Acute fatal poisoning by spontaneous ingestion of Enterolobium contortisiliquum (Mimosidae) pods in horses

A Review of Phototoxic Plants, Their Phototoxic Metabolites, and Possible Developments as Photosensitizers

This study provides a comprehensive overview of the current knowledge regarding phototoxic terrestrial plants and their phototoxic and photosensitizing metabolites. Within the 435,000 land plant species, only around 250 vascular plants have been documented as phototoxic or implicated in phototoxic occurrences in humans and animals. This work compiles a comprehensive catalog of these phototoxic plant species, organized alphabetically based on their taxonomic family. The dataset encompasses meticulous details including taxonomy, geographical distribution, vernacular names, and information on the nature and structure of their phototoxic and photosensitizing molecule(s). Subsequently, this study undertook an in-depth investigation into phototoxic molecules, resulting in the compilation of a comprehensive and up-to-date list of phytochemicals exhibiting phototoxic or photosensitizing activity synthesized by terrestrial plants. For each identified molecule, an extensive review was conducted, encompassing discussions on its phototoxic activity, chemical family, occurrence in plant families or species, distribution within different plant tissues and organs, as well as the biogeographical locations of the producer species worldwide. The analysis also includes a thorough discussion on the potential use of these molecules for the development of new photosensitizers that could be used in topical or injectable formulations for antimicrobial and anticancer phototherapy as well as manufacturing of photoactive devices.

Plants causing poisoning outbreaks of livestock in South America: A review

This paper reviews toxic plants for livestock in South America. We included 219 plants in this review, considering only the plants that caused at least one demonstrated outbreak of poisoning. Plants reported as toxic in other regions and present in South America, but with no confirmed outbreaks of poisoning in this region, are not included. We report the main aspects of the epidemiology, clinical signs, pathology and economical importance of the poisonings. Initially, the toxic plants are described based on their toxic compounds, but because the toxic compound is unknown in 92 (42%) of the plants we also classify them according to the affected system. This review highlights the great diversity of toxic plants capable of affecting livestock in South America, and for this reason studies in this regard should be intensified.

Acetogenin-induced fibrotic heart disease from avocado (Persea americana, Lauraceae) poisoning in horses

Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Grossly and histopathologically, there was severe cardiac fibroplasia. Immunohistochemically, there was a multifocal decrease or negative expression in the cTnC cardiomyocytes' cytoplasm. Persea americana leaves were confirmed in the alimentary tract using botanical anatomy and molecular techniques. The chemical investigation by (LC-ESI-MS) revealed the presence of the acetogenins, persin and avocadene 1-acetate from P. americana. Persin was present in leaves and fruits (seed and pulp), while avocadene 1-acetate was found in leaves and fruits (seed, peel, and pulp) with a higher concentration in the pulp. Four other horses have been examined by electrocardiogram, echocardiogram and serum Troponin 1 (cTnI). To establish a causal effect of consumption of P. Americana and heart fibroplasia in horses, long-time experiments must be carried out.

Phytochemistry and poisoning in ruminants by Enterolobium contortisiliquum (Vell.) Morong (Fabaceae): A systematic review

Enterolobium contortisiliquum (Vell.) Morong (Fabaceae) is a plant widely distributed in several regions of Brazil, occurring in the phytogeographic domains of Atlantic Forest, Cerrado, and Caatinga. Cases of serious poisoning in cattle, goats, and sheep in the country caused by the ingestion of beans of this species have been reported by several studies. The present work aimed to carry out a systematic review of cases of poisoning by E. contortisiliquum in ruminants and list the main chemical compounds isolated from this plant. For this, searches were performed in the Google Academic, PubMed®, ScienceDirect®, and SciELO databases. A total of 26 articles published in the last 20 years (2001-2021) were included. Studies on cases of natural and experimental poisoning indicate that this species mainly causes photosensitization, abortions, digestive problems, and acute ruminal lactic acidosis in animals that ingest the pods of the plant. The main chemical compounds that occur in the species belong to the triterpene saponins, monoterpene, phenylpropene, and triterpene classes. It is likely that triterpene saponins isolated from E. contortisiliquum are associated with reported cases of photosensitization in cattle. New studies must be conducted to assess the mechanisms of action of chemical compounds isolated from this species in in vivo systems.