Studies on the Toxic Substances in the Infected Cereals (III)

Acute Toxicities of New Trichothecene Mycotoxins: Deoxynivalenol and Its Monoacetate

Abstract

The acute toxicities of deoxynivalenol (I) and its monoacetate (II), new trichothecene mycotoxins of Fusarium roseum (No. 117 strain), were investigated, and resulting data were compared with those of nivalenol (III) and fusarenon (IV):
(1) The LD₅₀ values of I, II, III and IV in intraperitoneally administered DDY mice were 70, 49, 6.9 and 5.6mg/kg, respectively, in males and 77, 47, 6.2 and 5.2mg/kg, respectively, in females. The oral LD₅₀ values in male mice were 46mg/kg for I, 34mg/kg for II and 5.5mg/kg for IV. The acute symptom of mice administered with the toxins were marked dilatation with hemorrhage of the gastointestinal tract and engorgement of the testes.
(2) Deoxynivalenols (I and II) lacking C-4 hydroxy group were less toxic to mice than known trichothecenes, all of which have this functional group. This fact suggested that the C-4 hydroxyl group may play an important role in the mammalian toxicity of trichothecenes.
(3) The subcutaneous LD₅₀ values in 10-days old Pecking ducklings were 27mg/kg for I and 37mg/kg for II. The minimum vomiting doses of both toxins were approximately 10mg/kg.
(4) The subcutaneous minimum doses of I and II for vomiting and diarrhea in dogs were 0.1 and 0.2mg/kg, respectively. The relationships between doses and first and final vomiting times, and vomiting frequency were noted.
(5) The four toxins showed the marked cytotoxicity to protozoan, Tetrahymena pyriformis W and cultured mammalian cells. The median inhibitory doses of I, II, III and IV in the synchronously dividing Tetrahymena cells were 4.6, 29.0, 8.8 and 5.0μg/ml, respectively.