Gambierdiscus toxicus extracts

Figure 3. Body temperature response of mice receiving various quantities of cultured Gambierdiscus toxicus extract. Each point represents the mean S.E. of the rectal temperature of 8 animals.

Lipid-Extracted Toxins from a Dinoflagellate, Gambierdiscus toxicus... 

Crude and three diethyl ether extracted, acetone treated, fractions were isolated from large-scale cultures of Gambierdiscus toxicus. Crude extracts at. 04 mg/ml inhibited the histamine contraction response in smooth muscle of the guinea pig ileum. Three semi-purified fractions at 5 ng/ml, effectively inhibited the guinea pig ileum preparation. Two of these fractions followed Michaelis-Menten kinetics for a competitive inhibition. The third fraction inhibited in a non-reversible manner. This study has established the presence of three lipid extracted toxins in toxicus, outlined a method for their assay in small quantities, and identified at least two of the effects of these toxic extracts in animals. 

A dinoflagellate, Gambierdiscus toxicus has been reported to be the likely progenitor of ciguatoxin in the South Pacific (13-15). Recently, Tindall, (26), Miller, ]]) and Carlson, (18) reported on toxic extracts from G. toxicus and two species of Prorocentrum from the Caribbean. iHe physiological action of toxic extracts from G, toxicus were found to be similar to those induced by toxic extract from Scomberomorus cavalla (Kingfish) from the same region (19). 

Figure 1. The effects of soil and macroalgal extracts on (a) highest cell concentration and (b) maximum growth rate of Gambierdiscus toxicus, grown in natural seawater (ESNW) medium (shaded bars) or in artificial seawater (ESAW) medium (open bars). Vertical brackets indicate standard errors. CNTL=controls (ES medium without, added extracts) SE soil extract DI=Dictyota extract CH=Chaetomorpha extract TU Turbinaria extract ...

Figure 2. Growth of Gambierdiscus toxicus in (a) ESNW and (b) ESAW both supplemented with soil and macroalgae extracts. Controls ( ), Chaetomorpha extract ( ), Dictyota extract (A), Turbinaria extract ( ), and soil extract (O).

Figure 1. Dose-response curve of the lethality of the three different extracts used in this study. The extracts were administered to mice i.p. in PBS with 57o Tween-80. Lethality was assessed at 48 h. for animals maintaine d at 24 C. Extracts were Gambierdiscus toxicus, fish of Caribbean origin, and partially purified moray eel ciguatoxin.

Dickey RW, Miller DM, Tindall DR (1984) Extraction of a water soluble toxin from a dinoflagellate Gambierdiscus toxicus. Am Chem Soc 23 258-272. 

Legrand AM, Bagnis R (1984) Effects of highly purified maitotoxin extracted from dinofiagellate Gambierdiscus toxicus on action potential of isolated rat heart. J Mol Cell Cardiol 16 663-666. 

Miller DM, Tindall DR (1985) Physiological effects of HPLC-purified, water-soluble toxic extract from the dinoflagellate Gambierdiscus toxicus. In Toxic Dinoflagellates. Anderson D White AW (eds). Elsevier Science, NY, pp 375-378. 

Miller DM, Dickey RW, Tindall DR (1984) Lipid extracted toxins from a dinoflagellate, Gambierdiscus toxicus. In Seafood Toxins, Ragelis EP (ed). ACS Symposium Sertues 262, pp 241-255. 

Rubio MG (1987) The role of macroalgal extracts in the growth of the marine, benthic dinoflagellate Gambierdiscus toxicus Adachi and Fukuyo. M.S. Thesis, Florida Institute of Technology, Melbourne, Florida. 

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