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Avaliação da bioatividade do muco de peixes marinhos comparação dos perfis proteicos em c. lyra e H. didactylus
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Advisor(s)
Abstract(s)
O muco epidérmico é um fluido que cobre a superfície da epiderme dos peixes
formando uma barreira capaz de separar o ambiente interno do externo. O muco dos peixes
teleósteos é, tal como o de muitos outros vertebrados, produzido pelas células epidérmicas e
epiteliais.
Existem diversas espécies de peixes cujo muco epidérmico parece apresentar
propriedades bioativas e as espécies Halobatrachus didactylus e Callionymus lyra parecem
também ser exemplos disso. Uma das hipóteses a testar é que o muco produzido
abundantemente por ambas as espécies possua parecenças. Esta hipótese surge da observação
de que estes peixes, quando em estado de stress, provocam a morte de outros que com eles
partilhem um espaço confinado.
A comparação dos perfis proteicos SDS-PAGE das duas espécies, de famílias distintas
(Batrachoididae e Callionymidae), revelou algumas semelhanças. Seria o esperado caso o muco
apresentasse funções semelhantes em ambas as espécies. Para explorar em detalhe a
constituição do muco destas espécies foram ainda realizados perfis de HPLC-DAD. E, com
vista a uma potencial aplicação biomédica foram realizados ensaios antimicrobianos e
antioxidantes em C. lyra.
Os perfis de HPLC-DAD demonstraram um pico cromatográfico com 887 Da, em
ambas as espécies, podendo tratar-se do mesmo péptido. Relativamente aos ensaios, C. lyra
apresentou atividade antimicrobiana contra a bactéria Staphylococcus aureus e uma atividade
antioxidante significativa. Estes resultados preliminares são suficientemente promissores para
justificar continuar a avaliar as aplicações potenciais do muco destas espécies. No futuro, seria
interessante identificar os componentes mais promissores para diferentes aplicações em
biomedicina
ABSTRACT:
ABSTRACT: Epidermal mucus is a fluid that covers the surface of the epidermis of fish, forming a barrier that separates the internal and external environment. Like many other vertebrates the mucus of teleost fish is produced by epidermal and epithelial cells. There are several fish species whose skin mucus presents bioactive properties and species like Halobatrachus didactylus and Callionymus lyra are not an exception. One of the hypotheses to be tested is that the epidermal mucus produced abundantly by both species presents a strong effect. This hypothesis arises from the observation that these fish, in stress conditions, are lethal for other fish species while captive in confined spaces. The comparison of the SDS-PAGE protein profiles of the two species, families Batrachoididae and Callionymidae, revealed some similarities. It would be expected if the mucus had similar functions in both species. To better explore the constitution of the mucus of these species HPLC-DAD profiles were also performed. And, with a view to a potential biomedical application, antimicrobial and antioxidant assays were performed on C. lyra. The HPLC-DAD profiles show a chromatographic peak with 887 Da in both species, which could represent the same peptide. When it comes to assays, C. lyra show antibacterial activity against gram-positive bacteria Staphylococcus aureus and a significant antioxidant activity. Preliminary results are promising enough to justify further research to explore the potential of the mucus produced by these species. In the future, it would be interesting to identify the most promising mucus components for different applications in biomedicine.
ABSTRACT:
ABSTRACT: Epidermal mucus is a fluid that covers the surface of the epidermis of fish, forming a barrier that separates the internal and external environment. Like many other vertebrates the mucus of teleost fish is produced by epidermal and epithelial cells. There are several fish species whose skin mucus presents bioactive properties and species like Halobatrachus didactylus and Callionymus lyra are not an exception. One of the hypotheses to be tested is that the epidermal mucus produced abundantly by both species presents a strong effect. This hypothesis arises from the observation that these fish, in stress conditions, are lethal for other fish species while captive in confined spaces. The comparison of the SDS-PAGE protein profiles of the two species, families Batrachoididae and Callionymidae, revealed some similarities. It would be expected if the mucus had similar functions in both species. To better explore the constitution of the mucus of these species HPLC-DAD profiles were also performed. And, with a view to a potential biomedical application, antimicrobial and antioxidant assays were performed on C. lyra. The HPLC-DAD profiles show a chromatographic peak with 887 Da in both species, which could represent the same peptide. When it comes to assays, C. lyra show antibacterial activity against gram-positive bacteria Staphylococcus aureus and a significant antioxidant activity. Preliminary results are promising enough to justify further research to explore the potential of the mucus produced by these species. In the future, it would be interesting to identify the most promising mucus components for different applications in biomedicine.
Description
Dissertação de Mestrado apresentada
no ISPA – Instituto Universitário para obtenção de grau de
Mestre na especialidade de Biologia Marinha e Conservação
Keywords
Muco Bioativo Importância ecológica Atividade antimicrobiana Antioxidante Mucus Bioactive Ecological importance Antimicrobial activity Antioxidant