Antibacterial Activity of Silphium perfoliatum. Extracts

Abstract

Methanol and hexane extracts obtained from above-and below-ground organs of the cup plant Silphium perfoliatum. L. (Asteraceae) were analyzed by gas chromatography–mass spectrometry (GC-MS). Eighty-five components were identified in the extracts. Moreover, evaluation of the content of total secondary metabolites (flavonoids, o.-dihydroxyphenols, and glycoside-bonded oleanolic acid) was made in the methanol extract. It was found that leaf, inflorescence, and rhizome extracts of S. perfoliatum. were characterized by antibacterial action toward Gram-positive (Enterococcus faecalis., Staphylococcus aureus.) and Gram-negative (Escherichia coli., Pseudomonas aeruginosa. bacteria). All the extracts showed extremely high activity toward Staphylococcus aureus. FDA 209P strains (MIC values: 1.00 mg/mL for rhizome alcohol and hexane extracts; 2.50 mg/mL for leaf and inflorescence alcohol extracts and for leaf hexane extracts; 5.00 mg/mL for inflorescence hexane extracts). In general, alcohol extracts had slightly stronger antibacterial properties compared with lipophilic ones. Among the alcohol extracts, those made of S. perfoliatum. rhizomes had the highest activity compared with the leaf and inflorescence extracts.     

Directions and opportunities for immunoprophylaxis development among Polish Army soldiers sent to foreign missions

The Polish Army is engaged in stabilization activities and peace missions in countries often characterized by completely different customs, culture and religion, as well as different bacterial and viral flora. It might be expected that foreign military operations will be more and more important, as the number of local conflicts is escalating. The safety and health of our citizens in these circumstances is the absolute priority. This article is dedicated to the safety of soldiers in the context of the risks associated with infectious diseases that can be prevented by vaccination. The main goal of this study is to verify the model and condition of immunization in the Polish Army in the context of foreign contingents, as well as presentation of the possibilities to optimize solutions in this field.     

High-Temperature Oxidation of Fe3Al Intermetallic Alloy Prepared by Additive Manufacturing LENS

The isothermal oxidation of Fe-28Al-5Cr (at%) intermetallic alloy microalloyed with Zr and B (<0.08 at%) in air atmosphere, in the temperature range of 1000 to 1200 °C, was studied. The investigation was carried out on the thin-walled (<1 mm) elements prepared by Laser Engineered Net Shaping (LENS) from alloy powder of a given composition. Characterization of the specimens, after the oxidation, was conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM, with back-scatter detector (BSE) and energy-dispersive X-ray spectroscopy (EDS) attachments). The investigation has shown, that the oxidized samples were covered with a thin, homogeneous α-Al₂O₃ oxide layers. The intensity of their growth indicates that the material lost its resistance to oxidation at 1200 °C. Structural analysis of the thin-walled components’ has not shown intensification of the oxidation process at the joints of additive layers.     

Iatrogenic left main-stem dissection extending to the circumflex artery and retrogradely involving the left and non-coronary sinuses of Valsalva: iatrogenic aortocoronary dissection

We present the case of a 57-year-old female who experienced iatrogenic left main-stem (LMS) dissection during elective coronary angiography. The dissection immediately affected the circumflex artery (Cx), causing its total distal occlusion, and the left anterior descending artery (LAD), in which a metal stent, implanted six months earlier, provided blood flow. The dissection spread retrogradely to the left and non-coronary sinuses of Valsalva (SV). Ventricular fibrillation (VF) occurred but the patient was successfully defibrillated. The subsequent introduction of a catheter resulted in recurrent VF, again successfully defibrillated. Total arterial myocardial revascularisation with double skeletonised internal thoracic arteries was performed without complications and SV repair was avoided. At the one-year follow up, a control multi-slice CT (MSCT) angiography was conducted, revealing complete healing of the SV and LMS dissections. It also showed native blood flow, the left internal thoracic artery (LITA) graft to the Cx occlusion, and a patent right internal thoracic artery (RITA) graft implanted to the LAD.     

Neuroprotective effects of neuropeptide Y-Y2 and Y5 receptor agonists in vitro and in vivo

It is generally assumed that neurodegeneration is connected with glutamatergic hyperactivity, and that neuropeptide Y (NPY) inhibits glutamate release. Some earlier studies indicated that NPY may have neuroprotective effect; however, the results obtained so far are still divergent, and the role of different Y receptors remains unclear. Therefore in the presented study we investigated the neuroprotective potential of NPY and its Y2, Y5 or Y1 receptor (R) ligands against the kainate (KA)-induced excitotoxicity in neuronal cultures in vitro, as well as in vivo after intrahippocampal KA injection and also in an ischemic middle cerebral artery occlusion model after intraventricular injection of Y2R agonist. NPY compounds were applicated 30 min, 1, 3 or 6 h after the start of the exposure to KA, or 30 min after the onset of ischemia. Our results indicate the neuroprotective activity of NPY and its Y2R and Y5R ligands against the kainate-induced excitotoxicity in primary cortical and hippocampal cultures. Importantly, NPY was effective when given as late as 6 h, while Y2R or Y5R agonists 3 h, after starting the exposure to KA. In in vitro studies those protective effects were inhibited by the respective receptor antagonists. Neuroprotection was also observed in vivo after intrahippocampal injection of Y2R and Y5R agonists 30 min or 1 h after KA. No protection was found either in vitro or in vivo after the Y1R agonist. The Y2R agonist also showed neuroprotective activity in the ischemic model. The obtained results indicate that neuropeptide Y produces neuroprotective effect via Y2 and Y5 receptors, and that the compounds may be effective after delayed application.     

Acute and chronic treatment with mianserin differentially affects the anticonvulsant activity of conventional antiepileptic drugs in the mouse maximal electroshock model

Rationale Epilepsy often coexists with depression. Therefore, the probability of simultaneous treatment with antiepileptics and antidepressants and the possibility of interactions between them are relatively high. Objective The effects of acute and chronic administration of mianserin on the protective activity of valproate (VPA), carbamazepine, phenytoin, and phenobarbital were evaluated in the maximal electroshock in mice. Materials and methods Animals were subjected to electroconvulsions. Undesired effects were evaluated in the chimney test (motor impairment) and passive-avoidance task (memory deficit). Brain concentrations of antiepileptic drugs were assessed by immunofluorescence. Results When given acutely, mianserin (at doses greater than or equal to 20 mg/kg) significantly raised the electroconvulsive threshold. The antidepressant, at the subanticonvulsant doses, enhanced the anticonvulsant action of carbamazepine, phenytoin, and VPA. Mianserin administered chronically at 30 mg/kg significantly decreased the electroconvulsive threshold. In contrast to acute treatment, the antidepressant at subeffective doses diminished the anticonvulsant activity of VPA and phenytoin. Mianserin given either acutely or chronically did not affect the brain concentrations of antiepileptic drugs, so a pharmacokinetic contribution to the observed interactions is not probable. Acute and chronic treatment with mianserin and its combinations with antiepileptic drugs did not impair either motor coordination or long-term memory. Conclusion Although acute application of mianserin may potentiate the anticonvulsant action of some antiepileptics, its chronic administration can lead to the opposite effect. Therefore, as far as the presented results can be transferred to clinical conditions, the antidepressant therapy with mianserin should be limited or even avoided in epileptic patients.     

Antimycobacterial action of a new glycolipid‐peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica

In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface‐enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X‐ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid–peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid–peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria.