ESTUDO DA ATIVIDADE CITOTÓXICA DA SALIVA BRUTA DO CARRAPATO AMBLYOMMA DUBITATUM

INTRODUCTION: Neuroblastoma is an extracranial tumor that develops from the embryonic adrenal sympathetic lineage originating from the neural crest. It is the first cause of death in pediatric cancer in children aged between one and five years, accounting for 13% of deaths in this population. Toxins of animal origin are bioactive substances that have shown significant potential as antitumor agents, justifying their study as potential alternative agents in less invasive and more efficient neoplastic treatments AIMS: To study the in vitro effects of components from the ticks Ornithodoros brasiliensis salivary gland extract and its cytotoxic
potential on the SHSY5Y neuroblastoma cells line. MATERIALS AND METHODS: The salivary gland extract was produced by collaborators from the Institute Butantan, São Paulo. Neuroblastoma cells were treated with the extract for 48 48-hour incubation period, and their viability was investigated by methylene blue and LDH assays. Cells were labeled with annexin V and 7AAD to detect apoptosis and analyzed by flow cytometry. Data were statistically analyzed using the software GraphPad Prism version 9.3. RESULTS: In the methylene blue assay, cell viability dropped by 50%, starting from a concentration of 3.12 µg/ml and at the highest 100 µg/ml concentration. In the LDH assays, significant release was observed statistically only at the highest concentration (100 µg/ml). The apoptosis rate was also considered statistically different from the untreated control (p<0,33). FINAL CONSIDERATIONS: Results indicate a decrease in cell viability. Considering that the apoptosis level was relatively low, it is possible the extract influences cell cycle and proliferation delay. The extract is suggested to induce apoptosis because the viability dropped significantly, but it was observed that not all events were caused by this type of programmed cell death. Further characterization must be applied for the assessment of the mechanisms involved.

KEYWORDS: Neuroblastoma; Salivary gland; Viability; Treatment; Tick.