of silk fibroin (3%, 5%, and 7% (w/v)) were explored to investigate the potential of this technology to produce size- and porosity-controlled particles. Laser diffraction, helium pycnometry, nitrogen adsorption–desorption analysis and Fourier Transform Infrared with Attenuated Total Reflectance (FTIR-ATR) spectroscopy were performed to characterize the physicochemical properties of the material. The enzymatic degradation profile of the SF aerogel particles was evaluated by immersion in protease XIV solution, and the biological properties by cell viability and cell proliferation assays. The obtained aerogel particles were mesoporous with high and concentration dependent specific surface area (203–326 m2/g). They displayed significant antioxidant activity and sustained degradation in the presence of protease XIV enzyme. The in vitro assessment using human dermal fibroblasts (HDF) confirm the particles’ biocompatibility, as well as the enhancement in cell viability and proliferation.info:eu-repo/semantics/publishedVersio

Exploring the saccharomyces cerevisiae volatile metabolome: indigenous versus commercial strains

Winemaking is a highly industrialized process and a number of commercial Saccharomyces cerevisiae strains are used around the world, neglecting the diversity of native yeast strains that are responsible for the production of wines peculiar flavours. The aim of this study was to in-depth establish the S. cerevisiae volatile metabolome and to assess inter-strains variability. To fulfill this objective, two indigenous strains (BT2652 and BT2453 isolated from spontaneous fermentation of grapes collected in Bairrada Appellation, Portugal) and two commercial strains (CSc1 and CSc2) S. cerevisiae were analysed using a methodology based on advanced multidimensional gas chromatography (HS-SPME/GC×GC-ToFMS) tandem with multivariate analysis. A total of 257 volatile metabolites were identified, distributed over the chemical families of acetals, acids, alcohols, aldehydes, ketones, terpenic compounds, esters, ethers, furan-type compounds, hydrocarbons, pyrans, pyrazines and S-compounds. Some of these families are related with metabolic pathways of amino acid, carbohydrate and fatty acid metabolism as well as mono and sesquiterpenic biosynthesis. Principal Component Analysis (PCA) was used with a dataset comprising all variables (257 volatile components), and a distinction was observed between commercial and indigenous strains, which suggests inter-strains variability. In a second step, a subset containing esters and terpenic compounds (C10 and C15), metabolites of particular relevance to wine aroma, was also analysed using PCA. The terpenic and ester profiles express the strains variability and their potential contribution to the wine aromas, specially the BT2453, which produced the higher terpenic content. This research contributes to understand the metabolic diversity of indigenous wine microflora versus commercial strains and achieved knowledge that may be further exploited to produce wines with peculiar aroma properties

Effects of Resistance Exercise on Endothelial Progenitor Cell Mobilization in Women

This study aimed to determine the effect of a single bout of resistance exercise at different intensities on the mobilization of circulating EPCs over 24 hours in women. In addition, the angiogenic factors stromal cell-derived factor 1 (SDF-1α), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1-alpha (HIF-1α) and erythropoietin (EPO) were measured as potential mechanisms for exercise-induced EPCs mobilization. Thirty-eight women performed a resistance exercise session at an intensity of 60% (n = 13), 70% (n = 12) or 80% (n = 13) of one repetition maximum. Each session was comprised of three sets of 12 repetitions of four exercises: bench press, dumbbell curl, dumbbell squat, and standing dumbbell upright row. Blood was sampled at baseline and immediately, 6 hours, and 24 hours post-exercise. Circulating EPC and levels of VEGF, HIF-1α and EPO were significantly higher after exercise (P \u3c 0.05). The change in EPCs from baseline was greatest in the 80% group (P \u3c 0.05), reaching the highest at 6 hours post-exercise. The change in EPCs from baseline to 6 hours post-exercise was correlated with the change in VEGF (r = 0.492, P = 0.002) and HIF-1α (r = 0.388, P = 0.016). In general, a dose-response relationship was observed, with the highest exercise intensities promoting the highest increases in EPCs and angiogenic factors