11 research outputs found
Studies on the interactions of neutral Galleria mellonella cecropin D with living bacterial cells
Identification of MMP-1 and MMP-9 inhibitors from the roots of Eleutherococcus divaricatus, and the PAMPA test
Chemical and Phase Composition of the Friction Surfaces Fe–Mn–C–B–Si–Ni–Cr Hardfacing Coatings
Identification of MMP-1 and MMP-9 inhibitors from the roots of <i>Eleutherococcus divaricatus</i>, and the PAMPA test
<div><p>The purpose of this study was the isolation of metalloproteinases MMP-1 and MMP-9 inhibitors from the chloroform extract of the <i>Eleutherococcus divaricatus</i> roots. Using GC-MS, <sup>1</sup>H and <sup>13</sup>C NMR, HMQC, HMBC, COSY and DEPT, (+)-sesamin has been identified as a new anti-MMP inhibitor. We report for the first time that (+)-sesamin inhibited MMP-1 and MMP-9 activity in 40% and 17%, respectively. The high inhibitory potential has been shown by ursolic acid (90.9% and 89.8% for MMP-1 and MMP-9). In the PAMPA test, the Pe value for sesamin was established as 17.4 × 10<sup>− 6</sup> cm/s, that for ursolic acid as 30.0 × 10<sup>− 6</sup> cm/s. Verapamil and theophylline were used as a positive and negative control (Pe 42.1 and 2.9 × 10<sup>− 6</sup> cm/s). To our best knowledge, no information was available on this activity of sesamin and other compounds. These studies provide a biochemical basis for the regulation of MMP-1 and MMP-9 by <i>E.</i><i>divaricatus</i> compounds.</p></div
Synergistic action of Galleria mellonella apolipophorin III and lysozyme against Gram-negative bacteria
AbstractInsect immune response relies on the humoral and cellular mechanisms of innate immunity. The key factors are the antimicrobial polypeptides that act in concert against invading pathogens. Several such components, e.g. apolipophorin III (apoLp-III), lysozyme, and anionic peptide 2, are present constitutively in the hemolymph of non-challenged Galleria mellonella larvae. In the present study, we demonstrate an evidence for a synergistic action of G. mellonella lysozyme and apoLp-III against Gram-negative bacteria, providing novel insights into the mode of action of these proteins in insect antimicrobial defense. It was found that the muramidase activity of G. mellonella lysozyme considerably increased in the presence of apoLp-III. Moreover, apoLp-III enhanced the permeabilizing activity of lysozyme toward Escherichia coli cells. As shown using non-denaturing PAGE, the proteins did not form intermolecular complexes in vivo and in vitro, indicating that the effect observed was not connected with the intermolecular interactions between the proteins. Analysis of AFM images of E. coli cells exposed to G. mellonella lysozyme and/or apoLp-III revealed evident alterations in the bacterial surface structure accompanied by the changes in their biophysical properties. The bacterial cells demonstrated significant differences in elasticity, reflected by Young's modulus, as well as in adhesive forces and roughness values in comparison to the control ones. The constitutive presence of these two defense molecules in G. mellonella hemolymph and the fact that apoLp-III enhances lysozyme muramidase and perforating activities indicate that they can be regarded as important antibacterial factors acting at the early stage of infection against Gram-negative as well as Gram-positive bacteria
A New Method for the Isolation of Ergosterol and Peroxyergosterol as Active Compounds of Hygrophoropsis aurantiaca and in Vitro Antiproliferative Activity of Isolated Ergosterol Peroxide
In the present study, ergosterol peroxide and ergosterol were isolated for the first time from fresh fruit bodies of Hygrophoropsis aurantiaca (False Chanterelle). The substances were characterized mainly by spectroscopic methods (1H-NMR, 13C-NMR, DEPT-45, DEPT-90, DEPT-135, 2D-NMR). In our study, a new specific thin layer chromatographic method was developed for determination of ergosterol and ergosterol peroxide in H. aurantiaca extract. The method is based on the separation of n-hexane extract on silica gel (Silica Gel G) TLC plates using the optimized solvent system toluene/ethyl acetate (3:1; v/v). The main advantages of the developed method are the simplicity of operation and the low cost. The in vitro study results revealed the antiproliferative properties of ergosterol peroxide against LS180 human colon cancer cells. The described effect was attributed both to altered mitochondrial activity and decreased DNA synthesis. Additionally, in the same concentration range the investigated compound was not toxic to CCD 841 CoTr human colon epithelial cells. The present study suggests that fruit bodies of H. aurantiaca have great potential for producing substances and extracts with potential applications in medicine
Synergistic action of Galleria mellonella anionic peptide 2 and lysozyme against Gram-negative bacteria
AbstractLysozyme and antimicrobial peptides are key factors of the humoral immune response in insects. In the present work lysozyme and anionic defense peptide (GMAP2) were isolated from the hemolymph of the greater wax moth Galleria mellonella and their antibacterial activity was investigated. Adsorption of G. mellonella lysozyme on the cell surface of Gram-positive and Gram-negative bacteria was demonstrated using immunoblotting with anti-G. mellonella lysozyme antibodies. Lysozyme effectively inhibited the growth of selected Gram-positive bacteria, which was accompanied by serious alterations of the cell surface, as revealed by atomic force microscopy (AFM) imaging. G. mellonella lysozyme used in concentrations found in the hemolymph of naive and immunized larvae, perforated also the Escherichia coli cell membrane and the level of such perforation was considerably increased by GMAP2. GMAP2 used alone did not perforate E. coli cells nor influence lysozyme muramidase activity. However, the peptide induced a decrease in the turgor pressure of the bacterial cell. Moreover, in the samples of bacteria treated with a mixture of lysozyme and GMAP2 the sodium chloride crystals were found, suggesting disturbance of ion transport across the membrane leading to cell disruption. These results clearly indicated the synergistic action of G. mellonella lysozyme and anionic peptide 2 against Gram-negative bacteria. The reported results suggested that, thanks to immune factors constitutively present in hemolymph, G. mellonella larvae are to some extent protected against infection caused by Gram-negative bacteria