Avaliação da presença do grupo nitro na atividade antichagásica e mutagênica do candidato a fármaco hidroximetilnitrofural (NFOH)
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Data
2009-05-20
Autores
Bosquesi, Priscila Longhin [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A doença de Chagas constitui um dos maiores problemas de Saúde Pública em países do cone sul das Américas. Estima-se que 16 a 18 milhões de pessoas estejam infectadas e aproximadamente cento e vinte milhões estão sob risco de contaminação. No Brasil, apenas o benznidazol (BNZ) está disponível para o tratamento da doença, e apesar de seu uso clínico, este fármaco apresenta efeitos secundários indesejáveis, sendo ativo apenas na fase aguda da doença. O nitrofural (NF) é ativo contra o Trypanossoma cruzi, entretanto, a alta toxicidade impede o seu uso na parasitose. O hidroximetilnitrofural (NFOH) é um pró-fármaco do nitrofural, que apresenta maior atividade contra T. cruzi, e, além disso, pesquisas vêm demonstrando menor toxicidade do NFOH quando comparado ao fármaco matriz, nitrofural. Resultados obtidos nos testes de toxicidade aguda para o NFOH com camundongos e ratos, sugeriram baixa toxicidade deste, obtendo-se uma dose letal mediana (DL50) maior em relação ao fármaco de partida, NF (556,3 mg/kg). Por via oral os resultados caracterizaram o NFOH como pouco tóxico, segundo a OMS com um valor de DL50 acima de 2000mg/kg. No Teste de Ames os resultados indicaram que a latenciação do NF em NFOH foi capaz de diminuir a atividade mutagênica em aproximadamente quatro vezes, nos ensaios com (+S9) ou sem ativação metabólica (-S9), nas linhagens testadas. Contudo, este trabalho avaliou a influência do grupo nitro na molécula de nitrofural, através da substituição deste grupo por isósteros do grupo nitro e também o potencial mutagênico dos fármacos NF e BNZ, e do candidato a fármaco NFOH empregando-se o teste de micronúcleo em células do sangue periférico de camundongos. A atividade dos compostos sintetizados neste trabalho modificou-se drasticamente, ou seja, os compostos não apresentaram atividade antichagásica nas formas epimastigotas em nenhuma...
Chagas' disease is a major public health problem in countries of the southern cone of the Americas. It is estimated that 16 to 18 million people are infected and about hundred and twenty million are at risk of contamination. In Brazil, only benznidazole is available for the treatment of the disease, although its clinical use, this drug shows toxic side effects and is active only in the acute phase of illness. The nitrofurazone (NF) is active against Trypanossoma cruzi, although, it`s high toxicity prevents it from being used in parasitosis. The hydroxymethylnitrofurazone (NFOH) is the nitrofurazone prodrugs that presents the highest level of activity against the T. Cruzi, fact which is supported by researches that have been evidentiating it`s less significant toxicity when compared to the matrix drug nitrofurazone. Results obtained in tests of acute toxicity to the NFOH with mice and rats, suggested that low toxicity, resulting in a median lethal dose (LD50) more than in the drug of departure, NF (556,3 mg/kg). Orally NFOH characterized the results as somewhat toxic, according to the WHO with a value of LD50 over 2000 mg/kg. In the Ames Test results indicate that NF latentiation in the NFOH was able to reduce the mutagenic activity in about 4 times in trials with (S9 +) or without metabolic activation (-S9), the strains tested. However, this study evaluated the influence of nitro group in the molecule of nitrofurazone, by replacing this group by isosteric the nitro group and also the mutagenic potential of drugs NF and BNZ, and the drug candidate NFOH by using the test micronucleus test in cells in the peripheral blood of mice. The activity of compounds synthesized in this work has changed dramatically, ie the compound showed no activity in epimastigotes antichagasic in any of the concentrations used. However, the results obtained in the testing of mutagenicity by the micronucleus test... (Complete abstract click electronic access below)
Chagas' disease is a major public health problem in countries of the southern cone of the Americas. It is estimated that 16 to 18 million people are infected and about hundred and twenty million are at risk of contamination. In Brazil, only benznidazole is available for the treatment of the disease, although its clinical use, this drug shows toxic side effects and is active only in the acute phase of illness. The nitrofurazone (NF) is active against Trypanossoma cruzi, although, it`s high toxicity prevents it from being used in parasitosis. The hydroxymethylnitrofurazone (NFOH) is the nitrofurazone prodrugs that presents the highest level of activity against the T. Cruzi, fact which is supported by researches that have been evidentiating it`s less significant toxicity when compared to the matrix drug nitrofurazone. Results obtained in tests of acute toxicity to the NFOH with mice and rats, suggested that low toxicity, resulting in a median lethal dose (LD50) more than in the drug of departure, NF (556,3 mg/kg). Orally NFOH characterized the results as somewhat toxic, according to the WHO with a value of LD50 over 2000 mg/kg. In the Ames Test results indicate that NF latentiation in the NFOH was able to reduce the mutagenic activity in about 4 times in trials with (S9 +) or without metabolic activation (-S9), the strains tested. However, this study evaluated the influence of nitro group in the molecule of nitrofurazone, by replacing this group by isosteric the nitro group and also the mutagenic potential of drugs NF and BNZ, and the drug candidate NFOH by using the test micronucleus test in cells in the peripheral blood of mice. The activity of compounds synthesized in this work has changed dramatically, ie the compound showed no activity in epimastigotes antichagasic in any of the concentrations used. However, the results obtained in the testing of mutagenicity by the micronucleus test... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Química farmacêutica, Mutagenicidade - Teses, Bioisósteros, Hidroximetilnitrofural, Pharmaceutical chemistry
Como citar
BOSQUESI, Priscila Longhin. Avaliação da presença do grupo nitro na atividade antichagásica e mutagênica do candidato a fármaco hidroximetilnitrofural (NFOH). 2009. xvii, 104 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, 2009.