Intoxicação natural e experimental por Leucaena leucocephala em equinos

Abstract

RESUMO.-Este trabalho investigou as principais alterações clínicas e dermatopatológicas de equinos intoxicados natural e experimentalmente por Leucaena leucocephala. Os surtos ocorreram nos estados de São Paulo e Goiás, onde seis cavalos após a ingestão de casca e/ou folhas de L. leucocephala apresentaram alopecia, principalmente na crina e cauda. Nesses animais o diagnóstico foi baseado na observação da ingestão da planta e dos sinais clínicos. Nos animais intoxicados experimentalmente, foi realizado o exame clínico, biópsias da pele das regiões de crina, dorso e cauda e foi feita dosagem sérica de tri-iodotironina (T3) e tiroxina (T4). Alopecia da crina e cauda foi o principal sinal clínico observado, seguido de anorexia, emagrecimento e apatia em todos os equinos. Os níveis de T3 e T4 total apresentaram redução significativa (p≤0,05) na terceira semana de ingestão da leucena quando comparado aos níveis basais. As alterações histológicas observadas nas biópsias de pele demonstram acentuada telogenização dos folículos pilosos ao final dos experimentos. Os achados clí-nico-patológicos em equinos intoxicados são semelhantes aos observados em ruminantes. A intoxicação experimental de equinos por L. leucocephala evidenciou o acentuado declínio dos níveis dos hormônios tireoideanos, sugerindo efeito bociogênico da mimosina e seus compostos derivados, com hipotireoidismo transitório e alopecia devido à acentuada redução da atividade folicular. Goiás States, where six horses after ingestion of bark and/or leaves of the plant showed alopecia mainly in mane and tail. The diagnosis was based on the observation of plant intake and clinical signs. In horses experimentally poisoned, clinical examination was performed and skin biopsies were taken from mane, back and tail regions, and triiodothyronine (T3) and thyroxine (T4) serum levels were assayed. Alopecia in mane and tail was the main clinical sign, accompanied by anorexia, weight loss and lethargy in all horses. T3 and total T4 showed significant decrease in serum levels (p≤0.05) in the third week of leucaena intake compared with baseline levels. Marked telogenization of hair follicles at the end of the experiments were observed in skin biopsies. The clinical and pathological findings in poisoned horses are similar to those observed in ruminants. Experimental poisoning of horses by the plant highlights the marked decline in levels of thyroid hormones, suggesting goitrogenic effect of mimosine and its derived compounds, with transient hypothyroidism and alopecia due to accentuated reduction in follicular activity. Intoxicação natural e experimental por

Diffuse Alopecia and Thyroid Atrophy in Sheep

“…The differential diagnosis for sheep with diffuse alopecia includes poisoning by the plant Leucaena leucocephala, characterized by weight loss, ulcerations of the tongue and esophagus, sialorrhea, goiter, infertility, or death [48,49]. These clinical signs result from the action of mimosine [50], which prevents iodine peroxidation in the thyroid (iodination), with a decreased synthesis of T3 and T4 [51].…”

The Effect of Mimosine From Simplicia of the Lamtoro Leaf on the Histopatological of White Rats’ Testis

“…Efek toksik dari mimosin berpengaruh pada sapi, domba, kambing, babi, kuda, unggas, kelinci, dan tikus (Fayemi et al, 2011;Porto et al, 2017;Vijayakumar dan Srinivasan, 2018;Loh et al, 2020;Gotardo et al, 2021). Ternak ruminansia seperti sapi, kambing dan domba meskipun diketahui dapat mengubah mimosin menjadi 3,4 dihidroksipiridin (DHP) sehingga lebih tahan terhadap toksik mimosin, keracunan akibat mimosin juga terjadi seperti mengalami rendahnya kenaikan berat badan, alopecia, gondok, kesuburan reproduksi rendah, mengalami aborsi hingga kematian.…”

Delivery kinetics of natural active agents by PVA hydrogels intended for wound care

“…Leucaena leucocephala (Leucaena) is a leguminous plant that is used as ruminant animal feed, but when there is over 30% of Leucaena in these animals' feed, they could present intoxication [20]. The Leucaena flowers and leaves extract present tannins and flavonoids, although flowers extract presents mimosine (alkaloids), while leaves extract has steroids and saponin.…”