The extract of the jellyfish Phyllorhiza punctata promotes neurotoxic effects.

ABSTRACT Phyllorhiza punctata ( P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freeze-thaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A₂ were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 ± 34.7% of control twitch height, which were blocked with either 100 μ m of phentolamine or 1 m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-N^G-Nitroarginine methyl ester (0.5 m m) or 1 m m of lidocaine. PHY-N (1, 3 and 10 μg ml⁻¹) induced an increase in tonus of the biventer-cervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 μ m). Administration of 6 mg kg⁻¹ PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]