Production of functionally active palytoxin-like compounds by Mediterranean Ostreopsis cf. siamensis.
OBJECTIVE
Dinoflagellates from the genus Ostreopsis have been related to the production of palytoxin and analogues. Based on that, this paper describes functional studies of crude extracts from Ostreopsis cf. siamensis collected in the Mediterranean Sea in order to biochemically characterize their toxic compounds.


METHODS
We compared the effects of 5 crude dinoflagellates extracts with a commercially available palytoxin and a purified Ostreopsis ovata extract on metabolic activity, membrane potential, and cytosolic calcium levels by using fluorescent dyes.


RESULTS
All the extracts resulted to be neurotoxic. In addition, all of them induced a membrane depolarization and a calcium increment that were abolished when preincubating with ouabain, an inhibitor of the Na(+)/K(+) pump.


CONCLUSIONS
The effects observed were quite close to those induced by palytoxin and the Ostreopsis ovata extract as well, suggesting that Ostreopsis cf. siamensis is actually producing palytoxin-like compounds that are highly toxic and functionally active.
Cagide
Eva
E
Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Spain.
Louzao
M Carmen
MC
Espiña
Begoña
B
Vieytes
Mercedes R
MR
Jaen
David
D
Maman
Luz
L
Yasumoto
Takeshi
T
Botana
Luis M
LM
D000178:Acrylamides / Q000633:toxicity*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D003064:Cnidarian Venoms; D004141:Dinoflagellida / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D010042:Ouabain / Q000494:pharmacology; D014020:Tissue Extracts / Q000302:isolation & purification / Q000633:toxicity; D000095702:Polyether Toxins
D000178:Acrylamides; D002118:Calcium; D003064:Cnidarian Venoms; D005456:Fluorescent Dyes; D010042:Ouabain; D014020:Tissue Extracts; C010272:palytoxin; D000095702:Polyether Toxins