Reactive oxygen species involvement in apoptosis and mitochondrial damage in Caco-2 cells induced by enniatins A, A1, B and B1

Abstract The cytotoxic effects, the generation of reactive oxygen species (ROS) and lipid peroxidation (LPO) as well as the cell cycle disruption, the induction of apoptosis and changes in mitochondrial membrane potential (ΔΨ m ) as a function of increasing time have been determined in human colorectal adenocarcinoma (Caco-2) cells after exposure to enniatins (ENs) A, A 1 , B and B 1 . IC 50 values obtained by the MTT and Neutral Red assay, after 24, 48 and 72 h of exposure ranged from 0.5 ± 0.1 to >15 μM. A significant increase ( p  ≤ 0.05) in ROS generation and LPO production, as determined by the fluorescent probe H 2 -DCFDA and TBARS method respectively, was observed for all mycotoxins tested at 3.0 μM concentration. The highest increase in ROS generation (2.6 fold higher than control) and LPO production (111%, as compared to control) was observed with EN A. Cell cycle was significantly arrested at G2/M phase after 24 h of exposure to EN A, A 1 , B 1 , whereas after 72 h of exposure an arrest in S phase was observed almost for all mycotoxins tested. Moreover, after 24 and 48 h of exposure, ENs increased the early apoptotic cells, whereas after 72 h of exposure necrosis was observed. In addition the loss of ΔΨ m was produced on Caco-2 cells after ENs exposure. ENs A, A 1 , B and B 1 cytotoxicity involved early ROS generation that induced LPO oxidative damage, apoptosis and necrosis via the mitochondrial pathway. ENs A, A 1 and B 1 induced DNA damage. However the same effects cannot be proposed for EN B. Further studies on the toxicological effects induced by ENs A, A 1 , B and B 1 are needed.