Chemical composition, antioxidant and antibacterial activities of extracts obtained from the roots bark of Arbutus andrachne L. a Lebanese tree.

Context and purpose of the study: The leaves, fruits, barks and roots of Arbutus andrachne L (A. andrachne), have been adopted to have high therapeutic value resulting from the presence of antioxidant compounds such as flavonoids, phenolic and tannins. In the present work, three extracts obtained from A. andrachne roots bark were evaluated for their antioxidant and antibacterial activities .The total phenolic content, flavonoid, condensed tannins and anthocyanins were determined in order to correlate them with the antioxidant activity of extracts.Main findings: The highest amounts of phenolic and tannins were found in the ethyl-acetate, while the anthocyanins ones were highly observed in the methanol-water extract. The lowest IC50 values for DPPH (0.6 µg/mL), and metal chelating assay (13.45µg/mL) were recorded in the ethyl-acetate extract and the methanolic one respetively. Gram positive bacteria (S. aureus and E. faecalis) were more susceptible to the antimicrobial potential of the methanol extract, while E.coli and P. aeruginosa as Gram negative bacteria turned out to be more resistant to the same extract. The ethyl-acetate extract was more effective on E. faecalis than on S. aureus; while E. coli and P. aeruginosa were the most resistant to this extract.Brief summary and potential implications: An appropriate dose of antioxidants derived from A. andrachne bark of the roots extracts in the human diet can help to avoid the risk of contracting diseases where ROS are involved in the pathogenesis. In fact, phenolic compounds in these extracts are among the natural antioxidants being studied by the scientific community due to their biological properties, e.g., antioxidant and antimicrobial activities

Chemical composition, antioxidant and antibacterial activities of extracts obtained from the roots bark of Arbutus andrachne L. a Lebanese tree.

Context and purpose of the study: The leaves, fruits, barks and roots of Arbutus andrachne L (A. andrachne), have been adopted to have high therapeutic value resulting from the presence of antioxidant compounds such as flavonoids, phenolic and tannins. In the present work, three extracts obtained from A. andrachne roots bark were evaluated for their antioxidant and antibacterial activities .The total phenolic content, flavonoid, condensed tannins and anthocyanins were determined in order to correlate them with the antioxidant activity of extracts.Main findings: The highest amounts of phenolic and tannins were found in the ethyl-acetate, while the anthocyanins ones were highly observed in the methanol-water extract. The lowest IC50 values for DPPH (0.6 µg/mL), and metal chelating assay (13.45µg/mL) were recorded in the ethyl-acetate extract and the methanolic one respetively. Gram positive bacteria (S. aureus and E. faecalis) were more susceptible to the antimicrobial potential of the methanol extract, while E.coli and P. aeruginosa as Gram negative bacteria turned out to be more resistant to the same extract. The ethyl-acetate extract was more effective on E. faecalis than on S. aureus; while E. coli and P. aeruginosa were the most resistant to this extract.Brief summary and potential implications: An appropriate dose of antioxidants derived from A. andrachne bark of the roots extracts in the human diet can help to avoid the risk of contracting diseases where ROS are involved in the pathogenesis. In fact, phenolic compounds in these extracts are among the natural antioxidants being studied by the scientific community due to their biological properties, e.g., antioxidant and antimicrobial activities

[PHEMA/PEI]-Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma

The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]-Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50,100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]-Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). (C) 2016 Elsevier B.V. All rights reserved

Fast UHPLC-MS/MS for the Simultaneous Determination of Azithromycin, Erythromycin, Fluoxetine and Sotalol in Surface Water Samples

International audienceChromatographic development for the determination of pharmaceuticals in environmental water samples is particularly challenging when the analytes have significantly different physico-chemical properties (solubility, polarity, pKa) often requiring multiple chromatographic methods for each active component. This paper presents a method for the simultaneous determination of azithromycin, erythromycin (antibiotics), fluoxetine (anti-depressant) and sotalol (b-blocker) in surface waters by ultra-high-performance liquid chromatography coupled with ultra-high-resolution time-of-flight mass spectrometry. These pharmaceuticals—presenting a broad spectrum of polarity (0.24 ≤ log Kow ≤ 4.05)—were separated on a C-18 analytical column, after a simple filtration step for freshwater samples or after a liquid–liquid extraction with Methyl-tertio-butyl ether (MTBE) for seawater samples. The optimized separation method (in terms of nature of column and eluent, elution gradient, and of mass spectrometric parameters), enable one to reach limits of detection ranging between 2 and 7 ng L−1 and limits of quantification between 7 and 23 ng L−1 for the four targeted molecules, within a three minute run. This method was validated using samples collected from three different surface waters in Lebanon (freshwater and seawater) and analytical results were compared with those obtained in surface waters sampled in a French river, equivalent in terms of human activities. Using this method, we report the highest concentration of pharmaceuticals found in surface water (up to 377 ng L−1 and 268 ng L−1, respectively, for azithromycin and erythromycin, in the Litani river, Lebanon)

Clostridioides difficile Flagellin Activates the Intracellular NLRC4 Inflammasome

Clostridioides difficile (C. difficile), is a major cause of nosocomial diarrhea and colitis. C. difficile flagellin FliC contributes toxins to gut inflammation by interacting with the immune Toll-like receptor 5 (TLR5) to activate nuclear factor-kappa B (NF-kB) and mitogen-activated protein kinase (MAPK) signaling pathways. Flagella of intracellular pathogens can activate the NLR family CARD domain-containing protein 4 (NLRC4) inflammasome pathway. In this study, we assessed whether flagellin of the extracellular bacterium C. difficile internalizes into epithelial cells and activates the NLRC4 inflammasome. Confocal microscopy showed internalization of recombinant green fluorescent protein (GFP)-FliC into intestinal Caco-2/TC7 cell line. Full-length GFP-FliC activates NLRC4 in Caco-2/TC7 cells in contrast to truncated GFP-FliC lacking the C-terminal region recognized by the inflammasome. FliC induced cleavage of pro-caspase-1 into two subunits, p20 and p10 as well as gasdermin D (GSDMD), suggesting the caspase-1 and NLRC4 inflammasome activation. In addition, colocalization of GFP-FliC and pro-caspase-1 was observed, indicating the FliC-dependent NLRC4 inflammasome activation. Overexpression of the inflammasome-related interleukin (interleukin (IL)-1β, IL-18, and IL-33) encoding genes as well as increasing of the IL-18 synthesis was detected after cell stimulation. Inhibition of I-kappa-B kinase alpha (IKK-α) decreased the FliC-dependent inflammasome interleukin gene expression suggesting a role of the NF-κB pathway in regulating inflammasome. Altogether, these results suggest that FliC internalizes into the Caco-2/TC7 cells and activates the intracellular NLRC4 inflammasome thus contributing to the inflammatory process of C. difficile infection