Monitoração toxinológica do pescado comercializado nos municípios de São Sebastião e Caraguatatuba, SP / Toxinological monitoring of fisheries comercialized in São Sebastião and Caraguatatuba cities, São Paulo state

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The Paralytic Shellfish Poisoning (PSP) toxins are well-known natural bioactive compounds due to their accidental consumption in contaminated seafood. These molecules, of which the most potent representative is saxitoxin (STX), are a class of neurotoxic alkaloids, having different isoforms and varied toxicities, that are produced by some cyanobacteria and some species of dinoflagellates from the genus Alexandrium, Gymnodinium and Pyrodinium. PSP toxins are water-soluble neurotoxins that act on nerve and muscle cells by blocking sodium channels voltage-dependent, thus preventing the conductance of neuron signal leading to muscular paralysis. In severe cases, death may result due to respiratory failure. Diarrhetic Shellfish Poisoning (DSP) is a gastrointestinal illness with symptoms such as diarrhea, nausea, vomiting, headache, chills and moderate to severe abdominal pain. DSP is usually a consequence of consuming contaminated shellfish that have ingested dinoflagellates of the genera Dinophysis and Prorocentrun through their filter feeding activities. Contamination of seafood by PSP and DSP toxins has posed serious problems to the fisheries industry as well to public health. In this study, was stabilized a monitoring program to shellfish (Perna perna) and finfish (Sardinella brasiliensis, Anchoviella lepidentostole and Brevoortia aurea) collected in fish markets in Caraguatatuba and São Sebastião cities, São Paulo state. The extracts for PSP were prepared by two ways: according to AOAC (Association of Official Analytical Chemists), through the heating for 5 min of blend of 100 g of well mixed sample with 0.1 N HCl; or through of the concentration of ethanolic extracts from finfish’s muscle + skin. The PSP mouse bioassay for PSP toxins involves intraperitonial injection (i.p.) of 1 mL of the acid extract into each of three mice (~ 20 g). The mice were observed for classical PSP symptoms and the time to mouse death was recorded and the toxicity was determinate (in mouse units, MU) from the Sommer’s table. To DSP toxins, the extracts was prepared trough the extraction of digestive glands with acetone, and i.p injection in mice was used to determine the presence of theses toxins. In the mouse bioassay for the extracts prepared by AOAC method no positive results was obtained. For the mouse bioassay with ehtanolic extracts was obtained positive results to 77.8 % of the tested extracts. The media of MU of all samples, in this case, was 0,147 MU/g. To the mouse bioassay for the DSP toxins, three samples gives evidence of presence of the diarrhetic toxins, because the mice showed signal like diarrhea. The ethanolic extracts, that was positive to the PSP toxins, was fractionated by a Sep-Pak C18 cartridge. The first elution, with 0.1 M acetic acid, was analyzed by using prechromatographic oxidation and liquid chromatography with fluorescence detection. The HPLC analysis indicated the presence of the PSP toxins, confirming the bioassays. Therefore, in the first time in Brazil was demonstrated that the species S. brasiliensis, A. lepidentostole and B. aurea are carriers of toxins like PSP in little concentrations and that a monitoring program is necessary in our country to verify the presence of these toxins in organisms that are used as food by the population.

ASSUNTO(S)

hplc analysis toxinological monitoring análises em clae pescado diarrhetic shellfisch toxins mouse toxicity monitoração toxinológica toxinas diarréicas fisheries toxinas paralisantes paralytic shellfish toxins

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