<em>Caenorhabditis elegans</em> as a Model System for Discovering Bioactive Compounds Against Polyglutamine-Mediated Neurotoxicity

Age-related misfolding and aggregation of pathogenic proteins are responsible for several neurodegenerative diseases. For example, Huntington&#39;s ...

Hebei University of Economics and Business

Dictyophora indusiata is a medicinal mushroom traditionally used in China for a variety of conditions, including inflammatory and neural diseases. D. indusiata polysaccharides (DiPS) are shown to have in vitro antioxidant activity but in vivo evidence is lacking. This study aimes to explore the antioxidant capacity and related neuroptotective activities of DiPS using wild-type and neurodegenerative Caenorhabditis elegans models.

Antioxidant and neuroprotective effects of Dictyophora indusiata polysaccharide in Caenorhabditis elegans.

A method combining accelerated solvent extraction (ASE) with magnetic solid-phase extraction (MSPE) and gas chromatography-mass spectrometry (GC-MS) was developed for the simultaneous detection of polycyclic aromatic hydrocarbon (PAH) and organochlorinepesticide (OCP) residues in soil samples. The analytes in the soil samples were extracted using an acetone/-hexane (1:1, v/v) mixture for 5 min at 100℃. Then, the extraction pool was heated for 5 min under an extractive pressure of 11.032 MPa for three cycles. The extraction pool was washed with an acetone/-hexane (1:1, v/v) mixture accounting for 60% of the pool volume, followed by nitrogen purging for 100 s. The extract was purified by MSPE using self-made magnetic ZIF-8/nZVI materials at room temperature. The analytes were detected by GC-MS/MS. Under the optimized conditions, good linearities were obtained for the 16 PAHs and the 23 OCPs in the range of 5-200 μg/kg, with correlation coefficients () above 0.99. The limits of detection (LODs) were 0.04-1.21 μg/kg. At three spiked levels in the soil samples, the recoveries of the 39 analytes were between 63.9% and 112.1%, with relative standard deviations (RSDs) between 0.4% and 26.2%. The method was demonstrated to be successful for the determination of 16 PAH and 23 OCP residues in soil samples, with good recoveries.

[Determination of 16 polycyclic aromatic hydrocarbon and 23 organochlorine residues in soil by accelerated solvent extraction and magnetic solid phase purification- gas chromatography-tandem mass spectrometry].

In the aquaculture industry, fluoroquinolones are widely used as effective therapeutic agents to prevent animal diseases. The wide bactericidal activity of fluoroquinolones strongly depends on their concentration. Abuse of fluoroquinolones is considered the main reason for the possible occurrence of residues in aquatic products. The increasing presence of residues in aquatic products may pose potential risks to human health. Therefore, it is important to develop an efficient, sensitive, and reliable method for the simultaneous determination of fluoroquinolones in aquatic products. In the analysis of fluoroquinolones, many HPLC methods with different detection techniques have been applied. Among the most common used techniques, HPLC-MS is possible for the determination of very low level analytes in matrix. For the determination of low concentrations of fluoroquinolone residues in aquatic products, preliminary extraction and purification steps are frequently needed to achieve low detection limits. Accelerated solvent extraction (ASE) is well suited for the determination of organic pollutants in solid samples. ASE has the advantages of a high degree of automation, sufficient extraction, high speed, and less solvent consumption, but it has the disadvantage of poor purification effects. Magnetic solid-phase extraction (MSPE) has attracted considerable attention on account of its benefits such as easy separation, less solvent consumption, and quick adsorption of antibiotic residues in liquid samples. The combination of ASE with MSPE makes it possible to sufficiently extract and further purify the target compounds from complex solid samples. Compared with the currently used purification methods of SPE and QuECHERS, MSPE has advantages such as no need of centrifugation and filtration, less solvent consumption, and low cost by appropriate choice of magnetic materials. In this study, a method based on ASE-MSPE-HPLC-MS/MS was developed for the simultaneous determination of sarafloxacin, ofloxacin, enrofloxacin, danofloxacin, lomefloxacin, pefloxacin, ciprofloxacin, enoxacin, norfloxacin, and difloxacin in yellow croaker, grass carp, black fish, prawn, and macrobrachium. As a magnetic purification sorbent, a graphene oxide nanoscale-coated zerovalent iron adsorbent composite (GO@nZVI), was facilely prepared at room temperature. GO and nZVI solutions were rapidly vortex-mixed at 25℃, and then, the magnetite precipitate was magnetically isolated to obtain GO@nZVI. Simpler than the usually used preparation methods, GO@nZVI can be fabricated without complicated multi-step synthesis, fussy operation and harsh conditions. nZVI nanomaterials have strong multiple interactions (hydrogen bonding, electrostatic interaction or their combination) with GO composite only with appropriate adjustment of pH values. The synthesized magnetic purification sorbents were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD), indicating the successful formation of GO@nZVI. The magnetic material was used to purify and extract ten fluoroquinolone residues in aquatic products via MSPE, followed by ASE. In ASE step, the analytes were extracted from the aquatic products using methanol for 5 min at 70℃, under an extractive pressure of 10.34 MPa for three cycles. The extract was purified by MSPE using GO@nZVI. The target compounds were separated on an Agilent ZORBAX Eclipse Plus C18 column (100 mm×3.0 mm, 1.8 μm) with gradient elution, and analyzed in multiple reaction monitoring (MRM) mode with positive electrospray ionization (ESI). Under the optimized conditions, good linearities were obtained for the ten fluoroquinolones in the range of 1-100 μg/kg, with correlation coefficients above 0.99. LODs (=3) and LOQs (=10) were 0.02-0.29 μg/kg and 0.07-0.98 μg/kg, respectively. At three spiked levels, the recoveries of the fluoroquinolones were between 81.6% and 105.8%, with RSDs between 4.2% and 13.6%. Overall, the major advantages of this combined ASE-MSPE-HPLC-MS/MS method are facile preparation of the magnetic purification material, automated and simple operation, high sensitivity, short extraction time, and less solvent consumption. This sensitive, repetitive method could be successfully employed for the determination of ten fluoroquinolone residues in aquatic products, with good recoveries.

[Determination of 10 fluoroquinolones residues in aquatic products by accelerated solvent extraction, magnetic solid-phase extraction, and high-performance liquid chromatography-tandem mass spectrometry].

Ju Zhang

School of Bioscience and Bioengineering

Hebei University of Economics and Business

Caenorhabditis elegans as a Model System for Discovering Bioactive Compounds Against Polyglutamine-Mediated Neurotoxicity

Ju Zhang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}School of Bioscience and Bioengineering

Hebei University of Economics and Business

Caenorhabditis elegans as a Model System for Discovering Bioactive Compounds Against Polyglutamine-Mediated Neurotoxicity

School of Bioscience and Bioengineering