Neurotoxic activity induced by a haemolytic substance in the extract of the marine sponge Geodia corticostylifera.
In our search for marine bioactive compounds we chose a Brazilian Coast sponge, Geodia corticostylifera (Demospongiae), whose extracts showed previously antibacterial and antifungal activities. In the present work we studied the following toxic properties of G. corticostylifera extract: neurotoxic (in mouse neuromuscular junction); mouse acute toxicity (IP) and haemolytic (against mouse and frog erythrocytes). Insertion of ionic channels in planar lipid bilayers in presence of a haemolytic purified fraction of the extract was observed. The toxic activities of G. corticostylifera crude extract are related to the formation of ionic pores in the cell membrane, which induce the release of haemoglobin from erythrocytes, and depolarization of nerve and muscle membranes. These last physiological effects cause the blockade of the diaphragm contractions, leading to death through respiratory arrest.
Rangel
Marisa
M
Department of Physiology of Biosciences Institute and Marine Biology Center, University of Sao Paulo, Sao Paulo, 05508-900, SP, Brazil. mrangel@butantan.gov.br
Konno
Katsuhiro
K
Brunaldi
Kellen
K
Procopio
Joaquim
J
De Freitas
José Carlos
JC
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D047231:Geodia / Q000472:pathogenicity*; D006461:Hemolysis / Q000187:drug effects*; D007928:Lethal Dose 50; D008051:Lipid Bilayers; D008297:Male; D051379:Mice; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D009498:Neurotoxins / Q000633:toxicity*; D011898:Ranidae
D008051:Lipid Bilayers; D009498:Neurotoxins