Ethidium Research Articles

New Pd(II)-pincer type complexes as potential antitumor drugs: synthesis, nucleophilic substitution reactions, DNA/HSA interaction, molecular docking study and cytotoxic activity.

Two new complexes of Pd(II), [Pd(L1)Cl]Cl (Pd1) and [Pd(L2)Cl]Cl (Pd2), (where L1 = N2,N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide and L2 = N2,N6-di(benzo[d]thiazol-2-yl)pyridine-2.6-dicarboxamide) were synthesized. Characterization of the complexes was performed using elemental analysis, IR, 1H NMR spectroscopy and MALDI-TOF mass spectrometry. The nucleophilic substitution reactions of complexes with L-Methionine (L-Met), L-Cysteine (L-Cys) and guanosine-5'-monophosphate (5'-GMP) were studied by stopped-flow method at physiological conditions (pH = 7.2 and 37 °C). Complex Pd1 was more reactive than Pd2 in all studied reactions, while the order of reactivity of the selected ligands was: L-Met > L-Cys > 5'-GMP. The interaction of complexes with calf thymus-DNA (CT-DNA) was studied by Uv-Vis absorption and fluorescence emission spectroscopy. Competitive binding studies with intercalative agent ethidium bromide (EB) and minor groove binder Hoechst 33258 were performed as well. Both complexes interacted with DNA through intercalation and minor groove binding, where the latter was preferred. Additionally, the interaction of Pd1 and Pd2 complexes with human serum albumin (HSA) was studied employing fluorescence quenching spectroscopy. The results indicate a moderate binding affinity of complexes, with slightly stronger binding of the Pd1. Fluorescence competition experiments with site-markers (eosin Y and ibuprofen) for HSA were used to locate the binding site of Pd1 to the HSA. Additionally, the interaction with DNA and HSA was studied by molecular docking and the revealed results were in good agreement with the experimentally obtained ones. Pd1 complex exhibited cytotoxicity toward human (HCT116) and mouse cell lines (CT26) of colorectal cancer, mouse (4T1) and human (MDA-MB468) breast cancer lines and non-cancerous mouse mesenchymal stem cells (mMSC). In addition, Pd1 complex demonstrated significant selectivity towards cancer cells over non-cancerous mMSC, indicating a high potential to eliminate malignant cells without affecting normal cells. It induced apoptosis in CT26 cells, effectively arrested the cell cycle in the S phase, and selectively down-regulated cyclin D and cyclin E. Moreover, it can alter the expression of cell cycle regulators by increasing p21 and decreasing p-AKT. These findings confirm its ability to disrupt key tumor cell survival signals and suggest that the Pd1 complex is a potent candidate for effective cancer treatment.

Zwitterionic Nanochannels in Covalent Organic Framework Membranes for Improved Flux and Antifouling Property.

Zwitterionic membranes demonstrate excellent antifouling property in water purification. The covalent organic frameworks (COFs), due to the ordered channels and abundant organic functional groups, have distinct superiority in constructing zwitterionic surfaces.Here, the zwitterionic COF membrane is prepared with precise framework structures and uniform charge distribution. The negatively charged 4,4'-diaminobiphenyl-2,2'-sisulphonic acid sodium (SA) and positively charged ethidium bromide (EB) fragments are used to react with 1,3,5-triformylphloroglucinol (TP) at the gas-liquid interface to prepare zwitterionic COF membrane. The complementary charged fragments in the inter-layer and inner-layer facilitate the formation of continuous and tight hydration layer on the membrane surface and pore walls to resist the adsorption of pollutants. The zwitterionic COF membrane effectively resists both negatively charged bovine serum albumin and positively charged lysozyme pollutants with flux recovery ratio (FRR) of 97% and 85%, respectively. Furthermore, the regular nano-channels and balanced interactions between water and surface/pore walls of the zwitterionic membrane result in outstanding permeability of up to 146 L m-2 h-1 bar-1 and excellent dye/salt separation selectivity. The water permeation and antifouling mechanism of membranes are elucidated by experimental and molecular dynamics calculation. Zwitterionic COF membranes can find promising applications in preparing high-performance antifouling membranes.

In vitro and in silico effect of meldrum's acid-derived compounds on Staphylococcus aureus strains as NorA efflux pump inhibitors

The misuse of antibiotics has led to an alarming increase in bacterial strains resistant to these drugs. Efflux pumps, which expel antibiotics from bacterial cells, have emerged as one of the key mechanisms of bacterial resistance. In the quest to combat and mitigate bacterial resistance, researchers have turned their attention to efflux pump inhibitors as a potential solution. Meldrum's acid, a synthetic molecule widely utilized in the synthesis of bioactive compounds, has garnered significant interest in this regard. Hence, this study aims to investigate the antibacterial activity and evaluate the efficacy of three derivatives of meldrum's acid in inhibiting efflux mechanisms, employing both in silico and in vitro approaches. The antibacterial activity of the derivatives was assessed through rigorous broth microdilution testing. While the derivatives themselves did not exhibit direct antibacterial activity, they demonstrated remarkable potential in potentiating the effects of antibiotics. Additionally, fluorescence emission assays using ethidium bromide (EtBr) revealed fluorescence levels comparable to the positive control, indicating a possible blockade of efflux pumps. Molecular docking studies conducted in silico further supported these findings by revealing binding interactions similar to norfloxacin and CCCP, known efflux pump inhibitors. These results underscore the potential of meldrum's acid derivatives as effective inhibitors of efflux pumps. By inhibiting these mechanisms, the derivatives hold promise in enhancing the effectiveness of antibiotics and combatting bacterial resistance. This study contributes valuable insights into the development of novel strategies to address the pressing issue of bacterial resistance and paves the way for further research and exploration in this field.

Exploration of vanoxerine analogues as antibacterial agents.

Mycobacterium tuberculosis is a bacterial pathogen, responsible for approximately 1.3 million deaths in 2022 through tuberculosis infections. The complex treatment regimen required to treat tuberculosis and growing rates of drug resistance, necessitates the development of new anti-mycobacterial agents. One approach is to repurpose drugs from other clinical applications. Vanoxerine (GBR 12909) was previously shown to have anti-mycobacterial activity, through dissipating the membrane electric potential and hence, cellular energetics. Several vanoxerine analogues were synthesised in this study, which exhibited a range of activities against mycobacteria and enterococcus. All active analogues had similar impacts on the membrane electric potential and inhibition of ethidium bromide efflux. The most active compound displayed reduced inhibitory activity against the known human target of vanoxerine, the dopamine transporter. This work has identified a promising analogue, which could provide a starting point for further medicinal chemistry and drug development efforts to target mycobacteria.

Unwinding DNA strands by single-walled carbon nanotubes: Molecular docking and MD simulation approach

Despite the growing research into the use of carbon nano-tubes (CNTs) in science and medicine, concerns about their potential toxicity remain insufficiently studied. This study utilizes molecular docking calculations combined by molecular dynamics simulations to investigate the dynamic intricacies of the interaction between single-walled carbon nanotubes (swCNTs) and double-stranded DNA (dsDNA). By examining the influence of swCNT characteristics such as length, radius, and chirality, our findings shed light on the complex interplay that shapes the binding affinity and stability of the dsDNA-swCNT complex. Molecular docking results identify a zigzag swCNT, with a radius of 0.16 Å and a length of 38 Å, as exhibiting the highest binding affinity with dsDNA (−23.9 kcal/mol). Comprehensive analyses, spanning docking results, binding energies, RMSD, radius of gyration, and potential of mean force (PMF) profiles, provide a detailed understanding of the denaturation dynamics. The PMF profiles reveal the thermodynamic feasibility of the DNA-CNT interaction, outlining distinct energy landscapes and barriers: when the selected swCNT binds within the dsDNA groove, the system becomes trapped at the first and second local energy minima, occurring at 1.48 nm and 1.00 nm, respectively. Intramolecular hydrogen bond calculations show a significant reduction, affirming the denaturing effect of swCNTs on DNA. Furthermore, the study reveals a significant reduction in the binding affinity of Ethidium Bromide (EB) to dsDNA following its interaction with swCNT, with a decrease in EB binding to dsDNA of approximately 13.2 %. This research offers valuable insights into the toxic effects of swCNTs on dsDNA, contributing to a rationalization of the cancerous potential of swCNTs.

DNA interaction and cytotoxicity of a new asymmetric dimer cobalt(II) complex [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl)

The new, unusual and asymmetric cobalt(II) complex, [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl) (phen ​= ​1,10-phenanthroline), has been synthesized and characterized structurally by regular spectral and single crystal XRD analysis. An asymmetric complex crystallized in a monoclinic system with space group P21/c, a ​= ​14.093(5) Å, b ​= ​24.089(5) Å, c ​= ​14.241(5) Å, α ​= ​90.000(5)°, β ​= ​98.010(5)°, and γ ​= ​90.000(5)°. DNA binding interactions of complex with calf thymus DNA (CT-DNA) has investigated by UV–Vis absorption, ethidium bromide displacement assay, viscometric and cyclic voltammetric titrations, and the results infer an intercalation mode of binding. Complex cleaves effectively plasmid pBR322 DNA, and exhibits remarkable cytotoxic activity against human colon cancer cell line (HCT15).

Discovery of clinical isolation of drug-resistant Klebsiella pneumoniae with overexpression of OqxB efflux pump as the decisive drug resistance factor.

Background emergence of multidrug-resistant (MDR) bacterial strains is a public health concern that threatens global and regional security. Efflux pump-overexpressing MDR strains from clinical isolates are the best subjects for studying the mechanisms of MDR caused by bacterial efflux pumps. A Klebsiella pneumoniae strain overexpressing the OqxB-only efflux pump was screened from a clinical strain library to explore reverse OqxB-mediated bacterial resistance strategies. We identified non-repetitive clinical isolated K. pneumoniae strains using a matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry clinical TOF-II (Clin-TOF-II) and susceptibility test screening against levofloxacin and ciprofloxacin. And the polymorphism analysis was conducted using pulsed-field gel electrophoresis. Efflux pump function of resistant strains is obtained by combined drug sensitivity test of phenylalanine-arginine beta-naphthylamide (PaβN, an efflux pump inhibitor) and detection with ethidium bromide as an indicator. The quantitative reverse transcription PCR was performed to assess whether the oqxB gene was overexpressed in K. pneumoniae isolates. Additional analyses assessed whether the oqxB gene was overexpressed in K. pneumoniae isolates and gene knockout and complementation strains were constructed. The binding mode of PaβN with OqxB was determined using molecular docking modeling. Among the clinical quinolone-resistant K. pneumoniae strains, one mediates resistance almost exclusively through the overexpression of the resistance-nodulation-division efflux pump, OqxB. Crystal structure of OqxB has been reported recently by N. Bharatham, P. Bhowmik, M. Aoki, U. Okada et al. (Nat Commun 12:5400, 2021, https://doi.org/10.1038/s41467-021-25679-0). The discovery of this strain will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and builds on the foundation for addressing the threat posed by quinolone resistance.IMPORTANCEThe emergence of antimicrobial resistance is a growing and significant health concern, particularly in the context of K. pneumoniae infections. The upregulation of efflux pump systems is a key factor that contributes to this resistance. Our results indicated that the K. pneumoniae strain GN 172867 exhibited a higher oqxB gene expression compared to the reference strain ATCC 43816. Deletion of oqxB led a decrease in the minimum inhibitory concentration of levofloxacin. Complementation with oqxB rescued antibiotic resistance in the oqxB mutant strain. We demonstrated that the overexpression of the OqxB efflux pump plays an important role in quinolone resistance. The discovery of strain GN 172867 will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and promotes further study of antimicrobial resistance.

2-Ferrocene-4-amine-1H-benzo[d]imidazole and their derivatives: Synthesis, biological and docking study

An organometallic series based on 2-ferrocene-4-amine-1H-benzo[d]imidazole derivative has been synthesized and characterized through FTIR, H/CNMR, and LCMS. Their antimicrobial activity was assessed by testing them against B. subtills, Staphylococcus aureus, E. faecalis, S. marcescens, E. coli, K. pneumoniae, C. albicans, A. niger, Mucor sp. where they showed good zone of inhibition (ZOI) as compared to standards. The cytotoxicity of synthesized compounds was tested against Hela (cervical) and MCF-7 (breast) cancer cell lines where compound 5a and 5b displayed equivalent potency to the standard while 5e demonstrated highest cytotoxicity against both cell lines. Their comparative docking analysis with DNA suggested that docking score of 5e was −7.4 kcal/mol versus −6 kcal/mol of ethidium bromide, indicating that our designed compound acts via DNA intercalation.

Efficient ethidium bromide removal using sodium alginate/graphene oxide composite beads: Insights into adsorption mechanisms and performance

This study explores the efficacy of sodium alginate/graphene oxide (SA/GO) composite beads for ethidium bromide (EtBr) removal from aqueous solutions. GO was synthesized and crosslinked with SA to design composite beads, which were evaluated under various physicochemical conditions. Characterization techniques, including FESEM, TGA, XRD, and FTIR, were employed to analyze the beads before and after EtBr adsorption. Results demonstrated rapid EtBr adsorption onto SA/GO, following the Freundlich isotherm model with a maximum adsorption capacity of 2.97mmol g−1 (1171.05 mg g−1). The influence of solution pH and the negligible role of Br− ions suggested that electrostatic interaction was the primary mechanism for EtBr adsorption on SA/GO. XRD and FTIR analyses revealed that EtBr adsorption also occurred in the interlayer space of SA/GO beads, with the ethidium cations (Et+) entering this space in a horizontal or oblique (≥45°) orientation. The accumulation of Et+ within the interlayer space was estimated to form 1–6 basic inclined layers. SA/GO beads demonstrated promising characteristics for EtBr pollutant treatment, including low environmental impact, cost-effectiveness, rapid adsorption kinetics, and high removal efficiency. This study provides valuable insights into the adsorption mechanisms and performance of SA/GO beads, highlighting their potential for future field applications in the environmental remediation of EtBr contamination.

Magnetic resonance metrics for identification of cuprizone-induced demyelination in the mouse model of neurodegeneration: a review.

Neurodegenerative disorders, including Multiple Sclerosis (MS), are heterogenous disorders which affect the myelin sheath of the central nervous system (CNS). Magnetic Resonance Imaging (MRI) provides a non-invasive method for studying, diagnosing, and monitoring disease progression. As an emerging research area, many studies have attempted to connect MR metrics to underlying pathophysiological presentations of heterogenous neurodegeneration. Most commonly, small animal models are used, including Experimental Autoimmune Encephalomyelitis (EAE), Theiler's Murine Encephalomyelitis (TMEV), and toxin models including cuprizone (CPZ), lysolecithin, and ethidium bromide (EtBr). A contrast and comparison of these models is presented, with focus on the cuprizone model, followed by a review of literature studying neurodegeneration using MRI and the cuprizone model. Conventional MRI methods including T1 Weighted (T1W) and T2 Weighted (T2W) Imaging are mentioned. Quantitative MRI methods which are sensitive to diffusion, magnetization transfer, susceptibility, relaxation, and chemical composition are discussed in relation to studying the CPZ model. Overall, additional studies are needed to improve both the sensitivity and specificity of MRI metrics for underlying pathophysiology of neurodegeneration and the relationships in attempts to clear the clinico-radiological paradox. We therefore propose a multiparametric approach for the investigation of MR metrics for underlying pathophysiology.

Mitochondrial DNA replication is essential for neurogenesis but not gliogenesis in fetal neural stem cells.

Mitochondria are unique organelles that have their own genome (mtDNA) and perform various pivotal functions within a cell. Recently, evidence has highlighted the role of mitochondria in the process of stem cell differentiation, including differentiation of neural stem cells (NSCs). Here we studied the importance of mtDNA function in the early differentiation process of NSCs in two cell culture models: the CGR8-NS cell line that was derived from embryonic stem cells by a lineage selection technique, and primary NSCs that were isolated from embryonic day 14 mouse fetal forebrain. We detected a dramatic increase in mtDNA content upon NSC differentiation to adapt their mtDNA levels to their differentiated state, which was not accompanied by changes in mitochondrial transcription factor A expression. As chemical mtDNA depletion by ethidium bromide failed to generate living ρ° cell lines from both NSC types, we used inhibition of mtDNA polymerase-γ by 2'-3'-dideoxycytidine to reduce mtDNA replication and subsequently cellular mtDNA content. Inhibition of mtDNA replication upon NSC differentiation reduced neurogenesis but not gliogenesis. The mtDNA depletion did not change energy production/consumption or cellular reactive oxygen species (ROS) content in the NSC model used. In conclusion, mtDNA replication is essential for neurogenesis but not gliogenesis in fetal NSCs through as yet unknown mechanisms, which, however, are largely independent of energy/ROS metabolism.

Synthesis and Evaluation of amyloid beta peptide/ Ruthenium III -based complex drugs as drug delivery and anticancer activity

The development and characterization of anticancer complex drugs (ACD), specifically Amyloid Beta Peptide (ABP) - Ruthenium III (Ru III) - nivolumab (NB), were explored through analytical techniques. Fourier-transform infrared (FTIR) spectroscopy demonstrated the structural transformation of peptides from α-helical to β-sheet formations, aligning with amyloid fibril aggregation. Ruthenium (III) complex synthesis was confirmed through distinct absorption peaks in FTIR analysis. High-resolution scanning electron microscopy (HRSEM) revealed the fibrous and smooth morphology of ACD, while thermogravimetric analysis (TGA) confirmed the decomposition stages and stability of the ruthenium complexes. The encapsulation efficiency and in vitro release profile of nivolumab (NB) within ABP-RuIII-NB were investigated, showing a two-phase release over 40h. Cytotoxicity studies using acridine orange and ethidium bromide staining techniques indicated significant apoptosis in human oral squamous cell carcinoma (OSCC) -treated cells. These findings highlight the potential of ABP-RuIII-NB as an effective cancer treatment with controlled drug release and high cytotoxicity against cancer cells.

Antiproliferative and Apoptotic Effects of Solenostemma argel Leaf Extracts on Colon Cancer Cell Line HCT-116

Colorectal cancer ranks as the fourth most frequent cause of cancer-related fatalities on a global scale. The present study aims at assessing the anti-proliferative and apoptotic effects of Solenostemma argel extract on colorectal cancer cells (HCT-116). The antiproliferative activity was investigated using Sulfo-Rhodamine-B (SRB) assay and the apoptotic effects were demonstrated utilizing acridine orange/ ethidium bromide (AO/EB) staining method. The antiproliferative results demonstrated that the extract exhibited dose-dependent antiproliferative activity, with an IC50 value of 85.3 μg/ml. The apoptosis results clearly demonstrated the ability of the methanolic extract of Solenostemma argel in inducing apoptosis in HCT-116 cancer cells. In conclusion, the investigation highlights the considerable antiproliferative and apoptotic impacts of Solenostemma argel leaf extract on HCT-116 colorectal cancer cells. This underscores its potential as a promising chemopreventive agent specifically targeting HCT-116 colon cancer cells.

Nucleic acid binding affinity and antioxidant activity of N-m-Tolyl-4-Chlorophenoxyacetohydroxamicacid.

Hydroxamic acids represent a group of weak organic acids, both naturally occurring and synthetically derived, characterized by the general formula RC(= O)N(R'OH). In this study, we investigated the binding behavior of N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) through a combination of techniques including UV-visible spectroscopy, fluorescence emission analysis, viscometry, and computational simulations using AutoDock4 software. Our findings reveal that the mode of binding between the compound and the nucleic acids is consistent with intercalation. Competitive binding experiments demonstrated that the complex competes effectively with ethidium bromide (EB) for binding to ct-DNA/t-RNA, displacing EB from its binding sites. Additionally, the introduction of the compound into the DNA-EB system resulted in a quenching of fluorescence emission peaks. Analysis of absorption spectra indicated a red shift and hypochromic shift when the compound interacted with DNA, further supporting the intercalative binding mode. The calculated binding constant (Kb) value for the compound is 6.62 × 104M-1 and 5.40 × 103M-1 indicating a strong interaction with ct-DNA and t-RNA respectively. We determined the Stern-Volmer constants for ct-DNA and t-RNA as 9.96 × 104M-1 and 8.13 × 105M-1, respectively. The binding free energy values for ct-DNA/t-RNA were calculated to be -3.741 × 107 and -5.425 × 108kcal/mol, respectively. Viscometric studies corroborated the UV results, showing a continuous increase in relative viscosity of ct-DNA/t-RNA solutions with the addition of the optimal hydroxamic acid concentration. Furthermore, we assessed the antioxidant activity of the compound using DPPH-radical scavenging and β-carotene linoleic acid assays. Gel electrophoresis results demonstrated the compound's remarkable efficacy in preventing DNA damage. Collectively, all experimental evidence supports the conclusion that N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid binds to ct-DNA/t-RNA through an intercalative mechanism, which is consistent with our molecular docking simulations.

Copper(II) and Zinc(II) complexes of new water-soluble Schiff base ligands and their antiproliferative properties towards mesothelioma cell line

In this work, three Schiff base ligands (HL1-HL3) containing a triphenyl phosphonium cation and their Cu(II) and Zn(II) complexes with the general formulae of [M(L)Cl2] were synthesized and their structures were characterized by spectroscopic and analytical methods. Crystal structure of complex [Zn(L1)Cl2] was determined. In the structure of the complex, each Zn(II) ion is four coordinated binding to phenolate oxygen and imine nitrogen atoms of the ligand L1 and two chloride atoms in approximately tetrahedral geometry. The equilibrium geometry of three Schiff base ligands (HL1-HL3) and their Cu(II) and Zn(II) complexes were calculated using the density functional theory (DFT/B3LYP) method with the 6–31++G(d,p) basis set for the C, H, Cl, N, O, P atoms and LANL2DZ for the I atom. Frontier molecular orbitals (HOMO, LUMO) analyses were conducted for the optimized geometries of the compounds, and chemical reactivity descriptors such as hardness, softness, electrophilicity, and electronegativity were examined. Additionally, the molecular electrostatic potential (MEP) of all compounds was modeled using DFT calculations. These calculations were thoroughly examined, and their implications were discussed. The ligands and their metal complexes were investigated for their DNA binding properties. The compounds showed comparable DNA binding properties to ethidium bromide (EB) and 5-fluorouracyl (5-Fu) with DNA binding constant (Kb) 1.5–6.25 × 105 M−1. The cytotoxic properties of the compounds towards HUVEC and H2452 (mesothelioma cell line) cells were investigated using an MTS assay. The IC50 values determined for HUVEC cells were found to range between 27.28 µg/mL ([Cu(L2)Cl2]) and 273.1 µg/mL ([Zn(L2)Cl2]), while in H2452 cells, they varied from 39.48 µg/mL ([Cu(L2)Cl2]) to 319.3 µg/mL ([Zn(L3)Cl2]). The compounds HL1, HL3, and [Zn(L3)Cl2] exhibited antioxidant activity at the highest concentration (750 µg/mL) only, while [Zn(L1)Cl2], HL2, [Zn(L2)Cl2], [Cu(L2)Cl2], and [Cu(L3)Cl2] showed antioxidant activity at 250 µg/mL.

Dellaglioa Algida Cell-Free Supernatant Inhibits Pseudomonas Fluorescence and Pseudomonas Fragi by Destroying Cell Membranes.

The aim of this study was to examine the components of the cell-free supernatant (CFS) derived from a novel strain of psychrophilic Lactobacillus, Dellaglioa algida, and to further elucidate the impact of this CFS on various cellular processes. Specifically, we sought to understand its effects on the cell membrane, protein and DNA release, protease activity, and metabolites of Pseudomonas fluorescens and Pseudomonas fragi, thereby clarifying the antibacterial mechanism involved. The CFS components were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS), the Coomassie Brilliant Blue method, and the phenol-sulfuric acid method. The inhibitory effect of the CFS on Pseudomonas fluorescens and Pseudomonas fragi was assessed using the ethidium bromide (EB) assay, Oxford cup assay, and ultramicroassay. Additionally, we analyzed the metabolites produced by Pseudomonas fluorescens and Pseudomonas fragi when treated with the CFS. The findings reveal that the CFS of Dellaglioa algida contains 94 volatile components, with protein and sugar concentrations of 32.857 ± 0.9705 mg/mL and 98.250 ± 4.210 mg/L, respectively. The CFS induces varying degrees of damage to the cell membranes of both Pseudomonas fluorescens and Pseudomonas fragi, leading to the release of intracellular proteins and DNA. Furthermore, the CFS reduced the protease activity and metabolic capacity of Pseudomonas fluorescens and Pseudomonas fragi. These results enhance our understanding of the mechanism by which psychrophilic Dellaglioa algida inhibits Pseudomonas fluorescens and Pseudomonas fragi, confirming that its inhibitory effect predominantly occurs through damage to the biological cell membranes of Pseudomonas. Dellaglioa algida is a newly identified cold-adapted inhibitor of Pseudomonas, indicating that its CFS is an effective microbial inhibitor in cold environments. This discovery suggests potential applications in inhibiting the growth and reproduction of Pseudomonas fluorescens and Pseudomonas fragi in food, pharmaceuticals, perfumes, and other chemicals, providing a valuable new reference for industrial preservation.

Confocal image of three oxoaporphine alkaloids in cancer cell lines and their interaction with DNA by multispectroscopic and molecular docking techniques

Dicentrinone (Di), liriodenine (Li) and lysicamine (Ly) are three natural oxoaporphine alkaloids (OAs), which revealed significant biological activity such as anticancer, anti-inflammatory and antimicrobial activities and were considered as potential lead compounds for the development of new clinical chemicals. In the present study, confocal laser scanning fluorescence microscopy observation demonstrated these three natural OAs could traverse inside of the nucleus and get an opportunity to interact with DNA. Their interaction properties with DNA were then investigated simultaneously by two spectral fluorescent probes of ethidium bromide (EB) and methyl green (MG), as well as UV–vis absorption and cyclic voltammetry measurements, and further verified by the molecular docking analysis. Results indicated Di and Li were distinctly classified as the intercalative molecules to DNA, however, Ly was confirmed with a mixed-mode binding of partial intercalation and groove affinity. Their binding ability was revealed as the follows: Di ≥ Li > Ly, which was correlated with their structural changes. Thermodynamic studies revealed the binding process of Li and Ly with ctDNA was all spontaneous, the hydrophobic interaction was the major binding force for Li-ctDNA complex, however, the interaction between Ly and ctDNA relied on both hydrophobic and hydrogen binding force. Molecular docking provided detailed computational interaction of Di, Li and Ly with DNA, which proved the intercalation binding of Li-DNA complex and Di-DNA complex stabilizing mainly by the π-π binding force, however, apart from a small quantity of π-π interaction, another binding force in the Ly-DNA complex mainly was supplied from the weaker Pi-Alkyl, hydrogen bond and Pi-Anion interactions.

Development of Amphotericin B Decorated Gold Nanoparticles as a Promising Antileishmanial Nanoconjugate.

Leishmaniasis, attributed to the protozoan parasite Leishmania, manifests in diverse clinical forms, including cutaneous, mucocutaneous, and visceral leishmaniasis; VL constitutes a significant global health menace. Prevalent in tropical and subtropical regions, this affliction disproportionately impacts individuals below the poverty threshold, transmitted through the bite of female sandflies. Existing treatments, such as pentavalent antimony, miltefosine, and Amphotericin B, exhibit limitations. Despite the emergence of liposomal Amphotericin B (AmBisome) as a promising antileishmanial agent, its utility is impeded by adverse effects, elevated production expenses, and cytotoxicity. To address these challenges, our investigation introduces a potential remedy─a citrate-coated gold Amphotericin B nanoparticle formulation. Characterized using dynamic light scattering and transmission electron microscopy, this pioneering formulation exhibited efficacy against L. donovani Ag83 promastigotes as demonstrated by MTT cell viability testing. Evaluating internal reactive oxygen species (ROS) levels and dual staining with acridine orange and ethidium bromide unveiled its consequential impact on cell death. Significantly, our study discloses this novel nanoformulation's unprecedented inhibition of the trypanothione reductase enzyme. The findings posit the citrate-coated gold Amphotericin B nanoformulation as a promising and targeted antileishmanial agent, representing potential advancements in leishmaniasis therapeutics.

Targeted Gene Delivery to Muscle Cells In Vitro and In Vivo Using Electrostatically Stabilized DNA—Peptide Complexes

Genetic constructs must be delivered selectively to target tissues and intracellular compartments at the necessary concentrations in order to achieve the maximum therapeutic effect in gene therapy. Development of targeted carriers for non-viral delivery of nucleic acids into cells, including those in muscle, which is one of the most challenging tissues to transfect in vivo, remains a topical issue. We have studied ternary complexes of plasmid DNA and an arginine–histidine-rich peptide-based carrier coated with a glutamate–histidine-rich polymer bearing skeletal muscle targeting peptide (SMTP) for the gene delivery to muscle tissue. The relaxation of the ternary complexes after polyanion treatment was assessed using the ethidium bromide displacement assay. The developed polyplexes were used to transfect C2C12 myoblasts in full-media conditions, followed by analysis of their toxic properties using the Alamar Blue assay and expression analysis of lacZ and GFP reporter genes. After delivering plasmids containing the GFP and lacZ genes into the femoral muscles of mdx mice, which are model of Duchenne muscular dystrophy, GFP fluorescence and β-galactosidase activity were detected. We observed that the modification of ternary polyplexes with 10 mol% of SMTP ligand resulted in a 2.3-fold increase in lacZ gene expression when compared to unmodified control polyplexes in vivo. Thus, we have demonstrated that the developed DNA/carrier complexes and SMTP-modified coating are nontoxic, are stable against polyanion-induced relaxation, and can provide targeted gene delivery to muscle cells and tissues. The results of this study are useful for a range of therapeutic applications, from immunization to amelioration of inherited neuromuscular diseases.

One-Pot, Multi-Component Green Microwave-Assisted Synthesis of Bridgehead Bicyclo[4.4.0]boron Heterocycles and DNA Affinity Studies.

Anthranilic acids, salicylaldehydes and arylboronic acids reacted in EtOH/H2O (1/3) at 150 °C under microwave irradiation for 1 h to give, in excellent yields and purity, twenty-three bridgehead bicyclo[4.4.0]boron heterocycles via one-pot, three-component green synthesis. The scope and the limitations of the reactions are discussed in terms of the substitution of ten different anthranilic acids, three salicylaldehydes and three arylboronic acids. The replacement of salicylaldehyde with o-hydroxyacetophenone demanded a lipophilic solvent for the reaction to occur. Eight novel derivatives were isolated following crystallization in a toluene-containing mixture that included molecular sieves. The above one-pot, three-component reactions were completed under microwave irradiation at 180 °C within 1.5 h, thus avoiding the conventional prolonged heating reaction times and the use of a Dean-Stark apparatus. All derivatives were studied for their affinity to calf thymus DNA using proper techniques like viscosity and UV-vis spectroscopy, where DNA-binding constants were found in the range 2.83 × 104-8.41 × 106 M-1. Ethidium bromide replacement studies using fluorescence spectroscopy indicated Stern-Volmer constants between 1.49 × 104 and 5.36 × 104 M-1, whereas the corresponding quenching constants were calculated to be between 6.46 × 1011 and 2.33 × 1012 M-1 s-1. All the above initial experiments show that these compounds may have possible medical applications for DNA-related diseases.