Are the BPA analogues an alternative to classical BPA? Comparison between 2D and alternative 3D in vitro neuron model to assess cytotoxic and genotoxic effects.

BPA is used in a wide range of consumer products with very concern toxicological properties. The European Union has restricted its use to protect human health. Industry has substituted BPA by BPA analogues. However, there is a lack of knowledge about their impacts. In this work, BPA and 5 BPA analogues (BPS, BPAP, BPAF, BPFL and BPC) have been studied in classical SH-SY5Y and the alternative 3D in vitro models after 24 and 96h of exposure. Cell viability, percentage of ROS, cell cycle phases as well as the morphology of the spheroids were measured. The 2D model was more sensitive than the 3D models with differences in cell viability higher than 60% after 24h of exposure, and different mechanisms of ROS production. After chronic exposure, both models were more affected in comparison to the 24h exposure. After a recovery time (96h), the spheroids exposed to 2.5-40µM were able to recover cell viability and the morphology. Among the BPs tested, BPFL>BPAF>BPAP and >BPC revealed higher toxicological effects, while BPS was the only one with lower effects than BPA. To conclude, the SH-SY5Y 3D model is a suitable candidate to perform more reliable in vitro neurotoxicity tests.