A functional metabolomics analysis of lolitrem B and its biosynthetic intermediates in the murine brain

The neuroactive mycotoxin lolitrem B causes a neurological syndrome in grazing livestock resulting in hyperexcitability, muscle tremors, ataxia and, in severe cases, clonic seizures and death. Lolitrem B is the endpoint in a biosynthetic pathway of indole diterpenoid toxins present in fodder yet the neuroactive status of it’s pathways intermediates remains undefined. To define the effects of lolitrem B and it’s pathway intermediates terpendoles B, C and E in the brain, a functional metabolomic study was undertaken in which cordination and tremor were quantified and metabolomic profiling undertaken to determine quantification anad relative abundance of both toxin and key neurotransmitters in various brain regions. Marked differences were observed in the duration of tremor and coordination between pathway members, with some showing protracted effects and others none at all. Quantification of lolitrem B using LCMS/MS QQQ identified presence of Lolitrem B in liver and kidney, cerebral cortex, thalamus and brain stem but not in cerebellum. Metabolomic profiling by LCMS/MS-QToF of brain isolated from intoxicated animals using showed significnat variation in targetted neurotransmitter and amino acid profiles over time. This study demonstrates for the first time bioaccumulation of lolitrem B in the brain, with absence of detectable levels of toxin in the cerebellum, as determining a dynamic catecholenergic response over time. This data is indicates that the indole diterpenoid toxins induce alterations in catecholamine pathways in the brain as well identifying pathway intermediates with non-tremorgenic profiles. This study idetnfies a functional metabolomic approach for physiological profiling of neurotoxic agents in the brain.