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1.
Toxicology ; 430: 152346, 2020 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-31857189

RESUMEN

V-type agents are highly toxic organophosphorus nerve agents that inhibit acetylcholinesterase in the nervous system, causing a series of poison symptoms. Trace analytical methods are essential for the specific verification of exposure to these agents, especially for human exposure. This paper investigates the phosphonylated and disulfide adducts between human ceruloplasmin and O-ethyl S-(2-(diisopropylamino)ethyl) methylphosphonothioate (VX), O-isobutyl S-(2-(diethylamino)ethyl) methylphosphonothioate (VR), and O-butyl S-(2-(diethylamino)ethyl) methylphosphonothioate (Vs). After being digested by trypsin, the mixture of peptides was separated by a nano-liquid chromatography (nano-LC) and analyzed using quadrupole-orbitrap mass spectrometry (Q-Orbitrap-MS). The sensitive LC-MS/MS-assisted proteomics approach was developed to achieve the identification of human exposure to V-type agents based on these modified sites; results revealed that potential biomarkers could be derived from adducts based on the sulfur- and phosphorus-containing groups of V-type agents. This work offered a novel insight into the mechanism of disulfide-containing adducts resulting from the replacement of disulfide bridges by the thiolate groups from the V-type agents. Moreover, four disulfide adducts on human ceruloplasmin were also discovered during this research, specifically confirming exposure to the V-type agents. Furthermore, molecular simulation testified to the reactivity of the modified sites. Collectively, our findings suggest that the eleven binding sites on human ceruloplasmin have the potential use as a selective marker for prediction the V-type agent exposure in humans.


Asunto(s)
Ceruloplasmina/metabolismo , Sustancias para la Guerra Química/toxicidad , Etilaminas/toxicidad , Agentes Nerviosos/toxicidad , Sustancias para la Guerra Química/química , Cromatografía Liquida , Humanos , Simulación del Acoplamiento Molecular , Agentes Nerviosos/química , Compuestos Organotiofosforados/toxicidad , Proteómica , Espectrometría de Masas en Tándem
2.
Toxicol Lett ; 304: 50-57, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30658151

RESUMEN

Two emerging psychoactive substances, 2-(2,5-dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe), are being abused, leading to fatal and non-fatal intoxications. However, most of their adverse effects have been reported anecdotally. In the present study, cardiotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), and human ether-a-go-go-related gene (hERG) assay. Expression levels of p21 (CDC42/RAC)-activated kinase 1 (PAK1), one of known biomarkers for cardiotoxicity, were also analyzed. Both 25D-NBOMe and 25C-NBOMe at 100 µM reduced cell viability in MTT assay. At 2.0 mg/kg and 0.75 mg/kg, they prolonged QT intervals in rat ECG. PAK1 was down-regulated by treatment with these two test compounds. Furthermore, potassium channels were inhibited by 25D-NBOMe treatment in hERG assay. Taken together, these results suggest that both 25D-NBOMe and 25C-NBOMe have potential cardiotoxicity, especially regarding cardiac rhythm. Further studies are needed to confirm the relationship between PAK1 down-regulation and cardiotoxicity.


Asunto(s)
Bencilaminas/efectos adversos , Etilaminas/toxicidad , Cardiopatías/inducido químicamente , Frecuencia Cardíaca/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Fenetilaminas/farmacología , Psicotrópicos/efectos adversos , Potenciales de Acción , Animales , Bencilaminas/farmacología , Células CHO , Cardiotoxicidad , Supervivencia Celular , Cricetulus , Canal de Potasio ERG1/antagonistas & inhibidores , Canal de Potasio ERG1/metabolismo , Cardiopatías/metabolismo , Cardiopatías/fisiopatología , Masculino , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Fenetilaminas/efectos adversos , Psicotrópicos/farmacología , Ratas Sprague-Dawley , Quinasas p21 Activadas/metabolismo
3.
Drug Chem Toxicol ; 42(6): 649-656, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30025483

RESUMEN

To confirm the usefulness of zebrafish for evaluating the teratogenic potential of drug candidates, the effect of O-ethylhydroxylamine hydrochloride (OHY), which induces mutagenesis by methylation, was evaluated in teratogenicity studies in rats and zebrafish. In the rat teratogenicity study, OHY-induced cardiovascular malformations such as increased abnormal vascular structures and ventricular septal defects. In the teratogenicity study using zebrafish-injected microspheres and green fluorescent protein-expressing Tg zebrafish (flk1:EGFP), OHY exposure was associated with the loss or malformation of the mandibular arch, opercular artery, and fourth branchial arch. These results suggested that OHY-induced external malformations in zebrafish eleutheroembryos adequately reflect OHY's teratogenicity in rat fetuses. Moreover, the zebrafish teratogenicity study incorporating vascular morphological examinations, including those of blood vessels in the heart, head and trunk, is an easy and reliable screening method to detect potential drug-induced teratogenicity and phenotypic characteristics.


Asunto(s)
Anomalías Cardiovasculares/inducido químicamente , Modelos Animales de Enfermedad , Teratogénesis/efectos de los fármacos , Teratógenos/toxicidad , Animales , Sistema Cardiovascular/efectos de los fármacos , Sistema Cardiovascular/fisiopatología , Embrión no Mamífero , Etilaminas/toxicidad , Femenino , Proteínas Fluorescentes Verdes/genética , Hidroxilaminas/toxicidad , Masculino , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie , Pez Cebra
4.
ChemMedChem ; 13(19): 2104-2118, 2018 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-30098232

RESUMEN

Chagas disease, a neglected tropical disease caused by infection with the protozoan parasite Trypanosoma cruzi, is a potentially life-threatening illness that affects 5-8 million people in Latin America, and more than 10 million people worldwide. It is characterized by an acute phase, which is partly resolved by the immune system, but then develops as a chronic disease without an effective treatment. There is an urgent need for new antiprotozoal agents, as the current standard therapeutic options based on benznidazole and nifurtimox are characterized by limited efficacy, toxicity, and frequent failures in treatment. In vitro and in vivo assays were used to identify some new low-cost 5-nitroindazoles as a potential antichagasic therapeutic alternative. Compound 16 (3-benzyloxy-5-nitro-1-vinyl-1H-indazole) showed improved efficiency and lower toxicity than benznidazole in both in vitro and in vivo experiments, and its trypanocidal activity seems to be related to its effect at the mitochondrial level. Therefore, compound 16 is a promising candidate for the development of a new anti-Chagas agent, and further preclinical evaluation should be considered.


Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Etilaminas/uso terapéutico , Indazoles/uso terapéutico , Tripanocidas/uso terapéutico , Animales , Chlorocebus aethiops , ADN/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Inhibidores Enzimáticos/toxicidad , Etilaminas/síntesis química , Etilaminas/farmacología , Etilaminas/toxicidad , Femenino , Indazoles/síntesis química , Indazoles/farmacología , Indazoles/toxicidad , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones Endogámicos BALB C , Enfermedades Desatendidas/tratamiento farmacológico , ARN/metabolismo , Superóxido Dismutasa/antagonistas & inhibidores , Tripanocidas/síntesis química , Tripanocidas/farmacología , Tripanocidas/toxicidad , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/crecimiento & desarrollo , Células Vero
5.
Biomacromolecules ; 19(7): 2759-2771, 2018 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-29791802

RESUMEN

We show the potential of oligo(2-ethyl-2-oxazoline) (Oxn)-shielded graft copolymers of (2-aminoethyl)-methacrylate and N-methyl-(2-aminoethyl)-methacrylate for pDNA delivery in HEK cells. For the effect of grafting density and side chain length concerning improved transfection properties through the concept of shielding to be investigated, copolymers were synthesized via the macromonomer method using a combination of cationic ring opening polymerization and reversible addition-fragmentation chain transfer polymerization to vary the degree of grafting (DG = 10 and 30%) as well as the side chain degree of polymerization (DP = 5 and 20). Investigations of the polyplex formation, in vitro flow cytometry, and confocal laser scanning microscopy measurements on the copolymer library revealed classical shielding properties of the Ox side chains, including highly reduced cytotoxicity and a partial decrease in transfection efficiency, as also reported for polyethylene glycol shielding. In terms of the transfection efficiency, the best performing copolymers (A- g-Ox5(10) and M- g-Ox5(10)) revealed equal or better performances compared to those of the corresponding homopolymers. In particular, the graft copolymers with low DG and side chain DP transfected well with over 10-fold higher IC50 values. In contrast, a DG of 30% resulted in a loss of transfection efficiency due to missing ability for endosomal release, and a side chain DP of 20 hampered the cellular uptake.


Asunto(s)
Etilaminas/química , Metacrilatos/química , Oxazoles/química , Transfección/métodos , Animales , Etilaminas/toxicidad , Células HEK293 , Humanos , Metacrilatos/toxicidad , Ratones , Oxazoles/toxicidad , Ovinos
6.
Comput Methods Programs Biomed ; 142: 9-19, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28325450

RESUMEN

BACKGROUND AND OBJECTIVES: Early-phase virtual screening of candidate drug molecules plays a key role in pharmaceutical industry from data mining and machine learning to prevent adverse effects of the drugs. Computational classification methods can distinguish approved drugs from withdrawn ones. We focused on 6 data sets including maximum 110 approved and 110 withdrawn drugs for all and nervous system diseases to distinguish approved drugs from withdrawn ones. METHODS: In this study, we used support vector machines (SVMs) and ensemble methods (EMs) such as boosted and bagged trees to classify drugs into approved and withdrawn categories. Also, we used CORINA Symphony program to identify Toxprint chemotypes including over 700 predefined chemotypes for determination of risk and safety assesment of candidate drug molecules. In addition, we studied nervous system withdrawn drugs to determine the key fragments with The ParMol package including gSpan algorithm. RESULTS: According to our results, the descriptors named as the number of total chemotypes and bond CN_amine_aliphatic_generic were more significant descriptors. The developed Medium Gaussian SVM model reached 78% prediction accuracy on test set for drug data set including all disease. Here, bagged tree and linear SVM models showed 89% of accuracies for phycholeptics and psychoanaleptics drugs. A set of discriminative fragments in nervous system withdrawn drug (NSWD) data sets was obtained. These fragments responsible for the drugs removed from market were benzene, toluene, N,N-dimethylethylamine, crotylamine, 5-methyl-2,4-heptadiene, octatriene and carbonyl group. CONCLUSION: This paper covers the development of computational classification methods to distinguish approved drugs from withdrawn ones. In addition, the results of this study indicated the identification of discriminative fragments is of significance to design a new nervous system approved drugs with interpretation of the structures of the NSWDs.


Asunto(s)
Simulación por Computador , Sistema Nervioso/efectos de los fármacos , Retirada de Medicamento por Seguridad/estadística & datos numéricos , Máquina de Vectores de Soporte , Algoritmos , Área Bajo la Curva , Benceno/toxicidad , Carbono , Minería de Datos , Aprobación de Drogas , Monitoreo de Drogas , Etilaminas/toxicidad , Reacciones Falso Positivas , Humanos , Modelos Lineales , Seguridad del Paciente , Reconocimiento de Normas Patrones Automatizadas/métodos , Preparaciones Farmacéuticas/química , Vigilancia de Productos Comercializados/normas , Riesgo , Sensibilidad y Especificidad , Tolueno/toxicidad
7.
Org Biomol Chem ; 14(47): 11220-11229, 2016 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-27841892

RESUMEN

The marine secondary metabolite stryphnusin (1) was isolated from the boreal sponge Stryphnus fortis, collected off the Norwegian coast. Given its resemblance to other natural acetylcholinesterase antagonists, it was evaluated against electric eel acetylcholinesterase and displayed inhibitory activity. A library of twelve synthetic phenethylamine analogs, 2a-7a and 2b-7b, containing tertiary and quaternary amines respectively were synthesized to investigate the individual structural contributions to the activity. Compound 7b was the strongest competitive inhibitor of both acetylcholinesterase and butyrylcholinesterase with IC50 values of 57 and 20 µM, respectively. This inhibitory activity is one order of magnitude higher than the positive control physostigmine, and is comparable with several other marine acetylcholinesterase inhibitors. The physiological effect of compound 7b on muscle function and neuromuscular transmission was studied and revealed a selective mode of action at the investigated concentration. This data is of importance as the interference of therapeutic acetylcholinesterase inhibitors with neuromuscular transmission can be problematic and lead to unwanted side effects. The current findings also provide additional insights into the structure-activity relationship of both natural and synthetic acetylcholinesterase inhibitors.


Asunto(s)
Acetilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Etilaminas/química , Etilaminas/farmacología , Músculos/efectos de los fármacos , Músculos/fisiología , Unión Neuromuscular/efectos de los fármacos , Poríferos/química , Animales , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/toxicidad , Electrophorus , Etilaminas/aislamiento & purificación , Etilaminas/toxicidad , Halogenación , Concentración 50 Inhibidora , Ratones , Unión Neuromuscular/citología , Relación Estructura-Actividad
9.
J Biomater Sci Polym Ed ; 24(1): 45-60, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22289623

RESUMEN

Novel well-defined hydrophilic cationic polymers with different length of polycation chain for gene delivery, poly(vinyl pyrrolidone)-graft-poly(2-dimethylaminoethyl methacrylate)s (PPDs), were synthesized by atom transfer radical polymerization (ATRP). The chemical structures and compositions of these polymers were characterized by FT-IR, (1)H-NMR and GPC. The experimental results of dynamic light scattering (DLS), ζ-potential and transmission electron microscopy (TEM) indicated that PPD could condense plasmid DNA (pDNA) to form nanocomplexes. Agarose gel retardation assays demonstrated that PPD could encapsulate plasmid DNA completely when the N/P ratio is equal to or above 3. MTT assay and in vitro gene transfection results indicated that PPD/pDNA complexes exhibited high transfection efficiency concomitant with obvious cytotoxicity. Furthermore, bovine serum albumin (BSA) was utilized to assembly with the binary complexes of PPD/pDNA to screen the residual surface positive charges of complexes in order to decrease cytotoxicity of the binary complexes. Physicochemical properties were characterized and the results indicated that the coating of BSA was able to decrease the zeta potential of the nano-sized PPD/pDNA complexes nearly to electroneutrality without interfering with DNA condensation ability. The ternary complexes of BSA/PPD/pDNA demonstrated no cytotoxicity and also maintained high gene transfection efficiency in HepG2 cells in 10% serum compared with that in serum-free condition.


Asunto(s)
Materiales Biocompatibles Revestidos/química , ADN/administración & dosificación , Etilaminas/química , Metacrilatos/química , Povidona/química , Albúmina Sérica Bovina/química , Transfección , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/toxicidad , ADN/genética , Etilaminas/toxicidad , Células Hep G2 , Humanos , Metacrilatos/toxicidad , Plásmidos/administración & dosificación , Plásmidos/genética , Povidona/toxicidad , Albúmina Sérica Bovina/toxicidad
10.
Toxicology ; 303: 1-8, 2013 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-23142791

RESUMEN

Renal papillary injury is a common side effect observed during nonclinical and clinical investigations in drug development. The present study aimed to identify genomic biomarkers for early and sensitive detection of renal papillary injury in rats. We hypothesized that previously identified genomic biomarkers for tubular injury might be applicable for the sensitive detection of papillary injury in rats. We selected 18 genes as candidate biomarkers for papillary injury based on previously published studies and analyzed their expression profiles by RT-PCR in each kidney region, namely the cortex, cortico-medullary junction, and papilla in various nephrotoxicity models. Comparative analysis of gene expression profiles revealed that some genes were commonly upregulated or downregulated in the renal papilla, reflecting papillary injuries induced by 2-bromoethylamine hydrobromide, phenylbutazone, or n-phenylanthranilic acid. By applying receiver operator characteristics analysis, six candidate biomarkers were identified and their usefulness was confirmed by using an independent data set. The three top-ranked genes, Timp1, Igf1, and Lamc2, exhibited the best prediction performance in an external data set with area under the curve (AUC) values of greater than 0.91. An optimized support vector machine model consisting of three genes achieved the highest AUC value of 0.99. In conclusion, even though definitive validation studies are required for the establishment of their usefulness and reliability, these identified genes may prove to be the most promising candidate genomic biomarkers of renal papillary injury in rats.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/genética , Enfermedades Renales/inducido químicamente , Médula Renal/efectos de los fármacos , Laminina/genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Animales , Área Bajo la Curva , Regulación hacia Abajo/efectos de los fármacos , Etilaminas/toxicidad , Perfilación de la Expresión Génica , Marcadores Genéticos , Riñón/efectos de los fármacos , Riñón/patología , Enfermedades Renales/genética , Enfermedades Renales/patología , Médula Renal/patología , Masculino , Fenilbutazona/toxicidad , Curva ROC , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Toxicogenética/métodos , Regulación hacia Arriba/efectos de los fármacos , ortoaminobenzoatos/toxicidad
11.
Psychopharmacology (Berl) ; 226(3): 475-90, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23184281

RESUMEN

RATIONALE: Selective 5-HT2C receptor agonists, such as lorcaserin, are being developed for the treatment of obesity. Studies suggest that they may also have therapeutic potential for addictive behaviours including nicotine dependence, although few drugs of this class have been evaluated. OBJECTIVES: The primary aim was to evaluate the highly selective 5-HT2C agonist, CP-809101, against food-motivated (operant FR5 and progressive ratio schedules, palatability-induced feeding) and nicotine-motivated (intravenous self-administration, drug discrimination) behaviours in rats and to compare with equivalent findings for the structurally distinct 5-HT2C receptor agonists lorcaserin and Ro 60-0175. The secondary aims were to evaluate the side effect profiles of lorcaserin and CP-809101 and to determine the plasma levels of lorcaserin at a dose (1 mg/kg) that reduces both food and nicotine reinforcement for comparison to plasma concentrations reported in human trials. RESULTS: CP-809101 (0.3-3 mg/kg SC) reduced responding for both nicotine and food and blocked the discriminative stimulus properties of nicotine in a similar manner to lorcaserin and Ro 60-0175. Behaviours such as hypolocomotion, chewing and ptosis became evident following both CP-809101 and lorcaserin administration at higher doses. Plasma levels of lorcaserin were of similar range to those reported in obesity trials. CONCLUSIONS: These studies support the utility of 5-HT2C agonists as a therapeutic approach to treat nicotine dependence. Plasma exposure levels after acute lorcaserin treatment suggest that equivalent dosages could be used to evaluate these drugs in obesity and smoking cessation trials. Finally, there may be differences in the side effect profiles between lorcaserin and CP-809101, raising the possibility for tolerability differences amongst 5-HT2C agonists.


Asunto(s)
Benzazepinas/farmacología , Nicotina/administración & dosificación , Piperazinas/farmacología , Pirazinas/farmacología , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Animales , Conducta Animal/efectos de los fármacos , Benzazepinas/administración & dosificación , Benzazepinas/toxicidad , Relación Dosis-Respuesta a Droga , Etilaminas/administración & dosificación , Etilaminas/farmacología , Etilaminas/toxicidad , Conducta Alimentaria , Indoles/administración & dosificación , Indoles/farmacología , Indoles/toxicidad , Masculino , Motivación , Piperazinas/administración & dosificación , Piperazinas/toxicidad , Pirazinas/administración & dosificación , Pirazinas/toxicidad , Ratas , Ratas Sprague-Dawley , Receptor de Serotonina 5-HT2C/efectos de los fármacos , Receptor de Serotonina 5-HT2C/metabolismo , Esquema de Refuerzo , Autoadministración , Agonistas del Receptor de Serotonina 5-HT2/administración & dosificación , Agonistas del Receptor de Serotonina 5-HT2/toxicidad
12.
Food Chem Toxicol ; 50(5): 1256-70, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22343322

RESUMEN

SIM010603, a promising multi-targeted receptor tyrosine kinase (RTK) inhibitor, is now being considered for evaluation in phase clinical trial. In this work, the subchronic toxicity of SIM010603 in SD rats and beagle dogs have been characterized. Rats and dogs received SIM010603 orally (0-20 and 0-10mg/kg/day, respectively) on a consecutive daily dosing schedule for 28 days following a 14 days recovery period. Sunitinib was used as a positive control. The No Observed Adverse Effect Level (NOAEL) of SIM010603 was 5mg/kg/day for rats, and undefined for dogs. The treatment resulted in unscheduled mortality in dogs receiving 10mg/kg of SIM010603 or Sunitinib. The adverse effects of SIM010603 on rats and dogs mainly included gastrointestinal toxicity, skeletal toxicity, myelosuppression, thymus atrophy, bronchopneumonia, cardiovascular dysfunction, and pancreatic toxicity. Similar observations have also been noted with this class of RTK signaling inhibitors and are consistent with pharmacologic perturbations of physiologic/angiogenic processes associated with the intended molecular targets. Most treatment-induced effects were reversible or showed ongoing recovery upon discontinuation of treatment. SIM010603 has shown comparable toxicity effect on beagle dogs, while better tolerability on SD rats when compared to Sunitinib.


Asunto(s)
Etilaminas/farmacología , Indoles/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Administración Oral , Animales , Perros , Relación Dosis-Respuesta a Droga , Electrocardiografía , Etilaminas/farmacocinética , Etilaminas/toxicidad , Femenino , Indoles/farmacocinética , Indoles/toxicidad , Masculino , Nivel sin Efectos Adversos Observados , Tamaño de los Órganos/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/toxicidad , Ratas , Ratas Sprague-Dawley
13.
Asian Pac J Trop Biomed ; 2(3): 215-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23569900

RESUMEN

OBJECTIVE: To evaluate the acute toxicity of carboxymethyl chitosan-2, 2' ethylenedioxy bis-ethylamine-folate (CMC-EDBE-FA) and as well as possible effect on microbial growth and in vitro cell cyto-toxicity. METHODS: CMC-EDBE-FA was prepared on basis of carboxymethyl chitosan tagged with folic acid by covalently linkage through 2, 2' ethylenedioxy bis-ethylamine. In vivo acute toxicity, in vitro cyto-toxicity and antimicrobial activity of CMC-EDBE-FA nanoparticle were determined. RESULTS: Vancomycin exhibited the antibacterial activity against vancomycin sensitive Staphylococcus aureus, but CMC-EDBE-FA nanoparticle did not give any antibacterial activity as evidenced by minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), disc agar diffusion (DAD) and killing kinetic assay. Further, the CMC-EDBE-FA nanoparticle showed no signs of in vivo acute toxicity up to a dose level of 1 000 mg/kg p.o., and as well as in vitro cyto-toxicity up to 250 µg/mL. CONCLUSIONS: These findings suggest that CMC-EDBE-FA nanoparticle is expected to be safe for biomedical applications.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Quitosano/análogos & derivados , Ácido Fólico/toxicidad , Nanopartículas/toxicidad , Animales , Antibacterianos/química , Antibacterianos/farmacología , Antibacterianos/toxicidad , Quitosano/química , Quitosano/toxicidad , Etilaminas/química , Etilaminas/toxicidad , Ácido Fólico/química , Ácido Fólico/farmacología , Células HeLa , Humanos , Masculino , Ensayo de Materiales , Ratones , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Staphylococcus aureus/efectos de los fármacos , Vancomicina/farmacología
14.
Xenobiotica ; 41(2): 144-54, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21043805

RESUMEN

2-Bromoethanamine (BEA) causes renal papillary necrosis (RPN) in rats after a single dose and has been widely used as a model compound for studying the lesion. Although the metabolism of BEA may be an important determinant of toxicity, the metabolic fate of the compound has not been fully elucidated. To date, the only identified BEA metabolites are aziridine, 2-oxazolidone and 5-hydroxy-2-oxazolidone. In this study, stable isotope labelling (SIL) of BEA analogs ((¹³C and ²H) were used to differentiate generated BEA metabolites from endogenous molecules which enabled the accurate liquid chromatography mass spectrometry detection of more than 180 novel metabolites. BEA metabolism was evaluated in rats after acute administration of a non-toxic dose (50 mg/kg) and a toxic dose (250 mg/kg) that caused frank RPN and polyuria. Newly identified metabolites include three carbamoylation products, two mercapturic acids and a group of amino acid conjugates. Overall, the results indicate that BEA metabolism is very complex, suggest the potential formation of reactive intermediates and establish that BEA is subject to conjugation with glutathione. The results also demonstrate the utility and sensitivity of the SIL approach for identification of metabolites from small, reactive compounds.


Asunto(s)
Carbamatos/metabolismo , Etilaminas/orina , Glutatión/metabolismo , Marcaje Isotópico/métodos , Aminoácidos/metabolismo , Animales , Etilaminas/química , Etilaminas/toxicidad , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
15.
Toxicol Sci ; 118(2): 510-20, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20823374

RESUMEN

Chronic analgesic abuse has been shown to induce severe renal injury characterized by renal papillary necrosis (RPN), an injury detectable at late stage. While direct toxicity of the drug may exist, the molecular mechanisms underlying analgesics induction of RPN remain unknown. A major limitation to study the pathogenesis of RPN is the required chronic exposure before detection of injury. Here, we employed 2-bromoethanamine (BEA) to simulate rapid papillary toxicity using inner medullary collecting duct (IMCD3) cells. Although exposure to 10µM BEA had no effect on cellular viability under isotonic conditions, a 50% loss in cell viability was observed in the first 24 h when cells were subjected to sublethal hypertonic stress and nearly complete cell death after 48 h suggesting that BEA exerts cytotoxicity only under hypertonic conditions. Because TonEBP is a transcription factor critical for cell survival during hypertonic conditions, we undertook experiments to examine the effect of BEA on TonEBP expression and activity. Exposure of cells to 10µM BEA resulted in a substantial reduction in TonEBP protein expression after 24 h. In addition, TonEBP was not translocated to the nucleus in BEA-treated IMCD3 cells under acute hypertonic stress for transcription of target genes essential for osmolyte accumulation. Finally, we found a substantial decrease in TonEBP expression in medullary kidney tissues of mice injected with a single ip dose of BEA. Our data suggest that TonEBP is a potential target for BEA leading to the process of papillary necrosis in the settings of hypertonic stress.


Asunto(s)
Etilaminas/toxicidad , Médula Renal/efectos de los fármacos , Necrosis Papilar Renal/inducido químicamente , Túbulos Renales Colectores/efectos de los fármacos , Factores de Transcripción/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Expresión Génica/efectos de los fármacos , Soluciones Hipertónicas/farmacología , Médula Renal/metabolismo , Médula Renal/patología , Necrosis Papilar Renal/metabolismo , Necrosis Papilar Renal/patología , Túbulos Renales Colectores/metabolismo , Túbulos Renales Colectores/patología , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo , Estrés Fisiológico/fisiología , Factores de Transcripción/genética
16.
Neuroscience ; 169(1): 158-70, 2010 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-20447448

RESUMEN

Serotonin2C (5-HT(2C)) receptors act in the basal ganglia, a group of sub-cortical structures involved in motor behavior, where they are thought to modulate oral activity and participate in iatrogenic motor side-effects in Parkinson's disease and Schizophrenia. Whether abnormal movements initiated by 5-HT(2C) receptors are directly consequent to dysfunctions of the motor circuit is uncertain. In the present study, we combined behavioral, immunohistochemical and extracellular single-cell recordings approaches in rats to investigate the effect of the 5-HT(2C) agonist Ro-60-0175 respectively on orofacial dyskinesia, the expression of the marker of neuronal activity c-Fos in basal ganglia and the electrophysiological activity of substantia nigra pars reticulata (SNr) neuron connected to the orofacial motor cortex (OfMC) or the medial prefrontal cortex (mPFC). The results show that Ro-60-0175 (1 mg/kg) caused bouts of orofacial movements that were suppressed by the 5-HT(2C) antagonist SB-243213 (1 mg/kg). Ro-60-0175 (0.3, 1, 3 mg/kg) dose-dependently enhanced Fos expression in the striatum and the nucleus accumbens. At the highest dose, it enhanced Fos expression in the subthalamic nucleus, the SNr and the entopeduncular nucleus but not in the external globus pallidus. However, the effect of Ro-60-0175 was mainly associated with associative/limbic regions of basal ganglia whereas subregions of basal ganglia corresponding to sensorimotor territories were devoid of Fos labeling. Ro-60-0175 (1-3 mg/kg) did not affect the electrophysiological activity of SNr neurons connected to the OfMC nor their excitatory-inhibitory-excitatory responses to the OfMC electrical stimulation. Conversely, Ro-60-0175 (1 mg/kg) enhanced the late excitatory response of SNr neurons evoked by the mPFC electrical stimulation. These results suggest that oral dyskinesia induced by 5-HT(2C) agonists are not restricted to aberrant signalling in the orofacial motor circuit and demonstrate discrete modifications in associative territories.


Asunto(s)
Ganglios Basales/fisiopatología , Discinesia Inducida por Medicamentos/fisiopatología , Etilaminas/farmacología , Músculos Faciales/fisiopatología , Indoles/farmacología , Vías Nerviosas/efectos de los fármacos , Piridinas/farmacología , Receptor de Serotonina 5-HT2C/fisiología , Agonistas de Receptores de Serotonina/farmacología , Animales , Ganglios Basales/efectos de los fármacos , Discinesia Inducida por Medicamentos/etiología , Estimulación Eléctrica , Etilaminas/toxicidad , Regulación de la Expresión Génica/efectos de los fármacos , Genes fos , Indoles/toxicidad , Masculino , Boca , Vías Nerviosas/fisiopatología , Proteínas Oncogénicas v-fos/biosíntesis , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/fisiopatología , Piridinas/toxicidad , Ratas , Ratas Sprague-Dawley , Receptor de Serotonina 5-HT2C/efectos de los fármacos , Agonistas de Receptores de Serotonina/toxicidad , Sustancia Negra/efectos de los fármacos , Sustancia Negra/fisiopatología
17.
Toxicol Pathol ; 38(3): 346-58, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20233945

RESUMEN

Renal papillary necrosis (RPN) is a relatively common toxicity observed in preclinical drug safety testing. It is also observed in a variety of human diseases. RPN is difficult to diagnose without expensive scanning methods or histopathology. A noninvasive biomarker that could be detected at early stages of kidney damage would be of great value both to preclinical drug safety testing and in the clinic. An antibody raised to an unknown epitope of an antigen in rat kidney papilla was found to be specific for collecting duct cells in the kidney; this was termed renal papillary antigen 1 (RPA-1). In this study, the authors show that RPA-1 is an early biomarker of RPN in two different rat models of toxicity: 2-bromoethanamine (BEA) and N-phenylanthranilic acid (NPAA). RPA-1 can be detected in urine at early stages of toxicity and correlates well with the histopathology observed. We also characterized the biochemical properties of RPA-1 and found that the antigen is a high molecular weight membrane bound glycoprotein, with the epitope likely to be carried on an N-linked carbohydrate structure. This study demonstrates that RPA-1 is an excellent marker of RPN that can be used to detect this toxicity in preclinical safety testing.


Asunto(s)
Antígenos/análisis , Biomarcadores/análisis , Médula Renal/metabolismo , Necrosis Papilar Renal/metabolismo , Animales , Antígenos/metabolismo , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Etilaminas/toxicidad , Fenamatos/toxicidad , Inmunohistoquímica , Inmunoprecipitación , Médula Renal/inmunología , Necrosis Papilar Renal/inducido químicamente , Necrosis Papilar Renal/patología , Masculino , Ratas , Ratas Wistar
18.
Cell Death Differ ; 16(10): 1372-84, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19521424

RESUMEN

We have recently reported that cytostatic concentrations of the microsomal antiestrogen-binding site (AEBS) ligands, such as PBPE (N-pyrrolidino-(phenylmethyphenoxy)-ethanamine,HCl) and tamoxifen, induced differentiation characteristics in breast cancer cells through the accumulation of post-lanosterol intermediates of cholesterol biosynthesis. We show here that exposure of MCF-7 (human breast adenocarcinoma cell line) cells to higher concentrations of AEBS ligands triggered active cell death and macroautophagy. Apoptosis was characterized by Annexin V binding, chromatin condensation, DNA laddering and disruption of the mitochondrial functions. We determined that cell death was sterol- and reactive oxygen species-dependent and was prevented by the antioxidant vitamin E. Macroautophagy was characterized by the accumulation of autophagic vacuoles, an increase in the expression of Beclin-1 and the stimulation of autophagic flux. We established that macroautophagy was sterol- and Beclin-1-dependent and was associated with cell survival rather than with cytotoxicity, as blockage of macroautophagy sensitized cells to AEBS ligands. These results show that the accumulation of sterols by AEBS ligands in MCF-7 cells induces apoptosis and macroautophagy. Collectively, these data support a therapeutic potential for selective AEBS ligands in breast cancer management and shows a mechanism that explains the induction of autophagy in MCF-7 cells by tamoxifen and other selective estrogen receptor modulators.


Asunto(s)
Antineoplásicos Hormonales/farmacología , Apoptosis , Autofagia , Neoplasias de la Mama/metabolismo , Colesterol/metabolismo , Moduladores de los Receptores de Estrógeno/farmacología , Etilaminas/toxicidad , Pirrolidinas/toxicidad , Tamoxifeno/farmacología , Sitios de Unión , Diferenciación Celular , Femenino , Humanos , Ligandos , Mitocondrias/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Células Tumorales Cultivadas , Vitamina E/farmacología
19.
DNA Repair (Amst) ; 8(3): 400-12, 2009 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-19162564

RESUMEN

Neurons of the developing brain are especially vulnerable to environmental agents that damage DNA (i.e., genotoxicants), but the mechanism is poorly understood. The focus of the present study is to demonstrate that DNA damage plays a key role in disrupting neurodevelopment. To examine this hypothesis, we compared the cytotoxic and DNA damaging properties of the methylating agents methylazoxymethanol (MAM) and dimethyl sulfate (DMS) and the mono- and bifunctional alkylating agents chloroethylamine (CEA) and nitrogen mustard (HN2), in granule cell neurons derived from the cerebellum of neonatal wild type mice and three transgenic DNA repair strains. Wild type cerebellar neurons were significantly more sensitive to the alkylating agents DMS and HN2 than neuronal cultures treated with MAM or the half-mustard CEA. Parallel studies with neuronal cultures from mice deficient in alkylguanine DNA glycosylase (Aag(-/-)) or O(6)-methylguanine methyltransferase (Mgmt(-/-)), revealed significant differences in the sensitivity of neurons to all four genotoxicants. Mgmt(-/-) neurons were more sensitive to MAM and HN2 than the other genotoxicants and wild type neurons treated with either alkylating agent. In contrast, Aag(-/-) neurons were for the most part significantly less sensitive than wild type or Mgmt(-/-) neurons to MAM and HN2. Aag(-/-) neurons were also significantly less sensitive than wild type neurons treated with either DMS or CEA. Granule cell development and motor function were also more severely disturbed by MAM and HN2 in Mgmt(-/-) mice than in comparably treated wild type mice. In contrast, cerebellar development and motor function were well preserved in MAM-treated Aag(-/-) or MGMT-overexpressing (Mgmt(Tg+)) mice, even as compared with wild type mice suggesting that AAG protein increases MAM toxicity, whereas MGMT protein decreases toxicity. Surprisingly, neuronal development and motor function were severely disturbed in Mgmt(Tg+) mice treated with HN2. Collectively, these in vitro and in vivo studies demonstrate that the type of DNA lesion and the efficiency of DNA repair are two important factors that determine the vulnerability of the developing brain to long-term injury by a genotoxicant.


Asunto(s)
Alquilantes/toxicidad , Cerebelo , Reparación del ADN/fisiología , Animales , Bovinos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Cerebelo/química , Cerebelo/efectos de los fármacos , Cerebelo/crecimiento & desarrollo , Pollos , ADN/química , ADN/genética , Fragmentación del ADN/efectos de los fármacos , ADN Glicosilasas/deficiencia , Metilasas de Modificación del ADN/biosíntesis , Metilasas de Modificación del ADN/deficiencia , Enzimas Reparadoras del ADN/biosíntesis , Enzimas Reparadoras del ADN/deficiencia , Etilaminas/toxicidad , Humanos , Mecloretamina/toxicidad , Acetato de Metilazoximetanol/análogos & derivados , Acetato de Metilazoximetanol/toxicidad , Ratones , Actividad Motora/efectos de los fármacos , Neuronas/química , Neuronas/efectos de los fármacos , Ésteres del Ácido Sulfúrico/toxicidad , Proteínas Supresoras de Tumor/biosíntesis , Proteínas Supresoras de Tumor/deficiencia
20.
J Membr Biol ; 221(2): 73-85, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18197355

RESUMEN

Experiments were conducted to test the hypothesis that aliphatic hydrocarbons bind to pockets/crevices of sodium (Na(+)) channels to cause action potential (AP) block. Aliphatic solutes exhibiting successively greater octanol/water partitition coefficients (K (ow)) were studied. Each solute blocked Na(+) channels. The 50% effective concentration (EC(50)) to block APs could be mathematically predicted as a function of the solute's properties. The solutes studied were methyl ethyl ketone (MEK), cyclohexanone, dichloromethane, chloroform and triethylamine (TriEA); the K (ow) increased from MEK to TriEA. APs were recorded from frog nerves, and test solutes were added to Ringer's solution bathing the nerve. When combined with EC(50)s for solutes with log K (ow)s < 0.29 obtained previously, the solute EC(50)s could be predicted as a function of the fractional molar volume (dV/dm = [dV/dn]/100), polarity (P) and the hydrogen bond acceptor basicity (beta) by the following equation: EC(50) = 2.612({-2.117[dv/dm]+0.6424P+2.628 beta}) Fluidity changes cannot explain the EC(50)s. Each of the solutes blocks Na(+) channels with little or no change in kinetics. Na(+) channel block explains much of the EC(50) data. EC(50)s are produced by a combination of effects including ion channel block, fluidity changes and osmotically induced structural changes. As the solute log K (ow) increases to values near 1 or greater, Na(+) channel block dominates in determining the EC(50). The results are consistent with the hypothesis that the solutes bind to channel crevices to cause Na(+) channel and AP block.


Asunto(s)
Potenciales de Acción/efectos de los fármacos , Bloqueadores de los Canales de Sodio/toxicidad , Animales , Butanonas/toxicidad , Cloroformo/toxicidad , Ciclohexanonas/toxicidad , Relación Dosis-Respuesta a Droga , Etilaminas/toxicidad , Fluidez de la Membrana/efectos de los fármacos , Fluidez de la Membrana/fisiología , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/fisiología , Técnicas de Placa-Clamp , Cloruro de Potasio/toxicidad , Rana pipiens , Nervio Ciático/efectos de los fármacos , Nervio Ciático/fisiología , Solventes
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