Abstract :
Juvenile Dicentrarchus labrax L. (sea bass) was exposed to five different β-naphthoflavone (BNF) concentrations—0, 0.1, 0.3, 0.9 and 2.7 μM—for 0, 2, 4, 6, 8, 16, 24, 48, 72, 144, and 216 h. A battery of biomarkers was investigated, such as liver ethoxyresorufin-O-deethylase (EROD), liver cytochrome P450 (P450 content), liver aminotransferase (ALT activity), liver somatic index (LSI), micronuclei (MN), and erythrocytic nuclear abnormality (ENA) frequencies. Juveline D. labrax L. liver EROD induction started at 2 h exposure to 2.7 μM BNF and 6 h exposure to 0.1, 0.3, and 0.9 μM BNF, respectively. A significant liver EROD decrease was observed between 8 and 16 h for all BNF concentrations, followed by a slight increase after 48 h exposure to 0.9 and 2.7 μM BNF and a definitive decrease from 72 h exposure onward. Liver P450 content significantly increased at 2, 6, and 8 h exposure, respectively, to 2.7 μM, 0.9, 0.3, and 0.1 μM BNF. However, liver P450 content remained significantly higher than that of the control from 72 to 216 h in the sea bass exposed to 2.7 μM BNF. Sea bass ENA induction started at 4h exposure to 0.9 and 2.7 μM BNF, and significantly increased to 16 and 24 h exposure, whereas for 0.3 μM BNF a significant increase started after 8 h exposure. A significant ENA frequency increase was still observed at 144 and 216 h exposure to 0.9 and 2.7 μM BNF. The micronuclei induction was observed at 4, 6, and 8 h, respectively, after 2.7, 0.9, and 0.3 μM BNF exposure. However, there was a micronuclei frequency decrease for 0.3, 0.9, and 2.7 μM BNF exposure concentrations between 8 and 16 h, followed by a slight increase after 48, 72, and 144 h exposure, respectively, to 2.7, 0.9, and 0.3 μM BNF. Liver somatic index significantly increased after 216 h, whereas ALT activity significantly decreased at 144 and 216 h 2.7 μM BNF exposure.
