Report on toxicity data on trichothecene mycotoxins HT-2 and T-2 toxins

Report (0.4 Mb)

Summary

Project developed on the procurement project CT/EFSA/CONTAM/2010/03

T-2 and HT-2 toxin are secondary fungal metabolites belonging to the group of type A trichothecenes and are primarily produced by Fusarium species. Toxicity data on HT-2 toxin are very limited. As T-2 toxin is rapidly metabolised to HT-2 toxin and the acute toxicity of T-2 toxin and HT-2 toxin are within the same range, the toxicity of T-2 toxin in vivo is considered to include that of HT-2 toxin. T-2 toxin is rapidly absorbed via the oral and inhalation route. Dermal absorption is reported to be slow. T-2 toxin is rapidly distributed throughout the body and is rapidly metabolised. Glucuronide conjugates of the mother toxin and its metabolites are the major excretion products in urine and faeces. T-2- and HT-2 toxin are very toxic with oral LD50 values in rodents in the range of 5-10 mg/kg bw. T-2 is severely irritating to skin. The observed toxicity of trichothecenes is most likely a result of their ability to inhibit protein and - at higher doses - RNA and DNA synthesis, acting predominantly on actively dividing tissues such as bone marrow, lymph nodes, thymus and intestinal mucosa. In repeated-dose studies, T-2 toxin shows unspecific systemic effects such as body weight reduction and induces liver damage, reproductive toxicity, neurotoxicity as well as haematotoxic and immunotoxic effects. Recent findings in poultry are generally consistent with the effects observed in mammals. The most relevant study for risk assessment is a feeding study with pigs, in which a diet containing 0.5-3.0 mg/kg T-2 toxin led to immunosuppression in all dose groups (LOAEL 0.029 mg/kg bw/d).