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Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians

Sea cucumbers are slow-moving organisms that use morphological, but also a diverse combination of chemical defenses to improve their overall fitness and chances of survival. Since chemical defense compounds are also of great pharmaceutical interest, we pinpoint the importance of biological screening...

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Detalles Bibliográficos
Autores principales: Kamyab, Elham, Rohde, Sven, Kellermann, Matthias Y., Schupp, Peter J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7587958/
https://www.ncbi.nlm.nih.gov/pubmed/33086732
http://dx.doi.org/10.3390/molecules25204808
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author Kamyab, Elham
Rohde, Sven
Kellermann, Matthias Y.
Schupp, Peter J.
author_facet Kamyab, Elham
Rohde, Sven
Kellermann, Matthias Y.
Schupp, Peter J.
author_sort Kamyab, Elham
collection PubMed
description Sea cucumbers are slow-moving organisms that use morphological, but also a diverse combination of chemical defenses to improve their overall fitness and chances of survival. Since chemical defense compounds are also of great pharmaceutical interest, we pinpoint the importance of biological screenings that are a relatively fast, informative and inexpensive way to identify the most bioactive organisms prior to further costly and elaborate pharmacological screenings. In this study, we investigated the presence and absence of chemical defenses of 14 different sea cucumber species from three families (Holothuriidae, Stichopodidae and Synaptidae) against ecological factors such as predation and pathogenic attacks. We used the different sea cucumber crude extracts as well as purified fractions and pure saponin compounds in a portfolio of ecological activity tests including fish feeding assays, cytotoxicity tests and antimicrobial assays against environmental pathogenic and non-pathogenic bacteria. Furthermore, we quantified and correlated the concentrations of sea cucumber characteristic saponin compounds as effective chemical defensive compounds in all 14 crude extracts by using the vanillin–sulfuric acid test. The initial results revealed that among all tested sea cucumber species that were defended against at least one ecological threat (predation and/or bacterial attack), Bohadschia argus, Stichopus choloronotus and Holothuria fuscopunctata were the three most promising bioactive sea cucumber species. Therefore, following further fractionation and purification attempts, we also tested saponin-containing butanol fractions of the latter, as well as two purified saponin species from B. argus. We could demonstrate that both, the amount of saponin compounds and their structure likely play a significant role in the chemical defense strategy of the sea cucumbers. Our study concludes that the chemical and morphological defense mechanisms (and combinations thereof) differ among the ecological strategies of the investigated holothurian species in order to increase their general fitness and level of survival. Finally, our observations and experiments on the chemical ecology of marine organisms can not only lead to a better understanding of their ecology and environmental roles but also can help in the better selection of bioactive organisms/compounds for the discovery of novel, pharmacologically active secondary metabolites in the near future.
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spelling pubmed-75879582020-10-29 Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians Kamyab, Elham Rohde, Sven Kellermann, Matthias Y. Schupp, Peter J. Molecules Article Sea cucumbers are slow-moving organisms that use morphological, but also a diverse combination of chemical defenses to improve their overall fitness and chances of survival. Since chemical defense compounds are also of great pharmaceutical interest, we pinpoint the importance of biological screenings that are a relatively fast, informative and inexpensive way to identify the most bioactive organisms prior to further costly and elaborate pharmacological screenings. In this study, we investigated the presence and absence of chemical defenses of 14 different sea cucumber species from three families (Holothuriidae, Stichopodidae and Synaptidae) against ecological factors such as predation and pathogenic attacks. We used the different sea cucumber crude extracts as well as purified fractions and pure saponin compounds in a portfolio of ecological activity tests including fish feeding assays, cytotoxicity tests and antimicrobial assays against environmental pathogenic and non-pathogenic bacteria. Furthermore, we quantified and correlated the concentrations of sea cucumber characteristic saponin compounds as effective chemical defensive compounds in all 14 crude extracts by using the vanillin–sulfuric acid test. The initial results revealed that among all tested sea cucumber species that were defended against at least one ecological threat (predation and/or bacterial attack), Bohadschia argus, Stichopus choloronotus and Holothuria fuscopunctata were the three most promising bioactive sea cucumber species. Therefore, following further fractionation and purification attempts, we also tested saponin-containing butanol fractions of the latter, as well as two purified saponin species from B. argus. We could demonstrate that both, the amount of saponin compounds and their structure likely play a significant role in the chemical defense strategy of the sea cucumbers. Our study concludes that the chemical and morphological defense mechanisms (and combinations thereof) differ among the ecological strategies of the investigated holothurian species in order to increase their general fitness and level of survival. Finally, our observations and experiments on the chemical ecology of marine organisms can not only lead to a better understanding of their ecology and environmental roles but also can help in the better selection of bioactive organisms/compounds for the discovery of novel, pharmacologically active secondary metabolites in the near future. MDPI 2020-10-19 /pmc/articles/PMC7587958/ /pubmed/33086732 http://dx.doi.org/10.3390/molecules25204808 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Kamyab, Elham
Rohde, Sven
Kellermann, Matthias Y.
Schupp, Peter J.
Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title_full Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title_fullStr Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title_full_unstemmed Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title_short Chemical Defense Mechanisms and Ecological Implications of Indo-Pacific Holothurians
title_sort chemical defense mechanisms and ecological implications of indo-pacific holothurians
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7587958/
https://www.ncbi.nlm.nih.gov/pubmed/33086732
http://dx.doi.org/10.3390/molecules25204808
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