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 (ΔΨm) as a function of increasing time have been determined in human colorectal
adenocarcinoma (Caco-2) cells after exposure to
enniatins (ENs) A, A₁, B and B₁. IC₅₀ 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 H2-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, A₁, B₁, 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 72h of exposure
necrosis was observed. In addition the loss of ΔΨm was produced on Caco-2 cells after ENs exposure. ENs A, A₁, B and B₁ cytotoxicity involved early ROS generation that induced LPO oxidative damage, apoptosis and
necrosis via the mitochondrial pathway. ENs A, A₁ and B₁ induced DNA damage. However the same effects cannot be proposed for EN B. Further studies on the toxicological effects induced by ENs A, A₁, B and B₁ are needed.