Antioxidant effect of Morus indica L against paraquat-induced oxidative stress in Drosophila melanogaster

BACKGROUND: Mulberry extracts and active components have numerous good neurological and biological benefits, making them promising candidates in the research for new medications to treat neurological problems. METHODS: In the present study we evaluated the neuroprotective role of mulberry fruit extract against the paraquat (PQ) induced oxidative stress in Drosophila melanogaster. After the exposure to PQ, Flies were assayed for climbing activity, reactive oxygen species (ROS) and lipid peroxide (LPO) content, acetylcholine esterase activities (AChe), and also the antioxidant defense system such as superoxide dismutase (SOD), catalase activities (CAT) and glutathione synthetase (GSH) RESULTS: In a negative geotaxis assay, MF pre-treated flies exposed to PQ showed a lower incidence of mortality and enhanced climbing activities of flies when compared to untreated flies exposed to PQ. In addition, when exposed to PQ, untreated flies resulted in a significant (p ≤ 0.05) increase in oxidative stress markers such as ROS, LPO content and AChe and decreased the antioxidant defense system such as SOD, CAT, and GSH. However, flies pre-treated with MF when exposed to PQ ameliorated oxidative stress markers and by restoring the antioxidant defense system, additionally, the pre-treatment of MF flies also reduced AChe activities. CONCLUSION: The pre-treatment of flies with MF extract has the potential to reduce PQ-induced oxidative stress due to its antioxidative nature and ability to modify the activities of antioxidant defense systems. However, further research is needed to understand the exact mechanism of its activity

Preparation and characterization of 5-fu loaded microspheres of eudragit and ethylcellulose

En la presente investigación, se han preparado microesferas de Eudragit (RS 100, RL 100 y RSPO) y etilcelulosa cargadas con 5-fluorouracilo. Se ha utilizado la técnica de “evaporación del disolvente o/o” para preparar las microesferas utilizando el sistema de (metanol + acetona)/ parafina líquida. Se ha utilizado estearato de magnesio como estabilizador de gotículas y se ha añadido n-hexano para endurecer las microesferas. Las microesferas preparadas se caracterizan por sus propiedades micromeríticas y su eficaz compresión, así como a través de la espectroscopia infrarroja transformada de Fourier (FTIR, por sus siglas en inglés) y la cromatografía en capa fina. Se han tomado microfotografías para estudiar la forma de las microesferas. La mejor cinética de liberación se ha alcanzado con el modelo de Higuchi. El tamaño de la partícula principal, la eficacia de compresión y los rendimientos de producción han sido fuertemente influenciados por el tipo de polímero y su concentración. Tras la presente investigación, se ha determinado que el Eudragit y la Etilcelulosa tienen carreras muy prometedoras en la liberación controlada para el 5-FUIn the present investigation, 5-fluorouracil loaded microspheres of Eudragit (RS 100, RL 100 and RSPO) and ethylcellulose were prepared. “O/O solvent evaporation” technique was used for preparation of microspheres using (methanol + acetone)/liquid paraffin system. Magnesium stearate was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeretic properties and entrapment efficiency; as well by Fourier transform infrared spectroscopy (FTIR) and thin layer chromatography (TLC). Photomicrographs were taken to study the shape of microspheres. The best fit release kinetics was achieved with Higuchi plot. Mean particle size, entrapment efficiency and production yields were highly influenced by the type of polymer and polymer concentration. It is concluded from the present investigation that various Eudragit and Ethylcellulose are promising controlled release carriers for 5-FU

Integrative Genetic Manipulation of Plasmodium cynomolgi Reveals Multidrug Resistance-1 Y976F Associated With Increased In Vitro Susceptibility to Mefloquine

The lack of a long-term in vitro culture method has severely restricted the study of Plasmodium vivax, in part because it limits genetic manipulation and reverse genetics. We used the recently optimized Plasmodium cynomolgi Berok in vitro culture model to investigate the putative P. vivax drug resistance marker MDR1 Y976F. Introduction of this mutation using clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9) increased sensitivity to mefloquine, but had no significant effect on sensitivity to chloroquine, amodiaquine, piperaquine, and artesunate. To our knowledge, this is the first reported use of CRISPR-Cas9 in P. cynomolgi, and the first reported integrative genetic manipulation of this species

Meneco, a Topology-Based Gap-Filling Tool Applicable to Degraded Genome-Wide Metabolic Networks

International audienceIncreasing amounts of sequence data are becoming available for a wide range of non-model organisms. Investigating and modelling the metabolic behaviour of those organisms is highly relevant to understand their biology and ecology. As sequences are often incomplete and poorly annotated, draft networks of their metabolism largely suffer from incompleteness. Appropriate gap-filling methods to identify and add missing reactions are therefore required to address this issue. However, current tools rely on phenotypic or taxonomic information, or are very sensitive to the stoichiometric balance of metabolic reactions, especially concerning the co-factors. This type of information is often not available or at least prone to errors for newly-explored organisms. Here we introduce Meneco, a tool dedicated to the topological gap-filling of genome-scale draft metabolic networks. Meneco reformulates gap-filling as a qualitative combinatorial optimization problem, omitting constraints raised by the stoichiometry of a metabolic network considered in other methods, and solves this problem using Answer Set Programming. Run on several artificial test sets gathering 10,800 degraded Escherichia coli networks Meneco was able to efficiently identify essential reactions missing in networks at high degradation rates, outperforming the stoichiometry-based tools in scalability. To demonstrate the utility of Meneco we applied it to two case studies. Its application to recent metabolic networks reconstructed for the brown algal model Ectocarpus siliculosus and an associated bacterium Candidatus Phaeomarinobacter ectocarpi revealed several candidate metabolic pathways for algal-bacterial interactions. Then Meneco was used to reconstruct, from transcriptomic and metabolomic data, the first metabolic network for the microalga Euglena mutabilis. These two case studies show that Meneco is a versatile tool to complete draft genome-scale metabolic networks produced from heterogeneous data, and to suggest relevant reactions that explain the metabolic capacity of a biological system

High Resolution Methylome Map of Rat Indicates Role of Intragenic DNA Methylation in Identification of Coding Region

DNA methylation is crucial for gene regulation and maintenance of genomic stability. Rat has been a key model system in understanding mammalian systemic physiology, however detailed rat methylome remains uncharacterized till date. Here, we present the first high resolution methylome of rat liver generated using Methylated DNA immunoprecipitation and high throughput sequencing (MeDIP-Seq) approach. We observed that within the DNA/RNA repeat elements, simple repeats harbor the highest degree of methylation. Promoter hypomethylation and exon hypermethylation were common features in both RefSeq genes and expressed genes (as evaluated by proteomic approach). We also found that although CpG islands were generally hypomethylated, about 6% of them were methylated and a large proportion (37%) of methylated islands fell within the exons. Notably, we obeserved significant differences in methylation of terminal exons (UTRs); methylation being more pronounced in coding/partially coding exons compared to the non-coding exons. Further, events like alternate exon splicing (cassette exon) and intron retentions were marked by DNA methylation and these regions are retained in the final transcript. Thus, we suggest that DNA methylation could play a crucial role in marking coding regions thereby regulating alternative splicing. Apart from generating the first high resolution methylome map of rat liver tissue, the present study provides several critical insights into methylome organization and extends our understanding of interplay between epigenome, gene expression and genome stability

Aldose Reductase Inhibition Prevents Metaplasia of Airway Epithelial Cells

BACKGROUND: Goblet cell metaplasia that causes mucus hypersecretion and obstruction in the airway lumen could be life threatening in asthma and chronic obstructive pulmonary disease patients. Inflammatory cytokines such as IL-13 mediate the transformation of airway ciliary epithelial cells to mucin-secreting goblet cells in acute as well as chronic airway inflammatory diseases. However, no effective and specific pharmacologic treatment is currently available. Here, we investigated the mechanisms by which aldose reductase (AR) regulates the mucus cell metaplasia in vitro and in vivo. METHODOLOGY/FINDINGS: Metaplasia in primary human small airway epithelial cells (SAEC) was induced by a Th2 cytokine, IL-13, without or with AR inhibitor, fidarestat. After 48 h of incubation with IL-13 a large number of SAEC were transformed into goblet cells as determined by periodic acid-schiff (PAS)-staining and immunohistochemistry using antibodies against Mucin5AC. Further, IL-13 significantly increased the expression of Mucin5AC at mRNA and protein levels. These changes were significantly prevented by treatment of the SAEC with AR inhibitor. AR inhibition also decreased IL-13-induced expression of Muc5AC, Muc5B, and SPDEF, and phosphorylation of JAK-1, ERK1/2 and STAT-6. In a mouse model of ragweed pollen extract (RWE)-induced allergic asthma treatment with fidarestat prevented the expression of IL-13, phosphorylation of STAT-6 and transformation of epithelial cells to goblet cells in the lung. Additionally, while the AR-null mice were resistant, wild-type mice showed goblet cell metaplasia after challenge with RWE. CONCLUSIONS: The results show that exposure of SAEC to IL-13 caused goblet cell metaplasia, which was significantly prevented by AR inhibition. Administration of fidarestat to mice prevented RWE-induced goblet cell metaplasia and AR null mice were largely resistant to allergen induced changes in the lung. Thus our results indicate that AR inhibitors such as fidarestat could be developed as therapeutic agents to prevent goblet cell metaplasia in asthma and related pathologies

Identification of Functional Differences in Metabolic Networks Using Comparative Genomics and Constraint-Based Models

Genome-scale network reconstructions are useful tools for understanding cellular metabolism, and comparisons of such reconstructions can provide insight into metabolic differences between organisms. Recent efforts toward comparing genome-scale models have focused primarily on aligning metabolic networks at the reaction level and then looking at differences and similarities in reaction and gene content. However, these reaction comparison approaches are time-consuming and do not identify the effect network differences have on the functional states of the network. We have developed a bilevel mixed-integer programming approach, CONGA, to identify functional differences between metabolic networks by comparing network reconstructions aligned at the gene level. We first identify orthologous genes across two reconstructions and then use CONGA to identify conditions under which differences in gene content give rise to differences in metabolic capabilities. By seeking genes whose deletion in one or both models disproportionately changes flux through a selected reaction (e.g., growth or by-product secretion) in one model over another, we are able to identify structural metabolic network differences enabling unique metabolic capabilities. Using CONGA, we explore functional differences between two metabolic reconstructions of Escherichia coli and identify a set of reactions responsible for chemical production differences between the two models. We also use this approach to aid in the development of a genome-scale model of Synechococcus sp. PCC 7002. Finally, we propose potential antimicrobial targets in Mycobacterium tuberculosis and Staphylococcus aureus based on differences in their metabolic capabilities. Through these examples, we demonstrate that a gene-centric approach to comparing metabolic networks allows for a rapid comparison of metabolic models at a functional level. Using CONGA, we can identify differences in reaction and gene content which give rise to different functional predictions. Because CONGA provides a general framework, it can be applied to find functional differences across models and biological systems beyond those presented here

Synthesis of carboxmethyl chitosan and its effect on budesonide colon sensitive nano release system

In this investigation, colon sensitive nanoparticles were prepared using different agents by ion-gelation method. The carboxymethyl chitosan nanoparticles (CMCH-NPs) were used to deliver budesonide to the colon. The formation of Carboxymethyl chitosan (CMCH) was confirmed by H1NMR, FTIR, and degree of substitution (Ds). CMCH-NPs were evaluated for drug excipient interaction, loading efficiency % (LE), entrapment efficiency % (EE), scanning electron microscopy (SEM), zeta potential, particle size distribution, in-vitro release studies (also with enzymes), cytotoxicity, and stability studies. In-vitro release studies by dialysis bag method without enzymes revealed that N4 and N6 showed less than 10% cumulative drug release (% CDR) in pH1.2. SEM results of N6 showed spherical shaped aggregates and smoother surfaces than N4. Consequently, the presence of pepsin in pH 1.2, diastase in pH 4.5 and pancreatin in pH 7.4 buffers did not have any significant effect on the release kinetics of the N6 CMCH-NPs. On addition of the colonic enzymes in 10th hour, there was a marked increase in the release of budesonide (upto 98.27% ± 1.30%) due to the action of enzymes produced by the colonic microflora which causes the lysis of glycosidic bonds. The evidence for pH sensitivity along with the microbiotic activation of the CMCH-NPs in the colon was thus established. The cell viability (%) in all samples was above 96%, ensuring the biocompatibility of CMCH in the dose range of 0.2–2.4 mg/mL. Stability studies as per ICH Q1A (R2) guidelines were found to be stable.</p

Immobilization in fixed film reactors: an ultrastructural approach

An ultrastructural approach has been attempted to study the surface features of 29 packing media reported in literature and a few more potential candidates for immobilizing micro-organisms. The electron micrographs reveal important features like degree of smoothness/roughness, microcrystals and fibres, ridges, macro and micro pores their dimensions, depth and distribution and thereby the biomass accumulation capacity of the media. Based on microscopic observations the packing media have been classified as (i) smooth polypropylene bead, glass bead, peristaltic tube, porcelain, powdered activated carbon, perspex, polyvinyl chloride and glass (ii) uneven - straw, paddy stem, nylon, sand, gravel and stone (iii) porous - jute, gravel, soil, granulated clay, limestone, ceramic, shell, refractory brick, diatomaceous earth, casuarina seed, granular activated carbon thermocol, sponge, pumice stone and polyurethane foam. The results clearly show that ultrastructural examination and image analysis can be a quick, effective and direct visual technique for selecting support media for bioreactors. An example of application of quantitative image analysis for providing quantitative geometric description of surface features is also presented. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd