Characterization of the cellular damage induced by Aflatoxin B1 in sea bream (Sparus aurata Linnaeus, 1758) hepatocytes

Gilthead sea bream (Sparus aurata L.) is one of the most intensively farmed fish species in the Mediterranean, greatly studied for the relevant economic value, although its sensitivity to Aflatoxin B(1) (AFB(1)) has to be investigated, yet. The aim of this study was to perform an in vitro evaluation of cytotoxic potential of AFB(1) on S. aurata hepatocytes in order to grade the range of AFB(1) toxicity, and the boundary between acute and long-term toxicity. Primary monolayer cultures of hepatocytes from S. aurata juveniles were treated with a wide range of concentrations from 5x10(3) ng/ml to 2x10(-5) ng/ml of AFB(1) for a different period of exposure (24, 48, 72 hours). The cytotoxic activity was characterized by MTT reduction assay. After each exposition hepatocytes were examined for morphologic alterations and apoptosis induction. AFB(1) exposure significantly reduced cell viability in a dose- and time-dependent manner. Dose-response curves obtained after 24, 48 and 72 hrs revealed that prolonged exposure times lead to a significant increase of the toxic potency of AFB(1). Our results demonstrate that S. aurata hepatocytes are highly sensitive to AFB(1) exposure. Such scientific findings could provide new insights to investigate the real impact of aflatoxin on marine farmed fish.