In vitro inhibitory effects of antioxidants on cytotoxicity of T-2 toxin

T-2 toxin is a secondary fungal metabolite produced by various species of Fusarium. It is capable of killing cells by causing extensive damage to the cellular membrane. In this study, cytotoxicity of T-2 toxin in combination with different antioxidant materials, including vitamin C (vit. C), vitamin E (vit. E) and selenium (sel) was investigated in vitro using the neutral red cytotoxicity assay. Eleven primary and transformed cell lines established from different tissues were used in pre-test experiments to identify the most sensitive and resistant lines by measuring the half lethal concentration (LC(50)) of the toxin. Three cell lines including human gingival fibroblast (HGF), the most sensitive (LC(50)=0.25 ng/ml), human colorectal adenocarcinoma (SW742), the most resistant (LC(50)=5.5 ng/ml) and human hepatoma (HepG2), with median susceptibility (LC(50)=2 ng/ml) were selected to investigate the inhibitory effects of the antioxidant agents, on cytotoxicity of T-2 toxin. Our results demonstrated that co-incubation of cell lines with different concentrations of T-2 toxin and antioxidants decreased significantly, but did not totally inhibit, the cytotoxicity of T-2 toxin (P<0.001). These findings suggest that in addition to lipid peroxidation, which is inhibited by antioxidants, other unidentified mechanism(s) seem to be involved in cytotoxicity of T-2 toxin.