Poisoning in Ruminants by Palicourea Aubl. Species (Rubiaceae) in Brazil: A Review

Some species belonging to the genus Palicourea (Rubiaceae) are known to cause poisoning in production animals on Brazilian rural properties, being responsible for negatively affecting the livestock sector of the country. In this context, the present study aimed to review reports of spontaneous and experimental poisoning in ruminants caused by Palicourea species in different regions of Brazil. The documents were retrieved from various databases, covering the period from the first report published in 1986 to April 2025. Palicourea aeneofusca, Palicourea colorata (Syn. Psychotria colorata), Palicourea grandiflora, Palicourea hoffmannseggiana (Syn. Psychotria hoffmannseggiana), Palicourea marcgravii, and Palicourea violacea (Syn. Psychotria capitata) have been identified as causes of spontaneous poisoning in the following Brazilian states: Pernambuco, Sergipe, Paraíba, Goiás, São Paulo, Minas Gerais, Tocantins, Rondônia, and Distrito Federal. In general, Palicourea species cause sudden death in poisoned animals, especially P. marcgravii. Although cattle are more susceptible to poisoning by these plants, there are reports of cases in sheep, goats, and buffalo. Sodium monofluoroacetate occurs in Palicourea species and has been well reported as the main compound responsible for cases of poisoning in these animals. Despite epidemiological evidence of spontaneous poisoning cases in Brazil, the species P. colorata, P. grandiflora, P. hoffmannseggiana, and P. violacea have not yet been experimentally tested for their toxic potential, and studies of this nature are necessary.