Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Virol ; 95(12)2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-33827940

RESUMO

The antiapoptotic protein BCL2 inhibits death of HIV-infected cells. Previously, we showed that the BCL2 inhibitor venetoclax selectively kills acutely HIV-infected cells and reduces HIV DNA in latently infected CD4 T cells ex vivo after reactivation with anti-CD3/anti-CD28. However, there is a need to identify a combination therapy with venetoclax and a clinically relevant latency reversal agent. Ixazomib is an oral proteasome inhibitor which we have shown reactivates latent HIV and predisposes reactivated cells to cell death. Here, we determined that the combination of venetoclax and ixazomib kills more latently HIV-infected cells and leads to greater reduction in HIV replication than either treatment alone in vitro in a T cell model. However, combination treatment of ex vivo CD4 T cells from antiretroviral therapy (ART)-suppressed, HIV-positive participants resulted in unanticipated and unacceptable nonspecific toxicity in primary cells. Therefore, while we show proof of concept that multiple agents can enhance selective killing of HIV-infected cells, the combination of venetoclax and ixazomib has unacceptable toxicity in primary cells, and so further investigation is needed to identify a clinically relevant latency reversal agent to combine with venetoclax as a novel strategy to reduce the size of the HIV reservoir.IMPORTANCE A cure for HIV would require eliminating cells that contain the virus in a latent form from the body. Current antiretroviral medications are unable to rid the body of latently infected cells. Here, we show that a combination of investigational agents-ixazomib plus venetoclax-which reactivate latent virus and predispose infected cells to apoptosis may reduce latent virus in a T cell model, but at the expense of nonspecific toxicity in primary cells.


Assuntos
Fármacos Anti-HIV/farmacologia , Compostos de Boro/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Glicina/análogos & derivados , HIV-1/efeitos dos fármacos , Sulfonamidas/farmacologia , Fármacos Anti-HIV/toxicidade , Apoptose/efeitos dos fármacos , Compostos de Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Linfócitos T CD4-Positivos/virologia , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Quimioterapia Combinada , Glicina/farmacologia , Glicina/toxicidade , HIV-1/fisiologia , Humanos , Células Jurkat , Provírus/efeitos dos fármacos , Sulfonamidas/toxicidade , Resposta a Proteínas não Dobradas , Ativação Viral , Latência Viral , Replicação Viral/efeitos dos fármacos
2.
Plant Physiol ; 182(2): 1100-1113, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31767690

RESUMO

Stomatal movement, which regulates gas exchange in plants, is controlled by a variety of environmental factors, including biotic and abiotic stresses. The stress hormone abscisic acid (ABA) initiates a signaling cascade, which leads to increased H2O2 and Ca2+ levels and F-actin reorganization, but the mechanism of, and connection between, these events is unclear. SINE1, an outer nuclear envelope component of a plant Linker of Nucleoskeleton and Cytoskeleton complex, associates with F-actin and is, along with its putative paralog SINE2, expressed in guard cells. Here, we have determined that Arabidopsis (Arabidopsis thaliana) SINE1 and SINE2 play an important role in stomatal opening and closing. Loss of SINE1 or SINE2 results in ABA hyposensitivity and impaired stomatal dynamics but does not affect stomatal closure induced by the bacterial elicitor flg22. The ABA-induced stomatal closure phenotype is, in part, attributed to impairments in Ca2+ and F-actin regulation. Together, the data suggest that SINE1 and SINE2 act downstream of ABA but upstream of Ca2+ and F-actin. While there is a large degree of functional overlap between the two proteins, there are also critical differences. Our study makes an unanticipated connection between stomatal regulation and nuclear envelope-associated proteins, and adds two new players to the increasingly complex system of guard cell regulation.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Estômatos de Plantas/metabolismo , Transdução de Sinais/genética , Ácido Abscísico/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Cálcio/metabolismo , Cloreto de Cálcio/farmacologia , Secas , Peróxido de Hidrogênio/toxicidade , Microscopia Confocal , Mutação , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/genética , Estômatos de Plantas/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Tiazolidinas/toxicidade , Regulação para Cima
3.
Anal Bioanal Chem ; 413(11): 3069-3079, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33723626

RESUMO

Mitigation of the peroxide explosive threat, specifically triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD), is a priority among the law enforcement community, as scientists and canine (K9) units are constantly working to improve detection. We propose the use of paper spray ionization-high-resolution mass spectrometry (PSI-HRMS) for detection of peroxide explosives in biological matrices. Occurrence of peroxide explosives and/or their metabolites in biological samples, obtained from urine or blood tests, give scientific evidence of peroxide explosives exposure. PSI-HRMS promote analysis of samples in situ by eliminating laborious sample preparation steps. However, it increases matrix background issues, which were overcome by the formation of multiple alkali metal adducts with the peroxide explosives. Multiple ion formation increases confidence when identifying these peroxide explosives in direct sample analysis. Our previous work examined aspects of TATP metabolism. Herein, we investigate the excretion of a TATP glucuronide conjugate in the urine of bomb-sniffing dogs and demonstrate its detection using PSI from the in vivo sample.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/análise , Substâncias Explosivas/análise , Compostos Heterocíclicos com 1 Anel/análise , Espectrometria de Massas/métodos , Peróxidos/análise , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Cromatografia Líquida de Alta Pressão/métodos , Cães , Substâncias Explosivas/metabolismo , Substâncias Explosivas/toxicidade , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/toxicidade , Microssomos Hepáticos/metabolismo , Exposição Ocupacional , Papel , Peróxidos/química , Peróxidos/toxicidade
4.
Arch Toxicol ; 93(3): 659-671, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30617560

RESUMO

Cyclin-dependent kinases (CDKs) are a family of kinases associated predominantly with cell cycle control, making CDK inhibitors interesting candidates for anti-cancer therapeutics. However, retinal toxicity (loss of photoreceptors) has been associated with CDK inhibitors, including the pan-CDK inhibitor AG-012896. The purpose of this research was to use a novel planar sectioning technique to determine CDK expression profiles in the ex vivo human retina with the aim of identifying isoforms responsible for CDK retinotoxicity. Four CDK isoforms (CDK11, 16, 17 and 18) were selected as a result of IC50 data comparing neurotoxic (AG-012986 and NVP-1) and non-neurotoxic (dinaciclib and NVP-2) CDK inhibitors, with IC50s at CDK11 showing a clear difference between the neurotoxic and non-neurotoxic drugs. CDK11 was maximally expressed in the photoreceptor layer, whereas CDK16, 17 and 18 showed maximal expression in the inner nuclear layer. CDK5 (an isoform associated with retinal homeostasis) was maximally expressed in the retinal ganglion cell layer. Apart from CDK18, each isoform showed expression in the photoreceptor layer. The human Müller cell line MIO-M1 expressed CDK5, 11, 16 and 17 and AG-01298 (0.02-60 µM) caused a dose-dependent increase in MIO-M1 cell death. In conclusion, CDK11 appears the most likely candidate for mediation of photoreceptor toxicity. RNA profiling can be used to determine the distribution of genes of interest in relation to retinal toxicity in the human retina.


Assuntos
Quinases Ciclina-Dependentes/metabolismo , Inibidores de Proteínas Quinases/toxicidade , Retina/fisiologia , Testes de Toxicidade , Adulto , Benzamidas/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Pontos de Checagem do Ciclo Celular , Morte Celular/efeitos dos fármacos , Óxidos N-Cíclicos , Humanos , Indolizinas , Compostos de Piridínio/toxicidade , Retina/efeitos dos fármacos , Tiazóis/toxicidade
5.
Cell Biol Toxicol ; 34(2): 143-162, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28815372

RESUMO

A recent hypothesis suggesting that the pharmacological target TRPV1 (transient receptor potential vanilloid subfamily, member 1) may function as a tumour suppressor, which potentially impacts the development of TRPV1 antagonist therapeutics for a range of conditions. However, little is known about the long-term physiologic effects of TRPV1 blockade in the skin. In vitro and in vivo studies suggested that the potent TRPV1 competitive antagonist AMG-9810 promoted proliferation in N/TERT1 cells (telomerase-immortalised primary human keratinocytes 1) and tumour development in mouse skin that was mediated through EGFR/Akt/mTOR signalling. We attempted to reproduce the reported in vitro and in vivo findings to further explore this hypothesis to understand the underlying mechanism and the risk associated with TRPV1 antagonism in the skin. In vitro proliferation studies using multiple methods and topical application with AMG-9810 and structurally similar TRPV1 antagonists such as SB-705498 and PAC-14028 were performed. Although we confirmed expression of TRPV1 in primary human epidermal keratinocytes (HEKn) and spontaneously immortalised human keratinocytes (HaCaT), we were unable to demonstrate cell proliferation in either cell type or any clear evidence of increased expression of proteins in the EGFR/Akt/mTOR signalling pathway with these molecules. We were also unable to demonstrate skin tumour promotion or underlying molecular mechanisms involved in the EGFR/Akt/mTOR signalling pathway in a single-dose and two-stage carcinogenesis mouse study treated with TRPV1 antagonists. In conclusion, our data suggest that inhibiting the pharmacological function of TRPV1 in skin by specific antagonists has not been considered to be indicative of skin tumour development.


Assuntos
Proliferação de Células/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Neoplasias Cutâneas/metabolismo , Canais de Cátion TRPV/antagonistas & inibidores , Acrilamidas/toxicidade , Animais , Antracenos/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Capsaicina/análogos & derivados , Capsaicina/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cocarcinogênese , Feminino , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Camundongos , Camundongos Pelados , Piperidinas/toxicidade , Cultura Primária de Células , Piridinas/toxicidade , Pirrolidinas/toxicidade , Risco , Neoplasias Cutâneas/patologia , Canais de Cátion TRPV/genética , Ureia/análogos & derivados , Ureia/toxicidade
6.
Arch Toxicol ; 92(1): 143-156, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29110038

RESUMO

Palytoxin, isolated from a zoanthid of the genus Palythoa, is the most potent marine toxin known. Intoxication by palytoxin leads to vasoconstriction, hemorrhage, ataxia, muscle weakness, ventricular fibrillation, pulmonary hypertension, ischemia and death. Palytoxin and its numerous derivatives (congeners) may enter the food chain and accumulate mainly in fishes and crabs, causing severe human intoxication and death following ingestion of contaminated products. Furthermore, toxic effects in individuals exposed via inhalation or skin contact to marine aerosol in coincidence with Ostreopsis blooms, have been reported. Blooms of the benthic dinoflagellate Ostreopsis cf. ovata are a concern in the Mediterranean Sea, since this species produces a wide range of palytoxin-like compounds listed among the most potent marine toxins. Thus, the formerly unsuspected broad distribution of the benthic dinoflagellate Ostreopsis spp. has recently posed a problem of risk assessment for human health. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide. This review summarized and discussed the pharmacology and toxicology data of palytoxin and its congeners, including their cytotoxicity, human and animal toxicities. Moreover, the risk assessment and their control strategies including prevention and treatment assays were evaluated.


Assuntos
Acrilamidas/química , Acrilamidas/toxicidade , Venenos de Cnidários/química , Venenos de Cnidários/toxicidade , Acrilamidas/farmacocinética , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Venenos de Cnidários/farmacocinética , Humanos , Toxinas Marinhas/química , Toxinas Marinhas/farmacocinética , Toxinas Marinhas/toxicidade , Piranos/química , Piranos/toxicidade , Medição de Risco/métodos
7.
Cell Physiol Biochem ; 44(2): 467-478, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29141249

RESUMO

BACKGROUND/AIMS: ß-catenin is an integral component of the canonical Wnt signaling pathway, and its mutations are an autosomal recessive cause of colorectal cancer (CRC), medulloblastoma (MDB), and ovarian cancer. Nevertheless, little is known about its function in lung cancers. METHODS: We first knocked down ß-catenin by siRNA to investigate its effects on lung cancer cell proliferation, migration and apoptosis. Then we verified the interaction between ß-catenin and CREB binding protein (CBP) by immunofluoresence and co-immunoprecipition assays. Finally, the expression of ß-catenin and CBP in human lung adenocarcinoma specimens were analyzed by immunohistochemistry assay. RESULTS: ß-catenin knockdown inhibited cell proliferation, promoted apoptosis and suppressed cell migration in A549 and H460 cells accompanied by the decreased expression of Myc, PCNA, VEGF, CD44, MMP-9, MMP-13 and activated bax/caspase-3 pathway. Furthermore, co-immunoprecipition and immunofluoresence analyses revealed that CBP interacted with ß-catenin and contributed to ß-catenin-mediated lung cancer cell growth. Abolishment of their interaction by the Wnt/ß-catenin inhibitor ICG-001 remarkably suppressed cell proliferation. Immunohistochemistry assay of tissue microarrays from patients with lung cancer indicated that both CBP and ß-catenin were highly expressed in tumor tissues and predicted poor prognosis in lung adenocarcinoma patients. CONCLUSIONS: Our study has provided new evidence for the role of ß-catenin in promoting the growth of lung cancer cells through cooperation with CBP, and suggested that dual targeting of ß-catenin and CBP could be a potential therapeutic strategy in lung cancer treatment.


Assuntos
Adenocarcinoma/patologia , Proteína de Ligação a CREB/metabolismo , Neoplasias Pulmonares/patologia , beta Catenina/metabolismo , Células A549 , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Idoso , Apoptose/efeitos dos fármacos , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Proteína de Ligação a CREB/antagonistas & inibidores , Proteína de Ligação a CREB/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Masculino , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Microscopia de Fluorescência , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Pirimidinonas/toxicidade , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismo , beta Catenina/antagonistas & inibidores , beta Catenina/genética
8.
Bioorg Med Chem Lett ; 26(3): 774-777, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26764188

RESUMO

Direct coupling of a hydrophobic drug and a hydrophilic natural product via an ester bond produced an amphiphilic adduct that formed liposomes. Liposomes of resveratrol-norcantharidin adduct are capable of forming a tadpole-like nanoparticle and exhibited high toxicity in zebrafish embryos to give the better transportation and the effective concentration into cells. Using fluorescent chromophore showed the liposome in the stomach and intestinal villi rather than in the skin and muscle. This result may provide an insight into the mechanism of action of traditional Chinese medicines, which often contain a significant amount of flavonoids and polyphenol analogs.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Nanopartículas/química , Estilbenos/química , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Portadores de Fármacos/química , Embrião não Mamífero/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Lipossomos/química , Medicina Tradicional Chinesa , Tamanho da Partícula , Resveratrol , Estilbenos/toxicidade , Peixe-Zebra/crescimento & desenvolvimento
9.
Bioorg Med Chem Lett ; 26(16): 3955-7, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27422336

RESUMO

Levoglucosenone has been used as template for the synthesis of a wide variety of compounds with an impressive structural variability. However, scarce work has been done regarding the generation of new bioactive entities. Here we report the cytotoxic effect of levoglucosenone and some related derivatives against hepatocarcinoma cell lines. Compounds were obtained in only one synthetic step and one of them showed an activity within the range of IC50 values of cisplatin, a frequently administered chemotherapy drug.


Assuntos
Antineoplásicos/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Glucose/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glucose/síntese química , Glucose/química , Glucose/toxicidade , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia
10.
Pediatr Dermatol ; 33(2): 150-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26777394

RESUMO

BACKGROUND: Phosphodiesterase-4 (PDE4) is an emerging target in treating inflammatory skin diseases. Crisaborole topical ointment, 2% is a novel, boron-based, topical PDE4 inhibitor under investigation for treatment of mild to moderate atopic dermatitis (AD). METHODS: Adolescent patients aged 12 to 17 years with treatable AD lesions involving ≥ 10% to ≤ 35% body surface area (BSA) were enrolled into a phase 2a, open-label study comprising pharmacokinetic (PK), safety, tolerability, and efficacy assessments. Crisaborole topical ointment, 2% was applied twice daily to affected areas for 28 days, with dosage based on baseline treatable BSA. PK blood samples were collected on days 1, 2, 4, 6, 8, and 9. Safety assessments included adverse events (AEs), laboratory parameters, and vital signs. Efficacy assessments included the Investigator's Static Global Assessment (ISGA) score and severity of AD signs and symptoms. RESULTS: Twenty-three patients were enrolled; 22 completed the study (1 patient discontinued due to an AE [application site dermatitis]). PK analysis demonstrated limited exposure to crisaborole topical ointment, 2% after 8 days of dosing. Ten patients reported a total of 19 AEs, most commonly application site pain and nasopharyngitis (3 patients each). There were no clinically meaningful changes in laboratory or vital sign parameters. Efficacy was demonstrated by reductions in mean ISGA and AD sign and symptom severity scores. At day 29, eight patients (35%) had achieved an ISGA score ≤ 1 with ≥ 2-grade improvement. Mean treatable BSA declined from 17.6% to 8.2%. CONCLUSION: These results provide preliminary evidence for the limited systemic exposure, safety, and effectiveness of crisaborole topical ointment, 2% in adolescents with mild to moderate AD.


Assuntos
Compostos de Boro/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Dermatite Atópica/tratamento farmacológico , Inibidores da Fosfodiesterase 4/administração & dosagem , Administração Tópica , Adolescente , Compostos de Boro/farmacocinética , Compostos de Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Criança , Tolerância a Medicamentos , Feminino , Humanos , Masculino , Pomadas
11.
Drug Chem Toxicol ; 39(3): 303-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26599593

RESUMO

Norcantharidin (NCTD) is currently used in the treatment of several cancers such as leukemia, melanoma and hepatoma. The mechanism of action of NCTD is suggested to involve induction of apoptosis of cancer cells via production of reactive oxygen species. In this study, the genotoxic effect of different concentrations of NCTD (1, 10 and 20 µm) in human lymphocytes was investigated using sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) assays. The results revealed that NCTD significantly increased the rate of SCEs (p < 0.05) in a dose-dependent manner. In addition, NCTD significantly increased the number of high-frequency cells (SCEs ≥ 8, p < 0.05). However, NCTD did not have any significant effect on the rate of CAs (p > 0.05). In addition, no significant differences were detected in the mitotic index or proliferative index at examined doses (up to 20 µm). In conclusion, NCTD is genotoxic to human cultured lymphocytes as measured by SCE assay.


Assuntos
Antineoplásicos/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Dano ao DNA , Linfócitos/efeitos dos fármacos , Troca de Cromátide Irmã/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Linfócitos/patologia , Testes de Mutagenicidade
12.
Int J Toxicol ; 35(5): 543-57, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27138050

RESUMO

Tavaborole is a topical antifungal agent approved by the US Food and Drug Administration for the treatment of toenail onychomycosis. The effects of tavaborole on gestation, parturition (delivery, labor), offspring development, and survival during the perinatal and postnatal periods were assessed in mated female rats. Females (F0 generation) were administered single daily oral (gavage) doses of 15, 60, or 100 mg/kg/d from gestation day 6 through lactation day 20. The females were allowed to deliver naturally and rear their offspring until lactation day 21, at which time the F0 females were euthanized. One male and female from each litter were selected (F1 generation) and retained for assessments, including growth, neurobehavior, fertility, and their ability to produce an F2 generation. Reproductive and offspring parameters were determined for the F1 and F2 generations, as applicable. F1 females and F2 pups were euthanized on postnatal day 7. In the F0 females, decreased activity was observed in the 100 mg/kg/d dose group. Excess salivation was observed in the 60 and 100 mg/kg/d dose groups (slight to moderate), however, this finding was not considered adverse. There were no tavaborole-related effects on the growth, viability, development, neurobehavioral assessments, or reproductive performance of the F1 generation. Survivability and mean body weight of the F2 pups were unaffected. The no observed adverse effect level (NOAEL) for maternal toxicity (F0 generation) was 60 mg/kg/d, based on the decreased activity observed in the 100 mg/kg/d dose group. The NOAEL for the offspring effects was ≥100 mg/kg/d, based on the lack of test article-related changes.


Assuntos
Compostos de Boro/toxicidade , Compostos de Boro/uso terapêutico , Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Exposição Materna , Onicomicose/tratamento farmacológico , Administração Tópica , Animais , Animais Recém-Nascidos , Peso Corporal , Boro/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Fertilidade/efeitos dos fármacos , Desenvolvimento Fetal/efeitos dos fármacos , Masculino , Nível de Efeito Adverso não Observado , Gravidez , Ratos , Ratos Sprague-Dawley , Reprodução/efeitos dos fármacos , Testes de Toxicidade
13.
Int J Toxicol ; 35(5): 530-42, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27044640

RESUMO

Tavaborole is a topical antifungal agent approved by the US Food and Drug Administration for the treatment of toenail onychomycosis. As part of the nonclinical development program, reproductive and developmental toxicity studies were conducted (rat oral fertility and early embryonic development, rat (oral) and rabbit (dermal) embryo-fetal development). There were no effects on fertility or reproductive performance at doses up to 300 mg/kg/d (107 times the maximum recommended human dose [MRHD] based on mean area under the plasma concentration-time curve comparisons). In the rat embryo-fetal development toxicity studies, teratogenicity was not observed at doses up to 100 mg/kg/d (29 times the MRHD). However, several treatment-related skeletal malformations and variations were observed at 300 mg/kg/d (570 times the MRHD). In rabbit embryo-fetal development toxicity studies dosed via oral or dermal administration, the no observable adverse effect level for maternal toxicity and embryo-fetal toxicity was 50 mg/kg/d (16 times the MRHD) and 5% (26 times the MRHD), respectively.


Assuntos
Compostos de Boro/toxicidade , Compostos de Boro/uso terapêutico , Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Onicomicose/tratamento farmacológico , Reprodução/efeitos dos fármacos , Administração Cutânea , Animais , Animais Recém-Nascidos , Antifúngicos/uso terapêutico , Antifúngicos/toxicidade , Boro/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Fertilidade/efeitos dos fármacos , Desenvolvimento Fetal/efeitos dos fármacos , Masculino , Coelhos , Ratos , Testes de Toxicidade
14.
Environ Toxicol ; 30(5): 501-12, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24293352

RESUMO

A rapid cyanobacterial bloom of Cylindrospermopsis raciborskii (3.2 × 10(4) filaments/mL) was detected early November, 2012, in the Fancsika pond (East Hungary). The strong discoloration of water was accompanied by a substantial fish mortality (even dead cats were seen on the site), raising the possibility of some toxic metabolites in the water produced by the bloom-forming cyanobacteria (C. raciborskii). The potential neuronal targets of the toxic substances in the bloom sample were studied on identified neurons (RPas) in the central nervous system of Helix pomatia. The effects of the crude aqueous extracts of the Fancsika bloom sample (FBS) and the laboratory isolate of C. raciborskii from the pond (FLI) were compared with reference samples: C. raciborskii ACT 9505 (isolated in 1995 from Lake Balaton, Hungary), the cylindrospermopsin producer AQS, and the neurotoxin (anatoxin-a, homoanatoxin-a) producer Oscillatoria sp. (PCC 6506) strains. Electrophysiological tests showed that both FBS and FLI samples as well the ACT 9505 extracts modulate the acetylcholine receptors (AChRs) of the neurons, evoking ACh agonist effects, then inhibiting the ACh-evoked neuronal responses. Dose-response data suggested about the same range of toxicity of FBS and FLI samples (EC50 = 0.397 mg/mL and 0.917 mg/mL, respectively) and ACT 9505 extracts (EC50 = 0.734 mg/mL). The extract of the neurotoxin-producing PCC 6506 strain, however, proved to be the strongest inhibitor of the ACh responses on the same neurons (EC50 = 0.073 mg/mL). The presented results demonstrated an anatoxin-a-like cholinergic inhibitory effects of cyanobacterial extracts (both the environmental FBS sample, and the laboratory isolate, FLI) by some (yet unidentified) toxic components in the matrix of secondary metabolites. Previous pharmacological studies of cyanobacterial samples collected in other locations (Balaton, West Hungary) resulted in similar conclusions; therefore, we cannot exclude that this chemotype of C. raciborskii which produce anatoxin-a like neuroactive substances is more widely distributed in this region.


Assuntos
Cylindrospermopsis/metabolismo , Eutrofização , Neurotoxinas/biossíntese , Neurotoxinas/toxicidade , Uracila/análogos & derivados , Acetilcolina/metabolismo , Alcaloides , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Toxinas de Cianobactérias , Cylindrospermopsis/efeitos dos fármacos , Relação Dose-Resposta a Droga , Caracois Helix , Hungria , Lagos , Neurônios/efeitos dos fármacos , Oscillatoria/química , Oscillatoria/metabolismo , Receptores Colinérgicos/efeitos dos fármacos , Tropanos/química , Tropanos/metabolismo , Tropanos/toxicidade , Uracila/biossíntese , Uracila/toxicidade
15.
Arch Pharm (Weinheim) ; 348(12): 897-907, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26548647

RESUMO

The reaction of direct condensation between S-ethyl-N-(7-oxabicyclo-[2.2.1]heptane-2,3-dicarbonyl)isothiosemicarbazide (1) and primary amines was used for synthesizing new N-substituted amides of 3-(3-ethylthio-1,2,4-triazol-5-yl)-7-oxabicyclo-[2.2.1]heptane-2-carboxylic acid (2-12) as norcantharadin analogs. Moreover, the anticancer activity of the obtained compounds was studied. Among all compounds, the N-3-methylbutyl amide of 3-(3-ethylthio-1,2,4-triazol-5-yl)-7-oxabicyclo-[2.2.1]heptane-2-carboxylic acid (4) presented selective in vitro toxic and antiproliferative effects against the human hepatoma cell line Hep3B, without affecting normal human liver stellate cells (LX-2 cell line).


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Antineoplásicos/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Desenho de Fármacos , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/patologia , Humanos , Concentração Inibidora 50 , Neoplasias Hepáticas/patologia , Estrutura Molecular , Relação Estrutura-Atividade , Fatores de Tempo
16.
Toxicol Appl Pharmacol ; 277(3): 279-87, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24726521

RESUMO

1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH; formerly abbreviated as TBECH) and tris(methylphenyl) phosphate (TMPP; formerly abbreviated as TCP) are additive flame retardants that are detected in the environment and biota. A recent avian in vitro screening study of 16 flame retardants identified DBE-DBCH and TMPP as important chemicals for follow-up in ovo evaluation based on their effects on cytotoxicity and mRNA expression in avian hepatocytes. In this study, technical mixtures of DBE-DBCH and TMPP were injected into the air cell of chicken embryos at concentrations ranging from 0 to 54,900ng/g and from 0 to 261,400ng/g, respectively, to determine effects on pipping success, development, hepatic mRNA expression, thyroid hormone levels, and circulating bile acid concentrations. Both compounds were detectable in embryos at pipping and the ß-DBE-DBCH isomer was depleted more rapidly than the α-isomer in tissue samples. DBE-DBCH had limited effects on the endpoints measured, with the exception of the up-regulation of two phase I metabolizing enzymes, CYP3A37 and CYP2H1. TMPP exposure caused embryonic deformities, altered growth, increased liver somatic index (LSI) and plasma bile acid concentrations, and altered mRNA expression levels of genes associated with xenobiotic and lipid metabolism and the thyroid hormone pathway. Overall, TMPP elicited more adverse molecular and phenotypic effects than DBE-DBCH albeit at concentrations several orders of magnitude greater than those detected in the environment. The increase in plasma bile acid concentrations was a useful phenotypic anchor as it was associated with a concomitant increase in LSI, discoloration of the liver tissue, and modulation of hepatic genes involved with xenobiotic and lipid metabolism.


Assuntos
Ácidos e Sais Biliares/sangue , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Cicloexanos/toxicidade , Retardadores de Chama/toxicidade , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , RNA Mensageiro/metabolismo , Animais , Ácidos e Sais Biliares/metabolismo , Embrião de Galinha , Poluentes Ambientais/toxicidade , Fígado/metabolismo , Estrutura Molecular , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tiroxina/sangue
17.
Nat Med ; 13(9): 1102-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17767166

RESUMO

Schizophrenia is a chronic, complex and heterogeneous mental disorder, with pathological features of disrupted neuronal excitability and plasticity within limbic structures of the brain. These pathological features manifest behaviorally as positive symptoms (including hallucinations, delusions and thought disorder), negative symptoms (such as social withdrawal, apathy and emotional blunting) and other psychopathological symptoms (such as psychomotor retardation, lack of insight, poor attention and impulse control). Altered glutamate neurotransmission has for decades been linked to schizophrenia, but all commonly prescribed antipsychotics act on dopamine receptors. LY404039 is a selective agonist for metabotropic glutamate 2/3 (mGlu2/3) receptors and has shown antipsychotic potential in animal studies. With data from rodents, we provide new evidence that mGlu2/3 receptor agonists work by a distinct mechanism different from that of olanzapine. To clinically test this mechanism, an oral prodrug of LY404039 (LY2140023) was evaluated in schizophrenic patients with olanzapine as an active control in a randomized, three-armed, double-blind, placebo-controlled study. Treatment with LY2140023, like treatment with olanzapine, was safe and well-tolerated; treated patients showed statistically significant improvements in both positive and negative symptoms of schizophrenia compared to placebo (P < 0.001 at week 4). Notably, patients treated with LY2140023 did not differ from placebo-treated patients with respect to prolactin elevation, extrapyramidal symptoms or weight gain. These data suggest that mGlu2/3 receptor agonists have antipsychotic properties and may provide a new alternative for the treatment of schizophrenia.


Assuntos
Antipsicóticos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Óxidos S-Cíclicos/uso terapêutico , Receptores de Glutamato Metabotrópico/fisiologia , Esquizofrenia/tratamento farmacológico , Animais , Antipsicóticos/toxicidade , Benzodiazepinas/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Óxidos S-Cíclicos/toxicidade , Modelos Animais de Doenças , Método Duplo-Cego , Humanos , Olanzapina , Placebos , Receptores de Glutamato Metabotrópico/efeitos dos fármacos
18.
Int J Toxicol ; 33(5): 419-27, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25201897

RESUMO

Tavaborole, a cyclized boronic acid, has been approved by the Food and Drug Administration for the topical treatment of toenail onychomycosis. This novel, low-molecular-weight pharmaceutical compound has broad-spectrum antifungal activity against dermatophytes, yeasts, and molds responsible for the disease. Tavaborole was tested in 2-year carcinogenicity studies in mice (once daily dermal administration) and rats (once daily by oral gavage) as part of the extensive nonclinical safety program. There was no evidence of tavaborole-related neoplasms observed in either study. Based on the data gathered from these 2 carcinogenicity studies, tavaborole is considered noncarcinogenic.


Assuntos
Antifúngicos/toxicidade , Compostos de Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Carcinógenos/toxicidade , Administração Tópica , Animais , Antifúngicos/sangue , Compostos de Boro/sangue , Compostos Bicíclicos Heterocíclicos com Pontes/sangue , Testes de Carcinogenicidade , Relação Dose-Resposta a Droga , Feminino , Masculino , Camundongos , Onicomicose/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Análise de Sobrevida , Aumento de Peso/efeitos dos fármacos
19.
J Pharmacol Exp Ther ; 344(2): 436-46, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23192653

RESUMO

Pro-inflammatory cytokines play a critical role in the development of autoimmune and inflammatory diseases. Targeting the cytokine environment has proven efficient for averting inflammation. In this study, we reported that 6-[4-(aminomethyl)-2-chlorophenoxyl]benzo[c][1,2]oxaborol-1(3H)-ol (AN3485), a benzoxaborole analog, inhibited TLR2-, TLR3-, TLR4-, and TLR5-mediated TNF-α, IL-1ß, and IL-6 release from human PBMCs and isolated monocytes with IC(50) values ranging from 18 to 580 nM, and the inhibition was mediated at the transcriptional level. Topical administration of AN3485 significantly reduced PMA-induced contact dermatitis and oxazolone-induced delayed-type hypersensitivity in mice, indicating its capability of penetrating skin and potential topical application in skin inflammation. Oral administration of AN3485 showed dose-dependent suppression of LPS-induced TNF-α and IL-6 production in mice with an ED(90) of 30 mg/kg. Oral AN3485, 35 mg/kg, twice a day, suppressed collagen-induced arthritis in mice over a 20-day period. The potent anti-inflammatory activity in in vitro and in vivo disease models makes AN3485 an attractive therapeutic lead for a variety of cutaneous and systemic inflammatory diseases.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite/tratamento farmacológico , Compostos de Boro/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Dermatite Alérgica de Contato/tratamento farmacológico , Hipersensibilidade a Drogas/tratamento farmacológico , Hipersensibilidade Tardia/tratamento farmacológico , Receptores Toll-Like/antagonistas & inibidores , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacocinética , Anti-Inflamatórios não Esteroides/toxicidade , Artrite/imunologia , Artrite/metabolismo , Compostos de Boro/administração & dosagem , Compostos de Boro/farmacocinética , Compostos de Boro/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/biossíntese , Citocinas/metabolismo , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/imunologia , Dermatite Alérgica de Contato/metabolismo , Relação Dose-Resposta a Droga , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/metabolismo , Feminino , Humanos , Hipersensibilidade Tardia/induzido quimicamente , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
20.
Org Biomol Chem ; 11(3): 407-11, 2013 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-23192531

RESUMO

An unexpected intramolecular cyclization during the reaction of furfurylamine with maleimides is reported as a novel strategy for the efficient green synthesis of the 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton. Under the same reaction conditions, 7-oxabicyclo[2.2.1]hept-5-enes were synthesized when furfurylamine was N-protected by the acetyl group. Both types of bicycloheptenes were screened using the zebrafish model system for genetics and developmental biology.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Desenvolvimento Embrionário/efeitos dos fármacos , Furanos/química , Maleimidas/química , Modelos Animais , Peixe-Zebra/embriologia , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Ciclização , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Estrutura Molecular , Fenótipo , Relação Estrutura-Atividade , Peixe-Zebra/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA