83 research outputs found

    Silver nanoparticles from oregano leaves’ extracts as antimicrobial components for non-infected hydrogel contact lenses

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    The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles (AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA). The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis, and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9, 12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were 10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low (66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently, pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious contact lenses

    Distinct mechanisms for aerenchyma formation in leaf sheaths of rice genotypes displaying a quiescence or escape strategy for flooding tolerance

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    Background and Aims Rice is one of the few crops able to withstand periods of partial or even complete submergence. One of the adaptive traits of rice is the constitutive presence and further development of aerenchyma which enables oxygen to be transported to submerged organs. The development of lysigenous aerenchyma is promoted by ethylene accumulating within the submerged plant tissues, although other signalling mechanisms may also co-exist. In this study, aerenchyma development was analysed in two rice (Oryza sativa) varieties, ‘FR13A’ and ‘Arborio Precoce’, which show opposite traits in flooding response in terms of internode elongation and survival. Methods The growth and survival of rice varieties under submergence was investigated in the leaf sheath of ‘FR13A’ and ‘Arborio Precoce’. The possible involvement of ethylene and reactive oxygen species (ROS) was evaluated in relation to aerenchyma formation. Cell viability and DNA fragmentation were determined by FDA/FM4-64 staining and TUNEL assay, respectively. Ethylene production was monitored by gas chromatography and by analysing ACO gene expression. ROS production was measured by using Amplex Red assay kit and the fluorescent dye DCFH2-DA. The expression of APX1 was also evaluated. AVG and DPI solutions were used to test the effect of inhibiting ethylene biosynthesis and ROS production, respectively. Key Results Both the varieties displayed constitutive lysigenous aerenchyma formation, which was further enhanced when submerged. ‘Arborio Precoce’, which is characterized by fast elongation when submerged, showed active ethylene biosynthetic machinery associated with increased aerenchymatous areas. ‘FR13A’, which harbours the Sub1A gene that limits growth during oxygen deprivation, did not show any increase in ethylene production after submersion but still displayed increased aerenchyma. Hydrogen peroxide levels increased in ‘FR13A’ but not in ‘Arborio Precoce’. Conclusions While ethylene controls aerenchyma formation in the fast-elongating ‘Arborio Precoce’ variety, in ‘FR13A’ ROS accumulation plays an important role

    Antiproliferative Activity of Antibiotics through DNA Binding Mechanism: Evaluation and Molecular Docking Studies

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    The antiproliferative activity of three antibiotics clinically use, was studied through DNA inhibition mechanisms, ex vivo, in silico and in vitro. The ex vivo interaction of DNA with ciprofloxacin hydrochloride (CIP·HCl), penicillin G sodium salt (PEN·Na), and tetracycline hydrochloride (TC·HCl) was determined by UV-Vis spectra and viscosity measurements. Furthermore, their binding constants (Kb) toward CT-DNA were calculated (Kb = (2.8 ± 0.6) × 104 (CIP·HCl), (0.4 ± 0.1) × 104 (PEN·Na) and (6.9 ± 0.3) × 104 (TC·HCl) Μ−1). Docking studies on the binding interactions of antibiotics with DNA were performed to rationalize the ex vivo results. The in vitro antiproliferative activity of the antibiotics was evaluated against human breast adenocarcinoma (MCF-7) cells (IC50 values: 417.4 ± 28.2 (CIP·HCl), >2000 (PEN·Na) and 443.1 ± 17.2 (TC·HCl) μΜ). Cell cycle arrest studies confirmed the apoptotic type of MCF-7 cells. The toxicity of the studied agents was in vitro tested against human fetal lung fibroblast cells (MRC-5). The results are compared with the corresponding one for doxorubicin (DOX). Despite their low binding affinity to DNA (Kb) or their different mode of interaction, TC·HCl (anthracycline) or CIP·HCl (quinolones), exhibit notable antiproliferative activity and low toxicity

    Antiproliferative Activity of Antibiotics through DNA Binding Mechanism: Evaluation and Molecular Docking Studies

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    The antiproliferative activity of three antibiotics clinically use, was studied through DNA inhibition mechanisms, ex vivo, in silico and in vitro. The ex vivo interaction of DNA with ciprofloxacin hydrochloride (CIP·HCl), penicillin G sodium salt (PEN·Na), and tetracycline hydrochloride (TC·HCl) was determined by UV-Vis spectra and viscosity measurements. Furthermore, their binding constants (Kb) toward CT-DNA were calculated (Kb = (2.8 ± 0.6) × 104 (CIP·HCl), (0.4 ± 0.1) × 104 (PEN·Na) and (6.9 ± 0.3) × 104 (TC·HCl) Μ−1). Docking studies on the binding interactions of antibiotics with DNA were performed to rationalize the ex vivo results. The in vitro antiproliferative activity of the antibiotics was evaluated against human breast adenocarcinoma (MCF-7) cells (IC50 values: 417.4 ± 28.2 (CIP·HCl), >2000 (PEN·Na) and 443.1 ± 17.2 (TC·HCl) μΜ). Cell cycle arrest studies confirmed the apoptotic type of MCF-7 cells. The toxicity of the studied agents was in vitro tested against human fetal lung fibroblast cells (MRC-5). The results are compared with the corresponding one for doxorubicin (DOX). Despite their low binding affinity to DNA (Kb) or their different mode of interaction, TC·HCl (anthracycline) or CIP·HCl (quinolones), exhibit notable antiproliferative activity and low toxicity

    Rachele. Storia lombarda del 1848 con saggi di Alberto Mario Banti e Novella Bellucci

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    Il romanzo breve "Rachele. Storia lombarda del 1848" di Cristina Trivulzio di Belgiojoso, per la prima volta tradotto in italiano, è accompagnato da due saggi critici a cura di Alberto Mario Banti e Novella Bellucci e da una nota biografica e bibliografica su Cristina Trivulzio di Belgiojoso a cura di Flavia Caporuscio

    Synthesis, characterization and cytotoxic properties of bismuth(III) chloride complexes with heterocyclic thioamides

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    Bismuth(III) complexes of the formulae [BiCl3(MBZT)(2)] center dot H2O} (1), {[BiCl2(mu(2)-Cl)(MMI)(2)](2)center dot(CH3)(2)CO} (2), {[BiCl3(mu(2)-S-PYT)(PYT)](2)} (3) {([BiCl2(MBZIM)(4)](+))center dot 2(Cl-) center dot(H3O+)center dot 2H(2)O} (4) and [BiCl3(tHPMT)(3)] (5) (where MBZT: 2-mercaptobenzothiazole, MMI: 2-mercapto-1-methylimidazole, PYT: 2-mercaptopyridine, MBZIM: 2-mercaptobenzimidazole, tHPMT: 2-mercapto-3,4,5,6-tetrahydro-pyrimidine) are reported. The compounds were characterized by spectroscopic techniques including FT-IR, FT-Raman, UV-Vis, H-1-, C-13-NMR spectroscopies, TG-DTA, e. a, molar conductivity and by single-crystal X-ray diffraction analysis. While 1, 4 and 5 are mononuclear compounds, 2 and 3 are dinuclear complexes in which the two Bi3+ ions are bridged through Cl- and SR groups respectively. Interestingly, 3 is the first example of dinuclear Bi3+ complex containing two Bi-(mu-SR)-Bi bridges between the two metal centers formed by covalent bonds. Compounds 1-5 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma cervix (HeLa) and breast (MCF-7) cells. The toxicity of 1-5 was evaluated on normal human fetal lung fibroblast cells (MRC-5). The influence of 1-5, on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) was determined experimentally. (C) 2017 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Z457]; Oncology Department of Novartis Hellas S.A.C.I [81939]This research was carried out in partial fulfillment of the requirements for the master thesis of S.Y. under the supervision of I.I.O. I.I.O. and S.Y. acknowledge the financial support from The Scientific and Technological Research Council of Turkey (TUBITAK, Project No. 114Z457). The Unit of Bioactivity Testing of Xenobiotics, of the University of Ioannina-Greece, is also acknowledged for providing access to the facilities. CNB and SKH acknowledge the Oncology Department of Novartis Hellas S.A.C.I. for the financial support to CNB (project number: 81939)

    Platinum(II)-thiosemicarbazone drugs override the cell resistance due to glutathione; assessment of their activity against human adenocarcinoma cells

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    <p>New platinum(II) compounds of the thiosemicarbazone 1-(1H-Benzimidazol-2-yl)ethan-1-one thiosemicarbazone (BzimetTSCH), [Pt(BzimetTSCH)Cl]·2H<sub>2</sub>O (<b>1</b>) and [Pt(BzimetTSCH)(tpp)]Cl·H<sub>2</sub>O·MeCN (<b>2</b>) were synthesized. The complexes were characterized by FT-IR spectroscopy and <sup>1</sup>H NMR spectroscopy. The crystal structures of <b>1</b> and <b>2</b> were determined with single-crystal X-ray diffraction analysis. The coordination around platinum is square planar in both complexes. Compounds <b>1</b> and <b>2</b> were evaluated for their <i>in vitro</i> cytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The apoptotic pathway of cell death was confirmed by cell cycle arrest test. Since deactivation of cisplatin caused by glutathione (GSH) seems to be an important determinant of its cytotoxic effects, the reactions of <b>1</b> and <b>2</b> with GSH were investigated by UV-absorption spectroscopy. The genotoxicities on normal human fetal lung fibroblast cells (MRC-5) caused by <b>1</b> and <b>2</b> were evaluated by fluorescence microscopy. The absence of micronucleus in MRC-5 cells confirms the <i>in vitro</i> non toxic behavior of the compounds. Moreover, the <i>in vivo</i> genotoxicities of <b>1</b> and <b>2</b> were evaluated by the <i>Allium cepa</i> test. Due to negligible genototoxic effect and high antitumor activity which is similar to that of cisplatin, <b>2</b> could be a candidate for further study as potential drug since the mitotic index is unchanged.</p

    Organotin derivatives of cholic acid induce apoptosis into breast cancer cells and interfere with mitochondrion; Synthesis, characterization and biological evaluation

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    Organotin(IV) derivatives of cholic acid (CAH) with the formulae R3Sn(CA) (R = Ph- (1), n-Bu- (2)) and R2Sn (CA)2 (R = Ph- (3), n-Bu- (4) and Me- (5)) were synthesized. The compounds were characterized in solid state by melting point, FT-IR, 119Sn Mossbauer, ¨ X-ray fluorescence (XRF) spectroscopy and in solution by 1 H NMR, UV–Vis spectral data and by Electrospray Ionisation Mass spectrometry (ESI-MS), High Resolution Mass spectrometry (HRMS), and atomic absorption analysis. The in vitro bioactivity of 1–5 against human breast adenocarcinoma cancer cells MCF-7 (positive to hormone receptors) and MDA-MB-231 (negative to hormone receptors) reveal that triorganotin derivatives 1–2 exhibit significantly stronger activity than the corresponding diorganotin ones. Compound 5 is inactive against both cell lines at the concentrations tested. Triorganotins 1–2 inhibit selectively MCF-7 than MDA-MB-231 cells, suggesting hormone mimetic behavior of them. Organotins 1–4 inhibit both cancerous cell lines, stronger than cisplatin which rise up to 55-fold against MCF-7 and 170-fold against MDA-MB-231. The in vitro toxicity of 1–4 was evaluated on normal human fetal lung fibroblast cells (MRC-5), while their genotoxicity in vitro by micronucleus assay (MN). Moreover, the in vivo toxicity of 1–4 was tested by Artemia salina assay and their in vivo genotoxicity with Allium cepa test. The mechanism of action of 1–4 against MCF-7 was clarified in vitro by the means of cell morphology studies, cell cycle arrest, Acridine Orange/Ethidium Bromide (AO/EB) Staining, mitochondrial membrane permeabilization test and by their binding affinity toward the calf thymus (CT) DN
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