RESUMEN
GABA modulators such as phenobarbital (PB) and sodium channel blockers such as phenytoin (PHT) have long been the mainstay of pharmacotherapy for the epilepsies. In the context of neonatal seizures, both PB and PHT display incomplete clinical efficacy. Moreover, in animal models, neonatal exposure to these medications result in neurodegeneration raising concerns about safety. Cenobamate, a more recently approved medication, displays unique pharmacology as it is both a positive allosteric modulator of GABA-A receptors, and a voltage-gated sodium channel blocker. While cenobamate is approved for adult use, its efficacy and safety profile against neonatal seizures is poorly understood. To address this gap, we assessed the efficacy and safety of cenobamate in immature rodents. Postnatal day (P)7 rat pups were pretreated with cenobamate and challenged with the chemoconvulsant pentylenetetrazole (PTZ) to screen for anti-seizure effects. In a separate experiment, P7 rats were treated with cenobamate, and brains were processed to assess induction of cell death. Cenobamate displays dose-dependent anti-seizure efficacy in neonatal rats. Unlike PHB and PHT, it does not induce neurotoxicity in P7 rats. Thus, cenobamate may be effective at treating neonatal seizures while avoiding unwanted neurotoxic side effects such as cell death.
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Animales Recién Nacidos , Anticonvulsivantes , Carbamatos , Muerte Celular , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ratas Sprague-Dawley , Convulsiones , Animales , Convulsiones/inducido químicamente , Convulsiones/tratamiento farmacológico , Anticonvulsivantes/farmacología , Ratas , Muerte Celular/efectos de los fármacos , Carbamatos/farmacología , Carbamatos/uso terapéutico , Clorofenoles/farmacología , Pentilenotetrazol/toxicidad , Masculino , Femenino , Convulsivantes/toxicidad , Encéfalo/efectos de los fármacos , TetrazolesRESUMEN
A novel laccase mimic enzyme Cu-Mn with excellent photothermal properties was firstly prepared via a combination of hydrothermal and in situ synthesis. Cu-Mn nanozymes could catalyze the typical laccase substrate 2,4-dichlorophenol (2,4-DP) to generate the red quinone imine. Further, loading the MnO2 nanosheets with photothermal properties, Cu-Mn nanozymes possessed not only excellent laccase catalytic activity, but also high photothermal conversion efficiency. The presence of glutathione S-transferase (GST) recovered the glutathione (GSH)-induced weakness of the laccase activity and photothermal properties of Cu-Mn. Hence, a GST enzyme-regulated dual-mode sensing strategy was established based on Cu-Mn nanozymes. The detection limits of GST monitoring based on colorimetric and photothermal methods were 0.092 and 0.087 U/L with response times of 20 min and 8 min, respectively. Furthermore, the proposed method enabled the measuring of GST levels in human serum and was successfully employed in the primary evaluation of hepatitis patients. Another attraction, the impressive photothermal behavior also endowed the Cu-Mn nanozymes with promising antimicrobial properties, which exhibited significant antimicrobial effects against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). Unsurprisingly, multifunctional Cu-Mn nanozymes certainly explore new paths in biochemical analysis and antimicrobial applications.
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Antibacterianos , Técnicas Biosensibles , Cobre , Escherichia coli , Glutatión Transferasa , Lacasa , Staphylococcus aureus , Lacasa/química , Humanos , Antibacterianos/farmacología , Antibacterianos/química , Glutatión Transferasa/química , Escherichia coli/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Cobre/química , Cobre/farmacología , Catálisis , Oxidación-Reducción , Límite de Detección , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Clorofenoles/farmacología , Clorofenoles/química , Colorimetría/métodos , Óxidos/química , Compuestos de Manganeso/química , Compuestos de Manganeso/farmacología , Nanoestructuras/químicaRESUMEN
INTRODUCTION: Adjunctive cenobamate was effective and safe for the treatment of uncontrolled focal onset seizures in a randomized, double-blind, placebo-controlled, phase 2 study (YKP3089C017; NCT01866111). This post-hoc analysis assessed the efficacy of adjunctive cenobamate in the treatment of patients with different epileptic etiologies during the study. METHODS: Adult patients with uncontrolled focal seizures who previously received 1 to 3 antiseizure medications (ASMs) were randomly assigned in a ratio of 1:1:1:1 to receive placebo or cenobamate 100, 200 or 400 mg/day. Patients were further stratified based on their etiologic causes as genetic/presumed genetic, unknown cause, structural cause, and not reported (NR) groups. The frequency per 28 days for an 18-week double-blind treatment period, responder rates (≥50 %, ≥75 %, ≥90 %, and 100 %) during the maintenance phase (12 weeks), and safety were assessed. RESULTS: A total of 394 patients were categorized into the genetic/presumed genetic (n = 9; 2.28 %), unknown cause (n = 199; 50.51 %), structural cause (n = 177; 44.92 %), and NR (n = 13; 3.30 %) groups, with 4 patients were classified into either of the two etiological causes each. The baseline characteristics were comparable. The percentage of reduction in seizure frequency per 28 days was significantly higher in the cenobamate-treated structural (p = 0.01) and unknown cause (p = 0.0003) groups compared with the placebo group. Responder rates of ≥50 %, ≥75 %, ≥90 %, and 100 % were also higher with cenobamate therapy. Notably, no serious treatment-emergent adverse events (TEAEs) were observed in the genetic/presumed genetic group treated with cenobamate. The most common TEAEs (≥10 %) occurring in patients treated with cenobamate were nervous system disorders by system organ class, and somnolence was the most commonly reported TEAE. CONCLUSION: Cenobamate reduces seizures in adult patients previously treated with ASMs, with high responder rates and acceptable safety, regardless of underlying causes.
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Anticonvulsivantes , Carbamatos , Clorofenoles , Humanos , Método Doble Ciego , Masculino , Anticonvulsivantes/uso terapéutico , Femenino , Carbamatos/uso terapéutico , Carbamatos/efectos adversos , Adulto , Persona de Mediana Edad , Clorofenoles/efectos adversos , Clorofenoles/uso terapéutico , Clorofenoles/farmacología , Clorofenoles/administración & dosificación , Quimioterapia Combinada , Adulto Joven , Resultado del Tratamiento , Convulsiones/tratamiento farmacológico , Anciano , Adolescente , TetrazolesRESUMEN
A new Mg-doped Zn0.5Ni0.5Fe2O4 (Mg-FZN) photocatalyst was synthesised using a simple co-precipitation-doping technique to develop a dual-function material with the ability to degrade hazardous and refractory pollutants and inactivate bacterial strains. The characterization results revealed that Mg-FZN is an n-type semiconductor with a conduction band of -0.413 eV, an average pore width of 2.32 nm, and a crystal size of 31.45 nm. The photocatalytic activity of Mg-FZN was assessed based on the degradation of 2,4,5-trichlorophenol and achieved 83.8% degradation efficiency under optimised conditions. The radical quenching results revealed that h+ significantly contributed to the photodegradation process while â¢OH, and â¢O2- played key roles. Additionally, within 60 min, 25 mg of Mg-FZN had bactericidal effects on the bacteria E. coli and S. aureus in both the presence and absence of UV light. Mg-FZN showed H-bonding, electrostatic, and metal-contact interactions with the amino acid residues of the bacterial protein with high binding scores (-4.711 kcal/mol and -5.872 kcal/mol), according to molecular docking.
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Clorofenoles , Staphylococcus aureus , Simulación del Acoplamiento Molecular , Escherichia coli , Clorofenoles/farmacología , MetalesRESUMEN
Tetrachlorobisphenol A (TCBPA), an alternative to tetrabromobisphenol A (TBBPA), is ubiquitous in the environment and could potentially impact the reproductive system of organisms. However, the mechanisms underlying TCBPA-mediated reproductive effects remain unclear. Herein, we exposed Caenorhabditis elegans (C. elegans, L4 larvae) to TCBPA at environmentally relevant doses (0-100⯵g/L) for 24â¯h. Exposure to TCBPA at concentrations of 1-100⯵g/L impaired fertility of C. elegans, as indicated by brood size. After staining, the number of germline cells decreased in a dose-dependent manner, whereas germline cell corpses increased in exposed nematodes (10-100⯵g/L TCBPA). Moreover, the expression of genes related to the germline apoptosis pathway was regulated following exposure to 100⯵g/L TCBPA, indicating the potential role of DNA damage in TCBPA-induced apoptosis. Apoptosis was nearly abolished in ced-4 and ced-3 mutants and blocked in hus-1, egl-1, cep-1, and ced-9 mutants. Numerous foci were detected in TCBPA (100⯵g/L)-exposed hus-1::GFP strains. These results indicate that TCBPA induces hus-1-mediated DNA damage and further causes apoptosis via a cep-1-dependent pathway. Our data provide evidence that TCBPA causes reproductive toxicity via DNA damage-induced apoptosis.
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Proteínas de Caenorhabditis elegans , Clorofenoles , Animales , Apoptosis , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Clorofenoles/farmacología , Daño del ADNRESUMEN
Aquatic organisms have been used to investigate the safety of chemicals worldwide. One such assessment is an algal growth inhibition test. Algal growth inhibition tests are commonly performed using a growth chamber with fluorescent lamps as the lighting source, as test guidelines require continuous uniform fluorescent illumination. However, fluorescent lamps contain mercury, which has been identified as hazardous to humans and other organisms. The Minamata Convention (adopted in 2013) requires reduction or prohibition of products containing mercury. On the other hand, light-emitting diodes do not contain mercury and provide a photosynthetically effective wavelength range of 400-700 nm which is an adequate light intensity for algal growth. Light-emitting diodes are thus preferable to fluorescent lamps as a potential light source in algal growth inhibition tests. In this study, we investigated if light-emitting diodes could be substituted for fluorescent lamps in growth inhibition studies with green alga (Pseudokirchneriella subcapitata), diatom (Navicula pelliculosa), and cyanobacteria (Anabaena flos-aquae). Algal growth inhibition tests were performed using five different chemicals known to have different modes of action and are assigned as reference substances in the test guidelines. The results of each algal test showed similar values between light-emitting diodes and fluorescent lamps in terms of conditions for the growth inhibition rate and percent inhibition in yield of each chemical. It was therefore concluded that using light-emitting diodes instead of fluorescent lamps as a lighting source had no effect on the algal growth inhibition test results.
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Chlorophyta/crecimiento & desarrollo , Cianobacterias/crecimiento & desarrollo , Diatomeas/crecimiento & desarrollo , Luz/efectos adversos , Cloruro de Cadmio/farmacología , Clorofenoles/farmacología , Fluorescencia , Técnicas Microbiológicas , Presión Osmótica/efectos de los fármacos , Fosforilación Oxidativa/efectos de los fármacos , Pentaclorofenol/farmacología , Fotosíntesis/efectos de los fármacos , Dicromato de Potasio/farmacología , Cloruro de Sodio/farmacologíaRESUMEN
Flavonoids are small molecular secondary metabolites, which have a variety of biological functions. Transcriptional regulations of key enzyme genes play critical roles in the flavonoid biosynthesis. In this study, an R2R3-MYB transcription factor gene, SlMYB14, was isolated from tomato and characterized. The nucleus-localized SlMYB14 functions as a transcriptional activator in yeast. The expression of SlMYB14 could be induced by methyl jasmonic acid, wounding and ABA. SlMYB14 works downstream of SlMYC2 in the jasmonate signaling pathway. Overexpression of SlMYB14 under the control of CaMV35S promoter in tomato led to increased accumulation of flavonoids. RNA-sequencing analysis revealed that the transcript levels of several structural genes associated with flavonoid biosynthesis were up-regulated in transgenic tomato plants. Gel-shift assays confirmed that SlMYB14 protein could bind to the promoter regions of SlPAL genes. It was also found that overexpression of SlMYB14 improved the tolerance of transgenic plants to 2,4,6-trichlorophenol (2,4,6-TCP), an environmental organic pollutant which could cause serious oxidative damage to plant. These results suggest that SlMYB14 participates in the regulation of flavonoid biosynthesis and might play a role in maintaining reactive oxygen species homeostasis in plant. SlMYB14 gene also has the potential to contribute to the phytoremediation of 2,4,6-TCP-contaminated soils.
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Clorofenoles/farmacología , Contaminantes Ambientales/farmacología , Flavonoides/metabolismo , Proteínas de Plantas/fisiología , Proteínas Proto-Oncogénicas c-myb/fisiología , Solanum lycopersicum/metabolismo , Acetatos/metabolismo , Western Blotting , Mapeo Cromosómico , Ciclopentanos/metabolismo , Ensayo de Cambio de Movilidad Electroforética , Genes de Plantas/genética , Solanum lycopersicum/genética , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Proteínas Proto-Oncogénicas c-myb/genética , Proteínas Proto-Oncogénicas c-myb/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Análisis de Secuencia de ARN , Transducción de Señal , Transcriptoma , Tricomas/metabolismoRESUMEN
Introduction: Despite the introduction of numerous new antiseizure medications (ASMs) still about one-third of epilepsies remain drug-resistant. Therefore, new compounds with advanced efficacy are urgently needed. Cenobamate (CNB) is a new ASM that has been recently introduced in the United States for the treatment of adults with focal-onset seizures. The approval in Europe is under way.Areas covered: This review covers the pharmacological profile of CNB, the proof-of-concept trial, the two double-blind, placebo-controlled phase 2 trials investigating adjunct CNB in adults with focal-onset seizures, one open-label safety trial, and a variety of published abstract material that provided additional post hoc data.Expert opinion: In two placebo-controlled randomized multicenter phase 2 trials adjunct CNB showed unusually high efficacy with rates of seizure-free people with epilepsy (PWE) partially beyond 20%. However, during the clinical program cases of drug-related reactions with eosinophilia and systemic symptoms (DRESS syndrome) occurred. Therefore, an open-label safety study was performed in more than 1300 PWE with particularly slower titration schedules which did not add more cases with similar reactions. Taking into consideration the promising efficacy and the safety experience from the open-label trial, CNB applied according to the meanwhile recommended titration strategy, might offer a new prospect.
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Anticonvulsivantes/administración & dosificación , Carbamatos/administración & dosificación , Clorofenoles/administración & dosificación , Epilepsias Parciales/tratamiento farmacológico , Tetrazoles/administración & dosificación , Adulto , Animales , Anticonvulsivantes/efectos adversos , Anticonvulsivantes/farmacología , Carbamatos/efectos adversos , Carbamatos/farmacología , Clorofenoles/efectos adversos , Clorofenoles/farmacología , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Comprimidos , Tetrazoles/efectos adversos , Tetrazoles/farmacologíaRESUMEN
OBJECTIVE: To review the pharmacology, efficacy, and safety of oral cenobamate in the treatment of uncontrolled focal epilepsy. DATA SOURCES: The PubMed database and ClinicalTrials.gov were searched using the following terms: cenobamate, Xcopri, and YKP3089. STUDY SELECTION AND DATA EXTRACTION: Articles published in English between January 2000 and April 2020 related to pharmacology, safety, and clinical trials were assessed. DATA SYNTHESIS: In a phase 2 trial, cenobamate reduced the median percentage change in seizure frequency from baseline by 56% compared with 22% for placebo (P < 0.0001). In another phase 2 trial of multiple cenobamate doses, cenobamate reduced seizure frequency by 36% (P = 0.0071) in the 100-mg group and 55% (P < 0.0001) in both the 200- and 400-mg groups, compared to 24% with placebo. Adverse effects of cenobamate appear to be similar to those of other antiseizure medications and primarily affect the neurological system. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: In patients taking antiseizure medications who continue to have focal seizures, cenobamate has efficacy at multiple doses and is generally well tolerated. Cenobamate may be distinguished from other antiseizure medications by high rates of seizure freedom not seen in previous placebo-controlled trials, which has the potential to significantly improve quality of life. However, despite this efficacy, Drug Reaction with Eosinophilia and Systemic Symptoms may remain a significant concern with cenobamate. CONCLUSION: As seen in clinical trials, cenobamate as an adjunctive, once-daily treatment represents an efficacious and generally well-tolerated therapy for patients with drug-resistant focal epilepsy.
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Anticonvulsivantes/uso terapéutico , Carbamatos/uso terapéutico , Quimioterapia Adyuvante/métodos , Clorofenoles/uso terapéutico , Epilepsias Parciales/tratamiento farmacológico , Calidad de Vida/psicología , Tetrazoles/uso terapéutico , Adolescente , Adulto , Anciano , Animales , Anticonvulsivantes/farmacología , Carbamatos/farmacología , Clorofenoles/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ratas , Tetrazoles/farmacología , Adulto JovenRESUMEN
Tetrachlorobisphenol A (TCBPA) is used as flame retardant, and it has been widely detected in the environmental and human samples. TCBPA is an endocrine disrupting chemical, but its effects on the immune system remains poorly understood. Here the effects of TCBPA on immune system were studied using combined in vivo and in vitro assays. Results showed that TCBPA could suppress the immune response in BALB/c mice via reducing the ratio of CD3+ T lymphocytes to regulatory T cells. Moreover, TCBPA exposure significantly induced the increasing secretion of four pro-inflammatory cytokines (IL-2, IL-12, IFN-γ, and TNF-α) and four anti-inflammatory cytokines (IL-4, IL-5, IL-10, GM-CSF) in mice serum. Interestingly, uterine edema was observed in over 80% TCBPA-treated mice after 14- day exposure. TCBPA was detected in 18.6% serum samples of 150 female volunteers in this study. Therefore, our findings provided evidence that TCBPA exposure may cause adverse outcomes on immune system and uterus, suggesting that environmental exposure of TCBPA, as well as its adverse effects on human health should be of concern.
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Antiinflamatorios/farmacología , Clorofenoles/farmacología , Sistema Inmunológico/efectos de los fármacos , Animales , Citocinas , Femenino , Retardadores de Llama , Humanos , Terapia de Inmunosupresión , Ratones , Ratones Endogámicos BALB C , Transducción de Señal , Linfocitos T , ÚteroRESUMEN
INTRODUCTION: Uncontrolled epilepsy has persisted despite development of numerous antiseizure medications (ASMs) over the past 25 years, and more effective treatments are needed. Cenobamate is a new ASM approved in the US for treatment of adults with focal onset seizures. AREAS COVERED: This review outlines cenobamate study results from preclinical animal models through phase 2 and 3 clinical studies. Topics include mechanisms of action, pharmacokinetics, efficacy, and safety of cenobamate. Information on dosing, tolerability, and special populations are included to help healthcare providers understand this new ASM. EXPERT OPINION: Adjunctive cenobamate shows a high level of efficacy in patients with refractory focal epilepsy compared to that reported for other ASMs. Most notable are reductions in monthly seizure frequency (up to 55%) and unprecedented seizure-free rates (up to 28%) with cenobamate in patients with refractory epilepsy despite the concomitant use of 1-3 ASMs. Cenobamate was generally safe and well-tolerated, with a safety profile similar to other ASMs. Due to 3 early cases of DRESS, however, the cenobamate starting dose was lowered and titration rate slowed; no additional cases occurred. If efficacy responses in real-world use reflect what have been observed in clinical studies, cenobamate would be a welcome new treatment option.
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Anticonvulsivantes/farmacología , Carbamatos/farmacología , Clorofenoles/farmacología , Epilepsia Refractaria/tratamiento farmacológico , Tetrazoles/farmacología , Adulto , Animales , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/efectos adversos , Carbamatos/administración & dosificación , Carbamatos/efectos adversos , Clorofenoles/administración & dosificación , Clorofenoles/efectos adversos , Humanos , Tetrazoles/administración & dosificación , Tetrazoles/efectos adversosRESUMEN
BACKGROUND: Cenobamate is a novel tetrazole-derived carbamate compound with a dual mechanism of action. This drug can enhance the inactivated state of voltage-gated sodium channels, preferentially inhibiting the persistent component of the sodium channel current, and acts as a positive allosteric modulator of GABAA receptors, binding at a non-benzodiazepine site. OBJECTIVE: We assessed the efficacy and safety of adjunctive cenobamate for the treatment of focal-onset seizures in adult patients with epilepsy using meta-analytical techniques. METHODS: We systematically searched (May, week 4, 2020) MEDLINE (accessed by PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and the US National Institutes of Health Clinical Trials Registry ( http://www.clinicaltrials.gov ). There were no date limitations or language restrictions. Randomized, placebo-controlled, single or double-blinded, add-on trials of cenobamate in adult patients with uncontrolled focal-onset seizures were identified. Main outcomes included the proportion of patients with ≥ 50 and 100% reduction in seizure frequency during the maintenance treatment period compared with baseline and the incidence of treatment withdrawal and adverse events (AEs). Risk ratio (RR) with 95% confidence interval (CI) was estimated for each outcome. RESULTS: Two trials were included, overall enrolling 659 patients (442 for the add-on cenobamate group and 217 for the add-on placebo group). Seizure frequency reduction by at least 50% occurred during the maintenance phase in 50.1% of the patients randomized to cenobamate and 23.5% of the placebo-treated participants (RR 2.18, 95% CI 1.67-2.85; p < 0.001). The pooled estimated RR to achieve seizure freedom for the cenobamate group in comparison with placebo was 3.71 (95% CI 1.93-7.14; p < 0.001). Withdrawal from randomized treatment occurred in 16.7 and 11.1% of participants receiving cenobamate and placebo, respectively (RR 1.34, 95% CI 0.85-2.09; p = 0.205). Treatment was discontinued due to AEs in 12.2 and 4.1% of the patients in the active and control arms (RR 2.27, 95% CI 1.08-4.79; p = 0.031). AEs were reported in 76.9 and 66.8% of the patients during treatment with cenobamate and placebo (RR 1.14, 95% CI 1.02-1.26; p = 0.021). The cenobamate-associated AEs included somnolence, dizziness, fatigue, balance disorder, and diplopia. CONCLUSIONS: Adjunctive cenobamate in adult patients with uncontrolled focal-onset seizures is associated with a greater reduction in seizure frequency and a higher rate of AEs than placebo.
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Anticonvulsivantes/farmacología , Carbamatos/farmacología , Clorofenoles/farmacología , Convulsiones/tratamiento farmacológico , Tetrazoles/farmacología , Adulto , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/efectos adversos , Carbamatos/administración & dosificación , Carbamatos/efectos adversos , Clorofenoles/administración & dosificación , Clorofenoles/efectos adversos , Quimioterapia Combinada , Epilepsia/tratamiento farmacológico , Epilepsia/fisiopatología , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Convulsiones/fisiopatología , Tetrazoles/administración & dosificación , Tetrazoles/efectos adversos , Resultado del TratamientoRESUMEN
2,4-Dichlorophenol (2,4-DCP), an environmental pollutant, was reported to cause hepatotoxicity. The biochemical mechanisms of 2,4-DCP induced liver injury remain unknown. The present study showed that 2,4-DCP is chemically reactive and spontaneously reacts with GSH and bovine serum albumin to form GSH conjugates and BSA adducts. The observed conjugation/adduction apparently involved the addition of GSH and departure of chloride via the ipso substitution pathway. Two biliary GSH conjugates and one urinary N-acetyl cysteine conjugate were observed in rats given 2,4-DCP. The N-acetyl cysteine conjugate was chemically synthesized and characterized by mass spectrometry and NMR. As expected, 2,4-DCP was found to modify hepatic protein at cysteine residues in vivo by the same chemistry. The observed protein adduction reached its peak at 15 min and revealed dose dependency. The new findings allowed us to better understand the mechanisms of the toxic action of 2,4-DCP.
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Clorofenoles/farmacología , Contaminantes Ambientales/farmacología , Glutatión/antagonistas & inhibidores , Albúmina Sérica Bovina/antagonistas & inhibidores , Animales , Bovinos , Clorofenoles/química , Cisteína/antagonistas & inhibidores , Cisteína/química , Contaminantes Ambientales/química , Glutatión/química , Masculino , Ratones , Ratones Endogámicos , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Albúmina Sérica Bovina/químicaRESUMEN
Biofilm-forming bacteria, including the Gram-negative Pseudomonas aeruginosa, cause multiple types of chronic infections and are responsible for serious health burdens in humans, animals, and plants. Nitric oxide (NO) has been shown to induce biofilm dispersal via triggering a reduction in cyclic-di-GMP levels in a variety of bacteria. However, how NO, at homeostatic levels, also facilitates biofilm formation is unknown. Here, we found that complestatin, a structural analog of vancomycin isolated from Streptomyces, inhibits P. aeruginosa biofilm formation by upregulating NO production via nitrite reductase (NIR) induction and c-di-GMP degradation via phosphodiesterase (PDE) stimulation. The complestatin protein target was identified as a nitrite transporter from a genome-wide screen using the Keio Escherichia coli knockout library and confirmed using nitrite transporter knockout and overexpression strains. We demonstrated that the nitrite transporter stimulated biofilm formation by controlled NO production via appropriate NIR suppression and subsequent diguanylate cyclase (DGC) activation, not PDE activity, and c-di-GMP production in E. coli and P. aeruginosa Thus, this study provides a mechanism for NO-mediated biofilm formation, which was previously not understood.IMPORTANCE Bacterial biofilms play roles in infections and avoidance of host defense mechanisms of medically important pathogens and increase the antibiotic resistance of the bacteria. Nitric oxide (NO) is reported to be involved in both biofilm formation and dispersal, which are conflicting processes. The mechanism by which NO regulates biofilm dispersal is relatively understood, but there are no reports about how NO is involved in biofilm formation. Here, by investigating the mechanism by which complestatin inhibits biofilm formation, we describe a novel mechanism for governing biofilm formation in Escherichia coli and Pseudomonas aeruginosa Nitrite transporter is required for biofilm formation via regulation of NO levels and subsequent c-di-GMP production. Additionally, the nitrite transporter contributes more to P. aeruginosa virulence than quorum sensing. Thus, this study identifies nitrite transporters as new antibiofilm targets for future practical and therapeutic agent development.
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Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Clorofenoles/farmacología , Nitrito Reductasas/antagonistas & inhibidores , Nitritos/metabolismo , Péptidos Cíclicos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Biblioteca de Genes , Óxido Nítrico/metabolismo , Nitrito Reductasas/genética , Pseudomonas aeruginosa/enzimología , Pseudomonas aeruginosa/genética , VirulenciaRESUMEN
Cenobamate is a novel antiepileptic drug under investigation for use in patients with focal (partial-onset) seizures. To understand its potential molecular mechanism of action, the effects of cenobamate on GABAA-mediated currents and GABAA receptors in rodent hippocampal neurons were examined. Cenobamate potentiated GABA-induced currents (IGABA) in acutely isolated CA3 pyramidal cells in a concentration-dependent manner (EC50, 164 µM), which was not affected by flumazenil, a benzodiazepine receptor antagonist. Cenobamate enhanced tonic GABAA currents (Itonic), which is defined as a holding current shift by the GABAA receptor antagonist bicuculline (EC50, 36.63 µM). At therapeutically relevant concentrations, cenobamate induced minimal changes in the frequency, amplitudes, and decay time of spontaneous inhibitory postsynaptic currents in the CA1 neurons. Flumazenil failed to affect cenobamate-potentiated Itonic and Iphasic in CA1 neurons. Cenobamate showed positive allosteric modulation of GABA-induced IGABA mediated by GABAA receptors. This effect was similar for all tested hGABAA receptors containing six different alpha subunits (α1ß2γ2 or α2-6ß3γ2), with EC50 values ranging from 42 to 194 µM. Cenobamate did not displace the binding of flunitrazepam, a benzodiazepine derivative, or flumazenil to GABAA receptors. The results showed that cenobamate, a novel antiepileptic drug, acts as a positive allosteric modulator of high-affinity GABAA receptors, activated by GABA at a site independent of the benzodiazepine binding site and efficiently enhances Itonic inhibition in hippocampal neurons, which could be an underlying molecular mechanism stabilizing neural circuits of the epileptic hippocampus.
Asunto(s)
Anticonvulsivantes/farmacología , Región CA1 Hipocampal/efectos de los fármacos , Región CA3 Hipocampal/efectos de los fármacos , Carbamatos/farmacología , Clorofenoles/farmacología , Neuronas/efectos de los fármacos , Receptores de GABA-A/fisiología , Tetrazoles/farmacología , Animales , Región CA1 Hipocampal/fisiología , Región CA3 Hipocampal/fisiología , Femenino , Células HEK293 , Humanos , Masculino , Neuronas/fisiología , Ratas Sprague-Dawley , Ratas WistarRESUMEN
Addressing the ongoing antibiotic crisis requires the discovery of compounds with novel mechanisms of action that are capable of treating drug-resistant infections1. Many antibiotics are sourced from specialized metabolites produced by bacteria, particularly those of the Actinomycetes family2. Although actinomycete extracts have traditionally been screened using activity-based platforms, this approach has become unfavourable owing to the frequent rediscovery of known compounds. Genome sequencing of actinomycetes reveals an untapped reservoir of biosynthetic gene clusters, but prioritization is required to predict which gene clusters may yield promising new chemical matter2. Here we make use of the phylogeny of biosynthetic genes along with the lack of known resistance determinants to predict divergent members of the glycopeptide family of antibiotics that are likely to possess new biological activities. Using these predictions, we uncovered two members of a new functional class of glycopeptide antibiotics-the known glycopeptide antibiotic complestatin and a newly discovered compound we call corbomycin-that have a novel mode of action. We show that by binding to peptidoglycan, complestatin and corbomycin block the action of autolysins-essential peptidoglycan hydrolases that are required for remodelling of the cell wall during growth. Corbomycin and complestatin have low levels of resistance development and are effective in reducing bacterial burden in a mouse model of skin MRSA infection.
Asunto(s)
Antibacterianos , Descubrimiento de Drogas , Péptidos Cíclicos , Peptidoglicano/efectos de los fármacos , Peptidoglicano/metabolismo , Actinobacteria/química , Actinobacteria/genética , Actinobacteria/metabolismo , Animales , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacología , Vías Biosintéticas/genética , Pared Celular/metabolismo , Clorofenoles/química , Clorofenoles/metabolismo , Clorofenoles/farmacología , Modelos Animales de Enfermedad , Farmacorresistencia Microbiana/efectos de los fármacos , Farmacorresistencia Microbiana/genética , Femenino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana , Familia de Multigenes , N-Acetil Muramoil-L-Alanina Amidasa/antagonistas & inhibidores , Péptidos Cíclicos/química , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacología , Filogenia , Piel/microbiología , Infecciones Estafilocócicas/microbiologíaRESUMEN
Metabolic uncouplers are widely used for reducing excess sludge in biological wastewater treatment systems. However, the formation of microbial products, such as extracellular polymeric substances, polyhydroxyalkanoate and soluble microbial products by activated sludge in the presence of metabolic uncouplers remains unrevealed. In this study, the impacts of a metabolic uncoupler o-chlorophenol (oCP) on the reduction of activated sludge yield and formation of microbial products in laboratory-scale sequencing batch reactors (SBRs) were evaluated for a long-term operation. The results show the average reduction of sludge yield in the four reactors was 17.40%, 25.80%, 33.02% and 39.50%, respectively, when dosing 5, 10, 15, and 20 mg/L oCP. The oCP addition slightly reduced the pollutant removal efficiency and decreased the formation of soluble microbial products in the SBRs, but stimulated the productions of extracellular polymeric substances and polyhydroxyalkanoate in activated sludge. Furthermore, the significant reduction of electronic transport system activity occurred after the oCP addition. Microbial community analysis of the activated sludge indicates dosing oCP resulted in a decrease of sludge richness and diversity in the SBRs. Hopefully, this study would provide useful information for reducing sludge yield in biological wastewater treatment systems and behaviors of activated sludge in the presence of uncouplers.
Asunto(s)
Clorofenoles/farmacología , Aguas del Alcantarillado/microbiología , Desacopladores/farmacología , Aguas Residuales/microbiología , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos , ADN Bacteriano/biosíntesis , ADN Bacteriano/genética , Polímeros/química , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/químicaRESUMEN
New, more effective pharmacologic treatments for epilepsy are needed, as a substantial portion of patients (>30%) are refractory to currently available anti-epileptic drugs. Cenobamate (YKP3089) is an investigational anti-epileptic drug in clinical development. Two completed adequate and well-controlled studies demonstrated a significant reduction in focal seizures with cenobamate in patients with epilepsy. In this study, we characterized the effects of cenobamate on voltage-gated Na+ channels in acutely isolated rat hippocampal CA3 neurons using a whole-cell patch-clamp technique. While cenobamate had little effect on the peak component of transient Na+ current (INaT) induced by brief depolarizing step pulses, it potently inhibited the non-inactivating persistent component of INa (INaP). In addition, cenobamate potently inhibited the current by slow voltage-ramp stimuli. Cenobamate significantly shifted the steady-state fast inactivation relationship toward a hyperpolarizing range, indicating that cenobamate binds to voltage-gated Na+ channels at the inactivated state with a higher affinity. Cenobamate also accelerated the development of inactivation and retarded recovery from inactivation of voltage-gated Na+ channels. In current clamp experiments, cenobamate hyperpolarized membrane potentials in a concentration-dependent manner, and these effects were mediated by inhibiting the INaP. Cenobamate also increased the threshold for generation of action potentials, and decreased the number of action potentials elicited by depolarizing current injection. Given that the INaP plays a pivotal role in the repetitive and/or burst generation of action potentials, the cenobamate-mediated preferential blockade of INaP might contribute to anti-epileptic activity.
Asunto(s)
Anticonvulsivantes/farmacología , Región CA3 Hipocampal/efectos de los fármacos , Región CA3 Hipocampal/fisiología , Carbamatos/farmacología , Clorofenoles/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Bloqueadores de los Canales de Sodio/farmacología , Tetrazoles/farmacología , Canales de Sodio Activados por Voltaje/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Femenino , Cinética , Masculino , Neuronas/citología , Ratas , Sodio/metabolismoRESUMEN
BACKGROUND: Chlorophenols (CPs), suspected as endocrine disrupting chemicals, exposure during early life may contribute to body size. However, limited human data with inconsistent findings have examined the developmental effects of CPs exposure. OBJECTIVE: To explore associations between prenatal and postnatal CPs exposure and anthropometric parameters in children aged 3 years. METHODS: A subset of 377 mother-child pairs with urinary five CP concentrations were enrolled from a prospective birth cohort. Generalized linear models were conducted to evaluate associations of CPs exposure with children's anthropometric measures. RESULTS: Maternal urinary 2,4,6-trichlorophenol (2,4,6-TCP) concentrations were significantly negatively associated with weight z scores [regression coefficient (ß)â¯=â¯-0.51, 95% confidence interval (CI): -0.96, -0.05; pâ¯=â¯0.01], weight for height z scores (ßâ¯=â¯-0.54, 95% CI: -1.02, -0.06; pâ¯=â¯0.01) and body mass index (BMI) z scores (ßâ¯=â¯-0.53, 95% CI: -1.03, -0.03; pâ¯=â¯0.01) of children aged 3 years, after adjustment for potential confounders and postnatal CPs exposure. In the sex-stratified analyses, these inverse associations remained among boys, while in girls, positive associations of prenatal 2,4,6-TCP exposure with weight for height z scores and BMI z scores were observed. Postnatal exposure to 2,5-diclorophenol (2,5-DCP) was positively associated with weight z scores (ßâ¯=â¯0.26, 95% CI: 0.02, 0.50; pâ¯=â¯0.04), after controlling for possible confounders and maternal CPs exposure during pregnancy. Considering potential sex-specific effects, these associations were only observed in girls. CONCLUSIONS: Our findings indicate that prenatal 2,4,6-TCP exposure and postnatal 2,5-DCP exposure may have adverse and sex-specific effects on children's physical development.
Asunto(s)
Pesos y Medidas Corporales , Desarrollo Infantil/efectos de los fármacos , Clorofenoles/farmacología , Exposición a Riesgos Ambientales/efectos adversos , Exposición Materna/efectos adversos , Adulto , Preescolar , Clorofenoles/efectos adversos , Clorofenoles/orina , Disruptores Endocrinos/efectos adversos , Femenino , Humanos , Masculino , Embarazo , Estudios ProspectivosRESUMEN
Chlorophenols (CPs) have mainly been used as a biocide, wood treatment agent and a byproduct of bleaching in paper mills. They have been a topic of concern due to their wide spread and potential effects on human and wildlife. However, data on the thresholds and effects of the number of chlorine atoms on the endocrine-disrupting potential of CPs remain scarce. In this study, we adopted two in vitro models (reporter gene assays and H295R cell line) to investigate the endocrine-disrupting effects of four CPs (pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,4-dichlorophenol (2,4-DCP) and 2-chlorophenol (2-CP)). The molecular docking platform was adopted to further confirm the results of the in vitro assessment. Our results revealed that PCP exhibited oestrogen receptor alpha (ERα) agonistic activity at the concentration of 10-5â¯M and the value of REC20 was 1.9â¯×â¯10-6â¯M. PCP and 2, 4, 6-TCP showed anti-oestrogenic activities with a RIC20 value of 2.8â¯×â¯10-7and 2.9â¯×â¯10-6â¯M, respectively. Notably, only PCP exhibited thyroid hormone receptor beta (TRß) antagonistic activity occurred at the concentration of 10-5â¯M, with a RIC20 value of 1.3â¯×â¯10-6â¯M. The oestrogenic and thyroid hormone effects of CPs may be dependent on the number of chlorine atoms. A higher number of chlorine atoms indicated the higher effect of four CPs. The results of molecular docking were consistent with the reporter gene assay. For H295R cell line assay, PCP induced the StAR upregulation, while CYP17 was downregulated in a concentration-dependent manner by PCP and 2, 4, 6-TCP.