Polybrominated diphenyl ethers are flames retardants used into several products, showing increasing levels of accumulation into the environment and to different organisms. Their presence is associated with changes on cell homeostasis (neurotoxicity, endocrine disruptors, cancer) and toxic effects on several cell lines, such as apoptosis and DNA damage. However, the effects and mechanisms of PBDEs still under investigation because this class of contaminants has several differences in their chemical structure and can also be accumulated in different target organs (brain, liver, glands). This study will investigate the mechanisms of apoptosis induction of the PBDEs congeners (BDE-209, BDE-99, BDE-47) by assessing caspases signaling and citocrome c and Bax proteins by western blotting, and also evaluate the cytotoxic effects of BDE-154 congener by proliferation and cell viability assays, accumulation of reactive oxygen species-ROS analysis, mitochondrial membrane potential, exposure of phosphatidylserine, nuclear fragmentation and caspases signaling to compare these effects with the others congeners, in order to indentify the effect of the structure of the PBDEs with the final effect. For this purpose will be used as an experimental model the hepatoblastoma cells line (HepG2), since liver is a target orgen of PBDEs accumulation. Thus, HepG2 cells are an adequated experimental model to evaluate the risks of PBDEs on the health. In addition, the exposure effects to PBDEs will also be evaluated by testing their genotoxic (Comet assay) and mutagenic (Ames test) effects, because there are evidences in the literature showing that PBDEs can cause DNA damage. Ames and Comet assays are useful to identify compounds with differents genotoxic and mutagenic potentials due to their advantages as simplicity, fast performance and high sensitivity to various types of DNA damage. Finally, to assess the contamination level of the environment, PBDEs will be quantificated by gas chromatography coupled with mass spectrometry in sediments from the recharge region of Guaraní aquifer in the Ribeirao Preto (Brazil) city to assess the risks of contamination of the local population.
News published in Agência FAPESP Newsletter about the scholarship: