Search

Staphylococcus aureus is known to be a human pathogen and is often resistant to antibiotics, so there is a demand for new treatment alternatives that have the ability to reverse such resistance. The present study aimed to evaluate the antibacterial action and reversal of the efflux pump activity of the compounds Isopulegol (ISO) and its β-cyclodextrin inclusion complex (ISO/β-CD) in S. aureus strains carrying an efflux pump. (MsrA, TetK, NorA and MepA). The complex was obtained using the paste complexation method. The minimum inhibitory concentration (MIC) of ISO and ISO/β-CD was determined for the evaluation of antibacterial activity against multiresistant strains of S. aureus (RN4220, IS-58, 1199, 1199B and K2068) and the compounds showed a minimum inhibitory concentration (MIC) ≥ 1024 μg/mL. Modulation assays were performed using ISO and ISO/β-CD, which associated with antibiotics and Ethidium Bromide (EtBr) showed synergism and MIC reduction in some of the tested bacteria. Therefore, it can be concluded that the isolated compounds ISO and ISO/β-CD are effective in inhibiting the efflux pump mechanism against some of the tested strains; with modulation, only strains IS-58, SA 1199 and K2068 showed a MIC decrease effect, while all strains showed a reduction in MIC with ethidium bromide. [ABSTRACT FROM AUTHOR]

The excitation-dependent emission properties of carbon dots (Cdots) are extensively reported, but their red emission is often weak, limiting their wider application. Here we introduce ethidium bromide, as a functional precursor with red emission, to enhance the red emission for Cdots, with comparable intensity at a broad wavelength range to multi-emission Cdots (M-Cdots). We found that Cdots prepared with ethidium bromide/ethylenediamine exhibited strong blue and red emission at 440 and 615 nm, with optimal excitation at 360 and 470 nm as M-Cdots, respectively, but the Cdots from single ethidium bromide (EB-Cdots) possessed weak red emission. M-Cdots exhibited a broad absorption band at 478 nm, but a band blue-shifted to 425 nm was observed for EB-Cdots, while no absorption was observed at 478–425 nm for the Cdots prepared with citric acid and ethylenediamine. Thus, we proposed that C=O and C=N formed a π-conjugation structure as the absorption band at 478 nm for the red emission of M-Cdots, as also confirmed with the excitation at 470 nm. Moreover, the π-conjugation structure is fragile and sensitive to harsh conditions, so red emission was difficult to observe for the Cdots prepared with citric acid/ethylenediamine or single ethidium bromide. M-Cdots possess two centers for blue and red emission with different structures. The dual emission was therefore used for ratiometric sensing with dichromate (Cr2O72−) and formaldehyde (HCHO) as the targets using the intensity ratio of the emissions at 615 and 440 nm. Due to the comparable intensity at a broad wavelength range, we designed encryption codes with five excitations at 360, 400, 420, 450, and 470 nm as the inputs, and the emission colors were used for information decoding. Thus, we determined why red emission was difficult to realize for Cdots, and our results could motivate the design of red-emission Cdots for extensive applications. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effects of time, temperature, and burial in a natural environment on the viability of chondrocytes in porcine femoral condyles using confocal laser scanning microscopy. Hind trotters from 10 pigs were buried or left unburied. Samples were collected daily and stained with a combination of vital dyes (calcein-AM and ethidium homodimer-1). The chondrocytes showed an intense staining corresponding to their vitality. In the first 3 days, viability decreased slowly and showed no statistical difference between buried and unburied samples. After the first 3 days, it decreased rapidly, with the viability of the buried samples being 66% on day 4, decreasing to 25% on day 8 and to 16% on day 10, while in the unburied samples it decreased to 43% on day 4, 13% on day 8 and 5% on day 10. Our results indicate a time, temperature, and burial dependent decrease in chondrocyte viability and suggest the use of chondrocyte viability as a marker for estimating PMI in both the natural environment and in animals, as well as its potential use in humans. [ABSTRACT FROM AUTHOR]

Ethidium Bromide (EtBr) serves as an interpolating agent utilized for its fluorescent properties in gel electrophoresis, aiding in the detection of various DNA fragments. However, its usage has been associated with DNA mutations, inhibition of mitochondrial protein synthesis and other alterations, particularly at high concentrations. Due to its remarkable stability in the environment and propensity to degrade into mutagenic compounds, especially when exposed to bleaching agents, there are significant concerns regarding its widespread use. Given the potential toxic and mutagenic effects of EtBr and the possibility of its entry into the food chain, it becomes crucial to monitor its concentration at emission sources across different ecosystems, including aquatic, terrestrial, and plant environments. Improper disposal of EtBr poses substantial risks, including the induction of mutations and cancer. Various disposal methods have been explored, such as phytoremediation and employing bacteria capable of degrading this chemical. Proper management of EtBr disposal is paramount to mitigate its harmful impact on the environment and living organisms. [ABSTRACT FROM AUTHOR]

The interaction of methylene blue (MB) and ethidium bromide (EB) intercalators with synthetic single-strand (ss) polynucleotides poly(rA) and poly(rU) and the double-strand (ds) poly(rA)–poly(rU) formed as a result of their hybridization was investigated in 0.04 mole solution in the range of phosphate/ligand ratios r = 0 ≤ r ≤ 10. The absorption spectra of complexes of the ligands with the polynucleotides were obtained, and adsorption isotherms in Scatchard coordinates were constructed on the basis of changes in the absorption spectra. It was found that MB interacts cooperatively with poly(rA) and also with ds-poly(rA)–poly(rU), while cooperation is not detected in the case of poly(rU). There is also no cooperation in the interaction of EB with ss- and ds-polynucleotides. The binding parameters for the interaction of these ligands with the polynucleotides (the association constants K and the number of bases n per binding site and also the cooperation factor) in the interaction of MS with poly(rA) and ds-poly(rA)- poly(rU) were determined from the adsorption isotherms. Both ligands were found to bind to polynucleotides by at least two methods, and MB here exhibits much higher affinity to poly(rA) and EB to ds-poly(rA)-poly(rU). [ABSTRACT FROM AUTHOR]

In this work, a novel chromatin-loaded chitosan polyvinyl alcohol composite was developed as a simple, efficient and environmentally friendly adsorbent for the efficient removal of ethidium bromide (EtBr). SEM images showed that the composites were characterized by dense porous and uniformly distributed morphology. The BET analysis showed the presence of mesopores and macropores in the composites. FTIR and XRD results showed that the chromatin was uniformly dispersed in the chitosan-polyvinyl alcohol carrier through hydrogen bonding. The fluorescence microscopy images showed the change of fluorescence effect before and after the adsorption of the material, which indicated that the chromatin was uniformly distributed in the composites and had a good adsorption effect. The optimal experimental conditions were T = 30℃, t = 120 min, pH = 7.4, m = 0.2 g when the composite with only 5% chromatin content had the ability to adsorb EtBr efficiently (minimum concentration 2 mg·L−1: adsorption rate 99%; maximum concentration 20 mg·L−1: adsorption rate 90%).The adsorption kinetics and thermodynamics showed that the EtBr adsorption kinetics of the composite conformed to the pseudo-second-order kinetic model (0.995 < R2 < 0.999) and the Freundlich isothermal model, and was a spontaneous process (ΔH < 0). This study on the immobilization of chromatin will provide a new way and reference for the application of chromatin in the treatment of EtBr pollutants. [ABSTRACT FROM AUTHOR]

Valencene and nootkatone are aromatic sesquiterpenes with known biological activities, such as antimicrobial, antioxidant, anti-inflammatory, and antitumor. Given the evidence that encapsulation into nanosystems, such as liposomes, could improve the properties of several compounds, the present study aimed to evaluate the activity of these sesquiterpenes in their isolated state or in liposomal formulations against strains of Staphylococcus aureus carrying efflux pumps. The broth microdilution method evaluated the antibiotic-enhancing activity associated with antibiotics and ethidium bromide (EtBr). The minimum inhibitory concentration was assessed in strains of S. aureus 1199B, IS-58, and RN4220, which carry the efflux proteins NorA, Tet(K), and MsrA. In tests with strain 1199B, valencene reduced the MIC of norfloxacin and EtBr by 50%, while the liposomal formulation of this compound did not show a significant effect. Regarding the strain IS-58, valencene, and its nanoformulation reduced norfloxacin MIC by 60.3% and 50%, respectively. In the non-liposomal form, the sesquiterpene reduced the MIC of EtBr by 90%. Against the RN4220 strain, valencene reduced the MIC of the antibiotic and EtBr by 99% and 93.7%, respectively. Nootkatone and its nanoformulation showed significant activity against the 1199B strain, reducing the EtBr MIC by 21.9%. Against the IS-58 strain, isolated nootkatone reduced the EtBr MIC by 20%. The results indicate that valencene and nootkatone potentiate the action of antibiotics and efflux inhibitors in strains carrying NorA, Tet(K), and MsrA proteins, which suggests that these sesquiterpenes act as efflux pump inhibitors in S. aureus. Therefore, further studies are needed to assess the impact of incorporation into liposomes on the activity of these compounds in vivo. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus can exhibit resistance to various antibiotics. Among its resistance mechanisms, the active efflux of antibiotics can be seen as relevant. This study aimed to evaluate the ability of resveratrol to modulate norfloxacin resistance in S. aureus. The antimicrobial activity of resveratrol was assessed using the broth microdilution method to determine the minimum inhibitory concentration (MIC). Then, the modulatory effect of resveratrol was evaluated using the MIC determination for the antibiotic or ethidium bromide in the presence and absence of resveratrol at a sub-MIC level. The MIC of norfloxacin against S. aureus SA1199B (NorA-overexpressing strain) decreased 16-fold when in the presence of resveratrol, with a similar behavior being observed for ethidium bromide. An evaluation of the ethidium bromide accumulation was also performed, showing that in the presence of resveratrol, the SA1199B strain had augmented fluorescence due to the accumulation of ethidium bromide. Altogether, the results suggested that resveratrol may act by inhibiting NorA. These in vitro data were supported by docking results, with interactions between resveratrol and the NorA efflux pump predicted to be favorable. Our findings demonstrated that resveratrol may modulate norfloxacin resistance through the inhibition of NorA, increasing the effectiveness of this antibiotic against S. aureus. [ABSTRACT FROM AUTHOR]

Brazilian flora are highly diverse and have great potential for research into new medicines of plant origin. Platonia insignis Mart. is a fruit tree from the Amazon region with several potential pharmacological applications already demonstrated. The present study aimed to investigate the protective effect of a mixture of the biflavones volkensiflavone and moreloflavone obtained from P. insignis flowers against the lethality induced by ethidium bromide in efflux pump overproducer strains of Staphylococcus aureus. Microdilution tests were performed to determine the minimum inhibitory concentration of ethidium bromide in the absence or presence of biflavones. The addition of biflavones to the growth medium increased the minimum inhibitory concentration of ethidium bromide against all strains tested, indicating that biflavones protected the bacterial cells against cell damage induced by this biocide agent. Comparative analysis of the infrared absorption spectra of each isolated compound, as well as of the associated compounds, demonstrated the complexation reaction, indicating that there was a preferential interaction between the H2N- groups of primary amines of ethidium bromide with the carbonyls of biflavones that formed imines -C=NH. Such complexation could reduce the amount of free ethidium bromide molecules available for DNA intercalation, resulting in the observed protective effect. These results suggest a possible technological application of the biflavones from P. insignis as protective agents against cell damage induced by ethidium bromide. [ABSTRACT FROM AUTHOR]

The bacterial species Staphylococcus aureus presents a variety of resistance mechanisms, among which the expression of β-lactamases and efflux pumps stand out for providing a significant degree of resistance to clinically relevant antibiotics. The 1,8-naphthyridines are nitrogen heterocycles with a broad spectrum of biological activities and, as such, are promising research targets. However, the potential roles of these compounds on bacterial resistance management remain to be better investigated. Therefore, the present study evaluated the antibacterial activity of 1,8-naphthyridine sulfonamides, addressing their ability to act as inhibitors of β-lactamases and efflux pump (QacA/B and QacC) against the strains SA-K4414 and SA-K4100 of S. aureus. All substances were prepared at an initial concentration of 1024 μg/mL, and their minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. Subsequently, their effects on β-lactamase- and efflux pump-mediated antibiotic resistance was evaluated from the reduction of the MIC of ethidium bromide (EtBr) and β-lactam antibiotics, respectively. The 1,8-naphthyridines did not present direct antibacterial activity against the strains SA-K4414 and SA-K4100 of S. aureus. On the other hand, when associated with antibiotics against both strains, the compounds reduced the MIC of EtBr and β-lactam antibiotics, suggesting that they may act by inhibiting β-lactamases and efflux pumps such as QacC and QacA/B. However, further research is required to elucidate the molecular mechanisms underlying these observed effects. [ABSTRACT FROM AUTHOR]

Chalcones are present in a wide variety of plants, having in their structure two aromatic rings that are linked together by a chain composed of three carbon atoms with α, β‐unsaturated to carbonyl system. Bacteria have several drug resistance mechanisms, among them the efflux pump; this mechanism, when active, is able to expel different compounds from inside bacterial cells. Several efflux pumps have already been identified for Staphylococcus aureus bacteria, including MepA and NorA. Many chalcones have been isolated and identified with various activities, such as antimicrobial. In view of this, this article aimed to evaluate the antibiotic modifying effect of chalcone (E)‐1‐(2‐hydroxyphenyl)‐3‐(3‐nitrophenyl)prop‐2‐en‐1‐one against S. aureus carrier of NorA and MepA efflux pump. Regarding the antibiotic, there was a synergism when associated with ciprofloxacin in SA‐K2068 strain, showing this chalcone as an alternative to reverse the resistance to this medicine. The physicochemical properties calculated were fundamental in the description of the predicted pharmacokinetic properties. Despite the mutagenic risk caused by the metabolic activation of nitrochalcone, it is possible to notice a pharmacological principle in a longer half‐life for the performance of biological activities. The compound has a good bioavailability, as it is highly absorbed in the intestine and easily transported by plasma proteins, in addition to not presenting neurotoxic, hepatotoxic, and cardiotoxic damage. [ABSTRACT FROM AUTHOR]

Due to being low cost and eco-friendly, biological nanomaterial synthesis and development have made broad spectral progress. This study aimed to optimize the phytomediated synthesis of catalytically active, antibacterial palladium nanoparticles (PdNPs) for adsorption-based removal of ethidium bromide (EtBr) from an aqueous solution. Optimization of synthesis demonstrated that a precursor to extract ratio of 4:1, pH 3, and incubation at 80 °C for 60 min were the optimum conditions that led to the synthesis of negatively charged, highly stable, polycrystalline, spherical, and monodispersed PdNPs of 5–10 nm. When tested as catalysts, PdNPs successfully catalyzed Suzuki–Miyaura cross-coupling between aryl halides and arylboronic acids resulting in the synthesis of 4-acetylbiphenyl. Furthermore, the antibacterial activity test demonstrated that biogenic PdNPs were most effective and potent against Staphylococcus aureus and Proteus vulgaris followed by Escherichia coli, Bacillus subtilis, and Bacillus cereus. In addition, PdNPs were found as an excellent adsorbent for adsorption of EtBr from water as the adsorption reaction obeyed pseudo-second-order kinetics with a linear regression coefficient (R2 > 0.995). The adsorption reaction fitted well with the Freundlich and Temkin isotherm models, indicating multi-layer adsorption. Estimating thermodynamic parameters resulted in a positive value of ΔH0 and ΔG0, demonstrating adsorption was non-spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

Ethidium bromide (EtBr) is a chemical agent commonly used to identify and visualize the bonding of DNA and RNA in molecular biology research. However, ethidium bromide itself is mutagenic and toxic. Ethidium bromide also has carcinogenic properties to human cells, teratogenic, and difficult to decompose. Therefore, a research for the treatment of EtBr waste is very important. There are several materials that can be used to reduce EtBr waste, but there is also needed a material which is cheap and widely available in the market. One of the methods to treat ethidium bromide waste is using activated charcoal. Activated charcoal has strong adsorption capacity due to its high surface area and porous structure. Another advantage of activated charcoal as an adsorbent is economical, effective, and environmentally friendly. In this study, EtBr waste was mixed with activated charcoal then homogenized for one hour. The mixing of EtBr waste (0.5 mg/mL concentration of EtBr) and activated charcoal was varied with a ratios weight by volume of 1:1, 1:2, and 2:1. The mixture of the solution was filtered using Whatmann filter paper No.1 to take the filtrate. The filtrate was further analyzed. The more activated charcoal was added, the more EtBr molecules were adsorbed. The pH in the filtration results for each variation was pH 7.0 - 8.0, dissolved oxygen with range 5.0 - 9.0 mg/L, biochemical oxygen demand (BOD) with range 25.06 - 78.2 mg/L, and chemical oxygen demand (COD) with range 302.56 - 310.98 mg/L. The concentration range was obtained as follows, for a 1:1 ratio of 0.045 - 0.060 mg/mL, for a 1:2 ratio of 0.028 - 0.032 mg/mL, while a 2:1 ratio of 0.081 - 0.090 mg/mL. In addition, the results showed that activated charcoal was able to bind Ethidium bromide due to bond interactions that occur between the EtBr molecule and activated charcoal. [ABSTRACT FROM AUTHOR]

The distance between nodes of Ranvier, referred to as internode length, positively correlates with axon diameter, and is optimized during development to ensure maximal neuronal conduction velocity. Following myelin loss, internode length is reestablished through remyelination. However, remyelination results in short internode lengths and reduced conduction rates. We analyzed the potential role of neurofilament phosphorylation in regulating internode length during remyelination and myelination. Following ethidium bromide induced demyelination, levels of neurofilament medium (NF-M) and heavy (NF-H) phosphorylation were unaffected. Preventing NF-M lysine-serine-proline (KSP) repeat phosphorylation increased internode length by 30% after remyelination. To further analyze the role of NF-M phosphorylation in regulating internode length, gene replacement was used to produce mice in which all KSP serine residues were replaced with glutamate to mimic constitutive phosphorylation. Mimicking constitutive KSP phosphorylation reduced internode length by 16% during myelination and motor nerve conduction velocity by ~27% without altering sensory nerve structure or function. Our results suggest that NF-M KSP phosphorylation is part of a cooperative mechanism between axons and Schwann cells that together determine internode length, and suggest motor and sensory axons utilize different mechanisms to establish internode length.

Chemotherapy-inhibiting tumor cell evolution to drug-resistance is potentially suppressed by using a drug delivery vehicle (DDV) that has gating. Gating would be used to increase tumor-selectivity of delivery of DDV packaged drug. Tumor-selectivity increase would make possible increase in tumor-delivered drug dose, which would suppress opportunities to evolve drug resistance. Currently used DDVs do not have gating but gating is a natural feature of some bacteriophages (phages). Phage T4, which has recently been found highly persistent in murine blood, is a potential gated DDV. Thus, here, we proceed towards a T4-DDV by developing (1) improved procedure for generating high concentrations and amounts of phage T4, (2) elevated temperature-driven gate-opening and ethidium- and bleomycin-loading, and (3) purification of loaded T4 by rate zonal centrifugation. We test for loading by native agarose gel electrophoresis (AGE) with fluorescence detection. We observe loading in both phage T4 and T4 (tail-free) heads. The loaded particles have an openable, closed gate. Stored, mature T4 phages and phage heads do not release ethidium during at least a month at 4 °C and 6 days at 37 and 42 °C. Tumor-specific T4 phage delivery is projected via both the EPR effect and high T4 persistence. [ABSTRACT FROM AUTHOR]

With the recent stringent criteria for antibiotic susceptibility in probiotics, the presence of antibiotic resistance genes and plasmids associated with their transfer has become a limiting factor in the approval of probiotics. The need to remove genes related to antibiotic resistance and virulence through plasmid curing for the authorization of probiotics is increasing. In this study, we investigated the curing efficiency of ethidium bromide, acridine orange, and novobiocin at different concentrations and durations in five strains of plasmid-bearing lactic acid bacteria and examined the curing characteristics in each strain. Limosibacillus reuteri and Lacticaseibacillus paracasei exhibited curing efficiencies ranging from 5% to 44% following treatment with ethidium bromide (10-50 μg/ml) for 24-72 h, while Lactobacillus gasseri showed the highest efficiency at 14% following treatment with 10 μg/ml novobiocin for 24 h. Lactiplantibacillus plantarum , which harbors two or more plasmids, demonstrated curing efficiencies ranging from 1% to 8% after an additional 72-h treatment of partially cured strains with 10 μg/ml novobiocin. Plasmid curing in strains with larger plasmids exhibited lower efficiencies and required longer durations. In strains harboring two or more plasmids, a relatively low curing efficiency with a single treatment and a high frequency of false positives, wherein recovery occurred after curing, were observed. Although certain strains exhibited altered susceptibilities to specific antibiotics after curing, these outcomes could not be attributed to the loss of antibiotic resistance genes. Furthermore, the genomic data from the cured strains revealed minimal changes throughout the genome that did not lead to gene mutations.

Multiple sclerosis (MS) is a chronic neurodegenerative disease marked by oligodendrocyte loss, which results in central neuronal demyelination. AC/cAMP/CREB signaling dysregulation is involved in the progression of MS, including mitochondrial dysfunctions, reduction in nerve growth factors, neuronal inflammation, apoptosis, and white matter degeneration. Our previous research has shown that Forskolin (FSK), a naturally occurring direct adenylyl cyclase (AC)/cAMP/CREB activator, has neuroprotective potential to alleviate pathogenic factors linked with numerous neurological abnormalities. The current study intends to explore the neuroprotective potential of FSK at doses of 40 mg/kg and 60 mg/kg alone, as well as in combination with conventional medicines, such as Fingolimod (FNG), Donepezil (DON), Memantine (MEM), and Simvastatin (SIM) in EB-induced demyelinated experimental MS rats. Adult Wistar rats were divided into nine groups, and EB was infused stereotaxically in the rat brain's intracerebropeduncle (ICP) area. Chronic gliotoxin EB treatment results in demyelination as well as motor and cognitive dysfunctions. FSK, combined with standard medications, improves behavioral dysfunctions, such as neuromuscular and motor deficits and memory and cognitive abnormalities. Following pharmacological treatments improved remyelination by enhancing myelin basic protein and increasing AC, cAMP, and CREB levels in brain homogenates. Furthermore, FSK therapy restored brain mitochondrial-ETC complex enzymes and neurotransmitter levels while decreasing inflammatory cytokines and oxidative stress markers. The Luxol fast blue (LFB) stain results further indicate FSK's neuroprotective potential in preventing oligodendrocyte death. Therefore, the results of these studies contribute to a better understanding of the possible role that natural phytochemicals FSK could have in preventing motor neuron diseases, such as multiple sclerosis. [ABSTRACT FROM AUTHOR]

Copyright of Proceedings of the YSU B: Chemical & Biological Sciences / Gitakan Teghekagir. K'imia, Kensabanut'yun is the property of Publishing House of Yerevan State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

DNA strand displacement is a technique to exchange one strand of a double stranded DNA by another strand (invader). It is an isothermal, enzyme free method driven by single stranded overhangs (toeholds) and is employed in DNA amplification, mismatch detection and nanotechnology. We discovered that anomeric (α/β) DNA can be used for heterochiral strand displacement. Homochiral DNA in β‐D configuration was transformed to heterochiral DNA in α‐D/β‐D configuration and further to homochiral DNA with both strands in α‐D configuration. Single stranded α‐D DNA acts as invader. Herein, new anomeric displacement systems with and without toeholds were designed. Due to their resistance against enzymatic degradation, the systems are applicable to living cells. The light‐up intercalator ethidium bromide is used as fluorescence sensor to follow the progress of displacement. Anomeric DNA displacement shows benefits over canonical DNA in view of toehold free displacement and simple detection by ethidium bromide. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a severe immune-mediated neurological disease characterized by neuroinflammation, demyelination, and axonal degeneration in the central nervous system (CNS). This is frequently linked to motor abnormalities and cognitive impairments. The pathophysiological hallmarks of MS include inflammatory demyelination, axonal injury, white matter degeneration, and the development of CNS lesions that result in severe neuronal degeneration. Several studies suggested downregulation of nuclear factor erythroid-2-related factor-2 (Nrf2)/Heme oxygenase-1 (HO-1) signaling is a causative factor for MS pathogenesis. Acetyl-11-keto-β-boswellic acid (AKBA) is an active pentacyclictriterpenoid obtained from Boswellia serrata, possessing antioxidant and anti-inflammatory properties. The present study explores the protective potential of AKBA on behavioral, molecular, neurochemical, and gross pathological abnormalitiesandhistopathological alterations by H&E and LFB staining techniques in an experimental model of multiple sclerosis, emphasizing the increase inNrf2/HO-1 levels in the brain. Moreover, we also examine the effect of AKBA on the intensity of myelin basic protein (MBP) in CSF and rat brain homogenate. Specific apoptotic markers (Bcl-2, Bax, andcaspase-3) were also estimated in rat brain homogenate. Neuro behavioralabnormalities in rats were examined using an actophotometer, rotarod test, beam crossing task (BCT),and Morris water maze (MWM). AKBA 50 mg/kg and 100 mg/kg were given orally from day 8 to 35 to alleviate MS symptoms in the EB-injected rats. Furthermore, cellular, molecular, neurotransmitter, neuroinflammatory cytokine, and oxidative stress markers in rat whole brain homogenate, blood plasma, and cerebral spinal fluid were investigated. This study shows that AKBA upregulates the level of antioxidant proteins such as Nrf2 and HO-1 in the rat brain. AKBA restores altered neurochemical levels, potentially preventing gross pathological abnormalities during MS progression. [ABSTRACT FROM AUTHOR]

The efficient removal of Ethidium Bromide (EB), a toxic yet widely used chemical in biochemical industries and laboratories, is crucial to avoid its detrimental effect on human health, aquatic life, and the environment. One effective method is adsorption onto inert surfaces, but the choice of adsorbents is critical for the success of the removal protocols, primarily because of the limitations such as low adsorption capacity, high cost, limited availability, and a lack of understanding of the adsorption mechanism. In this work, Pyrophyllite Nanoclay (PNC), a naturally abundant aluminosilicate is explored as a promising adsorbent for EB. The adsorption process follows the Freundlich isotherm and displays pseudo-second-order kinetics. Under the optimized condition, PNC demonstrates nearly quantitative adsorption of EB and the maximum adsorption efficiency obtained from experiment was 6.53 mg/g (0.017 mmol/g) at room temperature under optimized condition. Through thermodynamic, kinetic analysis coupled with characterization techniques, the mechanism of adsorption is proposed. The adsorbent proves to be reusable, maintaining its performance over three cycles. The utility of the process is further validated and optimized using Response Surface Methodology (RSM). The present work focuses on the performance of PNC as adsorbent and elucidates distinctive surface adsorption mechanism (in comparison to other nanoclays), thus emphasizing the significance of structural, experimental, mechanistic and validation studies in choosing the right adsorbent for the removal toxic chemicals. [Display omitted] • Adsorption of Ethidium bromide on Pyrophyllite nanoclay (PNC) is investigated for the first time. • Kinetic and thermodynamic studies supported by characterization techniques reveal surface adsorption mechanism. • PNC is recyclable for at least three times. • Response Surface Methodology (RSM) optimization is conducted to validate the process. [ABSTRACT FROM AUTHOR]

In the present paper, an optimized method to extract common carp sperm DNA (csDNA) from common carp testis, the mechanism of ethidium bromide (EtBr) interaction with csDNA, as well as the removal of EtBr pollutant by csDNA was studied. The results showed that high salt extraction method was suitable for extracting csDNA. Under the optimum conditions, the yield of csDNA extraction was as high as 11.7%. In addition, the results of UV–vis spectra, fluorescence spectra, and observation with fluorescence microscope indicated that csDNA could be intercalated by EtBr to form a stable complex, which confirmed that csDNA could be applied in removing EtBr pollutant. Based on the csDNA intercalation, EtBr pollutant was removed by csDNA effectively, which was 94.13%. This work not only provides a smart method to extract high purity and quality csDNA from byproducts of common carp testis but also provides an easily available csDNA to remove EtBr from pollutants. [ABSTRACT FROM AUTHOR]

Bitter leaf (Vernonia amygdalina Del.) plant is a tree species that is highly cultivated in Nigeria for its nutritive and therapeutic values. This study aimed to determine the antioxidant and antigenotoxicity effects (in vitro) of 52 accessions of V. amygdalina collected from six geopolitical zones of Nigeria (North East, North West, North Central, South South, East and West) by evaluating the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO- ) scavenging antioxidant activities, flavonoid and phenolic contents as well as ethidium bromide-induced DNA (deoxyribonucleic acid) damage of bitter leaf. The results showed that accessions MN628016 (Oshimili South, Delta State) and MN628010 (Akoko Edo, Edo State), respectively had higher amounts of flavonoid (287.19 mg/g/FW) and phenolic (307.90 mg/g/FW) contents. The accessions MN627984 (Ikpoba Okha, Edo State) and MN627975 (Owerri, Imo State) had the highest nitric oxide (85.73%) and DPPH radical scavenging inhibitory effect (98.92%). The highest percentage fragmented DNA (45.05%), was observed in Allium cepa roots homogenised and mixed with ethidium bromide followed by the A. cepa roots homogenised and mixed with the leaf extract of V. amygdalina accession MN627977 (36.12%). However, V. amygdalina accessions MN628008 (457.62%, Warri North, Delta State) had the highest percentage increase of fragmented DNA followed by MN628024 (395.04%, Oshimili North, Delta State), MN628015 (345.54%; Aniocha North, Delta State) and MN627984 (342.04%; Ikpoba Okha, Edo State) while accession MN628010 (7.32%; Akoko Edo, Edo State) had the lowest. Accession MN628010 which possessed the highest amount of phenolic content had the lowest percentage increase of fragmented DNA and accession MN627984 which possessed the highest nitric oxide radical scavenging inhibitory effect was among the accessions with the highest percentage increase of fragmented DNA. The findings of this study suggest that the observed lowest percentage of fragmented DNA of A. cepa roots growth induced with the solution of ethidium bromide and treated with V. amygdalina accessions MN628010 extracts (antigenotoxic) could be as a result of the high antioxidant activities in the V. amygdalina accessions. In summary, the findings of this study showed that the 52 V. amygdalina accessions obtained from different locations of Nigeria will help to combat ethidium bromide induced genoxicities and any other genotoxicant that may lead to different complications in plant (A. cepa roots), as all the accessions possessed antioxidant and antigenotoxic properties, as such, possessed comparable amount of natural antioxidant activities and antigenotoxicity. [ABSTRACT FROM AUTHOR]

Ethidium bromide, which is commonly applied in molecular biological applications, is a mutagenic agent demanding proper treatment. In the present study, the magnetic fraction of fly ash, prepared from the ASTM class F material, was used as a catalyst for a heterogeneous Fenton process for degrading ethidium bromide in aqueous solution. The dosage of the catalyst, the initial pH of the solution, and the initial concentration of hydrogen peroxide significantly influenced the ethidium bromide removal rate. Under optimum conditions (2 mmol/L hydrogen peroxide and 100 g/L of the magnetic fraction of fly ash at pH 3), an ethidium bromide degradation efficiency of 98% was obtained within 4 h. The magnetic fraction of fly ash retained over 95% of its maximal ethidium bromide removal ability after three successive cycles. The heterogeneous Fenton process using the magnetic fraction of fly ash as a catalyst is robust and reusable. Therefore, the approach developed in this study may be an alternative cost-efficient heterogeneous Fenton catalyst for the removal of ethidium bromide from aqueous solution. [ABSTRACT FROM AUTHOR]

Lysophosphatidic acid (LPA) signaling via LPA receptors (LPA1 to LPA6) exhibits a variety of malignant properties in cancer cells. Intracellular ATP depletion leads to the development of necrosis and apoptosis. The present study aimed to evaluate the effects of LPA receptor-mediated signaling on the regulation of cancer cell functions associated with ATP reduction. Long-term ethidium bromide (EtBr) treated (MG63-EtBr) cells were established from osteosarcoma MG-63 cells. The intracellular ATP levels of MG63-EtBr cells were significantly lower than that of MG-63 cells. LPAR2, LPAR3, LPAR4 and LPAR6 gene expressions were elevated in MG63-EtBr cells. The cell motile and invasive activities of MG63-EtBr cells were markedly higher than those of MG-63 cells. The cell motile activity of MG-63 cells was increased by LPA4 and LPA6 knockdowns. In cell survival assay, cells were treated with cisplatin (CDDP) every 24 h for 3 days. The cell survival to CDDP of MG63-EtBr cells was lower than that of MG-63 cells. LPA2 knockdown decreased the cell survival to CDDP of MG-63 cells. The cell survival to CDDP of MG-63 cells was inhibited by (2 S)-OMPT (LPA3 agonist). Moreover, the cell survival to CDDP of MG-63 cells was enhanced by LPA4 and LPA6 knockdowns. These results indicate that LPA signaling via LPA receptors is involved in the regulation of cellular functions associated with ATP reduction in MG-63 cells treated with EtBr. [ABSTRACT FROM AUTHOR]

Ethidium bromide is extensively used in many biochemical laboratories. Due to its high toxicity, its removal from the wastewater before being disposed becoming an emerging issue. Swelling clay minerals, due to their inexpensive material cost, high efficiency, and vast reserves, have been evaluated for the removal of different types of contaminants. In this study, the removal of ethidium bromide, particularly its mechanism of removal was assessed, using Ca-montmorillonite (SAz-1) as a representative swelling clay minerals. The ethidium bromide removal could reach equilibrium within 1 h and a capacity of 1,276 mmol kg-1, same magnitude as the cation exchange capacity of SAz-1. The total amount of metal cations desorbed from SAz-1 to the amount of ethidium removed was linearly correlated with a slope of 0.7, suggesting cation exchange as the dominant mechanism. In addition, the less-than-unity desorption/adsorption ratio could be attributed to the removal of ethidium dimers bridged with bromide counterions. An increase of the basal spacing to 18.3 Å for SAz-1 after adsorption implied that intercalation of flat-lying ethidium dimers into the clay interlayer, which increased its thermal stability, and active participation of the amine groups of ethidium molecules in the adsorptive interaction was evidenced from Fourier transform infrared band shifts. The results suggested that Ca-montmorillonite is an excellent candidate for fast and effective removal of ethidium bromide from aqueous solution. As such, it could serve as an ideal packing material for kits to be manufactured and used for ethidium bromide removal in case of spill. [ABSTRACT FROM AUTHOR]

Ethidium bromide (EtBr) is widely used in most laboratories to detect nucleic acids in gel electrophoresis applications. It is a well-known carcinogenic and mutagenic agent, which can affect biotic components of the place in which it is disposed. Usually the gel-waste is either buried in the ground or incinerated, whereas the liquid waste is disposed of down the sink following the recommended methods of treatment. The recommended methods do not involve biological potential, but rather make use of chemicals, which may further deteriorate soil and water quality. The present study identifies and characterizes the EtBr-degrading bacterial isolates BR3 and BR4. A bibliographic review of the risk status of using these isolates for the treatment of lab waste in laboratory settings is also presented. BR3 was identified as Proteus terrae N5/687 (LN680103) and BR4 as Morganella morganii subsp. morganii ATCC 25830 (AJ301681) with 99.9% and 99.48% similarity, respectively, using an EzBioCloud microbial identifier. The literature revealed the bacterium Proteus terrae as a non-pathogenic and natural microflora of humans, but Morganella morganii as an opportunistic pathogen. These organisms belong to risk group II. Screening the sensitivity of these isolates to antibiotics revealed a sufficient number of antibiotics, which can be used to control them, if required. BR3 and BR4 exhibited resistance to individual antibiotics, ampicillin and vancomycin, whereas only BR3 was resistant to tetracycline. The current investigation, along with earlier reported work on these isolates, identifies BR3 as a useful isolate in the industrial application for the degradation of EtBr. Identical and related microorganisms, which are available in the culture collection repositories, can also be explored for such potential to formulate a microbial consortium for the bioremediation of ethidium bromide prior to its disposal. [ABSTRACT FROM AUTHOR]

Background: MDR in bacteria is threatening to public health. Overexpression of efflux pumps is an important cause of MDR. The co-administration of antimicrobial drugs and efflux pump inhibitors (EPIs) is a promising approach to address the problem of MDR.Objectives: To identify new putative EPIs and to characterize their mechanisms of action.Methods: The effects of four selected piperazine derivatives on resistance-nodulation-cell division (RND) pumps was evaluated in Escherichia coli strains overexpressing or not expressing RND pumps by assays aimed at evaluating antibiotic potentiation, membrane functionality, ethidium bromide accumulation and AcrB expression. The cytotoxicity of selected piperazines towards primary cultures of human dermal fibroblasts was also investigated.Results: Four molecules enhanced levofloxacin activity against strains overexpressing RND efflux pumps (AcrAB-TolC and AcrEF-TolC), but not against RND pump-deficient strains. They had little effects on membrane potential. Molecule 4 decreased, whereas the other three increased, membrane permeability compared with untreated control cells. The four molecules showed differences in the specificity of interaction with RND efflux pumps, by inactivating the transport of one or more antibiotics, and in the levels of ethidium bromide accumulation and of acrB expression inhibition.Conclusions: Piperazine derivatives are good candidates as inhibitors of RND efflux pumps. They decreased the activity of RND pumps by mixed mechanisms of action. Small structural differences among the molecules can be critical in defining their behaviour. [ABSTRACT FROM AUTHOR]

Cu(II) complex of 2-hydroxy-5-methoxyacetophenone-N(4)-ethyl thiosemicarbazone (Cu(HMAET)Cl) was synthesized and characterized by spectroscopic methods such as FT-IR, ¹H-NMR and UV-Vis. The Cu(II) complex's DNA-binding capacity was studied with the UV-Vis absorption titration and ethidium bromide (EB) displacement experiment using E. coli DNA. The results demonstrated that the Cu(II) complex could intercalate in the DNA's base pairs. The binding constant was found as 2.8x107 M-1. Also, the interaction study of the Cu(II) complex with bovine serum albumin (BSA) was investigated using the UV-Vis absorption and fluorescence spectroscopy techniques. It was concluded that the Cu(II) complex interacts strongly with BSA. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanocarriers with dual/multifunctionalities are thought to be good candidates for dual/multimodal applications such as combined drug delivery and bioimaging. In this study, new red fluorescent organosilica materials were conveniently produced with diurea-ethidium bromide (DU-EB) functional units integrated in the pore wall framework for simultaneous diagnosis and therapy. We found that the prepared mesoporous silica hybrid nanocarrier system exhibited strong red fluorescence under UV-light (365 nm) while retaining excellent photo- and chemical-stability. The integrated ethidium bromide functional units in the mesopore walls cause the red fluorescence. By loading/releasing doxorubicin (Dox)/5-fluorouracil (5-FU) as a model cargo, the synthesized DU-EB@MSH materials were tested at various pH levels (pH 5.0, 6.2 and 7.4), and the cytocompatibility of the red-fluorescent DU-EB@MSH nanocarrier system was assessed using human breast cancer (MCF-7) cells. The experimental results revealed that the drug release behavior is primarily determined by the pH of the intracellular medium, and red-fluorescence was induced by a UV-light (365 nm) trigger. All the study results suggested that the DU-EB@MSH drug carrier system could be useful for red-fluorescence bioimaging and chemotherapeutic applications in cancer therapy. [ABSTRACT FROM AUTHOR]

Copyright of Veterinarska Stanica is the property of Croatian Veterinary Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of National Academy of Sciences of Armenia Reports / Doklady Nacionalnaâ Akademiâ Nauk Armenii is the property of National Academy of Sciences of the Republic of Armenia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Molecular and cellular mechanisms underlying the peripheral conditioning lesion remain unsolved. We show here that injection of a chemical demyelinating agent, ethidium bromide, into the sciatic nerve induces a similar set of regeneration-associated genes and promotes a 2.7-fold greater extent of sensory axon regeneration in the spinal cord than sciatic nerve crush. We found that more severe peripheral demyelination correlates with more severe functional and electrophysiological deficits, but more robust central regeneration. Ethidium bromide injection does not activate macrophages at the demyelinated sciatic nerve site, as observed after nerve crush, but briefly activates macrophages in the dorsal root ganglion. This study provides a new method for investigating the underlying mechanisms of the conditioning response and suggests that loss of the peripheral myelin may be a major signal to change the intrinsic growth state of adult sensory neurons and promote regeneration.

The antibacterial activity of the monoterpene estragole was evaluated against two strains of bacteria with an efflux pump mechanism, which are Staphylococcus aureus 1199B and S. aureus K2068, which have a NorA and MepA pump, respectively. For that, the methodology proposed by CLSI with modifications was followed, and to evaluate the reversal of the efflux pump, subinhibitory concentrations (MIC/8) of estragole and standard pump inhibitors, CCCP and Chlorpromazine were used and it was verified whether they managed to modulate the action of Norfloxacin, Ciprofloxacin and Ethidium Bromide, an indicator of an efflux pump. It was observed that estragole positively modulated norfloxacin and ethidium bromide against the strain of S. aureus 1199B and that it also managed to reduce the MIC of ethidium bromide against the strain of S. aureus K2068. In the non-clinical acute toxicity tests with estragole, the animals treated with the dose of 625 mg/kg/v.o. showed no clinical signs of toxicity, according to the parameters evaluated. These results are promising, since it places estragole as a possible inhibitor of the efflux pump, thus managing to inhibit this mechanism of action in the strains tested. [ABSTRACT FROM AUTHOR]

Background: This study introduces a newly created strain (Rhodococcus equiEtBr25) by exposing R. equi ATCC 33701 to ethidium bromide (EtBr), a substrate for MDR transporters. Such an approach allowed us to investigate the resulting phenotype and genetic mechanisms underlying the efflux-mediated resistance in R. equi.Methods: R. equi ATCC 33701 was stimulated with increasing concentrations of EtBr. The antimicrobial susceptibility of the parental strain and R. equiEtBr25 was investigated in the presence/absence of efflux pump inhibitors (EPIs). EtBr efflux was evaluated by EtBr-agar method and flow cytometry. The presence of efflux pump genes was determined by conventional PCR before to quantify the expression of 30 genes coding for membrane transporters by qPCR. The presence of erm(46) and mutations in 23S rRNA, and gyrA/gyrB was assessed by PCR and DNA sequencing to exclude the occurrence of resistance mechanisms other than efflux.Results: R. equi EtBr25 showed an increased EtBr efflux. Against this strain, the activity of EtBr, azithromycin and ciprofloxacin was more affected than that of rifampicin and azithromycin/rifampicin combinations. Resistances were reversed by combining the antimicrobials with EPIs. Gene expression analysis detected a marked up-regulation of REQ_RS13460 encoding for a Major Facilitator Superfamily (MFS) transporter. G→A transition occurred in the transcriptional repressor tetR/acrR adjacent to REQ_RS13460.Conclusions: Exposure of R. equi to EtBr unmasked an efflux-mediated defence against azithromycin and ciprofloxacin, which seemingly correlates with the overexpression of a specific MFS transporter. This genotype may mirror an insidious low-level resistance of clinically important isolates that could be countered by EPI-based therapies. [ABSTRACT FROM AUTHOR]

In several "short live" packaging applications, plastic gloves, plays an important role. Garbage bags and toys are the majority of waste plastic. For their constancy in our landscape, incorrectly discarded plastic products are a major pollutant to the environment, potentially life-damaging. One of most troublesome plastic in this regard, between synthetic plastics Polyethylene (PE) is Polyethylene waste typically exists in the lack of adequate treatment methods burned that cause's severe air pollution. Polyethylene found inert can be biodegraded, if necessary the strains of microbial are used. In this research plastic degradation was analyzed by 30 days inoculation in broth culture method. The bacterial species obtained associated with degrading plastic were identified as Streptococcus pyrogen. The efficacy of plastic degradation as evaluated in broth culture method. The work illustrated that mutated Streptococcus pyrogen have grater tendency to degrade the plastic when compared with wild Streptococcus pyrogen in optimized media. [ABSTRACT FROM AUTHOR]

• The polyoxometalate compounds, stabilized by the biologically relevant ethidium counter cations. • The binding studies of Keggin-Ethidium hybrid with CT-DNA (calf thymus DNA). • The single crystal X-ray structure of Keggin-Ethidium hybrid compounds. • The supramolecular interactions between Keggin polyanion and ethidium cation. We report the synthesis and photoluminescence (PL) properties of three compounds [C 21 H 20 N 3 ] 2 [HPMo 12 O 40 ] (1), [C 21 H 20 N 3 ] 3 [PW 12 O 40 ]∙4C 3 H 7 NO (2) and [C 21 H 20 N 3 ] 4 [SiW 12 O 40 ] (3) consisting of ethidium cation (3,8-diamino-5-ethyl-6-phenylphenanthridinium) and Keggin type polyoxometalates. Compounds 1, 2 and 3 have been characterized unambiguously by the single crystal X-ray diffraction studies. The binding studies of inorganic-organic hybrid compounds 1, 2 and 3 with CT-DNA (calf thymus DNA) have been carried out and monitored by UV–Vis- and emission-spectroscopy. The compounds 1 and 2 show fluorescence enhancement where as compound 3 with silicotungstate polyanion shows fluorescence quenching. The photoluminescence properties of three hybrid compounds arise due to the interaction of ethidium cation with DNA. We have demonstrated that the interaction between ethidium cation and CT-DNA is influenced by a particular type of polyoxometalate (POM) Keggin anion. The crystal structures show supramolecular interactions between the Keggin anion and ethidium cation. Compounds 1, 2 and 3 are further characterized by routine spectral analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii contains RND-family efflux systems AdeABC and AdeIJK, which pump out a wide range of antimicrobial compounds, as judged from the MIC changes occurring upon deletion of the responsible genes. However, these studies may miss changes because of the high backgrounds generated by the remaining pumps and by β-lactamases, and it is unclear how the activities of these pumps compare quantitatively with those of the well-studied AcrAB-TolC system of Escherichia coli. We expressed adeABC and adeIJK of A. baumannii, as well as E. coli acrAB, in an E. coli host from which acrAB was deleted. The A. baumannii pumps were functional in E. coli, and the MIC changes that were observed largely confirmed the substrate range already reported, with important differences. Thus, the AdeABC system pumped out all β-lactams, an activity that was often missed in deletion studies. When the expression level of the pump genes was adjusted to a similar level for a comparison with AcrAB-TolC, we found that both A. baumannii efflux systems pumped out a wide range of compounds, but AdeABC was less effective than AcrAB-TolC in the extrusion of lipophilic β-lactams, novobiocin, and ethidium bromide, although it was more effective at tetracycline efflux. AdeIJK was remarkably more effective than a similar level of AcrAB-TolC in the efflux of β-lactams, novobiocin, and ethidium bromide, although it was less so in the efflux of erythromycin. These results thus allow us to compare these efflux systems on a quantitative basis, if we can assume that the heterologous systems are fully functional in the E. coli host.

Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role.

Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role.

Multiple Sclerosis (MS) is a progressive neurodegenerative disease with clinical signs of neuroinflammation and the central nervous system's demyelination. Numerous studies have identified the role of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) overexpression and the low level of peroxisome proliferator-activated receptor-gamma (PPAR-γ) in MS pathogenesis. Guggulsterone (GST), an active component derived from 'Commiphora Mukul,' has been used to treat various diseases. Traditional uses indicate that GST is a suitable agent for anti-inflammatory action. Therefore, we assessed the therapeutic potential of GST (30 and 60 mg/kg) in ethidium bromide (EB) induced demyelination in experimental rats and investigated the molecular mechanism by modulating the JAK/STAT and PPAR-γ receptor signaling. Wistar rats were randomly divided into six groups (n = 6). EB (0.1%/10 μl) was injected selectively in the intracerebropeduncle (ICP) region for seven days to cause MS-like manifestations. The present study reveals that long-term administration of GST for 28 days has a neuroprotective effect by improving behavioral deficits (spatial cognition memory, grip, and motor coordination) associated with lower STAT-3 levels. While elevating PPAR-γ and myelin basic protein levels in rat brains are consistent with the functioning of both signaling pathways. Also, GST modulates the neurotransmitter level by increasing Ach, dopamine, serotonin and by reducing glutamate. Moreover, GST ameliorates inflammatory cytokines (TNF, IL-1β), and oxidative stress markers (AchE, SOD, catalase, MDA, GSH, nitrite). In addition, GST prevented apoptosis, as demonstrated by the reduction of caspase-3 and Bax. Simultaneously, Bcl-2 elevation and the restoration of gross morphology alterations are also recovered by long-term GST treatment. Therefore, it can be concluded that GST may be a potential alternative drug candidate for MS-related motor neuron dysfunctions. [ABSTRACT FROM AUTHOR]

Oxidative stress has been shown to play an important role in the pathogenesis of multiple sclerosis (MS). Curcumin (CUR), an antioxidant compound, can be a potent treatment for neurodegenerative diseases, such as MS. CUR has poor bioavailability; therefore, it is used in nanoforms to increase its bioavailability. In the present study, the effects of CUR and conjugated linoleic acid-CUR (Lino-CUR) on spatial memory and oxidative stress in a putative animal model of MS were investigated. Forty-nine adult male Wistar rats (250 ± 50 g) were randomly divided into seven groups (n = 7): control, sham, ethidium bromide (EB), CUR (20 and 40 μg/kg) + EB, and Lino-CUR (20 and 40 μg/kg) + EB groups. Following MS induction, the groups were treated for 5 consecutive days. Finally, spatial memory and levels of oxidative stress parameters were assessed. Treatment with CUR and Lino-CUR at two doses significantly improved spatial memory and reduced oxidative stress parameters in the experimental models of MS. Furthermore, the effects of high dose (40 μg/kg) of Lino-CUR were more remarkable. These findings suggest that the microinjection of CUR in its synthetic form Lino-CUR significantly ameliorated spatial memory, through the reduction of oxidative stress markers in the brain of studied animals as a rat model of MS. [ABSTRACT FROM AUTHOR]

The interaction of (E)-4-(2-(7-bromo-10-ethyl-10H-phenothiazin-3-yl)vinyl)-1-methylpyridin-1-ium (PVP) dyes with calf-thymus DNA was examined by spectrophotometric UV-vis absorption/emission titration and competitive ethidium bromide displacement. The association constant values were situated in 106 M-1 range, typical to cationic dyes containing the monocyanine chromophore system. The variation of the counterion of the cationic PVP dye from iodide to tetrafluoroborate produced dissimilarities in the interaction pattern with DNA. The PVP iodide competitively displaced the ethidium bromide (EB) from the EB-DNA system, thus suggesting the intercalation ability of the dye, while the PVP tetrafluoroborate did not supported the intercalation of the dye. [ABSTRACT FROM AUTHOR]

G-quadruplex DNA in recognized as a potential target for anti-cancer drugs. In this work, an anthraquinonecarboxamido derivative of β-cyclodextrin (AQCC) is synthesized as a novel DNA binder that further can deliver an additional molecule at the target, carrying it in the cavity of modified cyclodextrin. The binding of AQCC with ethidium bromide (EtBr), berberine (Ber), duplex calf-thymus DNA (CT-DNA), quadruplexes (G4) viz., kit22, myc22, and telo24 are studied. The compound acts as a host molecule for the encapsulation of DNA binders viz., EtBr, Ber and enhances their fluorescence due to the encapsulation in its AQCC's cyclodextrin cavity. The binding constant of the host: guest complex of EtBr and Ber with AQCC's cavity are 6.4 × 105 and 3.3 × 106 mol−1 dm3, respectively. The proximity of the protons of the guest and host molecules is confirmed by two-dimensional rotating-frame Overhauser effect spectroscopy (2D ROESY). The conjugate displays a quenching of fluorescence selectively on the association with CT-DNA and quadruplex kit22 that is contrast to the spectral behavior with quadruplex myc22 and telo24. CT-DNA exhibits dissimilar fluorescence spectra in free- and EtBr-bound forms. In addition, kit22 exhibit dissimilar emission profile when AQCC encapsulates Ber. Therefore, the Ber-loaded complexes and the AQCC molecule bind to different G-quadruplexes with different binding strengths. In addition, the effect of Ber in binding to the target DNAs is pronounces since the Ber molecule has more affinity to bind to quadruplexes than the duplex. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction can occur in a variety of ways, most often due to the deletion or mutation of mitochondrial DNA (mtDNA). The easy generation of yeasts with mtDNA deletion is attractive for analyzing the functions of the mtDNA gene. Treatment of yeasts with ethidium bromide is a well-known method for generating ρ° cells with complete deletion of mtDNA from Saccharomyces cerevisiae. However, the mutagenic effects of ethidium bromide on the nuclear genome cannot be excluded. In this study, we developed a "mito-CRISPR system" that specifically generates ρ° cells of yeasts. This system enabled the specific cleavage of mtDNA by introducing Cas9 fused with the mitochondrial target sequence at the N-terminus and guide RNA into mitochondria, resulting in the specific generation of ρ° cells in yeasts. The mito-CRISPR system provides a concise technology for deleting mtDNA in yeasts. [ABSTRACT FROM AUTHOR]

Vibrio sp., ubiquitous in the aquatic ecosystem, are bacteria of interest because of their involvement in human health, causing gastroenteritis after ingestion of seafood, as well as their role in vibriosis leading to severe losses in aquaculture production. Their ability to enter a viable but non-culturable (VBNC) state under stressful environmental conditions may lead to underestimation of the Vibrio population by traditional microbiological enumeration methods. As a result, using molecular methods in combination with EMA or PMA allows the detection of viable (VBNC and culturable viable) cells. In this study, the impact of the EMA and PMA was tested at different concentrations on the viability of several Vibrio species. We compared the toxicity of these two DNAbinding dyes to determine the best pretreatment to use with qPCR to discriminate between viable and dead Vibrio cells. Our results showed that EMA displayed lethal effects for each strain of V. cholerae and V. vulnificus tested. In contrast, the concentrations of PMA tested had no toxic effect on the viability of Vibrio cells studied. These results may help to achieve optimal PMA-qPCR methods to detect viable Vibrio sp. cells in food and environmental samples. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of eight novel indole-thiazole and indole-thiazolidinone derivatives, as well as their ability to interact with DNA, analysed through the UV–vis absorption, fluorescence, circular dichroism (CD), viscosity techniques and molecular docking. The ctDNA interaction analysis demonstrated different spectroscopic effects and the affinity constants (Kb) calculated by the UV–vis absorption method were between 2.08 × 105 and 6.99 × 106 M−1, whereas in the fluorescence suppression constants (Ksv) ranged between 0.38 and 0.77 × 104 M−1 and 0.60–7.59 × 104 M−1 using Ethidium Bromide (EB) and 4′,6-Diamidino-2-phenylindole (DAPI) as fluorescent probes, respectively. Most derivatives did not alter significantly the secondary structure of the ctDNA according to the CD results. None of the compounds was able to change the relative viscosity of the ctDNA. These results prove that compounds interact with ctDNA via groove binding, which was confirmed by A-T rich oligonucleotide sequence assay with compound JF-252 , suggesting the importance of both the phenyl ring coupled to C-4 thiazole ring and the bromo-unsubstituted indole nucleus. • Unsubstituted and 5-bromo-indole with thiazole and thiazolidinone were synthetized. • Thiazole and thiazolidinone rings bear a naphthalene and lateral substituents. • DNA interaction was performed by different techniques with the eight derivatives. • Bromo-unsubstituted indole and phenyl linked to C4 thiazole ring favor DNA bond. • The mode of interaction for all derivative was proven to be by DNA groove. [ABSTRACT FROM AUTHOR]

Microdilution assays were performed in order to evaluate the antimicrobial activity of the ethanoic extract from the leaves of Bauhinia forficate (EEBF) against different microorganisms. The extract did not present inner antimicrobial activities against the tested strains. However, EEBF was able to modulate the norfloxacin-resistance against Staphylococcus aureus SA1199-B that overproduce the NorA efflux pump, once sub-inhibitory concentrations of EEBF reduced the minimal inhibitory concentratio of the norfloxacin in 87.5%. This modulatory effect was also found when the antibiotic was replaced by ethidium bromide, suggesting that EEBF acts probably by inhibition of NorA, allowing the antibiotic accumulation intracellularly, and making the line more sensitive. These results point out the EEBF potential as a source of NorA inhibitors that could be used in combination with norfloxacin for treatment of infections caused by multidrug-resistant S. aureus. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a pathological condition characterized by the demyelination of nerve fibers, primarily attributed to the destruction of oligodendrocytes and subsequent motor neuron impairment. Ethidium bromide (EB) is a neurotoxic compound that induces neuronal degeneration, resulting in demyelination and symptoms resembling those observed in experimental animal models of multiple sclerosis (MS). The neurotoxic effects induced by EB in multiple sclerosis (MS) are distinguished by the death of oligodendrocytes, degradation of myelin basic protein (MBP), and deterioration of axons. Neurological complications related to MS have been linked to alterations in the signaling pathway known as smo-shh. Purmorphine (PUR) is a semi-synthetic compound that exhibits potent Smo-shh agonistic activity. It possesses various pharmacological properties, including antioxidant, anti-inflammatory, anti-apoptotic, and neuromodulatory effects. Hence, the current investigation was conducted to assess the neuroprotective efficacy of PUR (at doses of 5 and 10 mg/kg, administered intraperitoneally) both individually and in conjunction with Fingolimod (FING) (at a dose of 0.5 mg/kg, administered intraperitoneally) in the experimental model of MS induced by EB. The administration of EB was conducted via the intracerebropeduncle route (ICP) over a period of seven days in the brain of rats. The Wistar rats were allocated into six groups using randomization, each consisting of eight rats (n = 8 per group). The experimental groups in this study were categorized as follows: (I) Sham Control, (II) Vehicle Control, (III) PUR per se, (IV) EB, (V) EB + PUR5, (VI) EB + PUR10, (VII) EB + FING 0.5, and (VIII) EB + PUR10 + FING 0.5. On the final day of the experimental timeline, all animal subjects were euthanized, and subsequent neurochemical estimations were conducted on cerebrospinal fluid, blood plasma, and brain tissue samples. In addition, we conducted neurofilament (NFL) analysis and histopathological examination. We utilized the luxol myelin stain to understand better the degeneration associated with MS and its associated neurological complications. The findings of our study indicate that the activation of SMO-Shh by PUR has a mitigating effect on neurobehavioral impairments induced by EB, as well as a restorative effect on cellular and neurotransmitter abnormalities in an experimental model of MS., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This study aimed to evaluate the antibacterial and inhibitory action of NorA, Tet(K), MsrA and MepA efflux pumps in S. aureus strains using the sesquiterpenes named trans-caryophyllene and caryophyllene oxide, both isolated and encapsulated in liposomes. The antibacterial and inhibitory action of these efflux pumps was evaluated through the serial microdilution test in 96-well microplates. Each sesquiterpene and liposome/sesquiterpene was combined with antibiotics and ethidium bromide (EtBr). The antibiotics named norfloxacin, tetracycline and erythromycin were used. The 1199 B, IS-58, RN4220 and K2068 S. aureus strains carrying NorA, Tet(K), MsrA and MepA, respectively, were tested. In the fluorescence measurement test, K2068 S. aureus was incubated with the sesquiterpenes and EtBr, and the fluorescence emission by EtBr was measured. The tested substances did not show direct antibacterial activity, with MIC >1024 μg/mL. Nonetheless, the isolated trans-caryophyllene and caryophyllene oxide reduced the MIC of antibiotics and EtBr, indicating inhibition of NorA, Tet(K) and MsrA. In the fluorescence test, these same sesquiterpenes increased fluorescence emission, indicating inhibition of MepA. Therefore, the sesquiterpenes named trans-caryophyllene and caryophyllene oxide did not show direct antibacterial action; however, in their isolated form, they showed possible inhibitory action on NorA, Tet(K), MsrA and MepA efflux pumps. They may also act in antibiotic potentiation. Further studies are needed to identify the mechanisms involved in antibiotic potentiation and efflux pump inhibitory action., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)