Trichothecene mycotoxins

Trichothecene mycotoxins are a family of tetracyclic sesquiterpenoid substances comprising over 200 compounds of widely varying toxicity. The epoxy group at C-12 and C-13 is considered essential for toxicity. Trichothecenes are broadly divided into two groups, the macrocyclic and nonmacrocyclic, based on the presence or absence of a macrocyclic ring linking C-4 and C-15 with diesters and triesters. Trichothecenes cause apoptosis and/or necrosis in the lymphoid, hematopoietic, and gastrointestinal systems resulting in leukopenia, vomiting, and diarrhea that can be lethal. In addition, trichothecenes are toxic to the skin and testes. Immune suppression and increased susceptibility to infection may occur, especially in the late phase of the disease. The toxic effects from trichothecenes largely resemble those following radiation exposure due to effects on rapidly dividing cells in the intestine, bone marrow, and testes. General clinical signs include emesis, food refusal and weight loss, dermal effects, and immune suppression with secondary infection. Clinical signs are dependent on the specific trichothecene involved, the dose, species, route of exposure, as well as the nature of the exposure. Spontaneous and experimental exposures may give somewhat different results, as can exposure to field contaminated materials, when compared to purified toxin. Respiratory, skin, and eye protection is required for personnel working with trichothecenes. There are no specific therapies for trichothecene toxicoses. Neither vaccines nor specific antidotes are readily available. Treatment in people and animals is symptomatic and supportive, and the only known prophylactic measure is avoidance of exposure.