Toxicity screening of 13 Gambierdiscus strains using neuro-2a and erythrocyte lysis bioassays
|Author(s)||Pisapia Francesco1, Holland William C.2, Hardison D. Ransom2, Litaker R. Wayne2, Fraga Santiago3, Nishimura Tomohiro4, Adachi Masao4, Lam Nguyen-Ngoc 5, Sechet Veronique1, Amzil Zouher1, Herrenknecht Christine6, Hess Philipp1|
|Affiliation(s)||1 : IFREMER, Phycotoxins Lab, Rue Ile Yeu,BP 21105, F-44311 Nantes, France.
2 : NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, CCFHR, 101 Pivers Isl Rd, Beaufort, NC 28516 USA.
3 : Ctr Oceanog Vigo, IEO, Subida Radio Faro 50, Vigo 36390, Spain.
4 : Kochi Univ, Fac Agr, LAQUES Lab Aquat Environm Sci, 200 Otsu, Nankoku, Kochi 7838502, Japan.
5 : VAST, Inst Oceanog, Cauda 01, Vinh Nguyen, Nha Trang, Vietnam.
6 : Univ Nantes, MMS EA2160, Fac Pharm, LUNAM, 9 Rue Bias, F-44035 Nantes, France.
|Source||Harmful Algae (1568-9883) (Elsevier Science Bv), 2017-03 , Vol. 63 , P. 173-183|
|WOS© Times Cited||75|
|Keyword(s)||Ciguatera fish poisoning, Gambierdiscus, Ciguatoxins, Maitotoxins, Neuro-2a assay, Erythrocyte lysis assay|
|Abstract||Species in the epi-benthic dinoflagellate genus Gambierdiscus produce ciguatoxins (CTXs) and maitotoxins (MTXs), which are among the most potent marine toxins known. Consumption of fish contaminated with sufficient quantities of CTXs causes Ciguatera Fish Poisoning (CFP), the largest cause of non-bacterial food poisoning worldwide. Maitotoxins, which can be found in the digestive system of fish, could also contribute to CFP if such tissues are consumed. Recently, an increasing number of Gambierdiscus species have been identified; yet, little is known about the variation in toxicity among Gambierdiscus strains or species.This study is the first assessment of relative CTX- and MTX-toxicity of Gambierdiscus species from areas as widespread as the North-Eastern Atlantic Ocean, Pacific Ocean and the Mediterranean Sea. A total of 13 strains were screened: (i) seven Pacific strains of G. australes, G. balechii, G. caribaeus, G. carpenteri, G. pacificus, G. scabrosus and one strain of an undetermined species (Gambierdiscus sp. Viet Nam), (ii) five strains from the North-Eastern Atlantic Ocean (two G. australes, a single G. excentricus and two G. silvae strains), and (iii) one G. carolinianus strain from the Mediterranean Sea. Cell pellets of Gambierdiscus were extracted with methanol and the crude extracts partitioned into a CTX-containing dichloromethane fraction and a MTX-containing aqueous methanol fraction. CTX-toxicity was estimated using the neuro-2a cytoxicity assay, and MTX-toxicity via a human erythrocyte lysis assay.Different species were grouped into different ratios of CTX- and MTX-toxicity, however, the ratio was not related to the geographical origin of species (Atlantic, Mediterranean, Pacific). All strains showed MTX-toxicity, ranging from 1.5 to 86 pg MTX equivalents (eq) cell−1. All but one of the strains showed relatively low CTX-toxicity ranging from 0.6 to 50 fg CTX3C eq cell−1. The exception was the highly toxic G. excentricus strain from the Canary Islands, which produced 1426 fg CTX3C eq cell−1. As was true for CTX, the highest MTX-toxicity was also found in G. excentricus. Thus, the present study confirmed that at least one species from the Atlantic Ocean demonstrates similar toxicity as the most toxic strains from the Pacific, even if the metabolites in fish have so far been shown to be more toxic in the Pacific Ocean.|