092 | Cellular and physiological responses of Mytilus galloprovincialis to the biocide octylisothiazolinone

Emanuela Castronovo¹, Cristiana Roberta Multisanti², Benedetta Napoli¹, Annalisa Cotugno³, Paolo Pastorino³, Caterina Faggio^1|4 | ¹Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina; ²Department of Veterinary Sciences, University of Messina; ³Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, Torino, Italy; ⁴Department of Eco-sustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Napoli, Italy.

Biocides belonging to the isothiazolinone class are antibacterial substances widely used as preservatives or disinfectants in numerous commercial products. Among these compounds, 2-n-octyl-4-isothiazolin-3-one (OIT) is increasingly identified as an emerging contaminant in aquatic environments [1]. The present study analysed the cellular and physiological effects of OIT, using the Mediterranean mussel, Mytilus galloprovincialis, as a model organism. Specimens were exposed to two sublethal concentrations of OIT (0.01 and 0.1 mg L⁻¹) for 14 days. Biological responses were evaluated at the cellular function level by analysing haemolymph cells (haemocytes) and digestive gland (DG) isolated cells samples. Specifically, the cytotoxic effect of OIT was determined by cell viability assays, i.e. the Neutral red (NR) retention assay and the Trypan blue (TB) exclusion test. In addition, the phagocytic capacity of haemocytes was examined using the yeast Saccharomyces cerevisiae (1×10⁷ cells/mL). Also, the osmoregulatory function of DG cells was assessed using the Regulated Volume Decrease (RVD) test. The results showed that exposure to OIT induced significant citotoxic effects in M. galloprovincialis, such as reduced cell viability, phagocytic, and osmoregulatory performances. These findings represent a starting point for future research. Also, contribute to undercover the indirect potential effects on human health, develop targeted interventions and sustainable management practices.
This work has been funded by the European Union – NextGenerationEU, as part of the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.1 (PRIN) under Grant Assigment Decree n. 1375 adopted on 01-09-2023 by the Italian Ministry of University and Research (MUR) – Project PRIN 2022 PNRR Title: Investigations of emerging pollutant:ecological and human health impacts of isothiazolinone biocides – Project ministerial code: P2022BH28Y 03 – CUP: C53D23009240001 – Beneficiary: University of Teramo (UniTE).