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Composition and biological activities of the aqueous extracts of three scleractinian corals from the Mexican Caribbean: Pseudodiploria strigosa , Porites astreoides and Siderastrea siderea

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ABSTRACT

Background: Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time.

Methods: Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A2 (PLA2), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration.

Results: Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings.

Conclusion: This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.

No MeSH data available.


Log-concentration response curves showing the vasoconstrictor activity of the extracts
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Fig3: Log-concentration response curves showing the vasoconstrictor activity of the extracts

Mentions: Assessment of the effect of the extracts on the vascular tone of isolated rat aortic rings showed that they induced a vasoconstrictor effect (Fig. 3). Table 3 shows the EC50 and Emax values calculated for the extracts. It is important to mention that the activity of the extracts was irregular; at concentrations lower than 10 μg of protein/mL the vasoconstriction was sustained, but at a higher concentration (approximately 100 μg of protein/mL) the vasoconstriction became transitory. At a concentration of 316 μg of protein/mL, the vasoconstriction induced by the extracts decreased considerably. These irregularities could be due to the presence of mixtures of vasorelaxant and vasoconstrictor components in the extracts. Comparisons between the activities induced by the extracts showed that P. strigosa extract was more potent and effective.Fig. 3


Composition and biological activities of the aqueous extracts of three scleractinian corals from the Mexican Caribbean: Pseudodiploria strigosa , Porites astreoides and Siderastrea siderea
Log-concentration response curves showing the vasoconstrictor activity of the extracts
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5121987&req=5

Fig3: Log-concentration response curves showing the vasoconstrictor activity of the extracts
Mentions: Assessment of the effect of the extracts on the vascular tone of isolated rat aortic rings showed that they induced a vasoconstrictor effect (Fig. 3). Table 3 shows the EC50 and Emax values calculated for the extracts. It is important to mention that the activity of the extracts was irregular; at concentrations lower than 10 μg of protein/mL the vasoconstriction was sustained, but at a higher concentration (approximately 100 μg of protein/mL) the vasoconstriction became transitory. At a concentration of 316 μg of protein/mL, the vasoconstriction induced by the extracts decreased considerably. These irregularities could be due to the presence of mixtures of vasorelaxant and vasoconstrictor components in the extracts. Comparisons between the activities induced by the extracts showed that P. strigosa extract was more potent and effective.Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Background: Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time.

Methods: Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A2 (PLA2), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration.

Results: Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings.

Conclusion: This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.

No MeSH data available.