4
Miscellaneous Seafood Toxicants
BRUCE W. HALSTEAD
Downloaded by CORNELL UNIV on October 5, 2016 | http://pubs.acs.org Publication Date: September 19, 1984 | doi: 10.1021/bk-1984-0262.ch004
World Life Research Institute, Colton, CA 92324 The expansion of marine fisheries into tropical waters has increased the risks of widespread human intoxications in temperate latitudes. This situation has been facilitated by increased travel, rapid transport of food stuffs, and improved refrigeration f a c i l i t i e s . This presentation directs attention to a broad spectrum of toxic protozoans, coelenterates, echinoderms, molluscs, arthropods, fishes, and mammals that may serve as transvectors of these poisons. The need for additional epidemiological, toxicological, and chemical research is noted. The expansion of marine f i s h e r i e s into t r o p i c a l waters, improved rapid transport of f i s h e r i e s products, and increased t r a v e l to remote areas of the world have introduced new and little-known intoxicants into temperate zone populations. With the expansion and i n t e n s i f i cation of things t o x i c o l o g i c a l , the subject of p a r a l y t i c s h e l l f i s h poisoning, ciguatera f i s h poisoning, and puffer poisoning have gradually made their debut into the consciousness of t o x i c o l o g i s t s and some c l i n i c i a n s . In reviewing the broad spectrum of marine biotoxicology i t becomes obvious that these three biotoxic categories represent only a small facet of the enormous array of toxic molecular structures that inhabit the marine environment. The purpose of t h i s presentation i s to d i r e c t attention to some of the other areas of t o x i c o l o g i c a l interest involving man's food resources and the enormous phylogenic range of marine bio toxins. Marine Invertebrate
Intoxications
Protozoans (Protistans). The r e l a t i o n s h i p of d i n o f l a g e l l a t e s to p a r a l y t i c s h e l l f i s h poisoning and the r o l e of Gambierdiscus toxicus in ciguatera f i s h poisoning are well documented. However, recent studies have shown the toxic d i n o f l a g e l l a t e s are also involved i n other forms of human biotoxic at ions as a r e s u l t of ingesting molluscs which serve as t h e i r transvectors. The d i n o f l a g e l l a t e species involved i n these intoxications include Prorocentrum r e d f i e l d i i , 0097-6156/84/0262-0037$06.00/0 © 1984 American Chemical Society
Ragelis; Seafood Toxins ACS Symposium Series; American Chemical Society: Washington, DC, 1984.
38
SEAFOOD TOXINS
Downloaded by CORNELL UNIV on October 5, 2016 | http://pubs.acs.org Publication Date: September 19, 1984 | doi: 10.1021/bk-1984-0262.ch004
_P. micans, and Dinophysis acuminata i n the Netherlands (1). Dinophysis f o r t i i has been incriminated i n Japan (2), and an unknown toxic species of the same genus has caused intoxications along the coast of Chile (3). The c l i n i c a l symptomatology i s of the g a s t r o i n t e s t i n a l type, consisting of nausea, vomiting, and diarrhea. No neurological disturbances have been reported. It i s f e l t that the problem of d i a r r h e t i c s h e l l f i s h poisoning i s probably more widespread than i s generally recognized and deserves greater i n v e s t i gational interest. The toxin involved has been designated by Yasumoto et a l (2) as dinophysitoxin. The chemical and pharmacologic a l c h a r a c t e r i s t i c s of the poison have not been f u l l y determined. Cnidarians (Coelenterates). J e l l y f i s h e s are commonly eaten i n Japan and elsewhere i n the Orient without any known cases of poisoning. The nematocysts of j e l l y f i s h e s and other coelenterate species contain proteinaceous toxins which are inactivated by heating and g a s t r i c juices and therefore are not responsible for dietary intoxications. However, biotoxications have resulted i n the Philippines, New Guinea, and Samoa from the ingestion of sea anemones which have been eaten raw. Rhodactis howesii, commonly known as metalelei, and Physobranchia douglasi, known as humane i n Samoa, are poisonous when eaten raw, but safe to eat when cooked. Radianthus paumotensis, l o c a l l y known as matamalu s am asama i n Samoa, and another unknown species of Radianthus, are considered to be poisonous when eaten either raw or cooked. The symptomatology consists of nausea, vomiting and abdomi n a l pain, p a l l o r , and prostration. The victim may lose consciousness (8-36 hours) and then dies i n an apparent state of shock. There i s believed to be a central nervous system involvement. Studies by Martin (4, 5) report that the sea anemone possesses a nondialyzable and heat l a b i l e toxin containing a polysaccharide moiety and e x h i b i ting UV absorption at 278 nm. Since the poison was inactivated by t r y p t i c digestion, i t s a c t i v i t y was believed to be due to a protein or polypeptide moiety. No curarelike action was found on rabbit phrenic nerve-muscle preparation. The toxin has an LDg^ (2-4 hours) of 3 mg/kg (IP i n mice). Martin claims that "R. howesii contains a p a r a l y t i c poison which d i f f e r s from other known poisons of this category." Echinoderms. Sea cucumbers are commonly eaten throughout the Orient and i n some of the P a c i f i c Islands where they are sold under the vernacular names of trepang (Malaysia), sea slugs, sea cucumbers (English), erico (Japan), and h a i shen (China). G a s t r o i n t e s t i n a l disturbances may result from the ingestion of these echinoderms. It i s believed that these intoxications are caused by saponins, which are well-known toxic components of echinoderms. Saponins are complex compounds, a group of glycosides composed of sugars, steroid or t r i terpenoid moieties. They are widely distributed i n plants, but are r e l a t i v e l y uncommon i n animals. The saponins derived from sea cucumbers are of the triterpenoid type. Several saponins have been i s o lated from various species of holothurians. Chanley et a l (6, 7) isolated a c r y s t a l l i n e saponin which was termed holothurin A, having an empirical formula of C50-52 81-85°25-26S > * absorption at 1748 and 1629 cm" , but no absorption i n the UV region. Yasumoto et a l (8) isolated a saponin which they designated as holothurin _B, H
Na
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