Metabolic pathways of trichothecenes

Abstract

Trichothecenes are a group of mycotoxins mainly produced by the fungi of Fusarium genus. Consumers are particularly concerned over the toxicity and food safety of trichothecenes and their metabolites from food-producing animals. The metabolism of T-2 toxin, deoxynivalenol (DON), nivalenol (NIV), fusarenon-X (FX), diacetoxyscirpenol (DAS), 3-acetyldeoxy-nivalenol (3-aDON), and 15-acetyldeoxynivalenol (15-aDON) in rodents, swine, ruminants, poultry, and humans are reviewed in this article. Metabolic pathways of these mycotoxins are very different. The major metabolic pathways of T-2 toxin in animals are hydrolysis, hydroxylation, de-epoxidation, and conjugation. After being transformed to HT-2 toxin, it undergoes further hydroxylation at C-3' to yield 3'-hydroxy-HT-2 toxin, which is considered as an activation pathway, whereas transformation from T-2 to T-2 tetraol is an inactivation pathway in animals. The typical metabolites of T-2 toxin in animals are HT-2 toxin, T-2 triol, T-2 tetraol, neosolaniol (NEO), 3'-hydroxy-HT-2, and 3'-hydroxy-T-2, whereas HT-2 toxin is the main metabolite in humans. De-epoxidation is an important pathway for detoxification in animals. De-epoxy products, DOM-1, and de-epoxy-NIV are the main metabolites of DON and NIV in most animals, respectively. However, the two metabolites are not found in humans. Deacetyl can occur rapidly on the acetyl derivatives, 3-aDON, 15-aDON, and FX. DAS is metabolized in animals to 15-monoacetoxyscirpenol (15-MAS) via C-4 deacetylation and then transformed to scirpentriol (SCP) via C-15 deacetylation. Finally, the epoxy is lost, yielding de-epoxy-SCP. De-epoxy-15-MAS is also the main metabolite of DAS. 15-MAS is the main metabolite in human skin. The review on the metabolism of trichothecenes will help one to well understand the fate of these toxins' future in animals and humans, as well as provide basic information for the risk assessment of them for food safety.

The progression of deoxynivalenol-induced growth suppression in nursery pigs and the potential of an algae-modified montmorillonite clay to mitigate these effects12

“…While it is known that DON is more rapidly and efficiently absorbed (55%) in pigs compared to other species and that pigs have limited ability to metabolize DON into less toxic forms (Prelusky et al, 1988;Goyarts and Dänicke, 2006;Wu et al, 2010), the variability in toxicity between individual pigs is not well characterized. During Exp.…”

Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

“…Interestingly, in salmon fed with high-DON feed, DON accumulated significantly in muscle and liver as a result of a high systemic uptake and relatively slow elimination. In the elimination experiments at the end of the study the half-lives in plasma and muscle were estimated to be higher than 15 h, whereas the plasma t 1/2 's were between 0.5 and 5 h in rodents, birds, pigs, sheep and cows (EFSA 2004a;Goyarts & Dänicke 2006;Wu et al 2010;VKM 2013). Accordingly, DON tissue accumulation has not been found in these species.…”

Preliminary survey on the co-occurrence of DON and T2+HT2 toxins in durum wheat in Italy

“…The T2 toxin is rapidly transformed to a large group of products, HT2 toxin resulting as the major metabolite with equivalent toxicity, and the sum of T2 and HT2 was considered in the determination EFSA 2011). T2 and HT2 toxins are reported to be implicated in human Alimentary Toxic Aleukia (ATA) due to the consumption of contaminated grain (Wu et al 2010). The main source of trichothecenes in the food chain is Fusarium-contaminated grain and for this reason Fusarium Head Blight (FHB or "scab") outbreak of cereal crops is of great interest.…”