RESUMO
We report here a concise route to synthesize various stereoisomers of tetrahydrofuran amino acids (TAAs) and the synthesis of TAA-containing linear cationic dodecapeptides. Some of these linear peptides show slightly better antimicrobial activities than their tetra- and octameric congeners, but no activity against Mycobacterium tuberculosis, for which octapeptides exhibited by far the best results; this implies that antibacterial activity is dependent on the length of these linear peptides. All the dodecapeptides described here were found to be toxic in nature against Vero cells. The study helps to delineate the optimal length of this series of linear peptides and select potential leads in the development of novel cationic peptide-based antibiotics.
Assuntos
Aminoácidos/farmacologia , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Furanos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Aminoácidos/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Furanos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células VeroRESUMO
Staphylococcus aureus is a WHO Priority II pathogen for its capability to cause acute to chronic infections and to resist antibiotics, thus severely impacting healthcare systems worldwide. In this context, it is urgently desired to discover novel molecules to thwart the continuing emergence of antimicrobial resistance. Disulphide containing small molecules has gained prominence as antibacterials. As their conventional synthesis requires tedious synthetic procedure and sometimes toxic reagents, a green and environmentally benign protocol for their synthesis has been developed through which a series of molecules were obtained and evaluated for antibacterial activity against ESKAPE pathogen panel. The hit compound was tested for cytotoxicity against Vero cells to determine its selectivity index and time-kill kinetics was determined. The activity of hit was determined against a panel of S. aureus multi-drug resistant clinical isolates. Also, its ability to synergize with FDA approved drugs was tested as was its ability to reduce biofilm. We identified bis(2-bromophenyl) disulphide (2t) as possessing equipotent antimicrobial activity against S. aureus including MRSA and VRSA strains. Further, 2t exhibited a selectivity index of 25 with concentration-dependent bactericidal activity, synergized with all drugs tested and significantly reduced preformed biofilm. Taken together, 2t exhibits all properties to be positioned as novel scaffold for anti-staphylococcal therapy.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Biocatálise , Dissulfetos/síntese química , Dissulfetos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Testes de Sensibilidade Microbiana/métodosRESUMO
BACKGROUND: Novel drug discovery against non-tuberculous mycobacteria is beset with a large number of challenges including the existence of myriad innate drug resistance mechanisms as well as a lack of suitable animal models, which hinders effective translation. In order to identify molecules acting via novel mechanisms of action, we screened the Library of Pharmacologically Active Compounds against non-tuberculous mycobacteria to identify such compounds. METHODS: Whole-cell growth inhibition assays were used to screen and identify novel inhibitors. The hit compounds were tested for cytotoxicity against Vero cells to determine the selectivity index, and time-kill kinetics were determined against Mycobacterium fortuitum. The compound's ability to synergize with amikacin, ceftriaxone, ceftazidime and meropenem was determined using fractional inhibitory concentration indexes followed by its ability to decimate mycobacterial infections ex vivo. Finally, the in vivo potential was determined in a neutropenic murine model mimicking mycobacterial infection. RESULTS: We have identified diphenyleneiodonium chloride (DPIC), an NADPH/NADH oxidase inhibitor, as possessing potent antimicrobial activity against non-tuberculous mycobacteria. DPIC exhibited concentration-dependent bactericidal activity against M. fortuitum and synergized with amikacin, ceftriaxone, ceftazidime and meropenem. When tested in a murine neutropenic M. fortuitum infection model, DPIC caused a significant reduction in bacterial load in kidney and spleen. The reduction in bacterial count is comparable to amikacin at a 100-fold lower concentration. CONCLUSIONS: DPIC exhibits all properties to be repositioned as a novel anti-mycobacterial therapy and possesses a potentially new mechanism of action. Thus, it can be projected as a potential new therapeutic against ever-increasing non-tuberculous mycobacterial infections.
Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Micobactérias não Tuberculosas/efeitos dos fármacos , Oniocompostos/farmacologia , Oniocompostos/uso terapêutico , Amicacina/farmacologia , Animais , Carga Bacteriana/efeitos dos fármacos , Chlorocebus aethiops , Modelos Animais de Doenças , Descoberta de Drogas , Cinética , Meropeném , Camundongos , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/microbiologia , Neutropenia , Micobactérias não Tuberculosas/crescimento & desenvolvimento , Oniocompostos/administração & dosagem , Bibliotecas de Moléculas Pequenas , Tienamicinas/farmacologia , Células VeroRESUMO
Cancer cells employ adaptive mechanisms to survive various stressors, including genotoxic drugs. Understanding the factors promoting survival is crucial for developing effective treatments. In this study, we unveil a previously unexplored long non-coding RNA, JUNI (JUN-DT, LINC01135), which is upregulated by genotoxic drugs through the activation of stress-activated MAPKs, JNK, and p38 and consequently exerts positive control over the expression of its adjacent gene product c-Jun, a well-known oncoprotein, which transduces signals to multiple transcriptional outputs. JUNI regulates cellular migration and has a crucial role in conferring cellular resistance to chemotherapeutic drugs or UV radiation. Depletion of JUNI markedly increases the sensitivity of cultured cells and spheroids to chemotherapeutic agents. We identified 57 proteins interacting with JUNI. The activity of one of them the MAPK phosphatase and inhibitor, DUSP14, is counteracted by JUNI, thereby, facilitating efficient JNK phosphorylation and c-Jun induction when cells are exposed to UV radiation. The antagonistic interplay with DUSP14 contributes not only to c-Jun induction but also augments the survival of UV-exposed cells. In summary, we introduce JUNI as a novel stress-inducible regulator of c-Jun, positioning it as a potential target for enhancing the sensitivity of cancer cells to chemotherapy.
Assuntos
Movimento Celular , Sobrevivência Celular , Fosfatases de Especificidade Dupla , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fosfatases de Especificidade Dupla/metabolismo , Fosfatases de Especificidade Dupla/genética , Movimento Celular/genética , Sobrevivência Celular/efeitos da radiação , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Linhagem Celular Tumoral , Raios Ultravioleta/efeitos adversos , Sistema de Sinalização das MAP Quinases/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismoRESUMO
Introduction: Basic pharmacokinetic (PK) and pharmacodynamic models of the phytocannabinoids Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are critical for developing translational models of exposure and toxicity. The neonatal period is a particularly important time to study the effects of cannabinoids, yet there are few studies of cannabinoid PKs by different routes such as direct injection or breast milk ingestion. To study this question, we have developed a translationally relevant rodent model of perinatal cannabinoid administration by measuring plasma levels of THC and CBD after different routes and preparations of these drugs. Materials and Methods: Adult animals and pups were injected with THC or CBD either intraperitoneally or subcutaneously, and plasma was analyzed by liquid chromatography-tandem mass spectrometry to measure cannabinoid levels collected at specified intervals. We also tested the effect of preparation of the drug using an oil-based vehicle (sesame oil) and an aqueous vehicle (Tween). Finally, we measured the plasma levels of cannabinoids in neonatal pups that were transmitted through breast milk after intraperitoneal injection to nursing dams. Results: We observed differences in the PK profiles of cannabinoids in adults and neonatal pups that were dependent on the route of administration and type of vehicle. Cannabinoids prepared in aqueous vehicle, injected intraperitoneally, resulted in a high peak in plasma concentration, which rapidly decreased. In contrast, subcutaneous injections using sesame oil as a vehicle resulted in a slow rise and low plateau in plasma concentration. Intraperitoneal injections with sesame oil as a vehicle resulted in a slower rise compared with aqueous vehicle, but an earlier and higher peak compared with subcutaneous injection. Finally, the levels of THC and CBD that were similar to direct subcutaneous injections were measured in the plasma of pups nursing from intraperitoneally injected dams. Conclusions: The route of administration and the preparation of the drug have important and significant effects on the PK profiles of THC and CBD in rats. These results can be used to create different clinically relevant exposure paradigms in pups and adults, such as short high-dose exposure or a low-chronic exposure, each of which might have significant and varying effects on development.
RESUMO
Staphylococcus aureus causes the majority of implant-related infections. These infections present as biofilms, in which bacteria adhere to the surface of foreign materials and form robust communities that are resilient to the human immune system and antibiotic drugs. The heavy use of broad-spectrum antibiotics against these pathogens disturbs the host's microbiome and contributes to the growing problem of antibiotic-resistant infections. The use of bacteriophages as antibacterial agents is a potential alternative therapy. In this study, bioluminescent strains of S. aureus were grown to form 48-h biofilms on polyether ether ketone (PEEK), a material used to manufacture orthopaedic implants, in either static or dynamic growth conditions. Biofilms were treated with vancomycin, staphylococcal phage, or a combination of the two. We showed that vancomycin and staph phages were able to independently reduce the total bacterial load. Most phage-antibiotic combinations produced greater log reductions in surviving bacteria compared to single-agent treatments, suggesting antimicrobial synergism. In addition to demonstrating the efficacy of combining vancomycin and staph phage, our results demonstrate the importance of growth conditions in phage-antibiotic combination studies. Dynamic biofilms were found to have a substantial impact on apparent treatment efficacy, as they were more resilient to combination treatments than static biofilms.
Assuntos
Infecções Estafilocócicas , Vancomicina , Humanos , Vancomicina/farmacologia , Staphylococcus aureus , Antibacterianos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Fagos de Staphylococcus , BiofilmesRESUMO
Due to the 2019 SARS-CoV-2 outbreak, low-cost, fast, and user-friendly diagnostic kits for biosensing SARS-CoV-2 in real samples employing multiple working electrodes are in high demand. Choosing SARS-CoV-2 detecting electrodes is difficult because each has advantages and limitations. Carbon-based electrochemical sensing applications have attracted attention from the electrochemical sensing community because carbon and carbon-based materials have been a godsend for testing utilizing an electrochemical platform. Carbon working electrode electrochemical platforms are cost-effective and fast. Covid-sensors use carbon-based materials because they can be easily changed (with inorganic and organic functionalities), have quick response kinetics, and are chemically resistant. Covid-19 sensing materials include graphene and graphite. This review explains how carbon materials have been employed in N and S protein electrochemical detection. Here, we discussed a carbon-based technology for SARS-CoV-2 biosensing. We've compared carbon-based electrochemical sensing to different electrodes.
RESUMO
Neurotransmitters (NTs) with hydroxyl groups can now be identified electrochemically, utilizing a variety of electrodes and voltammetric techniques. In particular, in monoamine, the position of the hydroxyl groups might alter the sensing properties of a certain neurotransmitter. Numerous research studies using electrodes modified on their surfaces to better detect specific neurotransmitters when other interfering factors are present are reviewed to improve the precision of these measures. An investigation of the monoamine neurotransmitters at nanoscale using electrochemical methods is the primary goal of this review article. It will be used to determine which sort of electrode is ideal for this purpose. The use of carbon materials, such as graphite carbon fiber, carbon fiber micro-electrodes, glassy carbon, and 3D printed electrodes are only some of the electrodes with surface modifications that can be utilized for this purpose. Electrochemical methods for real-time detection and quantification of monoamine neurotransmitters in real samples at the nanomolar level are summarized in this paper.
RESUMO
Background: Assessments for children with autism spectrum disorder (ASD) must adapt to the current COVID-19 pandemic through innovation in screening and assessment strategies using technology. To our knowledge there are no such studies reported from India. We aimed to study the predictive ability of video-based screening tool with definitive diagnosis in children with ASD. Method: Thirty-nine children were screened independently by two examiners with a video-based screening tool to start intervention followed by an in-person evaluation by clinical DSM-5 diagnosis three months later. Result: Similar to studies from developed countries, videos assessments showed a 94.87% correlation with the final diagnosis. Interobserver video agreement had a kappa correlation of 0.803, which was classified as substantial agreement. Conclusion: Video-based evaluations may be used as an interim assessment to initiate early intervention in children with ASD in resource-limited setups in the current pandemic situation. Large, well-designed prospective studies are required to confirm our results.
RESUMO
Amino acid-modified carbon interfaces have huge applications in developing electrochemical sensing applications. Earlier reports suggested that the amine group of amino acids acted as an oxidation center at the amino acid-modified electrode interface. It was interesting to locate the oxidation centers of amino acids in the presence of guanidine. In the present work, we modeled the arginine-modified carbon interface and utilized frontier molecular orbitals and analytical Fukui functions based on the first principle study computations to analyze arginine-modified CPE (AMCPE) at a molecular level. The frontier molecular orbital and analytical Fukui results suggest that the guanidine (oxidation) and carboxylic acid (reduction) groups of arginine act as additional electron transfer sites on the AMCPE surface. To support the theoretical observations, we prepared the arginine-modified CPE (AMCPE) for the cyclic voltammetric sensing of dopamine (DA). The AMCPE showed excellent performance in detecting DA in blood serum samples.
RESUMO
The alarming global rise in fatalities from multidrug-resistant Staphylococcus aureus (S. aureus) infections has underscored a need to develop new therapies to address this epidemic. Chemoproteomics is valuable in identifying targets for new drugs in different human diseases including bacterial infections. Targeting functional cysteines is particularly attractive, as they serve critical catalytic functions that enable bacterial survival. Here, we report an indole-based quinone epoxide scaffold with a unique boat-like conformation that allows steric control in modulating thiol reactivity. We extensively characterize a lead compound (4a), which potently inhibits clinically derived vancomycin-resistant S. aureus. Leveraging diverse chemoproteomic platforms, we identify and biochemically validate important transcriptional factors as potent targets of 4a. Interestingly, each identified transcriptional factor has a conserved catalytic cysteine residue that confers antibiotic tolerance to these bacteria. Thus, the chemical tools and biological targets that we describe here prospect new therapeutic paradigms in combatting S. aureus infections.
Assuntos
Benzoquinonas/farmacologia , Compostos de Epóxi/farmacologia , Indóis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Resistência a Vancomicina/efeitos dos fármacos , Antibacterianos/farmacologia , Benzoquinonas/química , Descoberta de Drogas , Compostos de Epóxi/química , Humanos , Indóis/química , Modelos Moleculares , Proteômica , Infecções Estafilocócicas/tratamento farmacológico , Vancomicina/farmacologiaRESUMO
Multidrug-resistant Acinetobacter baumannii (MDR-Ab) is one of the most significant nosocomial pathogens that is being increasingly isolated in healthcare settings worldwide. Owing to its inherent drug-resistant nature, coupled with its ability to readily acquire resistance to other antibiotic classes, there is a real dearth of antibiotics available to treat infections with MDR-Ab. A commercially available library was screened against MDR-Ab BAA-1605 to identify novel inhibitory molecules. The selectivity index of a hit was tested against Vero cells and in vitro efficacy was profiled against a panel of clinical MDR-Ab. The bacteriostatic or bactericidal nature was determined by time-kill experiments, and synergy with clinically approved drugs was determined by the chequerboard method. Additionally, in vivo efficacy was measured in a murine neutropenic A. baumannii thigh infection model. SRI-12742 was identified as a potent active hit, with a minimum inhibitory concentration (MIC) of 4 mg/L against BAA-1605. Its activity was then profiled against a MDR-Ab clinical strain panel (MICs 4 mg/L to >64 mg/L). SRI-12742 exhibited concentration-dependent bactericidal activity and caused an ca. 16 log10 CFU/mL reduction at 10â¯×â¯MIC in 24 h, which is comparable with minocycline. In a murine neutropenic thigh infection model of A. baumannii infection, SRI-12742 reduced CFU counts by ca. 0.9 log10 CFU, which is comparable with polymyxin B. In addition, SRI-12742 synergised with all classes of antibiotics tested. SRI-12742 exhibits all of the criteria necessary to be positioned as a novel lead with potential to be deployed for the treatment of infections caused by MDR-Ab.
Assuntos
Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Indóis/farmacologia , Acinetobacter baumannii/patogenicidade , Animais , Antibacterianos/química , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Células VeroRESUMO
Non-tuberculous mycobacteria (NTM) infections are increasingly being reported worldwide. They are a major concern for healthcare professionals for multiple reasons, ranging from the intrinsic resistance of NTM to most conventionally utilized antimicrobials to inharmonious diagnostic criteria utilized for evaluation of NTM-infected patients, leading to high morbidity. In this review, we highlight the paucity of drugs having potent anti-NTM activity amongst the new antimicrobials currently under various stages of development for anti-tubercular activity and issue a call for the establishment of a concerted dedicated drug discovery pipeline targeting NTM.
Assuntos
Antibacterianos/farmacologia , Descoberta de Drogas , Micobactérias não Tuberculosas/efeitos dos fármacos , Adamantano/análogos & derivados , Adamantano/farmacologia , Aminopiridinas/farmacologia , Azepinas/farmacologia , Benzamidas/farmacologia , Ensaios Clínicos como Assunto , Diarilquinolinas/farmacologia , Etilenodiaminas/farmacologia , Fluoroquinolonas/farmacologia , Humanos , Minociclina/análogos & derivados , Minociclina/farmacologia , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Nitroimidazóis/farmacologia , Oxazóis/farmacologia , Piperazinas/farmacologia , Compostos de Espiro/farmacologia , Tiazinas/farmacologia , Tigeciclina , Uridina/análogos & derivados , Uridina/farmacologiaRESUMO
Staphylococcus aureus subsp. aureus ATCC 29213 is one of the most commonly used strains in drug discovery research and for quality control. We report the completed draft genome sequence for the strain.
RESUMO
A series of novel hybrids possessing chalcone and thiazole moieties were synthesized and evaluated for their antibacterial activities. In general this class of hybrids exhibited potency against Staphylococcus aureus, and in particular, compound 27 exhibited potent inhibitory activity with respect to other synthesized hybrids. Furthermore, the hemolytic and toxicity data demonstrated that the compound 27 was nonhemolytic and nontoxic to mammalian cells. The in vivo studies utilizing a S. aureus septicemia model demonstrated that compound 27 was as potent as vancomycin. The results of antibacterial activities underscore the potential of this scaffold that can be utilized for developing a new class of novel antibiotics.
RESUMO
A series of novel ß-carboline-based N-heterocyclic carbenes was prepared via Mannich reaction between methyl 1-(dimethoxymethyl)-9H-pyrido[3,4-b]indole-3-carboxylate, formaldehyde, and primary amines. All compounds were evaluated for their antiproliferative activity using human breast cancer and lung cancer cell lines. Three compounds, 3c, 3j, and 3h, were discovered to display IC50 less than 10 µM against human breast cancer MDA-MB-231 cells at 24 h of treatment. Pharmacologically these compounds lead to G2/M phase cell cycle arrest and induction of cellular apoptosis by triggering intrinsic apoptotic pathway through depolarization of mitochondrial membrane potential and activation of caspases. At lower concentrations, these compounds also showed antimigratory and antiinvasive effects against highly metastatic human breast cancer MDA-MB-231 cells via aberration of MAP-kinase signaling and by the inhibition of matrix metalloproteinases. However, these analogues lack in vivo effect in mouse model which may be attributed to their strong affinity to HSA that was investigated spectroscopically with compound 3h.