Survey of Amaranthus spp. species and the search for the active principle responsible for poisoning in ruminants in the microregion of Garanhuns
pigweed; toxicology; renal system
Plant poisonings represent a major challenge for national livestock, ranking among the primary causes of cattle mortality and resulting in significant economic losses. Among the various groups of toxic plants, those with nephrotoxic action warrant particular attention, especially species of the genus Amaranthus, commonly known as caruru or bredo, which are widely distributed throughout the national territory. Although some species are used in human nutrition and occasionally in the diets of production animals, the literature describes the presence of potentially toxic compounds, such as oxalates, nitrates, and nitrites, highlighting a lack of regional phytochemical studies in Brazil. This study aimed to identify Amaranthus species occurring in the microregion of Garanhuns, in the Southern Agreste of Pernambuco, and to evaluate their spatial distribution, phytochemical profile, and bioactive potential of their extracts and fractions. Collections were conducted in rural areas across 19 municipalities, followed by botanical identification and georeferencing. Plant extracts were obtained by ethanol maceration, fractionated via liquid-liquid partitioning, and subjected to qualitative phytochemical screening, thin-layer chromatography, and quantification of total phenols and flavonoids. Additionally, the bioactive potential was investigated through the Artemia salina lethality test, with calculated using the Probit method at a 5% significance level. The species Amaranthus spinosus, A. blitum, and A. viridis were identified, with A. spinosus being the most widely distributed in the region. Inflorescence extracts exhibited the highest bioactivity, notably the chloroform fraction of A. spinosus and the ethyl acetate fraction of A. viridis. Compounds such as coumarins, anthraquinones, flavonoids, and terpenes are present in all three species studied. These results contribute to the phytochemical and toxicological knowledge of the genus Amaranthus, aiding in the understanding of the physiopathology of these poisonings and reinforcing the importance of plant identification for preventing outbreaks in animal production systems.