Harmful algal blooms produce marine biotoxins that can accumulate in fish and shellfish, thereby representing a threat for human consumers. The occurrence of algal blooms and associated biotoxins will likely increase due to global warming. At the European level, detection of marine neurotoxins in seafood is still based on ethically debated and expensive in vivo rodent bioassays.
A wide range of marine biotoxins is able to target the neuronal system. Consumption of seafood contaminated with such marine neurotoxins may result in mild symptoms such as dizziness, numbness and tingling of the mouth and digits, but also paralysis and in severe cases death. These symptoms are the result of biotoxin-induced perturbation of cellular homeostasis, alterations in ion channel and neurotransmitter receptor function, and subsequent changes in neuronal activity.
Jonathan Nicolas, Wageningen University, The Netherlands, and colleagues have investigated whether and to what extent a multielectrode array (MEA) approach can be used as a highly sensitive and high-throughput in vitro alternative for screening of marine neurotoxins in seafood. The MEA approach utilizes rat cortical neurons comprising a wide range of ion channels/pumps and neurotransmitter receptors targeted by marine neurotoxins.
The effects on neuronal activity of rat cortical neurons was tested for neurotoxic model compounds (amiodarone, clofilium, digoxin, diphenhydramine (DPH), isradipine, ouabain, sematilide, verapamil, and veratridine), pure marine neurotoxins (brevetoxin-3 (PbTx-3), domoic acid (DA), pacific ciguatoxin-1 (PCTX-1), palytoxin (PlTx), saxitoxin (STX) and tetrodotoxin (TTX)), and extracts from contaminated seafood (one from mussels contaminated with STX and one from fish contaminated with TTX). The MEA approach has a sensitivity of 88 % and a good reproducibility compared to existing in vitro alternatives.
- Detection of marine neurotoxins in food safety testing using a multielectrode array,
Jonathan Nicolas, Peter J.M. Hendriksen, Regina G.D.M. van Kleef, Aart de Groot, Toine F.H. Bovee, Ivonne M.C.M. Rietjens, Remco H.S. Westerink,
Mol. Nutr. Food Res. 2014.