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J. Venom. Anim. Toxins incl. Trop. Dis. Vol.9, No.2, p.575, 2003. Poster - ISSN 1678-9199. |
NAVES, J.L., FREITAS, J.C.
Biosciences Institute and CEBIMar, University of São Paulo, Brazil
Filter feeding animals, as clams and fishes, can accumulate dinoflagellates toxins and when eaten by men, cause paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning(DSP) intoxications. Among the species that occurs in the coast of São Paulo States, Prorocentrum gracile was isolated from phytoplankton samples and Prorocentrum sp is a benthic species epiphytic on the seaweed Galaxaura marginata. They were being isolated and cultivated to identify eventual toxins. These organisms were kept in constant temperature chamber at 12/12h photoperiod and maintained in multiplate wells with F/2 culture broth at 21oC. At the exponential phase of growth, the cells were transferred to bigger wells. The polar (EPs) (methanol) and apolar (EAs) (methylene chloride) extracts of the cultivated species are being tested, after solvent removal, for cytotoxicity in the embryo development of sea urchin eggs and in mouse erythrocytes. The EAs were tested in the hemolytic assay and the hemolysis was analyzed by the erythrocytes suspension transparence. P. gracile EP exhibited no antimitotic activity while Prorocentrum sp EP and EA induced cells anomalies and cell division inhibition at CE50 78.75 ug/mL (IC 32.56–190.5) and CE50 22.5 ug/mL (IC 2.96-170.8) respectively (n=3). EAs induced hemolysis in the following concentrations: P. gracile - CE50 218,5 ug/mL (IC 115.8-412.4), Prorocentrum sp - CE50 28.25 ug/mL (IC 11.48-69.50). The Prorocentrum sp EP also induced hemolysis (CE50 200.2 ug/mL, IC 97.89 – 409.2ug/mL). These results suggest the presence of cytotoxins in these dinoflagellates species.
Financial support: FAPESP.
CORRESPONDENCE TO:
Jeanete Lopes Naves, Rua Carlos Salles Block 835, Jundiai, SP, CEP: 13208100, Brasil, Email: jeanete@uol.com.br