An Integrated in Vitro Approach for Human Health and Environmental Risk Assessment of Mediterranean Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis Strains

Introduction: Harmful algal blooms are becoming a serious issue in the Mediterranean Sea (MS); dinoflagellate blooms are among the most worrying, as some representatives of this group are capable of producing potent marine toxins. Among these, the Ostreopsis genus are well known for the production of palytoxin-like compounds. Blooms of Ostreopsis cf. ovata have caused health issues, and damages to the economy and the environment. Ostreopsis cf. ovata often co-occurs with other benthic dinoflagellates such as Prorocentrum lima and Coolia monotis, in bloom events in the MS. Algae from the genus Prorocentrum are able to produce diverse toxins responsible for severe diarrhetic shellfish poisoning, while C. monotis is not included in the UNESCO-Intergovernmental Oceanographic Commission toxic species list. Materials and Methods: In this study, an integration of in vitro techniques has been applied for the first time to investigate the potential toxicity of the natural mixture of toxins produced by each of three dinoflagellates mentioned above. The proposed approach allowed to evaluate (1) skin and eye irritation potential on human threedimensional reconstructed tissues; (2) alteration of neuronal activity by means of microelectrode array (MEA) electrophysiology on mouse neuronal networks; and (3) environmental toxicity by lethal toxicity test on Artemia franciscana. Results: Results revealed no significant effect on human skin and eye irritation tests for all the tested species. Interestingly, MEA analyses on mean firing rate and mean bursting rate revealed strong inhibition of functional activity by Ostreopsis cf. ovata and P. lima. The same species showed an important ecotoxicological effect after 48 hours of exposure to A. franciscana. Conclusion: Our approach was found to be suitable for the assessment of the whole algal toxicity potential, also accounting for the potential synergic effects of the mixture of toxins produced by each species.