Contribution of Mass Spectrometry to the Advances in Risk Characterization of Marine Biotoxins: Towards the Characterization of Metabolites Implied in Human Intoxications

A significant spread and prevalence of algal toxins and, in particular, marine biotoxins have been observed worldwide over the last decades. Marine biotoxins are natural contaminants produced during harmful algal blooms being accumulated in seafood, thus representing a threat to human health. Significant progress has been made in the last few years in the development of analytical methods able to evaluate and characterize the different toxic analogs involved in the contamination, Liquid Chromatography coupled to different detection modes, including Mass Spectrometry, the method of choice due to its potential for separation, identification, quantitation and even confirmation of the different above-mentioned analogs. Despite this, the risk characterization in humans is still limited, due to several reasons, including the lack of reference materials or even the limited access to biological samples from humans intoxicated during these toxic events and episodes, which hampered the advances in the evaluation of the metabolites responsible for the toxicity in humans. Mass Spectrometry has been proven to be a very powerful tool for confirmation, and in fact, it is playing an important role in the characterization of the new biotoxins analogs. The toxin metabolization in humans is still uncertain in most cases and needs further research in which the implementation of Mass Spectrometric methods is critical. This review is focused on compiling the most relevant information available regarding the metabolization of several marine biotoxins groups, which were identified using Mass Spectrometry after the in vitro exposition of these toxins to liver microsomes and hepatocytes. Information about the presence of metabolites in human samples, such as human urine after intoxication, which could also be used as potential biomarkers for diagnostic purposes, is also presented.