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1.
J. venom. anim. toxins incl. trop. dis ; 21: 42, 31/03/2015. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-954758

Resumo

Background BmK I, a site-3-specific modulator of voltage-gated sodium channels (VGSCs), causes pain and hyperalgesia in rats, while BmK IT2, a site-4-specific modulator of VGSCs, suppresses pain-related responses. A stronger pain-related effect has been previously attributed to Buthus martensi Karsch (BmK) venom, which points out the joint pharmacological effect in the crude venom.Methods In order to detect the joint effect of BmK I and BmK IT2 on ND7-23 cells, the membrane current was measured by whole cell recording. BmK I and BmK IT2 were applied successively and jointly, and the synergistic modulations of VGSCs on ND7-23 cells were detected.Results Larger peak I Na and more negative half-activation voltage were elicited by joint application of BmK I and BmK IT2 than by application of BmK I or BmK IT2 alone. Compared to the control, co-applied BmK I and BmK IT2 also significantly prolonged the time constant of inactivation.Conclusions Our results indicated that site-4 toxin (BmK IT2) could enhance the pharmacological effect induced by site-3 toxin (BmK I), suggesting a stronger effect elicited by both toxins that alone usually exhibit opposite pharmacological effects, which is related to the allosteric interaction between receptor site 3 and site 4. Meanwhile, these results may bring a novel perspective for exploring the underlying mechanisms of scorpion sting-induced pain.(AU)


Assuntos
Animais , Regulação Alostérica , Picadas de Escorpião , Hiperalgesia
2.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 21: 1-7, Nov. 10, 2015. graf, tab, ilus
Artigo em Inglês | VETINDEX | ID: vti-27262

Resumo

Background BmK I, a site-3-specific modulator of voltage-gated sodium channels (VGSCs), causes pain and hyperalgesia in rats, while BmK IT2, a site-4-specific modulator of VGSCs, suppresses pain-related responses. A stronger pain-related effect has been previously attributed to Buthus martensi Karsch (BmK) venom, which points out the joint pharmacological effect in the crude venom.Methods In order to detect the joint effect of BmK I and BmK IT2 on ND7-23 cells, the membrane current was measured by whole cell recording. BmK I and BmK IT2 were applied successively and jointly, and the synergistic modulations of VGSCs on ND7-23 cells were detected.Results Larger peak I Na and more negative half-activation voltage were elicited by joint application of BmK I and BmK IT2 than by application of BmK I or BmK IT2 alone. Compared to the control, co-applied BmK I and BmK IT2 also significantly prolonged the time constant of inactivation.Conclusions Our results indicated that site-4 toxin (BmK IT2) could enhance the pharmacological effect induced by site-3 toxin (BmK I), suggesting a stronger effect elicited by both toxins that alone usually exhibit opposite pharmacological effects, which is related to the allosteric interaction between receptor site 3 and site 4. Meanwhile, these results may bring a novel perspective for exploring the underlying mechanisms of scorpion sting-induced pain.(AU)


Assuntos
Animais , Picadas de Escorpião , Testes de Toxicidade/veterinária , Dor
3.
J. venom. anim. toxins incl. trop. dis ; 21: 1-7, 31/03/2015. graf, tab, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1484639

Resumo

Background BmK I, a site-3-specific modulator of voltage-gated sodium channels (VGSCs), causes pain and hyperalgesia in rats, while BmK IT2, a site-4-specific modulator of VGSCs, suppresses pain-related responses. A stronger pain-related effect has been previously attributed to Buthus martensi Karsch (BmK) venom, which points out the joint pharmacological effect in the crude venom.Methods In order to detect the joint effect of BmK I and BmK IT2 on ND7-23 cells, the membrane current was measured by whole cell recording. BmK I and BmK IT2 were applied successively and jointly, and the synergistic modulations of VGSCs on ND7-23 cells were detected.Results Larger peak I Na and more negative half-activation voltage were elicited by joint application of BmK I and BmK IT2 than by application of BmK I or BmK IT2 alone. Compared to the control, co-applied BmK I and BmK IT2 also significantly prolonged the time constant of inactivation.Conclusions Our results indicated that site-4 toxin (BmK IT2) could enhance the pharmacological effect induced by site-3 toxin (BmK I), suggesting a stronger effect elicited by both toxins that alone usually exhibit opposite pharmacological effects, which is related to the allosteric interaction between receptor site 3 and site 4. Meanwhile, these results may bring a novel perspective for exploring the underlying mechanisms of scorpion sting-induced pain.


Assuntos
Animais , Dor , Picadas de Escorpião , Testes de Toxicidade/veterinária
4.
Tese em Português | VETTESES | ID: vtt-203814

Resumo

Salmonella Enteritidis é um dos patógenos veiculados pela carne de frango, que pode ser transmitido às aves pelo consumo de ração contaminada. Com a proibição da adição de antibióticos profiláticos à ração animal pelos países europeus, o uso de aditivos naturais tem ganhado destaque. Para verificar o efeito antimicrobiano dos aditivos naturais no trato digestório de frangos de corte, a digestão simulada pode ser um método eficiente e confiável. Para isso, o presente trabalho foi conduzido com o objetivo de avaliar o efeito antimicrobiano in vitro de óleos essenciais (OE) e ácidos orgânicos (AO), isolados ou em combinação, sobre a população de Salmonella Enteritidis na ração e no trato digestório simulado de frangos de corte. Para os OE, foram testadas doses de 12,5 a 800 ppm de isotiocianato de alila (ITA) e doses de 50 a 800 ppm de carvacrol (CV). Para os AO, foram utilizadas doses de 37 a 297 ppm de ácido propiônico (PROP) e doses de 23 a 930 ppm de ácido caproico (CAP). As diferentes doses dos antimicrobianos foram adicionadas em caldo TSB, em pH 6,0, e avaliadas frente a um pool de 5 cepas de Salmonella Enteritidis, incubado a 37ºC/24h. A partir dos valores de concentração inibitória mínima (CIM) dos compostos isolados, foram testadas combinações de OE + AO com doses reduzidas em 1/2, 1/4 e 1/8 da CIM para avaliar o efeito combinado dos aditivos. Os antimicrobianos selecionados foram adicionados em uma ração comercial para frangos de corte na fase inicial para avaliar seus efeitos sobre o crescimento de Salmonella Enteritidis. Para esta etapa, as concentrações de antimicrobianos utilizadas foram: T1 controle (inoculado apenas com Salmonella Enteritidis); T2 - 62,5 ppm de ITA + 175 ppm de CAP; T3 - 125 ppm de ITA + 350 ppm de CAP; T4 - 187,5 ppm de ITA + 525 ppm de CAP. As contagens de Salmonella foram realizadas a cada dois dias, durante 8 dias. Em seguida, o tratamento com melhor efeito contra Salmonella foi selecionado para a simulação da digestão (in vitro) de frangos, frente ao pool de Salmonella Enteritidis e Lactobacillus plantarum. Para isso, foi utilizada ração comercial de frangos de corte, na fase inicial, sem adição de antibióticos e com a inclusão de ITA e CAP nas concentrações de 187,5 ppm e 525 ppm. A ração com os antimicrobianos foi submetida ao processo de digestão in vitro pelo tempo total de 4h20min. Foram avaliados os compartimentos que simulavam as condições enzimáticas, de pH, temperatura e agitação do papo, proventrículo, moela, intestino delgado e intestino grosso. Entre os OEs, a menor CIM foi obtida para o ITA (25 ppm) enquanto que a CIM do CV foi de 150 ppm; e entre os AOs, o CAP apresentou efeito inibitório em menor dose (70 ppm), enquanto a CIM do PROP foi de 75 ppm. Nos testes de sinergia, a menor combinação que apresentou efeito sinérgico foi verificado com a concentração de 6,25 ppm de ITA e 17,5 ppm de CAP. Na ração, o T4 reduziu a presença de Salmonella Enteritidis de 2.63 ± 0,21 log para níveis indetectáveis (<1,25 log) após 8 dias (P<0,05). No processo de digestão in vitro, foi observada diferenças (P<0,05) nas contagens de Salmonella Enteritidis. No entanto, a população de Lactobacillus plantarum não sofreu alteração. A combinação de 187,5 ppm de ITA e 525 ppm de CAP foi eficiente contra Salmonella Enteritidis em ração e após o processo de digestão in vitro, não afetando a contagem de Lactobacillus plantarum no intestino delgado.


Salmonella Enteritidis is one of the pathogens spread by poultry, which can be transmitted to birds by the consumption of contaminated feed. By the banning of the addition of prophylactic antibiotics to animal feed by European countries, the use of natural antimicrobial compounds has gained prominence. To check the antimicrobials effect of natural additives in the digestive tract of broilers, the simulated digestion is an efficient method and reliable. This in vitro study was carried out to evaluate the antimicrobial effect of essential oils (EO) and organic acids (OA), alone or combined, against Salmonella Enteritidis and Lactobacillus plantarum. The tested doses of allyl isothiocyanate (AITC) were 12.5 to 800 ppm, while 50 to 800 ppm were tested to carvacrol (CV). Further, propionic and caproic acids (CAP) were tested using doses of 37 to 297 ppm and 23 to 930 ppm, respectively. The different doses of these antimicrobial agents were added in TSB broth, pH 6.0, and evaluated against five strains of Salmonella Enteritidis, incubated at 37ºC/24h, to find the minimal inhibitory concentration (MIC). After finding the MICs from these isolated compounds, the association of EO + OA in concentrations of 1/2, 1/4, and 1/8 from the MIC was tested to investigate if there is a synergic antimicrobial effect. The tested antimicrobials were included in a commercial feed for broiler chickens to assess its effects on growth of Salmonella Enteritidis. For this step, the antimicrobial concentrations used were T1 - control (only inoculated with S. Enteritidis); T2 - 62.5 ppm of AITC + 175 ppm of CAP; T3 - 125 ppm of AITC + 350 ppm of CAP; T4 - 187.5 ppm of AITC + 525 ppm of CAP. Afterwards, Salmonella counts were performed on 0, 2, 4, 6, and 8 days to assess the antibacterial effect of the AITC + CAP. Then treatment with a better antibacterial effect against Salmonella was selected to simulate the in vitro digestion of chickens, against the pool of Salmonella Enteritidis and Lactobacillus plantarum. For this, a commercial feed was used for broiler chickens in the initial stage of life, without antibiotics, with inclusion of AITC and CAP at concentrations of 525 ppm and 187.5 ppm, respectively, and a control treatment without antimicrobials. The feed with antimicrobials was submitted to in vitro digestion by 4h20min. The in vitro digestive process was mimicked in the crop, proventriculus, gizzard, small intestine and large intestine compartments of broilers, in enzymatic conditions, pH, temperature and agitation specific for this species. Among the EO, the lowest MIC was obtained for AITC (25 ppm), the MIC CV was 150 ppm; and among the OA, the CAP showed inhibitory effect in the smaller dose (70 ppm), the MIC PROP was 75 ppm. The association of 6.25 ppm of AITC and 17.5 mM of CAP was the lowest dose capable of presenting synergistic effect. In the feed, the T4 reduced from 2.63 ± 0,21 log to undetectable levels (<1.25 log) the presence Salmonella Enteritidis on 0 to 8 days. After the in vitro digestion, T4 also decreased (P<0.05) accounts of Salmonella Enteritidis. The Lactobacillus plantarum cultures collected from the digesta were not altered. The combination of 187.5 ppm of AITC and 525 ppm CAP was effective against Salmonella Enteritidis strains in the feed, and afterwards, in vitro digestion, however, did not affect the Lactobacillus plantarum colonies in the mimicked small intestine.

5.
Piracicaba; s.n; 22/11/2013. 64 p. ilus.
Tese em Português | VETINDEX | ID: biblio-1505358

Resumo

Esse trabalho teve como objetivo o estudo da toxicidade aguda e crônica da ação isolada e de misturas binárias de três medicamentos veterinários (Monensina, Sulfametazina e Enrofloxacina) para o organismo teste Daphnia magna. A toxicidade aguda da enrofloxacina determinada foi de CE50 - 54.36 mgL-1, da monensina CE50 - 15.11mgL-1 e da sulfametazina CE50 - 183.80 mgL-1. Para os ensaios de toxicidade crônica foram determinados 3 /"endpoints/" (sobrevivência, reprodução e tamanho do adulto) e foi determinado o CEO para a enrofloxacina de 0,33 mgL-1, da monensina 0,09 mgL-1 e da sulfametazina de 6,8 mgL-1. Para fazer uma comparação entre os testes das substâncias isoladas e das misturas binárias foi utilizado o conceito de unidade tóxica (UT), essa comparação foi feita através da soma das UT dos ensaios individuais e comparando com os resultados dos ensaios de misturas para determinar se houve ação sinérgica, aditiva ou antagônica. O ensaio agudo de mistura monensina/enrofloxacina apresentou ação sinérgica já os ensaios monensina/sulfametazina e sulfametazina/enrofloxacina apresentaram ação antagônica. Os ensaios crônicos de mistura monensina/enrofloxacina e monensina/sulfametazina apresentaram ação sinérgica, porém não foram dosedependente e o ensaio sulfametazina/enrofloxacina apresentou ação antagônica. Com base nesse estudo é possível concluir que a mistura desses medicamentos interfere na sua toxicidade, podendo causar efeitos sinérgicos ou antagônicos.


This work aims to study the acute and chronic toxicity of the isolated and binary mixtures action of three veterinary drugs (Monensin, Sulfamethazine and Enrofloxacin) for the test organism Daphnia magna. The determined acute toxicity of enrofloxacin was EC50 - 54.36 mgL-1, monensin EC50 - 15.11 mgL-1 and sulfamethazine EC50 - 183.80 mgL-1. In the chronic toxicity tests were determined 3 endpoints (survival, reproduction and adult size) and the LOEC determined for enrofloxacina was 0.33 mgL-1, monensin 0.09 mgL-1 and sulfamethazine 6.8 mgL-1. To make a comparison between the tests of isolated substances and binary mixtures it was used the concept of toxic unit (TU), this comparison was made by adding the UT of individual studies and comparing the test results of mixtures to determine whether there was a synergistic action, additive or antagonistic. The acute mixture assay monensin/enrofloxacin showed synergistic action yet the assays monensin/sulfamethazine and sulfamethazine/enrofloxacin showed antagonistic action. The chronic mixing assays monensin / enrofloxacin and monensin / sulfamethazine showed synergistic action, but were not dose-dependent and testing sulfamethazine / enrofloxacin present antagonistic action. Based on this study it can be concluded that the mixing of these drugs interferes with its toxicity, and may cause synergistic or antagonistic effect.


Assuntos
Anti-Infecciosos/toxicidade , Drogas Veterinárias/toxicidade , Monensin/toxicidade , Sulfametazina/toxicidade , Testes de Toxicidade Aguda/análise , Testes de Toxicidade Crônica/análise , Interações Medicamentosas/fisiologia
6.
Piracicaba; s.n; 22/11/2013. 64 p. ilus.
Tese em Português | VETTESES | ID: vtt-12484

Resumo

Esse trabalho teve como objetivo o estudo da toxicidade aguda e crônica da ação isolada e de misturas binárias de três medicamentos veterinários (Monensina, Sulfametazina e Enrofloxacina) para o organismo teste Daphnia magna. A toxicidade aguda da enrofloxacina determinada foi de CE50 - 54.36 mgL-1, da monensina CE50 - 15.11mgL-1 e da sulfametazina CE50 - 183.80 mgL-1. Para os ensaios de toxicidade crônica foram determinados 3 \"endpoints\" (sobrevivência, reprodução e tamanho do adulto) e foi determinado o CEO para a enrofloxacina de 0,33 mgL-1, da monensina 0,09 mgL-1 e da sulfametazina de 6,8 mgL-1. Para fazer uma comparação entre os testes das substâncias isoladas e das misturas binárias foi utilizado o conceito de unidade tóxica (UT), essa comparação foi feita através da soma das UT dos ensaios individuais e comparando com os resultados dos ensaios de misturas para determinar se houve ação sinérgica, aditiva ou antagônica. O ensaio agudo de mistura monensina/enrofloxacina apresentou ação sinérgica já os ensaios monensina/sulfametazina e sulfametazina/enrofloxacina apresentaram ação antagônica. Os ensaios crônicos de mistura monensina/enrofloxacina e monensina/sulfametazina apresentaram ação sinérgica, porém não foram dosedependente e o ensaio sulfametazina/enrofloxacina apresentou ação antagônica. Com base nesse estudo é possível concluir que a mistura desses medicamentos interfere na sua toxicidade, podendo causar efeitos sinérgicos ou antagônicos. (AU)


This work aims to study the acute and chronic toxicity of the isolated and binary mixtures action of three veterinary drugs (Monensin, Sulfamethazine and Enrofloxacin) for the test organism Daphnia magna. The determined acute toxicity of enrofloxacin was EC50 - 54.36 mgL-1, monensin EC50 - 15.11 mgL-1 and sulfamethazine EC50 - 183.80 mgL-1. In the chronic toxicity tests were determined 3 endpoints (survival, reproduction and adult size) and the LOEC determined for enrofloxacina was 0.33 mgL-1, monensin 0.09 mgL-1 and sulfamethazine 6.8 mgL-1. To make a comparison between the tests of isolated substances and binary mixtures it was used the concept of toxic unit (TU), this comparison was made by adding the UT of individual studies and comparing the test results of mixtures to determine whether there was a synergistic action, additive or antagonistic. The acute mixture assay monensin/enrofloxacin showed synergistic action yet the assays monensin/sulfamethazine and sulfamethazine/enrofloxacin showed antagonistic action. The chronic mixing assays monensin / enrofloxacin and monensin / sulfamethazine showed synergistic action, but were not dose-dependent and testing sulfamethazine / enrofloxacin present antagonistic action. Based on this study it can be concluded that the mixing of these drugs interferes with its toxicity, and may cause synergistic or antagonistic effect. (AU)


Assuntos
Testes de Toxicidade Aguda/análise , Testes de Toxicidade Crônica/análise , Monensin/toxicidade , Sulfametazina/toxicidade , Anti-Infecciosos/toxicidade , Drogas Veterinárias/toxicidade , Interações Medicamentosas/fisiologia
7.
Artigo em Inglês | VETINDEX | ID: vti-443954

Resumo

The goal of this work was to investigate a possible synergistic effect between ethanolic extracts of propolis from Brazil and Bulgaria and some antibiotics (Amoxicillin, Ampicillin and Cefalexin) against Salmonella Typhi. Brazilian and Bulgarian propolis showed an antibacterial action, but the sample from Bulgaria was shown to be more efficient. Both samples showed a similar synergistic effect with these antibiotics. One may conclude that the propolis samples show an important antibacterial action, as well as a synergistic effect with antibiotics against Salmonella Typhi.


O objetivo do presente trabalho foi investigar um possível efeito sinérgico entre extrato alcoólico de própolis do Brasil e Bulgária com alguns antibióticos (Amoxilina, Ampicilina e Cefalexina) utilizados contra Salmonella Typhi. Própolis do Brasil e Bulgária mostraram uma atividade antibacteriana, embora a amostra da Bulgária tenha sido mais eficiente. Ambas as amostras apresentaram um efeito sinérgico com os antibióticos estudados. Pode-se concluir que as amostras de própolis possuem atividade antibacteriana, bem como apresentam efeito sinérgico com antibióticos utilizados contra Salmonella Typhi.

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