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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.


Related in: MedlinePlus

Biological activities of the low-molecular-weight fractions obtained from the aqueous extracts. a Toxicity to crickets (A. domestica), 24 h post-injection, at a concentration of 50 μg of lyophilized powder/g. b Vasoconstrictor activity on isolated rat aortic rings at a concentration of 1000 μg of lyophilized powder/mL. c Representative recordings showing the vasoconstrictor activity of the fractions (1000 μg/mL) compared with the activity induced by phenylephrine (1 μM)
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Fig9: Biological activities of the low-molecular-weight fractions obtained from the aqueous extracts. a Toxicity to crickets (A. domestica), 24 h post-injection, at a concentration of 50 μg of lyophilized powder/g. b Vasoconstrictor activity on isolated rat aortic rings at a concentration of 1000 μg of lyophilized powder/mL. c Representative recordings showing the vasoconstrictor activity of the fractions (1000 μg/mL) compared with the activity induced by phenylephrine (1 μM)

Mentions: Two fractions were separated from each extract using FPLC. The peaks retained in the column (Ps2, Pa2, and Ss2) were passed through filters with 10 K cutoff in order to obtain the low-molecular-weight components. The MALDI-TOF mass spectrometry showed that these fractions contain low-molecular-weight peptides, within a mass range of 3000 to 6000 Da (Figs. 6, 7, and 8). These low-molecular-weight fractions were lethal to crickets, 24 h post-injection, at a dose of 50 μg of lyophilized filtrated fraction/g (Fig. 9a). Evaluation of the vasoconstrictor activity of these low-molecular-weight fractions showed that Ps2 and Pa2 induced vasoconstriction at a concentration of 1000 μg of lyophilized filtrated fraction/mL, whereas Ss2 did not display activity (Fig. 9b-c).Fig. 6


Composition and biological activities of the aqueous extracts of three scleractinian corals from the Mexican Caribbean: Pseudodiploria strigosa , Porites astreoides and Siderastrea siderea
Biological activities of the low-molecular-weight fractions obtained from the aqueous extracts. a Toxicity to crickets (A. domestica), 24 h post-injection, at a concentration of 50 μg of lyophilized powder/g. b Vasoconstrictor activity on isolated rat aortic rings at a concentration of 1000 μg of lyophilized powder/mL. c Representative recordings showing the vasoconstrictor activity of the fractions (1000 μg/mL) compared with the activity induced by phenylephrine (1 μM)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig9: Biological activities of the low-molecular-weight fractions obtained from the aqueous extracts. a Toxicity to crickets (A. domestica), 24 h post-injection, at a concentration of 50 μg of lyophilized powder/g. b Vasoconstrictor activity on isolated rat aortic rings at a concentration of 1000 μg of lyophilized powder/mL. c Representative recordings showing the vasoconstrictor activity of the fractions (1000 μg/mL) compared with the activity induced by phenylephrine (1 μM)
Mentions: Two fractions were separated from each extract using FPLC. The peaks retained in the column (Ps2, Pa2, and Ss2) were passed through filters with 10 K cutoff in order to obtain the low-molecular-weight components. The MALDI-TOF mass spectrometry showed that these fractions contain low-molecular-weight peptides, within a mass range of 3000 to 6000 Da (Figs. 6, 7, and 8). These low-molecular-weight fractions were lethal to crickets, 24 h post-injection, at a dose of 50 μg of lyophilized filtrated fraction/g (Fig. 9a). Evaluation of the vasoconstrictor activity of these low-molecular-weight fractions showed that Ps2 and Pa2 induced vasoconstriction at a concentration of 1000 μg of lyophilized filtrated fraction/mL, whereas Ss2 did not display activity (Fig. 9b-c).Fig. 6

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.


Related in: MedlinePlus