Intoxication of llamas by Astragalus punae in Argentina

Abstract

Several plants that contain indolizidine alkaloids, including swainsonine, are toxic to livestock, causing dysfunctional lysosomes and storage disease. Swainsonine induces a neurovisceral disease, known as locoism, in sheep, goats, and cattle, which occurs in several parts of the world, including, but not limited to, the western United States, China, and parts of Australia. In South America, locoism has been described in the Andean region of Argentina affecting sheep, cattle, and llamas. Intoxication by consumption of Astragalus punae was suspected in 4 llamas in Jujuy Province, northwestern Argentina. The grazing area contained abundant specimens of A. punae. The clinical course was ~15 d, and included moderate ataxia, incoordination of hindlimbs, and progressive loss of body condition. Microscopically, fine cytoplasmic microvacuolation was observed in the proximal convoluted renal tubules. Ultrastructurally, these changes consisted of severely dilated lysosomes. Swainsonine was detected in stem and leaf samples of A. punae at a concentration of 0.06%. Based on clinical history and signs, histologic and ultrastructural changes, and plant analysis, a diagnosis of swainsonine toxicosis caused by consumption of A. punae was made, which has not been reported previously, to our knowledge.

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“…M. Johnston (1947: 389) has been reported as a toxic species for llamas (Camelidae) in South America (Marin et al 2022). Those species of Astragalus containing nitrotoxins kill or permanently cripple thousands of sheep and cattle annually (Williams & Baneby 1977) and therefore have a serious economic impact on the livestock industry.…”

Metabolomic analysis of swainsonine poisoning in renal tubular epithelial cells

“…Locoweed, a plant species with a global distribution ( 1 ), has been documented in various countries including the United States ( 2 ), Brazil ( 3 ), Argentina ( 4 ), Australia ( 5 ), and China ( 6 ). The earliest instances of poisonous plant poisoning diseases in the western region of the country were documented in the United States in 1873 ( 7 ).…”

“…Previous studies have unequivocally demonstrated that SW can inflict damage on multiple organs, encompassing the cerebrum, cerebellum, liver, kidneys, pancreas, and thyroid gland ( 1 ). Notably, renal injury is observed at relatively lower dosages or at earlier time points ( 4 , 14 ).…”

“…At present, studies on SW primarily focuses on its biosynthesis and toxicity mechanisms, with limited reports on the metabolic pathways it participates in after entering cells. Previous research has indicated that locoweed poisoning primarily affects the kidney, causing severe damage to this organ and the renal epithelial cells, especially the proximal tubular epithelial cells, are the most significantly affected ( 4 , 14 ). In this study, rat primary renal tubular epithelial cells were utilized as an experimental model to investigate the metabolomic perturbation following locoweed poisoning.…”