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1.
J Virol ; 95(10)2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33658344

RESUMO

Infection with the Zika virus (ZIKV), a member of the Flaviviridae family, can cause serious neurological disorders, most notably microcephaly in newborns. Here we investigated the innate immune response to ZIKV infection in cells of the nervous system. In human neural progenitor cells (hNPCs), a target for ZIKV infection and likely involved in ZIKV-associated neuropathology, viral infection failed to elicit an antiviral interferon (IFN) response. However, pharmacological inhibition of TLR3 partially restored this deficit. Analogous results were obtained in human iPSC-derived astrocytes, which are capable of mounting a strong antiviral cytokine response. There, ZIKV is sensed by both RIG-I and MDA5 and induces an IFN response as well as expression of pro-inflammatory cytokines such as interleukin-6 (IL-6). Upon inhibition of TLR3, also in astrocytes the antiviral cytokine response was enhanced, whereas amounts of pro-inflammatory cytokines were reduced. To study the underlying mechanism, we used human epithelial cells as an easy to manipulate model system. We found that ZIKV is sensed in these cells by RIG-I to induce a robust IFN response and by TLR3 to trigger the expression of pro-inflammatory cytokines, including IL-6. ZIKV induced upregulation of IL-6 activated the STAT3 pathway, which decreased STAT1 phosphorylation in a SOCS-3 dependent manner, thus reducing the IFN response. In conclusion, we show that TLR3 activation by ZIKV suppresses IFN responses triggered by RIG-I-like receptors.ImportanceZika virus (ZIKV) has a pronounced neurotropism and infections with this virus can cause serious neurological disorders, most notably microcephaly and the Guillain-Barré syndrome. Our studies reveal that during ZIKV infection, recognition of viral RNA by TLR3 enhances the production of inflammatory cytokines and suppresses the interferon response triggered by RIG-I-like receptors (RLR) in a SOCS3-dependent manner, thus facilitating virus replication. The discovery of this crosstalk between antiviral (RLR) and inflammatory (TLR) responses may have important implications for our understanding of ZIKV-induced pathogenesis.

2.
Arch Virol ; 166(12): 3275-3287, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34536126

RESUMO

Zika virus (ZIKV) is a public health problem due to its association with serious fetal and neurological complications and the lack of antiviral agents and licensed vaccines against this virus. Surveillance studies have alerted about the potential occurrence of a new South American epidemic episode due to the recent circulation of an African ZIKV strain detected in Brazil. Therefore, it is essential to discover antiviral agents, including natural substances, that are capable of neutralizing the action of ZIKV. Several Psychotria species have antimicrobial and anti-inflammatory properties. Thus, a methanol extract and dimethyltryptamine from Psychotria viridis were evaluated for their ability to inhibit ZIKV infection in vitro by measuring the effective concentration that protects 50% of cells and investigating their possible mechanisms of action. The tested samples showed antiviral activity against ZIKV. The extract showed virucidal activity, affecting viral and non-cellular elements, inactivating the virus before infection or when it becomes extracellular after the second cycle of infection. It was also observed that both extract and dimethyltryptamine could inhibit the virus at intracellular stages of the viral cycle. In addition to dimethyltryptamine, it is believed that other compounds also contribute to the promising virucidal effect observed for the methanol extract. To our knowledge, this is the first report of the activity of a methanolic extract and dimethyltryptamine from Psychotria viridis against cellular ZIKV infection. These two samples, extracted from natural sources, are potential candidates for use as antiviral drugs to inhibit ZIKV infections.


Assuntos
Psychotria , Infecção por Zika virus , Zika virus , Antivirais/farmacologia , Antivirais/uso terapêutico , Humanos , Metanol , N,N-Dimetiltriptamina/uso terapêutico , Extratos Vegetais/farmacologia , Infecção por Zika virus/tratamento farmacológico
3.
Anaerobe ; 63: 102194, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32205191

RESUMO

Being aware of the remarkable antimicrobial potential of S. officinalis L., we aimed to evaluate the antimicrobial activity of the S. officinalis dichloromethane crude extract (SOD), dichloromethane-soluble fractions (SODH and SODD), SODD subfractions (SODD1 and SODD2), and pure substances (manool, salvigenin, and viridiflorol) against periodontopathogens. This bioassay-guided study comprises five antimicrobial tests-determination of the Minimum Inhibitory Concentration (MIC), determination of the Minimum Bactericidal Concentration (MBC), determination of the antibiofilm activity, construction of the Time-kill curve (determination of Bactericidal Kinetics), and determination of the Fractional Inhibitory Concentration Index-on six clinical bacterial isolates and three standard bacterial strains involved in periodontal disease. SOD has moderate activity against most of the tested bacteria, whereas SODD1, SODH1, SODH3, and manool afford the lowest results. The Porphyromonas gingivalis (ATTC and clinical isolate) biofilm is considerably resistant to all the samples. In association with chlorhexidine gluconate, only SODH1 exerts additive action against P. gingivalis (clinical isolate). Therefore, SODH1 and manool are promising antibacterial agents and may provide therapeutic solutions for periodontal infections.


Assuntos
Periodontite Agressiva , Antibacterianos/farmacologia , Extratos Vegetais/farmacologia , Salvia officinalis/metabolismo , Periodontite Agressiva/tratamento farmacológico , Periodontite Agressiva/microbiologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Diterpenos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Boca/microbiologia , Porphyromonas gingivalis/efeitos dos fármacos
4.
Immunogenetics ; 70(6): 355-362, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29164277

RESUMO

Dengue is the most prevalent arthropod-borne viral illness in humans worldwide. Single-nucleotide polymorphisms (SNPs) in genes involved in the immune response, such as dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), IgG Fc receptor II-A (FcγRIIa), vitamin D receptor (VDR), and tumor necrosis factor alpha (TNF-α), were previously reported to be associated with susceptibility to dengue disease in different human populations. Therefore, due to the relevant association of host immune and genetic status with disease susceptibility/severity of dengue, this work aims to verify the frequency of anti-dengue virus antibodies and some dengue-associated risk SNPs in a population in Minas Gerais State, Southeast Brazil. A total of 1560 individuals were genotyped for polymorphisms in DC-SIGN (rs4804803), FcγRIIa (rs1801274), VDR (rs7975232), and TNF-α (rs1800629). The presence of anti-dengue antibodies (IgM and/or IgG) in these samples was also assayed. Anti-dengue antibodies were detected at an overall frequency of 16.86%, indicating a virus infection in asymptomatic individuals. The genotypic frequencies of all SNPs studied did not differ between the asymptomatic and control groups. Regarding the allelic frequencies of the four SNPs analyzed, a higher frequency was detected of the G allele of FcγRIIa/rs1801274 in the asymptomatic individuals when compared to that in the control group (p = 0.03). Therefore, the results showed a high prevalence of asymptomatic individuals in Minas Gerais State, with a potential association between the presence of the G allele of FcγRIIa/rs1801274 and protection against symptomatic disease.


Assuntos
Dengue/genética , Dengue/imunologia , Receptores de IgG/genética , Adulto , Arginina/genética , Brasil , Moléculas de Adesão Celular/genética , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lectinas Tipo C/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Prevalência , Receptores de Calcitriol/genética , Receptores de Superfície Celular/genética , Fator de Necrose Tumoral alfa/genética
5.
Anaerobe ; 52: 43-49, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29885640

RESUMO

Diterpenes are an important class of plant metabolites that can be used in the search for new antibacterial agents. ent-Copalic acid (CA), the major diterpene in Copaifera species exudates, displays several pharmacological properties. This study evaluates the CA antibacterial potential against the anaerobic bacteria Peptostreptococcus anaerobius and Actinomyces naeslundii. Antimicrobial assays included time-kill and biofilm inhibition and eradication assays. Time-kill assays conducted for CA concentrations between 6.25 and 12.5 µg/mL evidenced bactericidal activity within 72 h. CA combined with chlorhexidine dihydrochloride (CHD) exhibited bactericidal action against P. anaerobius within 6 h of incubation. As for A. naeslundii, the same combination reduced the number of microorganisms by over 3 log10 at 24 h and exerted a bactericidal effect at 48 h of incubation. CA at 500 and 2000 µg/mL inhibited P. anaerobius and A. naeslundii biofilm formation by at least 50%, respectively. CA at 62.5 and 1.000 µg/mL eradicated 99.9% of pre-formed P. anaerobius and A. naeslundii biofilms, respectively. These results indicated that CA presents in vitro antibacterial activity and is a potential biofilm inhibitory agent. This diterpene may play an important role in the search for novel sources of agents that can act against anaerobic bacteria.


Assuntos
Actinomyces/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Diterpenos/farmacologia , Peptostreptococcus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Actinomyces/fisiologia , Fabaceae/química , Testes de Sensibilidade Microbiana , Peptostreptococcus/fisiologia
6.
Anaerobe ; 47: 201-208, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28627377

RESUMO

The search for new, effective and safe antimicrobial compounds from plant sources has continued to play an important role in the maintenance of human health since ancient times. Such compounds can be used to help to eradicate microorganisms from the root canal system, preventing/healing periapical diseases. Mikania glomerata (Spreng.), commonly known as "guaco," is a native climbing plant from Brazil that displays a wide range of pharmacological properties. Many of its activities have been attributed to its phytochemical composition, which is mainly composed of diterpenes, such as ent-kaurenoic acid (KA). The present study evaluated the potential activity of an ent-kaurenoic-rich (KA) extract from Mikania glomerata (i.e. Mikania glomerata extract/MGE) and its major compound KA against bacteria that can cause endodontic infections. Time-kill assays were conducted and the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), anti-biofilm activity, and synergistic antimicrobial activity of MGE and KA were determined. The MGE exhibited MIC and MBC values, which ranged from 6.25 to 100 µg/mL and 12.5 to 200 µg/mL respectively. The MIC and MBC results obtained for the KA, ranged from 3.12 to 100 µg/mL and 3.12 to 200 µg/mL respectively. Time-kill and anti-biofilm activity assays conducted for KA at concentrations between 3.12 and 12.5 µg/mL exhibited bactericidal activity between 6 and 72 h of incubation and 50% inhibition of biofilm formation for Porphyromonas gingivalis (clinical isolate), Propionibacterium acnes (ATCC 6919), Prevotella nigrescens (ATCC 33563), P. melaninogenica (ATCC 25845), Aggregatibacter actinomycetemcomitans (ATCC 43717). For synergistic antimicrobial activity, KA combined with chlorhexidine dichlorohydrate (CHD) had an additive effect with increased efficacy against P. gingivalis (clinical isolate) compared to CHD alone. It was concluded that M. glomerata extract and its major compound ent-kaurenoic acid (KA) showed in vitro antibacterial activity, the latter being a potential biofilm inhibitory agent. They may play important roles in the search for novel sources of agents that can act against bacteria present in endodontic infections.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Diterpenos/farmacologia , Mikania/química , Extratos Vegetais/farmacologia , Pulpite/microbiologia , Antibacterianos/isolamento & purificação , Bactérias/isolamento & purificação , Biofilmes/efeitos dos fármacos , Brasil , Clorexidina/farmacologia , Diterpenos/isolamento & purificação , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação
7.
Med Mycol ; 54(5): 515-23, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26868902

RESUMO

Dental prosthesis supports Candida species growth and may predispose the oral cavity to lesions. C. tropicalis has emerged as a colonizer of prosthesis and has shown resistance to clinically used antifungal agents, which has increased the search for new antifungals. This work describes the effectiveness of fifteen essential oils (EOs) against C. tropicalis The EOs were obtained by hydrodistillation and were chemically characterized by gas chromatography-mass spectrometry. The antifungal activities of the EOs were evaluated by the microdilution method and showed that Pelargonium graveolens (Geraniaceae) (PG-EO) was the most effective oil. Geraniol and linalool were the major constituents of PG-EO. The 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay showed that all the clinical C. tropicalis strains formed viable biofilms. Scanning electron microscopy examination of the biofilms revealed a complex architecture with basal layer of yeast cells and an upper layer of filamentous cells. Treatments with PG-EO, linalool, and geraniol significantly reduced the number of viable biofilm cells and inhibited biofilm formation after exposure for 48 h. PG-EO, geraniol, and linalool were not toxic to normal human lung fibroblasts (GM07492A) at the concentrations they were active against C. tropicalis Together, our results indicated that C. tropicalis is susceptible to treatment with PG-EO, geraniol, and linalool, which could become options to prevent or treat this infection.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Óleos Voláteis/farmacologia , Pelargonium/química , Monoterpenos Acíclicos , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/toxicidade , Candida tropicalis/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Monoterpenos/isolamento & purificação , Monoterpenos/farmacologia , Monoterpenos/toxicidade , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/toxicidade , Terpenos/isolamento & purificação , Terpenos/farmacologia , Terpenos/toxicidade
8.
Artigo em Inglês | MEDLINE | ID: mdl-24246722

RESUMO

Bixin is a carotenoid found in the seeds of Bixa orellana L., a plant native to tropical America that is used in the food industry. The aim of this study was to investigate the effect of bixin on DNA damage and pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in the liver and colon of Wistar rats. The animals received bixin at daily doses of 0.1, 1.0 and 10mg/kg body weight (bw) by gavage. For the assessment of DNA damage in hepatocytes and colon cells with the comet assay, the administration of bixin was for 7 days. The animals received a single subcutaneous injection of 25mg/kg bw of DMH, and were euthanized 4h later. For the evaluation of the frequency of aberrant crypt foci (ACF), the animals were treated with the different doses of bixin for 4 weeks. Four doses of 40mg/kg bw DMH, two doses in the first week and two doses in the second week, were administered and euthanasia occurred at 4 weeks after the beginning of treatment. Bixin reduced the frequency of DNA damage in hepatocytes at the highest two doses tested (1.0 and 10mg/kg bw). On the other hand, no differences in the frequency of DNA damage in colon cells were observed between animals treated with bixin plus DMH and those treated with DMH alone. In addition, the frequency of ACF did not differ significantly between the group treated with bixin plus DMH and the DMH group. The results suggest that bixin does not suppress the formation of ACF, indicating the absence of a protective effect against colon carcinogenesis.


Assuntos
1,2-Dimetilidrazina/toxicidade , Carotenoides/farmacologia , Neoplasias do Colo/induzido quimicamente , Dano ao DNA/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Lesões Pré-Cancerosas/induzido quimicamente , Animais , Neoplasias do Colo/prevenção & controle , Masculino , Lesões Pré-Cancerosas/prevenção & controle , Ratos , Ratos Wistar
9.
Anaerobe ; 30: 146-52, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25270831

RESUMO

Endodontic infections have a polymicrobial nature, but anaerobic bacteria prevail among the infectious microbes. Considering that it is easy to eliminate planktonic bacteria, biofilm-forming bacteria still challenge clinicians during the fight against endodontic diseases. The chemical constituents of the oleoresin of Pinus elliottii, a plant belonging to the family Pinaceae, stand out in the search for biologically active compounds based on natural products with potential application in the treatment of endodontic infections. Indeed, plant oleoresins are an abundant natural source of diterpenes that display significant and well-defined biological activities as well as potential antimicrobial action. In this context, this study aimed to (1) evaluate the in vitro antibacterial activity of the oleoresin, fractions, and subfractions of P. elliottii as well as the action of dehydroabietic acid against 11 anaerobic bacteria that cause endodontic infection in both their planktonic and biofilm forms and (2) assess the in vitro antibiofilm activity of dehydroabietic acid against the same group of bacteria. The broth microdilution technique helped to determine the minimum inhibitory concentration (MIC) of the oleoresin and fractions. This same technique aided determination of the MIC values of nine subfractions of Fraction 1, the most active fraction. The MIC, minimum bactericidal concentration, and antibiofilm activity of dehydroabietic acid against the tested anaerobic bacteria were also examined. The oleoresin and fractions, especially fraction PE1, afforded promising MIC values, which ranged from 0.4 to 50 µg/mL. Concerning the nine evaluated subfractions, PE1.3 and PE1.4 furnished the most noteworthy MIC values, between 6.2 and 100 µg/mL. Dehydroabietic acid displayed antibacterial activity, with MIC values lying from 6.2 to 50 µg/mL, as well as bactericidal effect for all the investigated bacteria, except for Prevotella nigrescens. Assessment of the antibiofilm activity revealed significant results--MICB50 lay between 7.8 and 62.5 µg/mL, and dehydroabietic acid prevented all the evaluated bacteria from forming a biofilm. Hence, the chemical constituents of P. elliottii are promising biomolecules to develop novel therapeutic strategies to fight against endodontic infections.


Assuntos
Abietanos/farmacologia , Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Pinus/química , Extratos Vegetais/farmacologia , Pulpite/microbiologia , Abietanos/isolamento & purificação , Antibacterianos/isolamento & purificação , Bactérias Anaeróbias/isolamento & purificação , Bactérias Anaeróbias/fisiologia , Biofilmes/crescimento & desenvolvimento , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação
10.
PLoS Negl Trop Dis ; 18(4): e0012100, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38635656

RESUMO

Zika virus (ZIKV), an arbovirus from the Flaviviridae family, is the causative agent of Zika fever, a mild and frequent oligosymptomatic disease in humans. Nonetheless, on rare occasions, ZIKV infection can be associated with Guillain-Barré Syndrome (GBS), and severe congenital complications, such as microcephaly. The oligosymptomatic disease, however, presents symptoms that are quite similar to those observed in infections caused by other frequent co-circulating arboviruses, including dengue virus (DENV). Moreover, the antigenic similarity between ZIKV and DENV, and even with other members of the Flaviviridae family, complicates serological testing due to the high cross-reactivity of antibodies. Here, we designed, produced in a prokaryotic expression system, and purified three multiepitope proteins (ZIKV-1, ZIKV-2, and ZIKV-3) for differential diagnosis of Zika. The proteins were evaluated as antigens in ELISA tests for the detection of anti-ZIKV IgG using ZIKV- and DENV-positive human sera. The recombinant proteins were able to bind and detect anti-ZIKV antibodies without cross-reactivity with DENV-positive sera and showed no reactivity with Chikungunya virus (CHIKV)- positive sera. ZIKV-1, ZIKV-2, and ZIKV-3 proteins presented 81.6%, 95%, and 66% sensitivity and 97%, 96%, and 84% specificity, respectively. Our results demonstrate the potential of the designed and expressed antigens in the development of specific diagnostic tests for the detection of IgG antibodies against ZIKV, especially in regions with the circulation of multiple arboviruses.


Assuntos
Arbovírus , Febre de Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Humanos , Infecção por Zika virus/diagnóstico , Zika virus/genética , Epitopos , Anticorpos Antivirais , Imunoglobulina G
11.
Virus Res ; 340: 199291, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38065303

RESUMO

Here, the antiviral activity of aminoadamantane derivatives were evaluated against SARS-CoV-2. The compounds exhibited low cytotoxicity to Vero, HEK293 and CALU-3 cells up to a concentration of 1,000 µM. The inhibitory concentration (IC50) of aminoadamantane was 39.71 µM in Vero CCL-81 cells and the derivatives showed significantly lower IC50 values, especially for compounds 3F4 (0.32 µM), 3F5 (0.44 µM) and 3E10 (1.28 µM). Additionally, derivatives 3F5 and 3E10 statistically reduced the fluorescence intensity of SARS-CoV-2 protein S from Vero cells at 10 µM. Transmission microscopy confirmed the antiviral activity of the compounds, which reduced cytopathic effects induced by the virus, such as vacuolization, cytoplasmic projections, and the presence of myelin figures derived from cellular activation in the face of infection. Additionally, it was possible to observe a reduction of viral particles adhered to the cell membrane and inside several viral factories, especially after treatment with 3F4. Moreover, although docking analysis showed favorable interactions in the catalytic site of Cathepsin L, the enzymatic activity of this enzyme was not inhibited significantly in vitro. The new derivatives displayed lower predicted toxicities than aminoadamantane, which was observed for either rat or mouse models. Lastly, in vivo antiviral assays of aminoadamantane derivatives in BALB/cJ mice after challenge with the mouse-adapted strain of SARS-CoV-2, corroborated the robust antiviral activity of 3F4 derivative, which was higher than aminoadamantane and its other derivatives. Therefore, aminoadamantane derivatives show potential broad-spectrum antiviral activity, which may contribute to COVID-19 treatment in the face of emerging and re-emerging SARS-CoV-2 variants of concern.


Assuntos
COVID-19 , SARS-CoV-2 , Chlorocebus aethiops , Humanos , Animais , Camundongos , Ratos , Tratamento Farmacológico da COVID-19 , Células HEK293 , Células Vero , Amantadina , Antivirais/farmacologia , Antivirais/uso terapêutico
12.
Mutat Res ; 753(2): 101-6, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23545536

RESUMO

Usnic acid is one of the most common and abundant metabolites found in various lichen genera, which are important sources of biologically active compounds. The aim of this study was to evaluate the genotoxic and antigenotoxic potential of (+)-usnic acid (UA) by the micronucleus and comet assays in V79 cell cultures and Swiss mice. For assessment of genotoxicity, V79 cells were treated with 15, 30, 60, and 120µg/mL UA, established based on clonogenic efficiency cytotoxic assay. Swiss mice were treated with UA doses of 25, 50, 100, and 200mg/kg body weight. The same concentrations of UA were combined with methyl methanesulfonate (MMS) for evaluation of antigenotoxicity. The in vitro results demonstrated that UA induced DNA damage at concentrations of 60 and 120µg/mL in the comet assay. However, no genotoxic effect was observed in the micronucleus test using V79 cells at the concentrations tested. No genotoxic effects were observed for the different UA treatments in in vivo test system. Combined administration of UA and MMS significantly reduced the frequencies of micronuclei and DNA damage in vitro and in vivo when compared to treatment with MMS alone. Although the mechanisms underlying the protective effect of UA are not completely understood, the antioxidant activity of this metabolite may explain its protective effect against MMS-induced genotoxicity.


Assuntos
Antimutagênicos/farmacologia , Benzofuranos/farmacologia , Benzofuranos/toxicidade , Ensaio Cometa/métodos , Testes para Micronúcleos/métodos , Animais , Antioxidantes/farmacologia , Medula Óssea/efeitos dos fármacos , Linhagem Celular , Relação Dose-Resposta a Droga , Masculino , Metanossulfonato de Metila/toxicidade , Camundongos
13.
Molecules ; 18(7): 7865-72, 2013 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-23884123

RESUMO

We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA) was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL-1) against Staphylococcus aureus (ATCC and clinical isolate), Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect), but its bactericidal effect was clearly noted thereafter (between 12 and 24 h). In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis.


Assuntos
Diterpenos/farmacologia , Mastite Bovina/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Bovinos , Diterpenos/química , Feminino , Mastite Bovina/microbiologia , Mikania/química , Extratos Vegetais/farmacologia , Staphylococcus aureus/patogenicidade
14.
Molecules ; 18(4): 4588-98, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-23599016

RESUMO

The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcus mutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC50 of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C. bakeriana.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias Aeróbias/efeitos dos fármacos , Bactérias Anaeróbias/efeitos dos fármacos , Cassia/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Animais , Anti-Infecciosos/toxicidade , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Cárie Dentária/microbiologia , Testes de Sensibilidade Microbiana , Óleos Voláteis/toxicidade , Streptococcus mutans/efeitos dos fármacos , Células Vero
15.
Braz J Microbiol ; 54(2): 769-777, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36854899

RESUMO

Fast, precise, and low-cost diagnostic testing to identify persons infected with SARS-CoV-2 virus is pivotal to control the global pandemic of COVID-19 that began in late 2019. The gold standard method of diagnostic recommended is the RT-qPCR test. However, this method is not universally available, and is time-consuming and requires specialized personnel, as well as sophisticated laboratories. Currently, machine learning is a useful predictive tool for biomedical applications, being able to classify data from diverse nature. Relying on the artificial intelligence learning process, spectroscopic data from nasopharyngeal swab and tracheal aspirate samples can be used to leverage characteristic patterns and nuances in healthy and infected body fluids, which allows to identify infection regardless of symptoms or any other clinical or laboratorial tests. Hence, when new measurements are performed on samples of unknown status and the corresponding data is submitted to such an algorithm, it will be possible to predict whether the source individual is infected or not. This work presents a new methodology for rapid and precise label-free diagnosing of SARS-CoV-2 infection in clinical samples, which combines spectroscopic data acquisition and analysis via artificial intelligence algorithms. Our results show an accuracy of 85% for detection of SARS-CoV-2 in nasopharyngeal swab samples collected from asymptomatic patients or with mild symptoms, as well as an accuracy of 97% in tracheal aspirate samples collected from critically ill COVID-19 patients under mechanical ventilation. Moreover, the acquisition and processing of the information is fast, simple, and cheaper than traditional approaches, suggesting this methodology as a promising tool for biomedical diagnosis vis-à-vis the emerging and re-emerging viral SARS-CoV-2 variant threats in the future.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Inteligência Artificial , Nasofaringe , Aprendizado de Máquina , Análise Espectral
16.
Radiol Bras ; 56(4): 207-214, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37829583

RESUMO

Objective: To present an update of the recommendations of the Brazilian College of Radiology and Diagnostic Imaging, the Brazilian Society of Mastology, and the Brazilian Federation of Gynecology and Obstetrics Associations for breast cancer screening in Brazil. Materials and Methods: Scientific evidence published between January 2012 and July 2022 was gathered from the following databases: Medline (PubMed); Excerpta Medica (Embase); Cochrane Library; Ebsco; Cumulative Index to Nursing and Allied Health Literature (Cinahl); and Latin-American and Caribbean Health Sciences Literature (Lilacs). Recommendations were based on that evidence and were arrived at by consensus of a joint committee of experts from the three entities.Recommendations: Annual mammographic screening is recommended for women between 40 and 74 years of age. For women at or above the age of 75, screening should be reserved for those with a life expectancy greater than seven years. Women at higher than average risk are considered by category: those with dense breasts; those with a personal history of atypical lobular hyperplasia, classical lobular carcinoma in situ, or atypical ductal hyperplasia; those previously treated for breast cancer; those having undergone thoracic radiotherapy before age 30; and those with a relevant genetic mutation or a strong family history. The benefits of complementary screening are also addressed according to the subcategories above. The use of tomosynthesis, which is an evolved form of mammography, should be considered in screening, whenever accessible and available.


Objetivo: Apresentar a atualização das recomendações do Colégio Brasileiro de Radiologia e Diagnóstico por Imagem, da Sociedade Brasileira de Mastologia e da Federação Brasileira das Associações de Ginecologia e Obstetrícia para o rastreamento do câncer de mama no Brasil. Materiais e Métodos: Foram feitas buscas das evidências científicas publicadas nas bases Medline (PubMed), Excerpta Medica (Embase), Cochrane Library, Ebsco, Cinahl e Lilacs, entre janeiro de 2012 e julho de 2022. As recomendações foram baseadas nessas evidências, mediante consenso da comissão de especialistas das três entidades.Recomendações: O rastreamento mamográfico anual é recomendado para as mulheres de risco habitual entre 40 e 74 anos. Acima de 75 anos deve ser reservado para as que tenham expectativa de vida maior que sete anos. Mulheres com risco maior que o habitual, entre elas as com mamas densas, com história pessoal de hiperplasia lobular atípica, carcinoma lobular in situ clássico, hiperplasia ductal atípica, tratamento de câncer de mama ou de irradiação no tórax antes dos 30 anos, ou ainda portadoras de mutação genética ou com forte história familiar, se beneficiam do rastreamento complementar, sendo consideradas de forma individualizada. A tomossíntese é uma evolução da mamografia e deve ser considerada no rastreamento, sempre que acessível e disponível.

17.
Rev Bras Ginecol Obstet ; 45(8): e480-e488, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37683660

RESUMO

OBJECTIVE: To present the update of the recommendations of the Brazilian College of Radiology and Diagnostic Imaging, the Brazilian Society of Mastology and the Brazilian Federation of Associations of Gynecology and Obstetrics for breast cancer screening in Brazil. METHODS: Scientific evidence published in Medline, EMBASE, Cochrane Library, EBSCO, CINAHL and Lilacs databases between January 2012 and July 2022 was searched. Recommendations were based on this evidence by consensus of the expert committee of the three entities. RECOMMENDATIONS: Annual mammography screening is recommended for women at usual risk aged 40-74 years. Above 75 years, it should be reserved for those with a life expectancy greater than seven years. Women at higher than usual risk, including those with dense breasts, with a personal history of atypical lobular hyperplasia, classic lobular carcinoma in situ, atypical ductal hyperplasia, treatment for breast cancer or chest irradiation before age 30, or even, carriers of a genetic mutation or with a strong family history, benefit from complementary screening, and should be considered individually. Tomosynthesis is a form of mammography and should be considered in screening whenever accessible and available.


OBJETIVO: Apresentar a atualização das recomendações do Colégio Brasileiro de Radiologia e Diagnóstico por Imagem da Sociedade Brasileira de Mastologia e da Federação Brasileira das Associações de Ginecologia e Obstetrícia para o rastreamento do câncer de mama no Brasil. MéTODOS: Foram pesquisadas evidências científicas publicadas nas bases de dados Medline EMBASE Biblioteca Cochrane EBSCO CINAHL e Lilacs entre janeiro de 2012 e julho de 2022. As recomendações foram baseadas nessas evidências por consenso do comitê de especialistas das três entidades. RECOMENDAçõES: A mamografia anual é recomendada para mulheres com risco habitual entre 40 e 74 anos. Acima de 75 anos deve ser reservado para aqueles com expectativa de vida superior a sete anos. Mulheres com risco maior do que o normal incluindo aquelas com mamas densas com história pessoal de hiperplasia lobular atípica carcinoma lobular in situ clássico hiperplasia ductal atípica tratamento para câncer de mama ou irradiação de tórax antes dos 30 anos ou ainda portadoras de doença genética mutação ou com forte histórico familiar beneficiam-se de triagem complementar e devem ser considerados individualmente. A tomossíntese é uma forma de mamografia e deve ser considerada na triagem sempre que acessível e disponível.


Assuntos
Neoplasias da Mama , Obstetrícia , Radiologia , Feminino , Humanos , Gravidez , Brasil , Neoplasias da Mama/diagnóstico por imagem , Detecção Precoce de Câncer , Mamografia , Guias de Prática Clínica como Assunto
18.
Polymers (Basel) ; 14(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35215641

RESUMO

This study assessed the effects of immersion media [distilled water (dw), phosphate buffered saline (pbs) and simulated body fluid (sbf)] in the physical properties [fluid uptake/sorption/solubility and alkalinization activity (pH)] and bioactivity of a bioceramic sealer: the BioRoot RCS (BioRoot) (Septodont). The epoxy-resin sealer AH Plus (Dentsply) was used as comparison. Sealers were immersed in dw, pbs and sbf to evaluate the fluid uptake/sorption/solubility and pH's media. Bioactivity was assessed with SEM/EDS, FTIR-ATR and XRD. BioRoot solubility was as follows: sbf > pbs = dw. BioRoot had alkaline pH, and AH Plus had neutral pH, regardless of the medium. BioRoot presented mineral precipitates and peaks indicating hydroxyapatite-precursors in pbs and sbf. AH Plus physical properties were not affected by immersion media and it had no bioactivity. pbs and sbf should be preferred to investigate bioceramic sealers over distilled water, because they were able to highlight the sealer properties. BioRoot maintained the alkaline environment and favored hard tissue deposition.

19.
Nat Prod Res ; 36(22): 5904-5909, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34994265

RESUMO

The expression of virulence factors, such as biofilm formation, in association with the acquisition of resistance to multiple drugs, has evidenced the need for new and effective antimicrobial agents against Staphylococcus aureus. The evaluation of the pharmacological properties of plant-derived compounds is a promising alternative to the development of new antimicrobials. In this study, we aimed to evaluate the antibacterial, antibiofilm, and the synergistic and cytotoxic effects of netzahualcoyonol isolated from Salacia multiflora (Lam.) DC. roots. Netzahualcoyonol presented bacteriostatic (1.56-25.0 µg/mL) and bactericidal (25.0-400.0 µg/mL) effects against Gram-positive bacteria, disrupted the biofilm of S. aureus, and presented a synergistic effect after its combination with ß-lactams and aminoglycosides. The low cytotoxicity of netzahualcoyonol (Selectivity Index (SI) for S. aureus (2.56), S. saprophyticus (20.56), and Bacillus subtilis (1.28)) suggests a good security profile. Taken together, these results show that netzahualcoyonol is promising for the development of a new effective antibacterial agent.


Assuntos
Celastraceae , Salacia , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Bactérias Gram-Positivas , Antibacterianos/farmacologia
20.
Immunol Lett ; 235: 9-14, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33901540

RESUMO

An alarming disease caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) named COVID-19 has emerged as an unprecedented public health problem and ignited a world health crisis. As opposed to what was believed at the beginning of the pandemic, the virus has not only spread but persevere causing secondary waves and challenging the concept of herd immunity against viral infections. While the majority of SARS-CoV-2-infected individuals may remain asymptomatic, a fraction of individuals may develop low to high-grade severity signs and symptoms of COVID-19. The disease is multifactorial and can progress quickly, leading to severe complications and even death in a few days. Therefore, understanding the pre-existing factors for disease development has never been so pressing. In this scenario, the insights on the mechanisms underlying disease allied to the immune response developed during the viral invasion could shed light on novel predictive factors and prognostic tools for COVID-19 management and interventions. A recent genome-wide association study (GWAS) revealed several molecules that significantly impacted critically ill COVID-19 patients, leading to the core mechanisms of COVID-19 pathogenesis. Considering these findings and the fact that ACE-2 polymorphisms alone cannot explain disease progress and severity, this review aims at summarizing the most important and recent findings of the research and expert consensus of possible cytokine-related polymorphisms existing in the differential expression of paramount immune molecules that could be crucial for providing guidelines for decision-making and appropriate clinical management of COVID-19.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Citocinas , Pandemias , Polimorfismo Genético , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/imunologia , COVID-19/genética , COVID-19/imunologia , COVID-19/mortalidade , Citocinas/genética , Citocinas/imunologia , Estudo de Associação Genômica Ampla , Humanos
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