Histopathological assessment of UV-filters (TiO2-NPs and BP-3) in Scophthalmus maximus liver at environmentally-relevant concentrations

• Main Author: Monteiro, João Pedro Marcos
• Other Authors: Martins, Marta, Mieiro, Cláudia
• Format: Master Thesis
• Language: English
• Published: 2019
• Subjects: TiO2-NPs; BP-3; Histopathology; Inflammatory/immune response; Fat vacuolation of hepatocytes; Intraperitoneal injection; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia do Ambiente; Scophthalmus maximus; Turbot
• Online Access: http://hdl.handle.net/10362/93004

The worldwide usage of sunscreens, formulated with organic and inorganic compounds has been increasing year by year, that was also associated with the increase of coastal and maritime tourism and the awareness of the dangers arising from exposure to solar radiation. This increase of sunscreens usage by humans raise the concern about the potential increases of the concentrations of these compounds in aquatic systems. Several studies have revealed the toxicity in aquatic organisms associated with exposure of UV-filter compounds, such as titanium dioxide nanoparticles (TiO2-NPs) and benzophenone-3 (BP-3), however most of them do not consider environmentally-relevant concentrations of these compounds. In the present study, Scophthalmus maximus (turbot fish) were exposed through intraperitoneal injection to environmentally-relevant concentrations of both UV-filters, TiO2-NPs, BP-3 and their mixture. The toxicity assessment of these compounds was performed after 3 and 7 days using histopathological analyses of turbot liver and semi-quantitative histopathological indices. Overall, the histopathological observations of fish liver suggested a slight increase in the immune/inflammatory response after exposure to UV-filter compounds, as well as a slight intensification of the progressive alteration fat vacuolization of hepatocytes. Despite these observed alterations, no significant differences between treatments were observed and no link was found between alterations and exposure time. Through microscopic observations made using Nuclear Red (NR) staining, no nanoparticle clusters were found in the liver, suggesting that there was no accumulation of nanoparticles during the exposure time. Summing up, this work suggested that environmentally-relevant concentrations of this compounds leads to slight alterations in turbot hepatic tissue. Nevertheless, further research about the potential effects of UV-filters compound mixtures are still needed for better understanding of possible interaction effects.