Perennial ryegrass toxicosis: effects of the indole diterpenoid mycotoxins on movement and metabolism in a mouse model

Priyanka Reddy, Myrna A Deseo, Martin Combs, Jane Quinn, Simone Rochfort

Research output: Other contribution to conferencePosterpeer-review


The mycotoxin lolitrem B is found in endophyte-infected perennial ryegrass (Lolium perenne) and is present in around 90% of ryegrass pastures in Australia and New Zealand. Ingestion causes a neurological syndrome in grazing livestock called Perennial Rye Grass Toxicosis (PRGT) (Cunningham, 1959; Combs et al., 2014) where clinical signs include hyperexcitability, muscle tremors, ataxia (“staggers”) and, in severe cases, clonic seizures and death (Combs et al., 2014). It remains unclear whether these neurological signs result only from the blockade of large conductance potassium channels (BK channels) by indole diterpenoid toxins, primarily lolitrem B (Munday-Finch SC., 1997; Imlach, 2011). Furthermore, the toxicity of biosynthetic pathway intermediates of lolitrem B is also largely undefined. To address these questions, lolitrem B and several intermediates were purified from infected perennial ryegrass. Using a time-series analysis, the effects on movement in dosed mice were quantified for lolitrem B and related compounds. Animals exposed to lolitrem B showed a significant increase in tremor and decreased ability to maintain stability during accelerated rotarod testing, while the other metabolites showed varied effects. Metabolic profiling of the mice tissues and serum were undertaken for animals exposed to lolitrem B at key time points. This study suggests the possible mechanism and quantity of residual lolitrem B in tissue samples. Characterization of clinical signs and metabolic changes associated with exposure to the family of indole diterpenoid toxins present in perennial ryegrass will provide useful information for generation of animal safe grass varieties for the dairy and meat industries.
Original languageEnglish
Number of pages1
Publication statusPublished - 2017
EventMetabolomics 2017: 13th Annual Conference of the Metabolomics Society - Brisbane Convention and Exhibition Centre, Brisbane, Australia
Duration: 25 Jun 201729 Jun 2017


ConferenceMetabolomics 2017
Internet address


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