Abstract
Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs). The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required. These are expressed as “Toxicity Equivalence Factors” (TEFs). At present, TEFs are largely based on relative specific activities following intraperitoneal injection in a mouse bioassay rather than on acute toxicity determinations. A more relevant parameter for comparison would be median lethal doses via oral administration, since this is the route through which humans are exposed to PSTs. In the present study, the median lethal doses of gonyautoxin 5, gonyautoxin 6, decarbamoyl neosaxitoxin and of equilibrium mixtures of decarbamoyl gonyautoxins 2&3, C1&2 and C3&4 by oral administration to mice have been determined and compared with toxicities via intraperitoneal injection. The results indicate that the TEFs of several of these substances require revision in order to more accurately reflect the risk these toxins present to human health.
Highlights
Paralytic shellfish poisoning (PSP) is a serious and sometimes fatal outcome of the consumption of seafood contaminated with saxitoxin and its congeners, which are produced by marine dinoflagellates of the genera Alexandrium, Gymnodinium and Pyrodinium and by several genera of freshwater cyanobacteria [1,2]
Evaluation of the safety of seafood for human consumption has been based on a mouse bioassay (MBA), which involves intraperitoneal injection of an extract of the seafood in Toxins 2017, 9, 73; doi:10.3390/toxins9020073
As a continuation of these studies, we report the acute toxicities of gonyautoxin 5 (GTX5), gonyautoxin 6 (GTX6), decarbamoyl gonyautoxin 2&3, decarbamoyl neosaxitoxin, N-sulfocarbamoyl gonyautoxin 2&3 (C1&2) and
Summary
Paralytic shellfish poisoning (PSP) is a serious and sometimes fatal outcome of the consumption of seafood contaminated with saxitoxin and its congeners, which are produced by marine dinoflagellates of the genera Alexandrium, Gymnodinium and Pyrodinium and by several genera of freshwater cyanobacteria [1,2]. Toxins 2017, 9, 73 mice, with death as the endpoint This assay has been approved as a reference method for paralytic shellfish toxins by the Association of Official Analytical Chemists [4]. Such an assay is, deemed by many to be ethically unacceptable and, further, its validity is questionable since it involves intraperitoneal injection rather than the oral route through which humans are exposed to the PSP toxins. The use of the MBA is being phased out in several countries, and alternative chemical and functional assays for the paralytic shellfish toxins have been subjected to interlaboratory validations and approved by AOAC following review These include two HPLC fluorescence methods [5,6], one using pre-column oxidation (AOAC 2005.06) and the other using post-column oxidation
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have