Abstracts / Toxicology Letters 196S (2010) S37–S351 S345

P310-002Cell cycle alterations and apoptosis assessment in SHSY5Yhuman neuroblastoma cells exposed to okadaic acid

V. Valdiglesias, J. García-Lestón, E. Pásaro, J. Méndez, B. Laffon

University of A Coruna, Spain

Okadaic acid (OA) and its derivates, the dinophysistoxins, arebiotoxins generated mainly from dinoflagellates of Dinophysis andProrocentrum genus. The ingestion of contaminated shellfish withthese toxins induces acute and strong gastrointestinal symptomsknown as Diarrhoeic Shellfish Poisoning (DSP). DSP toxins are themost abundant and frequent in European coasts and OA is the mainrepresentative of them.

At the molecular level, OA is a specific inhibitor of ser-ine/threonine protein phosphatases 1 (PP1) and 2A (PP2A). Thisinhibition can result in the hyperphosphorylation of many pro-teins in the cell and loss of regulation of cellular processes. Ithas long been recognized that OA can induce apoptosis or growthinhibition in several cell models, but the molecular mechanismsand the components involved in these processes have not beenclarified yet. Furthermore, there are conflicting reports on theeffect of OA on both cell proliferation and apoptosis in many celltypes.

Despite neurological symptoms of OA have not been reportedand it is not considered to be neurotoxic, previous studies reporteda possible neuronal apoptosis-inductor role of OA. In the presentstudy, the effects of OA on the cell cycle and apoptosis in thehuman neuroblastoma SHSY5Y cell line have been examined. Neu-ronal cells were treated with different OA concentrations, from 5 to1000 nM, in presence and absence of S9 fraction with the purposeof determining if this compound acts directly or it needs metabolicactivation. After treatments, the OA-induced alterations of cell cycleand the rate of apoptosis/necrosis were evaluated by means of flowcytometry methodologies.

Research supported by Xunta de Galicia(INCITE08PXIB106155PR).

doi:10.1016/j.toxlet.2010.03.1090

P310-003Aflatoxin M1 levels in breast milk samples from Ankara, Turkey

A. Gürbay 1, S. Atasayar Sabuncuoglu 1, G. Girgin 1, G. Sahin 1, S.Yigit 2, M. Yurdakök 2, G. Tekinalp 2

1 Hacettepe University, Faculty of Pharmacy, Department ofPharmaceutical Toxicology, Turkey, 2 Hacettepe University, Faculty ofMedicine, Department of Pediatrics, Section of Neonatology, Turkey

The quality of nutrition is very important in the first two years oflife. For that reason, feeding of infants with safe milk is essen-tial for childhood and later periods of human life. However, intoday’s world, contamination of foods as well as breast milk withvarious pollutants including aflatoxins (AFs) is considered as anunavoidable problem. Therefore, the objective of this study was todetermine the levels of AF M1 in breast milk samples collected from75 mothers in Ankara, Turkey. AF M1 levels of the samples weredetermined by high performance liquid chromatography (HPLC)with a fluorescence detector following an extraction procedure.The limit of detection was found to be 5 ng/l. Breast milk AF M1levels were found in the ranges of 60.90–299.99 ng/l. The resultsof the present study suggest the importance of AF research in bio-logical fluids and foods. Since restriction of breast feeding is not an

acceptable advice for mothers, protective diet oriented governmen-tal strategies should be taken into consideration. Besides, educationof people regarding the hazards of mycotoxins is needed in Turkeyas all over the world.

Acknowledgment: This study was supported by Hacettepe Uni-versity Research Foundation (0401301003).

doi:10.1016/j.toxlet.2010.03.1091

P310-004Basal cytotoxicity of pure cylindrospermopsin in the humancell lines Caco-2 and HUVEC

S. Pichardo, D. Gutiérrez-Praena, A. Jos, A.M. Camean

Universidad de Sevilla, Spain

Cyanobacterial toxins have become recognized as a hazard forthe human health. The cyanotoxin cylindrospermopsin (CYN) isa potent toxic alkaloid first isolated from Cylindrospermopsis raci-borskii, although it can be produced by other cyanobacterial species.The presence of CYN has been reported in different water bodiesand therefore there is a human potential exposure.

CYN is a potent inhibitor of protein synthesis and glutathionesynthesis. However, other effects such as genotoxicity have beendescribed. In order to exhibit these effects, various in vitro modelshave been used which were representative of the organs targetedby the toxin. CYN toxicity on gastrointestinal tract (Caco-2 cells) hasbeen scarcely investigated and studies dealing to other locationslike vessel endothelium (HUVEC cells) are still missing.

In this sense, in the present study Caco-2 and HUVEC cell lineswere used to compare the effect of CYN between both cellular types,by exploring the basal cytotoxicity involved in CYN pathogenicity.Cells were exposed to concentrations between 0 and 40 g/mL pureCYN for 24 h and 48 h. The basal cytotoxicity biomarkers studiedwere protein content (PT), neutral red (NR) and tetrazolium saltreduction (MTS).

NR assay results showed that there is a decrease in atime–concentration-dependent manner in the cellular viability. Inthe same way, MTS assay revealed that there is a reduction in themitochondrial activity when concentration and time increase. PTalso indicated a decrease in similar conditions. Therefore, it hasbeen demonstrated that CYN are able to induce toxic effects in theCaco-2 and HUVEC cell lines in a time–concentration dependentmanner, being HUVEC the most sensitive.

Acknowledgements: The authors wish to thank the MICINN(AGL2009-10026) for the financial support for this study and theCell Culture Service of CITIUS for providing technical assistance.

doi:10.1016/j.toxlet.2010.03.1092

P310-005Oxidative stress induction on Caco-2 and HUVEC cell lines bypure cylindrospermopsin

D. Gutierrez-Praena, S. Pichardo, A. Jos, A.M. Camean

University of Seville, Spain

Cylindrospermopsin (CYN) is a toxin produced by several cyanobac-terial species. There is an increasing environmental interest as itfrequently occurs in drinking water reservoirs. The massive pro-liferation of these organisms is largely due to eutrophication in awide range of ecological habitats. Moreover, this toxin can producetoxic effects in humans.