title: Systemic toxic effects induced by the aqueous extract of the fire coral Millepora complanata and partial purification of thermostable neurotoxins with lethal effects in mice.
abstract: Millepora complanata is a cnidarian widely distributed in the coral reefs of the Mexican Caribbean. This species is popularly known as "fire coral", since contact with it causes severe pain, skin eruptions and blisters. Intravenous administration of of M. complanata aqueous extract induces violent convulsions and death in mice within 1 min (LD50=4.62µgprotein/g of body weight). Doses less than the LD50 produced histopathological damage in kidneys and lungs. Such histopathological damage was completely eliminated after incubation of the extract in heat denaturing conditions. Unexpectedly, the denatured extract conserved its lethal effect. These findings demonstrated that the extract contained hemolytic and phospholipase activities that might be responsible for the histopathological damage, and additionally it contained other unidentified thermostable toxins with lethal effects in mice. Chromatographic analysis of the extract led to the isolation of a 61 kDa vasoconstrictor protein. Furthermore, several non-peptidic vasoconstrictor fractions were separated. Particularly interesting was the fraction MC1-IIA obtained as a result of three-step chromatography processes (ion exchange, gel filtration and reverse phase). Like the original crude extract, this fraction induced vasoconstriction and delayed hemolysis and lethal effects in mice. A subsequent chromatographic analysis of MC1-IIA showed that this fraction contained at least four non-peptidic compounds. MS and NMR spectroscopic data analyses indicated that these metabolites were poly-oxygenated alkylbenzenes. The present study constitutes the first report of the presence of non-peptidic lethal toxins in an organism of the class Hydrozoa, and evidences the great structural diversity of the toxins produced by the Millepora species.
authors.affiliation: Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, México.
authors.forename: Alejandro
authors.initials: A
authors.lastname: García-Arredondo
authors.affiliation: Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, México. Electronic address: rojasa@uaq.mx.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Rojas-Molina
authors.affiliation: Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, México.
authors.forename: Moustapha
authors.initials: M
authors.lastname: Bah
authors.affiliation: Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, México.
authors.forename: César
authors.initials: C
authors.lastname: Ibarra-Alvarado
authors.affiliation: Laboratorio de Patología Experimental, Facultad de Medicina, Universidad Autónoma de Querétaro, Querétaro 76176, México.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Gallegos-Corona
authors.affiliation: Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76201, México.
authors.forename: Martín
authors.initials: M
authors.lastname: García-Servín
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D004912:Erythrocytes; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D007928:Lethal Dose 50; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D051379:Mice; D009498:Neurotoxins / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000187:drug effects / Q000473:pathology
chemical_list: D009498:Neurotoxins
keywords: Hemolysis; Histopathology; Millepora complanata; Neurotoxin; Systemic toxicity; Vasoconstriction