Avaliação do potencial de aplicação do ácido elágico nanoencapsulado em ciclodextrina no tratamento de candidose bucal
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Data
2019-03-28
Autores
Sampaio, Aline da Graça [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O aumento crescente da prevalência das infecções fúngicas no cenário mundial e aumento da ocorrência de resistência aos antifúngicos convencionais sugerem que pesquisas para a descoberta de novas moléculas antifúngicas são urgentemente necessárias. O objetivo geral deste estudo é contribuir para a prospecção de alternativas terapêuticas, avaliando nanoencapsulados da substância bioativa ácido elágico (NAE) no tratamento da candidose bucal. Os seguintes objetivos específicos foram: complexar ácido elágico em ciclodextrina, em concentração com atividade antifúngica frente C. albicans; caracterizar quimicamente o encapsulado; prospectar possíveis mecanismos de ação; avaliar ação de concentrações subinibitórias sobre a produção de exoenzimas e aderência às células epiteliais; avaliar citotoxicidade do NAE nas condições de tratamento efetivas in vitro e in vivo (Drosophila melanogaster) e avaliar ação no tratamento in vivo de lesões de candidose oral induzida em modelo murino. Os dados foram analisados estatisticamente, adotando-se significância de 5%. HP-β-CD formou complexos solúveis de inclusão com AE. A porcentagem de AE/HP-β-CD foi de 15,25 ± 0,49%. As análises de MEV e FTIR confirmaram a formação de complexo de inclusão. AE/HP-β-CD manteve a atividade antifúngica do AE puro, com CIM 25 µg/ml para C. albicans ATCC 18804 e 50 µg/ml para C. albicans SC 5314. O tratamento de C. albicans com sub-CIMs indicou aumento da CIM na presença de sorbitol para ATCC 18804 (50 µg/ml), sugerindo ação sobre parede celular. Os resultados sugerem que não há ação sobre membrana celular. Não foi detectado efeito sobre morfogênese e produção de enzimas extracelulares. Efeito protetor de AE a 3,2, 6,4 e 32 µg/ml foi observado em modelo D. melanogaster infectado com C. albicans que resultou na sobrevivência de 45, 33 e 34%. Baixa toxicidade foi observada nas concentrações de 200 e 250 µg/ml. No modelo de candidose bucal em camundongos foi observada redução significativa da invasão de hifas no epitélio no grupo tratado AE/HP-β-CD em relação aos controles, em 24 horas e 48 horas. Conclui-se que AE/HP-β-CD apresentou efeito inibitório sobre C. albicans in vitro, com baixa toxicidade. Em modelo Drosophila melanogaster apresentou efeito protetor frente à infecção fúngica. Em modelo murino levou à redução na invasão epitelial pelo fungo.
The increase in the prevalence of fungal infections worldwide and the rise in the occurrence of antifungal resistance suggest that new researches for the discovery of antifungal molecules are needed. The aim of this study is to contribute to the prospection of therapeutic alternatives, evaluating nanoencapsulates of ellagic acid (NAE) for the treatment of oral candidosis. In order to reach the general aim, the following specific objectives were determined: to complex the ellagic acid in cyclodextrin at effective concentration against C. albicans; to chemically characterize the encapsulate; to test the activity of the encapsulate using an invasive candidosis in vitro model, searching for the mechanisms of action; to evaluate the activity of subinhibitory concentrations on the exoenzymes production, and adherence to epithelial cells; to evaluate the cytotoxicity of NAE in the effective treatment conditions in vitro and in vivo (Drosophila melanogaster); and to evaluate the in vivo effectiveness for the treatment of oral candidosis in murine model. The obtained data was statistically analyzed (level of significance 5%). HP-β-CD formed soluble inclusion complexes with EA. The percentage of EA/HP-β-CD was 15.25 ± 0.49%. SEM and FTIR analyses confirmed the formation of inclusion complex. AE/HP-β-CD showed the same antifungal activity of pure EA with MIC value of 25 µg/ml for C. albicans ATCC 18804 and 50 µg/ml for C. albicans SC 5314. Treatment with sub-MIC on C. albicans revealed increased MIC value in the presence of sorbitol for ATCC 18804 (50 µg/ml), suggesting activity on cell wall. Results suggest no effect on cell membrane. No effects of EA on morphogenesis and production of extracellular enzymes were detected. Protective effect of EA at 3.2, 6.4 e 32 µg/ml was observed in D. melanogaster model, resulting in survivals of 45, 33 and 34%. Low cytotoxicity was observed for concentrations of 200 and 250 µg/ml. In vivo tests in murine models indicated reduction in epithelial invasion after treatment EA/HP-β-CD for 24 and 48 h when compared to control. In conclusion, EA/HP-β-CD showed inhibitory effect on C. albicans in vitro, with low toxicity. Protective effect against fungal infection was observed in D. melanogaster model. In murine model of oral candidosis, EA/HP-β-CD reduced fungal epithelial invasion.
The increase in the prevalence of fungal infections worldwide and the rise in the occurrence of antifungal resistance suggest that new researches for the discovery of antifungal molecules are needed. The aim of this study is to contribute to the prospection of therapeutic alternatives, evaluating nanoencapsulates of ellagic acid (NAE) for the treatment of oral candidosis. In order to reach the general aim, the following specific objectives were determined: to complex the ellagic acid in cyclodextrin at effective concentration against C. albicans; to chemically characterize the encapsulate; to test the activity of the encapsulate using an invasive candidosis in vitro model, searching for the mechanisms of action; to evaluate the activity of subinhibitory concentrations on the exoenzymes production, and adherence to epithelial cells; to evaluate the cytotoxicity of NAE in the effective treatment conditions in vitro and in vivo (Drosophila melanogaster); and to evaluate the in vivo effectiveness for the treatment of oral candidosis in murine model. The obtained data was statistically analyzed (level of significance 5%). HP-β-CD formed soluble inclusion complexes with EA. The percentage of EA/HP-β-CD was 15.25 ± 0.49%. SEM and FTIR analyses confirmed the formation of inclusion complex. AE/HP-β-CD showed the same antifungal activity of pure EA with MIC value of 25 µg/ml for C. albicans ATCC 18804 and 50 µg/ml for C. albicans SC 5314. Treatment with sub-MIC on C. albicans revealed increased MIC value in the presence of sorbitol for ATCC 18804 (50 µg/ml), suggesting activity on cell wall. Results suggest no effect on cell membrane. No effects of EA on morphogenesis and production of extracellular enzymes were detected. Protective effect of EA at 3.2, 6.4 e 32 µg/ml was observed in D. melanogaster model, resulting in survivals of 45, 33 and 34%. Low cytotoxicity was observed for concentrations of 200 and 250 µg/ml. In vivo tests in murine models indicated reduction in epithelial invasion after treatment EA/HP-β-CD for 24 and 48 h when compared to control. In conclusion, EA/HP-β-CD showed inhibitory effect on C. albicans in vitro, with low toxicity. Protective effect against fungal infection was observed in D. melanogaster model. In murine model of oral candidosis, EA/HP-β-CD reduced fungal epithelial invasion.
Descrição
Palavras-chave
Candida albicans, Ácido elágico, Ciclodextrina, Ellagic acid, Cyclodextrin