Anti-acetylcholinesterase, antidiabetic, anti-inflammatory, antityrosinase and antixanthine oxidase activities of Moroccan propolis

Biological properties of Moroccan propolis have been scarcely studied. In the present work, the total phenols and flavonoids from 21 samples of propolis collected in different places of Morocco or 3 supplied in the market were determined, as well as the invitro capacity for inhibiting the activities of acetylcholinesterase, -glucosidase, -amylase, lipoxygenase, tyrosinase, xanthine oxidase and hyaluronidase. The results showed that samples 1 (region Fez-Boulemane, Sefrou city) (IC50=0.065, 0.006, 0.020, 0.050, 0.014mgmL(-1)) and 23 (marketed) (IC50=0.018, 0.002, 0.046, 0.037, 0.008mgmL(-1)) had the best invitro capacity for inhibiting the -amylase, -glucosidase, lipoxygenase, tyrosinase and xanthine oxidase activities, respectively. A negative correlation between IC50 values and concentration of phenols, flavones and flavanones was found. These activities corresponded to the generally higher amounts of phenols and flavonoids. In the same region, propolis samples have dissimilar phenol content and enzyme inhibitory activities

The Use of Dietary Additives in Fish Stress Mitigation: Comparative Endocrine and Physiological Responses

In the last years, studies on stress attenuation in fish have progressively grown. This is mainly due to the interest of institutions, producers, aquarists and consumers in improving the welfare of farmed fish. In addition to the development of new technologies to improve environmental conditions of cultured fish, the inclusion of beneficial additives in the daily meal in order to mitigate the stress response to typical stressors (netting, overcrowding, handling, etc.) has been an important research topic. Fish are a highly diverse paraphyletic group (over 27,000 species) though teleost infraclass include around 96% of fish species. Since those species are distributed world-wide, a high number of different habitats and vital requirements exist, including a wide range of environmental conditions determining specifically the stress response. Although the generalized endocrine response to stress (based on the release of catecholamines and corticosteroids) is detectable and therefore provides essential information, a high diversity of physiological effects have been described depending on species. Moreover, recent omics techniques have provided a powerful tool for detecting specific differences regarding the stress response. For instance, for transcriptomic approaches, the gene expression of neuropeptides and other proteins acting as hormonal precursors during stress has been assessed in some fish species. The use of different additives in fish diets to mitigate stress responses has been deeply studied. Besides the species factor, the additive type also plays a pivotal role in the differentiation of the stress response. In the literature, several types of feed supplements in different species have been assayed, deriving in a series of physiological responses which have not focused exclusively on the stress system. Immunological, nutritional and metabolic changes have been reported in these experiments, always associated to endocrine processes. The biochemical nature and physiological functionality of those feed additives strongly affect the stress response and, in fact, these can act as neurotransmitters or hormone precursors, energy substrates, cofactors and other essential elements, implyingmulti-systematic and multi-organic responses. In this review, the different physiological responses among fish species fed stress-attenuating diets based on biomolecules and minerals have been assessed, focusing on the endocrine regulation and its physiological effects

Synthesis of hollow poly(aniline-co-pyrrole)–Fe3O4 composite nanospheres and their microwave absorption behavior

Hollow poly(aniline-co-pyrrole)-Fe3O4 (HPAP-Fe3O4) nanospheres with significant electromagnetic properties were successfully prepared via the oxidative polymerization of a mixture of aniline and pyrrole in the presence of a magnetic fluid, using a non-ionic surfactant as a template. The products were characterized by field emission scanning electron microscopy, transmission electron microscopy. Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis and Xray photoelectron spectroscopy. The electromagnetic (EM) and microwave absorbing properties of the nanocomposites were also investigated. The HPAP-Fe3O4 nanospheres exhibit superparamagnetic properties, and the conductivity increases with Fe3O4 content. The reflection loss evaluation based on the absorbing wall theory at 2 mm thickness shows that the reflection loss is reinforced in the frequency range of 0.5-10 GHz by the presence of Fe3O4 nanoparticles, and the frequency of minimum reflection loss shifts to a higher value with increasing Fe3O4 content. HPAP-Fe-06 exhibits the best microwave absorbing property between 0.5 and 10 GHz.ArticleSYNTHETIC METALS. 162(3-4):337-343 (2012)journal articl

Letrozole-loaded nonionic surfactant vesicles prepared via a slurry-based proniosome technology: Formulation development and characterization

Slurry-based Letrozole (LTZ)-loaded proniosomes were designed using sucrose or sorbitol as carriers and various ratios of cholesterol (CH) and Tween 80 (T80) as lipid composition. Proniosomes were hydrated and probe-sonicated to generate nano-vesicles. The proniosome powders were characterized in terms of morphology using scanning electron microscopy, and drug crystallinity using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The niosomes generated from proniosomes were characterized and compared to conventional niosomes, in terms of size, zeta potential, drug entrapment, storage stability, and drug release. All formulations had size measurements in the range of 100–194 nm, polydispersity index (PDI) values below 0.3, and zeta potential values below – 23 mV. Drug entrapment was the highest for niosomes generated from sucrose-based proniosomes (CH:T80; 1:1), reaching 74% compared to less than 50% for conventional niosomes. Storage for 3 months at 4 °C resulted in minor drug leakage whilst most drug was leaked from vesicles stored at room temperature. DSC and XRD studies showed that LTZ was converted into its amorphous form upon incorporation into proniosomes. Drug release exhibited a biphasic pattern, being fast at the first 24 h (up to 65% released) followed by a very slow release phase for a duration of one month, releasing at least 95%. The release profile of niosomes fits best with the Higuchi model. Overall, in this study, a facile approach to generating niosomes incorporating LTZ using a slurry-based proniosome technology was demonstrated. The niosomes provided high drug entrapment and controlled biphasic release over one month

Enzymatic processing of protein-based fibers

Wool and silk are major protein fiber materials used by the textile industry. Fiber protein structure-function relationships are briefly described here, and the major enzymatic processing routes for textiles and other novel applications are deeply reviewed. Fiber biomodification is described here with various classes of enzymes such as protease, transglutaminase, tyrosinase, and laccase. It is expected that the reader will get a perspective on the research done as a basis for new applications in other areas such as cosmetics and pharma.This work was financially supported by the National Natural Science Foundation of China (21274055,51373071, 31201134 and 31470509), the Program for New Century Excellent Talents in University (NCET-12-0883), the Program for Changjiang Scholars and Innovative Research Team in University (IRT1135), the Jiangsu Provincial Natural Science Foundation of China (BK2012112), and the Fundamental Research Funds for the Central Universities (JUSRP51312B)

Conserved and highly expressed tRNA derived fragments in zebrafish

Background: Small non-coding RNAs (sncRNAs) are a class of transcripts implicated in several eukaryotic regulatory mechanisms, namely gene silencing and chromatin regulation. Despite significant progress in their identification by next generation sequencing (NGS) we are still far from understanding their full diversity and functional repertoire. Results: Here we report the identification of tRNA derived fragments (tRFs) by NGS of the sncRNA fraction of zebrafish. The tRFs identified are 18–30 nt long, are derived from specific 5′ and 3′ processing of mature tRNAs and are differentially expressed during development and in differentiated tissues, suggesting that they are likely produced by specific processing rather than random degradation of tRNAs. We further show that a highly expressed tRF (5′tRF-ProCGG) is cleaved in vitro by Dicer and has silencing ability, indicating that it can enter the RNAi pathway. A computational analysis of zebrafish tRFs shows that they are conserved among vertebrates and mining of publicly available datasets reveals that some 5′tRFs are differentially expressed in disease conditions, namely during infection and colorectal cancer. Conclusions: tRFs constitute a class of conserved regulatory RNAs in vertebrates and may be involved in mechanisms of genome regulation and in some diseases. Keywords: tRNA derived fragments, Zebrafish, Small non coding RNAs, tRNAspublishe

Present and past climatic effects on the current distribution and genetic diversity of the Iberian spadefoot toad (Pelobates cultripes): an integrative approach

Aim: Predicting species responses to global change is one of the most pressing issues in Conservation Biogeography. A key part of the problem is understanding how organisms have reacted to climatic changes in the past. Here we use species distribution modelling to infer the effects of climate changes since the Last Interglacial (LIG, about 130,000 ybp) on patterns of genetic structure and diversity in the Western Spadefoot toad (Pelobates cultripes) in combination with spatially-explicit phylogeographic analyses. Location: Iberian Peninsula and mainland France. Methods: 524 individuals from 54 populations across the species range were sampled to document patterns of genetic diversity and infer their evolutionary history based on data from mtDNA and fourteen polymorphic microsatellites. Generalized linear models based on distribution data were used to infer climatic favourability for the species in the present and in projected scenarios for the LIG, the Mid Holocene and the last glacial maximum (LGM). Results: Estimates of genetic diversity show a decreasing trend from south to north, suggesting persistence of higher historical population sizes in the southern Iberian Peninsula. Species distribution models show differences in climatic favourability through time, with significant correlations between historically stable favourable areas and current patterns of genetic diversity. These results are corroborated by Bayesian Skyline Plots and continuous diffusion phylogeographic analyses. Main conclusions: The results indicate the presence of southern refugia, with moderate recent expansions at the northern end of the species’ range. Populations at the northern range margin exhibit the lowest genetic diversity and occupy historically unstable areas, classified as marginal in terms of favourability, rendering them most vulnerable to climate-mediated changes in the medium to long term