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MBio Jun 2023The continued challenges of the COVID-19 pandemic combined with the growing problem of antimicrobial-resistant bacterial infections has severely impacted global health....
The continued challenges of the COVID-19 pandemic combined with the growing problem of antimicrobial-resistant bacterial infections has severely impacted global health. Specifically, the Gram-negative pathogen Klebsiella pneumoniae is one of the most prevalent causes of secondary bacterial infection in COVID-19 patients, with approximately an 83% mortality rate observed among COVID-19 patients with these bacterial coinfections. K. pneumoniae belongs to the ESKAPE group of pathogens, a group that commonly gives rise to severe infections that are often life-threatening. Recently, K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae has drawn wide public attention, as the mortality rate for this infection can be as high as 71%. The most predominant and clinically important multidrug efflux system in K. pneumoniae is the acriflavine resistance B (AcrB) multidrug efflux pump. This pump mediates resistance to different classes of structurally diverse antimicrobial agents, including quinolones, β-lactams, tetracyclines, macrolides, aminoglycosides, and chloramphenicol. We here report single-particle cryo-electron microscopy (cryo-EM) structures of K. pneumoniae AcrB, in both the absence and the presence of the antibiotic erythromycin. These structures allow us to elucidate specific pump-drug interactions and pinpoint exactly how this pump recognizes antibiotics. Klebsiella pneumoniae has emerged as one of the most problematic and highly antibiotic-resistant pathogens worldwide. It is the second most common causative agent involved in secondary bacterial infection in COVID-19 patients. K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae is a major concern in global public health because of the high mortality rate of this infection. Its drug resistance is due, in a significant part, to active efflux of these bactericides, a major mechanism that K. pneumoniae uses to resist to the action of multiple classes of antibiotics. Here, we report cryo-electron microscopy (cryo-EM) structures of the prevalent and clinically important K. pneumoniae AcrB multidrug efflux pump, in both the absence and the presence of the erythromycin antibiotic. These structures allow us to understand the action mechanism for drug recognition in this pump. Our studies will ultimately inform an era in structure-guided drug design to combat multidrug resistance in these Gram-negative pathogens.
Topics: Humans; Acriflavine; Klebsiella pneumoniae; Cryoelectron Microscopy; Pandemics; COVID-19; Anti-Bacterial Agents; Bacterial Proteins; Erythromycin; Klebsiella Infections; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests
PubMed: 37067435
DOI: 10.1128/mbio.00659-23 -
Molecules (Basel, Switzerland) Sep 2023Derivatives combining acridine, pyrrole, and thiazolidine rings have emerged as promising candidates in the field of antitumor drug discovery. This paper aims to...
Derivatives combining acridine, pyrrole, and thiazolidine rings have emerged as promising candidates in the field of antitumor drug discovery. This paper aims to highlight the importance of these three structural motifs in developing potent and selective anticancer agents. The integration of these rings within a single molecule offers the potential for synergistic effects, targeting multiple pathways involved in tumor growth and progression. Spiro derivatives were efficiently synthesized in a two-step process starting from isothiocyanates and 2-cyanoacetohydrazide. The thiourea side chain in spiro derivatives was utilized as a key component for the construction of the thiazolidine-4-one ring through regioselective reactions with bifunctional reagents, namely methyl-bromoacetate, dietyl-acetylenedicarboxylate, ethyl-2-bromopropionate, and ethyl-2-bromovalerate. These reactions resulted in the formation of a single regioisomeric product for each derivative. Advanced spectroscopic techniques, including 1D and 2D NMR, FT-IR, HRMS, and single-crystal analysis, were employed to meticulously characterize the chemical structures of the synthesized derivatives. Furthermore, the influence of these derivatives on the metabolic activity of various cancer cell lines was assessed, with IC values determined via MTT assays. Notably, derivatives containing ester functional groups exhibited exceptional activity against all tested cancer cell lines, boasting IC values below 10 μM. Particularly striking were the spiro derivatives with methoxy groups at position 3 and nitro groups at position 4 of the phenyl ring. These compounds displayed remarkable selectivity and exhibited heightened activity against HCT-116 and Jurkat cell lines. Additionally, 4-oxo-1,3-thiazolidin-2-ylidene derivatives demonstrated a significant activity against MCF-7 and HCT-116 cancer cell lines.
Topics: Humans; Acridines; Pyrroles; Thiazolidines; Spectroscopy, Fourier Transform Infrared; Antineoplastic Agents; HCT116 Cells
PubMed: 37764394
DOI: 10.3390/molecules28186616 -
Cureus Nov 2023Increased colorectal carcinoma (CRC) and osteosarcoma prevalence, low survival rate, poor prognosis, and the limitations of existing anticancer therapies like side...
INTRODUCTION
Increased colorectal carcinoma (CRC) and osteosarcoma prevalence, low survival rate, poor prognosis, and the limitations of existing anticancer therapies like side effects of drugs, non-specificity, short half-life, etc., pose a need for novel anticancer drugs. Farnesol, an organic sesquiterpene compound, found in the essential oils of various plants has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. However, the anticancer effect of farnesol against CRC and osteosarcoma has not yet been adequately elucidated.
AIM
The aim of the study was to analyze the anticancer effects of farnesol against human osteosarcoma and CRC cell lines.
MATERIALS AND METHODS
Human osteosarcoma (Saos-2) and colorectal carcinoma (HCT-116) cell lines were procured and cultured at 37C and 5% CO. The cells were treated with 10, 20, 40, 60, 80, and 100 µM/ml and 20, 40, 60, 80, 100, and 120 µM/ml of farnesol for 24 hours, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay was performed to assess the cytotoxicity of farnesol on Saos-2 and HCT-116 cells. Acridine orange/ethidium bromide staining was carried out to analyze apoptosis. 4',6-diamidino-2-phenylindole staining was done to observe the nuclear changes. Dichloro-dihydro-fluorescein diacetate staining was performed to assess the farnesol-induced reactive oxygen species (ROS)-mediated cell death.
RESULTS
Farnesol reduced the viability and proliferation of Saos-2 and HCT-116 cells in a dose-dependent manner. Farnesol was able to alter the cellular and nuclear morphology of Saos-2 and HCT-116 cells, promoting cell death. Farnesol-induced apoptosis in human osteosarcoma and colorectal carcinoma cell lines. Early apoptosis was observed in farnesol-treated HCT-116 cells. Additionally, ROS-mediated apoptotic cell death was reported in Saos-2 cells.
CONCLUSION
Farnesol has the potential to induce cytotoxicity against human osteosarcoma and CRC cell lines.
PubMed: 38149135
DOI: 10.7759/cureus.49372 -
Cytotherapy Feb 2024Accurate assessment of cell viability is crucial in cellular product manufacturing, yet selecting the appropriate viability assay presents challenges due to various...
BACKGROUND AIMS
Accurate assessment of cell viability is crucial in cellular product manufacturing, yet selecting the appropriate viability assay presents challenges due to various factors. This study compares and evaluates different viability assays on fresh and cryopreserved cellular products, including peripheral blood stem cell (PBSC) and peripheral blood mononuclear cell (PBMC) apheresis products, purified PBMCs and cultured chimeric antigen receptor and T-cell receptor-engineered T-cell products.
METHODS
Viability assays, including manual Trypan Blue exclusion, flow cytometry-based assays using 7-aminoactinomycin D (7-AAD) or propidium iodide (PI) direct staining or cell surface marker staining in conjunction with 7-AAD, Cellometer (Nexcelom Bioscience LLC, Lawrence, MA, USA) Acridine Orange/PI staining and Vi-CELL BLU Cell Viability Analyzer (Beckman Coulter, Inc, Brea, CA, USA), were evaluated. A viability standard was established using live and dead cell mixtures to assess the accuracy of these assays. Furthermore, precision assessment was conducted to determine the reproducibility of the viability assays. Additionally, the viability of individual cell populations from cryopreserved PBSC and PBMC apheresis products was examined.
RESULTS
All methods provided accurate viability measurements and generated consistent and reproducible viability data. The assessed viability assays were demonstrated to be reliable alternatives when evaluating the viability of fresh cellular products. However, cryopreserved products exhibited variability among the tested assays. Additionally, analyzing the viability of each subset of the cryopreserved PBSC and PBMC apheresis products revealed that T cells and granulocytes were more susceptible to the freeze-thaw process, showing decreased viability.
CONCLUSIONS
The study demonstrates the importance of careful assay selection, validation and standardization, particularly for assessing the viability of cryopreserved products. Given the complexity of cellular products, choosing a fit-for-purpose viability assay is essential.
Topics: Leukocytes, Mononuclear; Reproducibility of Results; Cell Survival; Trypan Blue; Cryopreservation; Flow Cytometry
PubMed: 38085197
DOI: 10.1016/j.jcyt.2023.11.008 -
Frontiers in Oncology 2023Early-life osteosarcoma is associated with severe morbidity and mortality, particularly affecting young children and adults. The present cancer treatment regimen is...
INTRODUCTION
Early-life osteosarcoma is associated with severe morbidity and mortality, particularly affecting young children and adults. The present cancer treatment regimen is exceedingly costly, and medications like ifosfamide, doxorubicin, and cisplatin have unneeded negative effects on the body. With the introduction of hyphenated technology to create medications based on plant molecules, the application of ayurvedic medicine as a new dimension (formulation, active ingredients, and nanoparticles) in the modern period is rapidly growing. The primary source of lead compounds for the development of medications for avariety of ailments is plants and their products. Traditionally, (cumin) has been used as medication to treat a variety of illnesses and conditions.
METHODS
The cumin seed was successfully extracted with solvents Hexane, Chloroform, Methanol, Ethanol and Acetone. Following the solvent extraction, the extract residue was assayed in MG63 cells for their anti-proliferative properties.
RESULTS
First, we used the [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] (MTT) assay to test the extracted residue's cytotoxicity. The results show that hexane extract Half-maximal inhibitory concentration (IC50 86 µG/mL) effciently inhibits cells by causing programmed cell death. Furthermore, using the Acridine orange/ethidium bromide (AO/EB) staining method, the lactate dehydrogenase assay, and the reactive oxygen species assay using the Dichloro-dihydro-fluorescein diacetate (DCHFDA) staining method, we have demonstrated that the hexane extract causes apoptosis in MG63 cells. Furthermore, flow cytometry research revealed that the hexane extract stops the cell cycle in the S phase. In addition, the hexane extract limits colony formation and the migration potential as shown by the scratch wound healing assay. Furthermore, the extract from cumin seeds exhibits remarkable bactericidal properties against infections that are resistant to drugs. Gas chromatography analysis was used to quantitatively determine the hexane and methanolic extract based on the experimental data. The primary chemical components of the extract are revealed by the study, and these help the malignant cells heal. The present study finds that there is scientific validity in using cumin seeds as a novel method of anticancer therapy after undergoing both intrinsic and extrinsic research.
PubMed: 38125945
DOI: 10.3389/fonc.2023.1322875 -
JBRA Assisted Reproduction Sep 2023Human sperm motility and hyperactivation (HA) are induced by different factors such as intracellular calcium concentration. Repaglinide is an antidiabetic drug that, via...
OBJECTIVE
Human sperm motility and hyperactivation (HA) are induced by different factors such as intracellular calcium concentration. Repaglinide is an antidiabetic drug that, via the blocking of ATP-sensitive potassium channels (K-ATP channels), depolarization of the β-cell membrane, and opening of the voltage-gated calcium channels leads to an increase in intracellular calcium. The present study aimed to examine the effects of repaglinide on in vitro sperm motility parameters, viability, and DNA integrity in normozoospermic and asthenozoospermic men.
METHODS
Semen samples were collected from two groups of normozoospermic donors and asthenozoospermic patients. The samples were washed free of seminal plasma and then treated with medium alone (control) or with 100 nM and 1µM concentrations of repaglinide. After 1 h of incubation, percent sperm motility and hyperactivation were assessed; after 2 h of incubation, sperm viability and DNA fragmentation rate were evaluated by the Eosin-Y and acridine orange staining, respectively.
RESULTS
In both groups, repaglinide at a concentration of 100 nM and 1µM significantly improved percent sperm motility, hyperactivation, and vital sperms with normal DNA; in specimens from normozoospermic men, the 1µM concentration had a noticeable effect on progressive motility; in samples from asthenozoospermic men, the highest hyperactivation rate was seen at a concentration of 100 nM as compared with the 1µM concentration and controls (p<0.05).
CONCLUSIONS
Our results suggest that repaglinide can improve sperm motility, hyperactivity, viability, and DNA integrity in both normozoospermic and asthenozoospermic men.
Topics: Humans; Male; Sperm Motility; Calcium; Semen; DNA; Dietary Supplements
PubMed: 37698460
DOI: 10.5935/1518-0557.20230038 -
ACS Omega Aug 2023A monoterpene alcohol known as lemonol was investigated experimentally as well as theoretically in order to gain insights into its geometrical structure, vibrational...
A monoterpene alcohol known as lemonol was investigated experimentally as well as theoretically in order to gain insights into its geometrical structure, vibrational frequencies, solvent effects on electronic properties, molecular electrostatic potential, Mulliken atomic charge distribution, natural bond orbital, and Nonlinear Optical properties. The frontier molecular orbital energy gap values of 5.9084 eV (gas), 5.9261 eV (ethanol), 5.9185 eV (chloroform), 5.9253 eV (acetone), and 5.9176 eV (diethyl ether) were predicted, and it shows the kinetic stability and chemical reactivity of lemonol. Topological studies were conducted using Multiwfn software to understand the binding sites and weak interactions in lemonol. The antiproliferative effect of lemonol against the breast cancer cell line Michigan Cancer Foundation (MCF-7) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while nuclear damage, condensation, and reactive oxygen species generation were identified using acridine orange/ethidium bromide, propidium iodide, and dichlorodihydrofluorescein diacetate staining. The theoretical and experimental findings are highly correlated, confirming the structure, and the results of in vitro studies suggest that lemonol acts as a potent inhibitor against the human breast cancer cell line MCF-7, highlighting its strong antiproliferative activity.
PubMed: 37663516
DOI: 10.1021/acsomega.3c04922 -
Journal of Enzyme Inhibition and... Dec 2023The copper-catalysed azide-alkyne cycloaddition was applied to prepare three enantiomeric pairs of heterodimers containing a tacrine residue and a...
The copper-catalysed azide-alkyne cycloaddition was applied to prepare three enantiomeric pairs of heterodimers containing a tacrine residue and a 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) or 1,4-dideoxy-1,4-imino-L-arabinitol (LAB) moiety held together linkers of variable lengths containing a 1,2,3-triazole ring and 3, 4, or 7 CH groups. The heterodimers were tested as inhibitors of butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). The enantiomeric heterodimers with the longest linkers exhibited the highest inhibition potencies for AChE (IC = 9.7 nM and 11 nM) and BuChE (IC = 8.1 nM and 9.1 nM). AChE exhibited the highest enantioselectivity (. 4-fold). The enantiomeric pairs of the heterodimers were found to be inactive (GI > 100 µM), or to have weak antiproliferative properties (GI = 84-97 µM) against a panel of human cancer cells.
Topics: Humans; Butyrylcholinesterase; Acetylcholinesterase; Tacrine; Alkynes
PubMed: 36458374
DOI: 10.1080/14756366.2022.2150762 -
Bioorganic & Medicinal Chemistry Aug 2023Multi-target drug discovery is one of the most active fields in the search for new drugs against Alzheimer's disease (AD). This is because the complexity of AD...
Multi-target drug discovery is one of the most active fields in the search for new drugs against Alzheimer's disease (AD). This is because the complexity of AD pathological network might be adequately tackled by multi-target-directed ligands (MTDLs) aimed at modulating simultaneously multiple targets of such a network. In a continuation of our efforts to develop MTDLs for AD, we have been focusing on the molecular hybridization of the acetylcholinesterase inhibitor tacrine with the aim of expanding its anti-AD profile. Herein, we manipulated the structure of a previously developed tacrine-quinone hybrid (1). We designed and synthesized a novel set of MTDLs (2-6) by replacing the naphthoquinone scaffold of 1 with that of 2,5,8-quinolinetrione. The most interesting hybrid 3 inhibited cholinesterase enzymes at nanomolar concentrations. In addition, 3 exerted antioxidant effects in menadione-induced oxidative stress of SH-SY5Y cells. Importantly, 3 also showed low hepatotoxicity and good anti-amyloid aggregation properties. Remarkably, we uncovered the potential of the quinolinetrione scaffold, as a novel anti-amyloid aggregation and antioxidant motif to be used in further anti-AD MTDL drug discovery endeavors.
Topics: Humans; Tacrine; Alzheimer Disease; Acetylcholinesterase; Ligands; Neuroblastoma; Cholinesterase Inhibitors; Antioxidants; Amyloid beta-Peptides
PubMed: 37487339
DOI: 10.1016/j.bmc.2023.117419 -
Drug Design, Development and Therapy 2024Tacrine, an FDA-approved acetylcholinesterase inhibitor, has shown efficacy in treating Alzheimer's disease, but its clinical use is limited by hepatotoxicity. This...
INTRODUCTION
Tacrine, an FDA-approved acetylcholinesterase inhibitor, has shown efficacy in treating Alzheimer's disease, but its clinical use is limited by hepatotoxicity. This study investigates the protective effects of red ginseng against tacrine-induced hepatotoxicity, focusing on oxidative stress.
METHODS
A network depicting the interaction between compounds and targets was constructed for RG. Effect of RG was determined by MTT and FACS analysis with cells stained by rhodamine 123. Proteins were extracted and subjected to immunoblotting for apoptosis-related proteins.
RESULTS
The outcomes of the network analysis revealed a significant association, with 20 out of 82 identified primary RG targets aligning with those involved in oxidative liver damage including notable interactions within the AMPK pathway. in vitro experiments showed that RG, particularly at 1000μg/mL, mitigated tacrine-induced apoptosis and mitochondrial damage, while activating the LKB1-mediated AMPK pathway and Hippo-Yap signaling. In mice, RG also protected the liver injury induced by tacrine, as similar protective effects to silymarin, a well-known drug for liver toxicity protection.
DISCUSSION
Our study reveals the potential of RG in mitigating tacrine-induced hepatotoxicity, suggesting the administration of natural products like RG to reduce toxicity in Alzheimer's disease treatment.
Topics: Mice; Animals; Tacrine; Alzheimer Disease; Acetylcholinesterase; Network Pharmacology; AMP-Activated Protein Kinases; Cholinesterase Inhibitors; Chemical and Drug Induced Liver Injury; Panax
PubMed: 38419811
DOI: 10.2147/DDDT.S450305