Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24.073
Filtrar
1.
Gut ; 69(1): 158-167, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30833451

RESUMO

OBJECTIVE: Hepatitis D virus (HDV) is a circular RNA virus coinfecting hepatocytes with hepatitis B virus. Chronic hepatitis D results in severe liver disease and an increased risk of liver cancer. Efficient therapeutic approaches against HDV are absent. DESIGN: Here, we combined an RNAi loss-of-function and small molecule screen to uncover host-dependency factors for HDV infection. RESULTS: Functional screening unravelled the hypoxia-inducible factor (HIF)-signalling and insulin-resistance pathways, RNA polymerase II, glycosaminoglycan biosynthesis and the pyrimidine metabolism as virus-hepatocyte dependency networks. Validation studies in primary human hepatocytes identified the carbamoyl-phosphatesynthetase 2, aspartate transcarbamylase and dihydroorotase (CAD) enzyme and estrogen receptor alpha (encoded by ESR1) as key host factors for HDV life cycle. Mechanistic studies revealed that the two host factors are required for viral replication. Inhibition studies using N-(phosphonoacetyl)-L-aspartic acid and fulvestrant, specific CAD and ESR1 inhibitors, respectively, uncovered their impact as antiviral targets. CONCLUSION: The discovery of HDV host-dependency factors elucidates the pathogenesis of viral disease biology and opens therapeutic strategies for HDV cure.


Assuntos
Aspartato Carbamoiltransferase/genética , Ácido Aspártico/análogos & derivados , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Di-Hidro-Orotase/genética , Receptor alfa de Estrogênio/metabolismo , Fulvestranto/farmacologia , Hepatite D Crônica/tratamento farmacológico , Ácido Fosfonoacéticos/análogos & derivados , Pirimidinas/biossíntese , Antivirais/farmacologia , Aspartato Carbamoiltransferase/antagonistas & inibidores , Aspartato Carbamoiltransferase/metabolismo , Ácido Aspártico/farmacologia , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/antagonistas & inibidores , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/metabolismo , Linhagem Celular , Di-Hidro-Orotase/antagonistas & inibidores , Di-Hidro-Orotase/metabolismo , Antagonistas do Receptor de Estrogênio/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Inativação Gênica , Hepatite D Crônica/genética , Hepatite D Crônica/metabolismo , Vírus Delta da Hepatite/fisiologia , Hepatócitos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Resistência à Insulina , Estágios do Ciclo de Vida , Mutação com Perda de Função , Ácido Fosfonoacéticos/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Viral/metabolismo , Transdução de Sinais , Replicação Viral
2.
Mikrobiyol Bul ; 53(4): 374-387, 2019 Oct.
Artigo em Turco | MEDLINE | ID: mdl-31709935

RESUMO

Human immunodeficiency virus (HIV) comprises two genotypes, namely HIV-1 (group M, N, O and P) and HIV-2 (group A to H), which differ in their envelope glycoproteins and other antigenic epitopes despite their morphological and biological resemblance.Group M of HIV-1 responsible for 95% of HIV infections worldwide is composed of nine subgroups. In addition to subgroups, group M contains also two recombinant forms, known as circulating recombinant form (CRF) and unique recombinant form (URF). The first case of HIV/acquired immun deficiency virus (AIDS) in Turkey was reported in 1985 and the current number of cases reached a total of 18.557 including 1736 with AIDS based upon the surveillance data of Ministry of Health between October 1985 and November 2018. The aim of this study was to determine the prevalence of HIV-1 strains isolated from HIV positive autopsy cases detected by HIV polymerase chain reaction (PCR) and determine drug resistance. Twenty eight cases [17 males, 11 female: age ranged between 3 months and 66 years (median: 35 years)] found to be HIV positive among the autopsy cases sent for HIV1 PCR study and serological screening between 2011-2017 were recruited in the study. For identification of subtypes in HIV-1 isolates, most-preferred analysis tool was used [HIVdb Stanford University Genotypic Resistance Interpretation Algorithm (www.hivdb.stanford.edu)]. Phylogenetic tree was made according to direct sequencing of HIV-1 reverse transcriptase (pol) region and phylogenetic analysis was evaluated in 23 cases. Los Alamos National Laboratory were trimmed from full-length genomes. Phylogenetic analysis of the 870 base pair of the pol gene region was performed using CLC Sequence Viewer v8.0 (Qiagen Aarhus A/S, www.qiagenbioinformatics.com) software. The phylogenetic tree was obtained according to the neighbor-joining method and the Jukes-Cantor nucleotide distance scale and bootstrap value was set at 1000. In our study, subtype B was found to be most frequent type (39.3%; 11/28). Subtype A (17.9%; 5/28), CRF02_AG (14.3%; 4/28), subtype C (10.7%; 3/28), B+CRF02_AG recombinant (3.6%; 1/28), CRF01_AE (3.6%; 1/28), subtype D (3.6%; 1/28), as well as subtype F (3.6%; 1/28) and subtype G (3.6%; 1/28) strains were also detected in the circulation. Analysis of our results showed that 32.1% (9/28) of the samples exhibited resistance mutations. Detected mutations were as follows: M41L, T215C, K65R, M184V, responsible for nucleoside reverse transcriptase inhibitor (NRTI) resistance; K103N, Y181C, G190A, responsible for non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance; D30N, M46I, responsible for protease inhibitor (PI) resistance. NRTI, NNRTI and PI mutation rates in the samples were found as 21.4%, 7.1% and 3.6%, respectively. Although number of samples analyzed in our study is low, we can propose that they resemble the strains circulating in Turkey. The results of our study; although the subtype B is still dominant in our country, it supports other studies reporting that there are non-B subtypes and an increase in CRF rates in recent years. Phylogenetic analysis is widely regarded as the gold standard technique to determine the subtypes of HIV-1. Molecular epidemiologic studies related to HIV may be important in monitoring HIV subtype patterns and spreading pathways in that country. As a result; the opportunity to collect postmortem HIV sequences in a database appears to have occurred, and as this database expands, its usability is available. Therefore, it is thought that HIV subtypes and mutation information may be useful.


Assuntos
Infecções por HIV , HIV-1 , Epidemiologia Molecular , Adolescente , Adulto , Idoso , Antivirais/farmacologia , Autopsia , Criança , Pré-Escolar , Farmacorresistência Viral , Feminino , Genótipo , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/efeitos dos fármacos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação , Filogenia , Turquia/epidemiologia
3.
Expert Opin Drug Metab Toxicol ; 15(10): 779-785, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31593639

RESUMO

Introduction: Interferon (IFN) had both antiviral and immunomodulatory effects, and was one of the approved treatments for hepatitis B virus (HBV). Herein, we reviewed the pharmacokinetics and pharmacodynamics of pegylated IFN-α (PegIFN-α) for the treatment of HBV. Areas covered: The steady-state serum levels of PegIFN-α were reached within 5 to 8 weeks, and the week 48 mean trough concentrations were approximately 2-fold higher than week 1. There was also no difference of the pharmacokinetics in male or female, healthy volunteers or patients with hepatitis B or C infection. PegIFN-α did not affect the metabolism of the cytochrome P450 (CYP) isozymes, except inhibition of CYP1A2. There was also no pharmacokinetic interaction between PegIFN-α and HBV nucleot(s)ide analogues (NUCs). Forty-eight weeks of PegIFN-α achieved 32% of HBeAg seroconversion, 32-43% of HBV DNA suppression, 41-59% of ALT normalization, and 3% of HBsAg seroconversion rate with a post-treatment durable response up to 80% in the initial responders. Expert opinion: On-treatment HBsAg titer guided the treatment of HBV with PegIFN-α. The recommendation of PegIFN-α and NUC combination or switch remained controversial. New immunotherapeutic agents are now in development. Although, PegIFN-α should continue to play a role in the treatment of HBV.


Assuntos
Hepatite B Crônica/tratamento farmacológico , Interferon alfa-2/administração & dosagem , Interferon-alfa/administração & dosagem , Polietilenoglicóis/administração & dosagem , Animais , Antivirais/administração & dosagem , Antivirais/farmacocinética , Antivirais/farmacologia , DNA Viral/efeitos dos fármacos , Interações de Medicamentos , Feminino , Antígenos E da Hepatite B/sangue , Humanos , Interferon alfa-2/farmacocinética , Interferon alfa-2/farmacologia , Interferon-alfa/farmacocinética , Interferon-alfa/farmacologia , Masculino , Polietilenoglicóis/farmacocinética , Polietilenoglicóis/farmacologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacologia
4.
Cent Eur J Public Health ; 27(3): 212-216, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31580556

RESUMO

OBJECTIVES: Survey was conducted to assess state of viral hepatitis care in Central and Eastern Europe (CEE). METHODS: Representatives of 16 CEE countries completed on-line survey in April-May 2017 that collected information on basic epidemiology and availability of key services for HCV and HBV infections. Sources of information provided ranged from national surveillance data to expert opinion. RESULTS: The burden of viral hepatitis varied between countries, ranging from 6,500 to 2 million for HCV and from 10,000 to 3 million for HBV. Access to routine HCV RNA testing and genotyping was reported by 11 and 9 countries, respectively. HCV resistance testing was available in 7 countries. Direct acting antivirals (DAAs) were available in 13 countries, most frequently Sofosbuvir and Ledipasvir/Sofosbuvir (12 countries apiece) and Ombitasvir/Paritaprevir/Dasabuvir (9 countries). HBV DNA testing and HBV genotyping were routinely available in 10 and 7 countries, respectively. Eleven countries reported available treatment with Tenofovir. CONCLUSIONS: There are gaps in viral hepatitis care in CEE. Despite the availability of registered modern drugs for HCV and HBV, the access to treatment is limited. Ensuring quality health care is essential to reduce the epidemic and achieve the WHO's goal of eliminating viral hepatitis as a major public health challenge.


Assuntos
Antivirais , Hepatite B/prevenção & controle , Hepatite C , Antivirais/farmacologia , Europa (Continente)/epidemiologia , Europa Oriental , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Hepatite C/prevenção & controle , Humanos
5.
Chem Biodivers ; 16(10): e1900391, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31479201

RESUMO

A series of novel 2-oxoimidazolidine derivatives were synthesized and their antiviral activities against BK human polyomavirus type 1 (BKPyV) were evaluated in vitro. Bioassays showed that the synthesized compounds 1-{[(4E)-5-(dichloromethylidene)-2-oxoimidazolidin-4-ylidene]sulfamoyl}piperidine-4-carboxylic acid (5) and N-Cyclobutyl-N'-[(4E)-5-(dichloromethylidene)-2-oxoimidazolidin-4-ylidene]sulfuric diamide (4) exhibited moderate activities against BKPyV (EC50 =5.4 and 5.5 µm, respectively) that are comparable to the standard drug Cidofovir. Compound 5 exhibited the same cytotoxicity in HFF cells and selectivity index (SI50 ) as Cidofovir. The selectivity index of compound 4 is three times less than that of Cidofovir due to the higher toxicity of this compound. Hence, these compounds may be taken as lead compound for further development of novel ant-BKPyV agents.


Assuntos
Antivirais/farmacologia , Vírus BK/efeitos dos fármacos , Cidofovir/farmacologia , Desenho de Drogas , Imidazolidinas/farmacologia , Antivirais/síntese química , Antivirais/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cidofovir/química , Relação Dose-Resposta a Droga , Humanos , Imidazolidinas/síntese química , Imidazolidinas/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
6.
Int J Nanomedicine ; 14: 6217-6229, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496682

RESUMO

Background: Viral and microbial infections constitute one of the most important life-threatening problems. The emergence of new viral and bacterial infectious diseases increases the demand for new therapeutic drugs. Purpose: The objective of this study was to use the aqueous and hexane extracts of Lampranthus coccineus and Malephora lutea F. Aizoaceae for the synthesis of silver nanoparticles, and to investigate its possible antiviral activity. In addition to the investigation of the phytochemical composition of the crude methanolic extracts of the two plants through UPLC-MS metabolomic profiling, and it was followed by molecular docking in order to explore the chemical compounds that might contribute to the antiviral potential. Methods: The formation of SNPs was further confirmed using a transmission electron microscope (TEM), UV-Visible spectroscopy and Fourier transform infrared spectroscopy. The antiviral activity of the synthesized nanoparticles was evaluated using MTT assay against HSV-1, HAV-10 virus and Coxsackie B4 virus. Metabolomics profiling was performed using UPLC-MS and molecular docking was performed via Autodock4 and visualization was done using the Discovery studio. Results: The early signs of SNPs synthesis were detected by a color change from yellow to reddish brown color. The TEM analysis of SNPs showed spherical nanoparticles with mean size ranges between 10.12 nm to 27.89 nm, and 8.91 nm 14.48 nm for Lampranthus coccineus and Malephora lutea aqueous and hexane extracts respectively. The UV-Visible spectrophotometric analysis showed an absorption peak at λmax of 417 nm.The green synthesized SNPs of L. coccineus and M. lutea showed remarkable antiviral activity against HSV-1, HAV-10, and CoxB4 virus. Metabolomics profiling of the methanolic extract of L. coccineus and M. lutea resulted in identifying 12 compounds. The docking study predicted the patterns of interactions between the compounds of L. coccineus and M. lutea with herpes simplex thymidine kinase, hepatitis A 3c proteinase, and Coxsackievirus B4 3c protease, which was similar to those of the co-crystal inhibitors and this can provide a supposed explanation for the antiviral activity of the aqueous and nano extracts of L. coccineus and M. lutea. Conclusion: These results highlight that SNPs of L. coccineus and M. lutea could have antiviral activity against HSV-1, HAV-10, and CoxB4 virus.


Assuntos
Aizoaceae/química , Antivirais/farmacologia , Química Verde , Nanopartículas Metálicas/química , Prata/farmacologia , Animais , Antivirais/química , Morte Celular/efeitos dos fármacos , Ligantes , Metabolômica , Nanopartículas Metálicas/ultraestrutura , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Prata/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Células Vero
7.
N Engl J Med ; 381(12): 1136-1147, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31532960

RESUMO

BACKGROUND: Maribavir is a benzimidazole riboside with activity against cytomegalovirus (CMV). The safety and efficacy of maribavir for preemptive treatment of CMV infection in transplant recipients is not known. METHODS: In a phase 2, open-label, maribavir dose-blinded trial, recipients of hematopoietic-cell or solid-organ transplants (≥18 years of age, with CMV reactivation [1000 to 100,000 DNA copies per milliliter]) were randomly assigned to receive maribavir at a dose of 400, 800, or 1200 mg twice daily or the standard dose of valganciclovir for no more than 12 weeks. The primary efficacy end point was the percentage of patients with a response to treatment, defined as confirmed undetectable CMV DNA in plasma, within 3 weeks and 6 weeks after the start of treatment. The primary safety end point was the incidence of adverse events that occurred or worsened during treatment. RESULTS: Of the 161 patients who underwent randomization, 159 received treatment, and 156 had postbaseline data available - 117 in the maribavir group and 39 in the valganciclovir group. The percentage of patients with postbaseline data available who had a response to treatment within 3 weeks was 62% among those who received maribavir and 56% among those who received valganciclovir. Within 6 weeks, 79% and 67% of patients, respectively, had a response (risk ratio, 1.20; 95% confidence interval, 0.95 to 1.51). The percentages of patients with a response to treatment were similar among the maribavir dose groups. Two patients who had a response to treatment had a recurrence of CMV infection within 6 weeks after starting maribavir at a dose of 800 mg twice daily; T409M resistance mutations in CMV UL97 protein kinase developed in both patients. The incidence of serious adverse events that occurred or worsened during treatment was higher in the maribavir group than in the valganciclovir group (52 of 119 patients [44%] vs. 13 of 40 [32%]). A greater percentage of patients in the maribavir group discontinued the trial medication because of an adverse event (27 of 119 [23%] vs. 5 of 40 [12%]). A higher incidence of gastrointestinal adverse events was reported with maribavir, and a higher incidence of neutropenia was reported with valganciclovir. CONCLUSIONS: Maribavir at a dose of at least 400 mg twice daily had efficacy similar to that of valganciclovir for clearing CMV viremia among recipients of hematopoietic-cell or solid-organ transplants. A higher incidence of gastrointestinal adverse events - notably dysgeusia - and a lower incidence of neutropenia were found in the maribavir group. (Funded by ViroPharma/Shire Development; EudraCT number, 2010-024247-32.).


Assuntos
Antivirais/uso terapêutico , Benzimidazóis/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/fisiologia , Ribonucleosídeos/uso terapêutico , Valganciclovir/uso terapêutico , Viremia/tratamento farmacológico , Adulto , Idoso , Aloenxertos , Antivirais/efeitos adversos , Antivirais/farmacologia , Benzimidazóis/efeitos adversos , Benzimidazóis/farmacologia , Citomegalovirus/efeitos dos fármacos , Infecções por Citomegalovirus/virologia , Disgeusia/induzido quimicamente , Feminino , Gastroenteropatias/induzido quimicamente , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Transplante de Órgãos/efeitos adversos , Ribonucleosídeos/efeitos adversos , Ribonucleosídeos/farmacologia , Valganciclovir/efeitos adversos , Valganciclovir/farmacologia , Ativação Viral/efeitos dos fármacos
8.
J Agric Food Chem ; 67(41): 11380-11387, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31535865

RESUMO

Southern rice black-streaked dwarf virus (SRBSDV) causes disease in crops, which reduces the quality and yield. Several commercial antiviral agents are available to control the SRBSDV induced disease. However, the mechanism of antiviral agents controlling SRBSDV is largely unknown. Identifying targets in SRBSDV is a key step of antiviral agent discovery. Here, we investigated the potential protein target of the antiviral agent dufulin. We cloned and expressed a soluble viroplasmic P6 protein in the prokaryote Escherichia coli and the eukaryote Spodoptera frugiperda 9. The dissociation constants of dufulin with the purified P6 protein from E. coli and S. frugiperda 9 expression systems were 4.49 and 4.95 µM, respectively, indicating a strong binding affinity between dufulin and P6 protein. In vivo, dufulin significantly inhibited the expression of both P6 protein and P6 gene in the SRBSDV-infected rice leaves. This inhibition on P6 protein expression was also observed in transformed Nicotiana benthamiana where the P6 was overexpressed. Our data also showed that dufulin inhibited the duplication of SRBSDV in a dose-dependent manner in infected rice leaves with a half maximum effective concentration of 3.32 mM. It is therefore concluded that dufulin targets the viroplasmic protein P6 to inhibit the virulence of SRBSDV.


Assuntos
Antivirais/farmacologia , Benzotiazóis/farmacologia , Doenças das Plantas/virologia , Reoviridae/efeitos dos fármacos , Proteínas Virais/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Oryza/virologia , Reoviridae/genética , Reoviridae/metabolismo , Proteínas Virais/genética
9.
Life Sci ; 235: 116797, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472146

RESUMO

Chrysin is a promising phytochemical that is categorized under the class of flavonoids based on its chemical structure. Naturally, it is widely present in propolis, honey, passion fruit, and even in mushrooms and other plant sources, whereas its synthetic counterparts are also being employed for pharmacological purposes. It has widely been employed in treatment of various degenerative disorders and provides cytotoxic and anti-inflammatory functions. Its antioxidant and disease preventing abilities are attributed to its structural diversity arising in ring-A and absence of oxygenation in B and C ring. In this review, the scientific studies are being reported emphasizing benefits and its allied health claims on chrysin in numerous metabolic malfunctions.


Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Antivirais/farmacologia , Flavonoides/farmacologia , Humanos
10.
Phytochemistry ; 167: 112101, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31473556

RESUMO

In an effort to identify inhibitors of Chikungunya virus (CHIKV) replication, a systematic study of 594 extracts of plant species originating from the French Guiana plateau region was performed in a virus-cell-based assay for CHIKV assay. The extract obtained from the stem bark of Sagotia racemosa was selected for its potent antiviral activity. Using a classical bioassay-guided procedure, three undescribed degraded diterpenoids, i.e. trigohowilols C and D and trigoflavidol D, as well as trigoxyphin K, stictic acid, hyperhomosekikaic acid and five known flavonoids were isolated. The structures of these compounds were elucidated by extensive NMR spectroscopic data analysis. Although trigohowilols C and D were isolated from the most active fraction they didn't show any antiviral activity. By using the Feature-Based Molecular Networking (FBMN) and Network Annotation Propagation (NAP) workflows, it has been shown that the strong anti-CHIKV activity found for this fraction might be due to the presence of analogues of 12-O-tetradecanoylphorbol-13-acetate (TPA), one of the most potent inhibitors of CHIKV replication identified to date.


Assuntos
Antivirais/isolamento & purificação , Antivirais/farmacologia , Vírus Chikungunya/efeitos dos fármacos , Euphorbiaceae/química , Fenantrenos/isolamento & purificação , Fenantrenos/farmacologia , Ésteres de Forbol/química , Antivirais/química , Vírus Chikungunya/fisiologia , Informática , Fenantrenos/química , Replicação Viral/efeitos dos fármacos , Fluxo de Trabalho
11.
Acta Virol ; 63(3): 261-269, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507191

RESUMO

Bovine viral diarrhea virus (BVDV) exists in two main biotypes: cytopathic (cp) and noncytopathic (ncp). Although some studies were done on the effect of interferon alpha (IFN-α) on BVDV, the effect of exogenous IFN against BVDV biotypes remains unclear. In the present study, we evaluated the comparative effect of exogenous human IFN-α (HuIFN-α) on different BVDV biotypes and genotypes. The results showed that exogenous HuIFN-α greatly inhibited the growth of different BVDV biotypes and genotypes. However, HuINF-α has a significant inhibitory effect on cp biotype compared to ncp one without significant variation between different genotypes. The effect of HuIFN-α on BVDV reached the maximum level at early stages of infection (0-20 h post infection) and increased in a dose-dependent manner (10-500 U/ml). Quantitative real-time RT-PCR was used to evaluate the effect of exogenous HuIFN-α on RNA synthesis of both BVDV biotypes. HuIFN-α reduced RNA production of cp by 4 logs compared to only 2 logs for ncp strains. Additionally, the antiviral effect of IFN-α against both BVDV biotypes seems to be independent of the RNA-dependent protein kinase (PKR) activation as assayed by direct analysis of in vivo phosphorylation of eIF2-α and by 2-aminopurine (2-AP) treatment. Collectively, these results indicated that the exogenous HuIFN-α treatment has an inhibitory effect not only on cp BVDV biotype but also on the ncp BVDV. The antiviral effect of exogenous HuIFN-α was biotype, time, dose but not genotype dependent. PKR has no role in the inhibitory effect suggesting that other IFN-antiviral pathways were involved. Keywords: BVDV biotypes; HuIFN-α; RNA synthesis; PKR-independent.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Vírus da Diarreia Viral Bovina , Interferon-alfa , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/tratamento farmacológico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Vírus da Diarreia Viral Bovina/efeitos dos fármacos , Humanos , Interferon-alfa/farmacologia , Interferon-alfa/uso terapêutico , Replicação Viral/efeitos dos fármacos
12.
Acta Virol ; 63(3): 278-285, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507193

RESUMO

Dengue virus (DENV) infection is one of the most widely-spread flavivirus infections with no effective antiviral drugs available. Peptide inhibitors have been considered as one of the best drug candidates due to their high specificity, selectivity in their interactions and minimum side effects. In this study, we employed computational studies using YASARA, HADDOCK server and PyMOL software to generate short and linear peptides based on a reference peptide, CP5-46A, to block DENV NS2B-NS3 protease. The inhibition potencies of the peptides were evaluated using in-house DENV2 serine protease and fluorogenic peptide substrates. In vitro analyses were performed to determine the peptides cytotoxicity and the inhibitory effects against DENV2 replication in WRL-68 cells. Our computational analyses revealed that the docking energy of AYA3, a 16 amino acid (aa) (-81.2 ± 10.6 kcal/mol) and AYA9, a 15 aa peptide (-83.8 ± 6.8 kcal/mol) to DENV NS2B-NS3 protease were much lower than the reference peptide (46 aa; -70.9 ± 7.8 kcal/mol) and the standard protease inhibitor, aprotinin (58 aa; -48.2 ± 10.6 kcal/mol). Both peptides showed significant inhibition against DENV2 NS2B-NS3 protease activity with IC50 values of 24 µM and 23 µM, respectively. AYA3 and AYA9 peptides also demonstrated approximately 68% and 83% of viral plaque reduction without significantly affecting cell viability at 50 µM concentration. In short, we generated short linear peptides with lower cytotoxic effect and substantial antiviral activities against DENV2. Further studies are required to investigate the inhibitory effects of these peptides in vivo. Keywords: peptide inhibitors; dengue virus; NS2B-NS3 protease; plaque reduction.


Assuntos
Antivirais , Vírus da Dengue , Peptídeos , Inibidores de Proteases , Replicação Viral , Antivirais/farmacologia , Biologia Computacional , Vírus da Dengue/enzimologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Peptídeos/síntese química , Peptídeos/farmacologia , Inibidores de Proteases/farmacologia , Replicação Viral/efeitos dos fármacos
13.
Acta Virol ; 63(3): 309-315, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507197

RESUMO

Influenza virus is activated by proteolytic cleavage of hemagglutinin by trypsin. After determining the optimal trypsin concentration, intracellular and extracellular influenza A/PR/8/34 (H1N1) and A/Victoria/361/2011 (H3N2) virus productions were compared in cultures treated with T-705 (favipiravir) and GS 4071 (an active form of oseltamivir). Although both drugs efficiently inhibited extracellular viral RNA release in a dose-dependent manner, T-705 inhibited it to the level of the inoculum without trypsin treatment, while GS 4071 inhibited it to a final level 10 times higher than that without trypsin. T-705 inhibited intracellular viral RNA production to the level of input virus in both trypsin-treated and untreated cells. In contrast, GS 4071 dose-dependently inhibited intracellular viral RNA production in cells treated with trypsin but allowed viral RNA synthesis. The level of maximum inhibition by GS 4071was 10 times higher than that of cells without trypsin and 1,000 times greater than the inoculum titer in cells without trypsin. T-705 inhibited both intracellular and extracellular virus production 1,000 and 10 times more strongly, respectively, than GS 4071. T-705 has powerful anti-influenza activity in the absence of trypsin and even in the trypsin-optimized growth condition, suggesting the therapeutic advantage in treatment of influenza complicated with bacterial pneumonia. Keywords: influenza; T-705; Tamiflu; trypsin; bacterial trypsin-like protease.


Assuntos
Amidas , Antivirais , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Pirazinas , Tripsina , Amidas/farmacologia , Antivirais/farmacologia , Linhagem Celular , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Oseltamivir/farmacologia , Pirazinas/farmacologia , RNA Viral/biossíntese , Tripsina/farmacologia
14.
Mol Biol (Mosk) ; 53(4): 541-560, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31397431

RESUMO

The human respiratory syncytial virus (RSV) is one of the most common viral pathogens that affects the lower respiratory tract and could be a reason of bronchiolitis and/or pneumonia. Currently, there are no available effective ways of treating the RSV infection. Attempts to develop preventive vaccine have been unsuccessful. The only therapeutic agent used for RSV treatment is virazole (ribavirin); however, it induces adverse effects. Medications based on neutralizing monoclonal antibodies, such as IGIV (Respigam), palivizumab (Synagis), and MEDI-524 (Numab), are under clinical trials; however, their use will be limited by their high cost. One of the promising approaches for antiviral therapy is the use of natural peptides (defensins and cathelicidins), or their synthetic analogs. The majority of currently described antiviral peptides are developed against the human immunodeficiency virus, the herpes simplex virus, and the influenza virus. At the same time, a body of experimental data evidencing anti-RSV activity of peptides has been accumulated. The main advantages of peptide drugs are their wide spectrum of antiviral activity and low toxicity. However, there are obstacles in implementing peptide-based drugs in clinical practice. Due to their low resistance to the action of serum proteases, most authors consider peptides promising only for local application. Given that RSV affects the epithelium of the respiratory tract, where the protease activity is lower than in the systemic circulation, it is possible to develop locally active peptide drugs, for example, as inhalation forms. Their stability could also be increased by the synthesis of dendrimer peptides and by the development of recombinant peptides as precursor proteins. Anti-RSV peptides can be divided into several groups: (1) attachment and/or fusion blockers; (2) peptides displaying direct virucidal activity, disrupting the viral envelope. Such peptides, which suppress early stages of the viral life cycle, are considered prophylactic agents. However, for several peptides, their immunoregulatory properties have been described, which opens the possibility for therapeutic use. This review summarizes the information on the antiviral properties of such peptides and mechanisms of their action and describes the prospects of the future development of antiviral peptides.


Assuntos
Antivirais/farmacologia , Peptídeos/farmacologia , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Antivirais/uso terapêutico , Humanos , Peptídeos/uso terapêutico
15.
Medicine (Baltimore) ; 98(32): e16683, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31393369

RESUMO

Interferon-alpha (IFN-α) is currently the preferred antiviral treatment for children with chronic hepatitis B (CHB) aged >1-year-old. However, the evidence regarding the exact efficacy and safety in the real world is not sufficient. This study aimed to investigate the efficacy of IFN-α therapy in children with CHB and to provide a theoretical basis for practically identifying ideal antiviral therapies for CHB children.Clinical manifestations, baseline characteristics, related laboratory tests, and adverse events were retrospectively analyzed in children with CHB who visited the Children's Hospital of Fudan University, were treated with IFN-α and were followed up from January 2003 to October 2018.A total of 18 immune-active patients without advanced fibrosis were enrolled, and their average age at the start of treatment was 4.45 ±â€Š2.75 years old. IFN α-2b was administered subcutaneously by body surface area (BSA) category, based on 3 MU/m, for a median 48 weeks. Before treatment, the alanine aminotransferase (ALT) range was 81 to 409 U/L (median 158 U/L). The median hepatitis B virus (HBV)-DNA load was 9.89 × 10 IU/mL, and the HBV-DNA load varied from 3.10 × 10 to 4.56 × 10 IU/mL. The ALT levels of 17 children became normal at an average of 12 weeks during treatment, and those of 1 child became normal at 6 weeks after IFN-α withdrawal. Sixteen (88.9%, 16/18) children became HBV-DNA negative (<10 IU/mL) at an average of 24 weeks during treatment, while 1 became negative at 96 weeks after IFN-α withdrawal and 1 remained HBV-DNA positive. HBV e antigen (HBeAg) seroconversion occurred in 13 of 14 (92.9%, 13/14) HBeAg-positive patients at an average of 12 weeks during treatment. HBV s antigen (HBsAg) loss or seroconversion occurred in 4 (22.2%, 4/18) patients at an average of 21 weeks during treatment. Only mild flu-like symptoms and transient neutropenia appeared in some children at the early treatment stage. No severe abnormal results were observed in other laboratory parameters.The antiviral monotherapy of 48 weeks of IFN-α was well tolerated and good responded, which was associated with higher rates of HBeAg seroconversion and HBsAg clearance in the children in this study than in previously reported adults and pediatric patients.


Assuntos
Antivirais/administração & dosagem , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/administração & dosagem , Adolescente , Antivirais/farmacologia , Criança , Pré-Escolar , China , Estudos de Coortes , Feminino , Seguimentos , Humanos , Injeções Subcutâneas , Interferon-alfa/farmacologia , Masculino , Soroconversão/efeitos dos fármacos , Carga Viral/efeitos dos fármacos
16.
J Agric Food Chem ; 67(33): 9241-9253, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31369258

RESUMO

Antiviral compounds targeting viral replicative processes have been studied as an alternative for the control of begomoviruses. Previously, we have reported that the peptide AmPep1 has strong affinity binding to the replication origin sequence of tomato yellow leaf curl virus (TYLCV). In this study, we describe the mechanism of action of this peptide as a novel alternative for control of plant-infecting DNA viruses. When AmPep1 was applied exogenously to tomato and Nicotiana benthamiana plants infected with TYLCV, a decrease in the synthesis of the two viral DNA strands (CS and VS) was observed, with a consequent delay in the development of disease progress in treated plants. The chemical mechanism of action of AmPep1 was deduced using Raman spectroscopy and molecular modeling showing the formation of chemical interactions such as H bonds and electrostatic interactions and the formation of π-π interactions between both biomolecules contributing to tampering with the viral replication.


Assuntos
Amaranthus/química , Antivirais/química , Antivirais/farmacologia , Begomovirus/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , RNA Viral/química , Replicação Viral/efeitos dos fármacos , Begomovirus/química , Begomovirus/genética , Begomovirus/fisiologia , Sequências Repetidas Invertidas/efeitos dos fármacos , Lycopersicon esculentum/virologia , Doenças das Plantas/virologia , Proteínas de Plantas/química , RNA Viral/genética , Tabaco/virologia
17.
J Microbiol Biotechnol ; 29(8): 1230-1239, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31370111

RESUMO

Scutellaria baicalensis Georgi has been widely used in China for treatment of various diseases. This study investigated the effect of Scutellaria baicalensis Georgi extracts (SBE) against Coxsackievirus B3 (CVB3)-induced myocarditis in vitro and in vivo. In vitro, Hela cells and primary myocardial cells were infected with CVB3 and treated with SBE (50-800 µg/ml) and ribavirin (200 µM) for 48 h and then determined by CCK8 assay. Real-time PCR and western blotting assays were performed. In vivo, a myocarditis model was induced in male BALB/c mice by injecting CVB3 suspension intraperitoneally for three times, followed by treatment with SBE (400 and 200 mg/kg) and ribavirin (100 mg/kg) for 28 days. SBE ameliorated the cytotoxicity of CVB3 in Hela cells, especially at 400 µg/ml (39.93% vs 65.67%, p < 0.05) without influencing cell growth and also significantly reduced CVB3 replication in primary myocardial cells. The levels of AKT, ERK, and p38 were increased after CVB3 infection. SBE could downregulate the expressions of AKT and p38. In vivo, the mortality rate from CVB3 reached to 66.67%, while 10.00% and 23.33% of this came after 400 and 200 mg/kg SBE treatment, respectively (p < 0.05). The CVB3 replication was obviously reduced after SBE administration from day 5. Similarly, the levels of AKT, ERK, and p38 mRNAs and proteins were increased, and SBE suppressed the expression of AKT and p38. Our study indicates that SBE is a promising potent antiviral agent against CVB3-induced myocarditis by inhibition of virus replication via depressing AKT and p38 expressions.


Assuntos
Antivirais/farmacologia , Infecções por Coxsackievirus/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Miocardite/tratamento farmacológico , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Scutellaria baicalensis/química , Animais , Modelos Animais de Doenças , Enterovirus/patogenicidade , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Miocardite/patologia , Ribavirina/farmacologia , Replicação Viral/efeitos dos fármacos
18.
Arch Virol ; 164(11): 2691-2698, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31428916

RESUMO

Aleutian mink disease virus is one of the greatest threats to modern mink farming. The disease reduces fecundity and causes high mortality among kits. The aim of this study was to evaluate the effectiveness of methisoprinol in counteracting the effects of Aleutian disease, both by inhibiting replication of the virus and by mitigating the harmful effects of the disease on the fecundity and weight of infected animals. The study included 300 individuals with confirmed infection, divided according to antibody titres into three experimental groups, which received a 20% methisoprinol solution, and three control groups, which did not receive the immunostimulant. In the mink from the experimental groups, the number of copies of the genetic material of the virus in the spleens and lymph nodes was one order of magnitude lower than in the case of the control groups. Mink receiving the supplement also showed higher fecundity (on average 5.83 in the experimental groups and 4.83 in the control groups), and the weight of their offspring before slaughter was over 200 g higher. Given the lack of effective methods for immunoprophylaxis and treatment, methisoprinol supplementation can be an effective means of counteracting the effects of AMDV on persistently infected farms.


Assuntos
Vírus da Doença Aleutiana do Vison/efeitos dos fármacos , Doença Aleutiana do Vison/tratamento farmacológico , Doença Aleutiana do Vison/prevenção & controle , Antivirais/farmacologia , Inosina Pranobex/farmacologia , Doença Aleutiana do Vison/mortalidade , Vírus da Doença Aleutiana do Vison/genética , Animais , Fazendas , Feminino , Linfonodos/virologia , Vison/virologia , Baço/virologia , Replicação Viral/efeitos dos fármacos
19.
J Agric Food Chem ; 67(37): 10498-10504, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31452369

RESUMO

Owing to the changing needs of agriculture, the exploration of new pest control agents remains as critical as ever. The analogues 3a-3v of the natural product cerbinal were synthesized from genipin by an efficient and practical method under additive-free conditions. The antiviral and insecticidal effects of cerbinal and these cyclopenta[c]pyridines (3a-3v) were evaluated systematically. Most of the synthesized compounds exhibited higher anti-TMV activities than the lead compound cerbinal. Compound 3s (2-(4-methoxyphenyl)) had the most promising inhibitory activities against TMV (inactivation effect 49.0 ± 0.8%, curative effect 41.2 ± 4.3%, and protection effect 51.5 ± 2.7% at 500 µg/mL). Among the synthesized compounds, only 3v (2-(2-chloro-4-(trifluoromethoxy)phenyl)) reached the activity level of cerbinal against Plutella xylostella. This suggested that the cyclopenta[c]pyridines obtained by modifications of cerbinal at position 2 are very significant for the anti-TMV activity, and yet were exceptionally less active for the insecticidal activities.


Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Produtos Biológicos/síntese química , Produtos Biológicos/farmacologia , Indenos/química , Indenos/farmacologia , Inseticidas/química , Inseticidas/farmacologia , Animais , Antivirais/química , Produtos Biológicos/química , Descoberta de Drogas , Indenos/síntese química , Inseticidas/síntese química , Iridoides/química , Estrutura Molecular , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Relação Estrutura-Atividade , Vírus do Mosaico do Tabaco/efeitos dos fármacos , Vírus do Mosaico do Tabaco/crescimento & desenvolvimento
20.
J Agric Food Chem ; 67(36): 10000-10009, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31442045

RESUMO

Improving plant resistance against systemic diseases remains a challenging research topic. In this study, we developed a dual-action pesticide-loaded hydrogel with the capacity to significantly induce plant resistance against tobacco mosaic virus (TMV) infection and promote plant growth. We produced an alginate-lentinan-amino-oligosaccharide hydrogel (ALA-hydrogel) by coating the surface of an alginate-lentinan drug-loaded hydrogel (AL-hydrogel) with amino-oligosaccharide using electrostatic action. We determined the formation of the amino-oligosaccharide film using various approaches, including Fourier transform infrared spectrometry, the ζ potential test, scanning electron microscopy, and elemental analysis. It was found that the ALA-hydrogel exhibited stable sustained-release activity, and the release time was significantly longer than that of the AL-hydrogel. In addition, we demonstrated that the ALA-hydrogel was able to continuously and strongly induce plant resistance against TMV and increase the release of calcium ions to promote Nicotiana benthamiana growth. Meanwhile, the ALA-hydrogel maintained an extremely high safety to organisms. Our findings provide an alternative to the traditional approach of applying pesticide for controlling plant viral diseases. In the future, this hydrogel with the simple synthesis method, green synthetic materials, and its efficiency in the induction of plant resistance will attract increasing attention and have good potential to be employed in plant protection and agricultural production.


Assuntos
Antivirais/química , Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/química , Lentinano/química , Lentinano/farmacologia , Doenças das Plantas/virologia , Vírus do Mosaico do Tabaco/fisiologia , Tabaco/virologia , Alginatos/química , Antivirais/farmacologia , Preparações de Ação Retardada/química , Resistência à Doença , Hidrogéis/química , Doenças das Plantas/imunologia , Tabaco/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA