A survey of Senecio spp. affecting livestock in Uruguay and their associated pyrrolizidine alkaloid content

Abstract

In Eastern Uruguay there has been a significant increase of seneciosis in grazing livestock with most affected localities related to counties neighboring the Brazilian border. A survey in 28 farms associated with poisoning outbreaks in grazing cattle in Eastern Uruguay was carried out. Fifty populations of Senecio plants were collected for alkaloid analysis and species identification. Four species were identified: S. oxyphyllus DC, S. madagascariensis Poir, S. brasiliensis (Spreng.) Less., and S. selloi DC. Alkaloids were identified by a combination of GC-MS and HPLC-MS analysis and included: retrorsine in S. oxyphyllus; retrorsine, usaramine, and senecivernine/senecionine in S. selloi; retrorsine, senecivernine/senecionine, integerrimine, and usaramine in S. madagascariensis; and integerrimine, retrorsine and senecionine in S. brasiliensis. Total mean alkaloid concentration was reported to be highest in S. brasiliensis (17.6mg/g) followed by S. oxyphyllus (6.2mg/g), S. selloi (1.8mg/g) and S. madagascariensis (0.6mg/g). Alkaloid concentrations were also reported to be higher in 2015 vs. 2016 probably due to a common environmental factor. The species S. oxyphyllus and S. madagascariensis were not previously recognized as toxic plants in Eastern Uruguay. Particularly, S. oxyphyllus was present in 82% of the farms surveyed and occurred in high density with relative high concentrations of pyrrolizidine alkaloids suggesting S. oxyphyllus may be the main species involved in the reported outbreaks of seneciosis.

Review of the Biology, Distribution, and Management of the Invasive Fireweed (Senecio madagascariensis Poir)

“…In Uruguay, S. madagascariensis has been regarded as a serious threat to producers since its detection in late 1990s in grazing pastures near the western cities of La Concordia and Dolores in the region of Soriano and near the southwestern region of Colonia [ 34 ]. By 2010, farmers from the open eastern rangelands of Uruguay bordering Brazil were recording significant increases of seneciosis (intense acute or chronic necrosis of liver) in their grazing livestock [ 35 , 36 ].…”

“…In countries such as Brazil, Columbia, and Uruguay, where S. madagascariensis is spreading into new areas, there is growing concern that it is contributing to an increase in PA poisoning [ 33 , 35 , 48 ].…”

Senecio spp. transboundary introduction and expansion affecting cattle in Uruguay: Clinico-pathological, epidemiological and genetic survey, and experimental intoxication with Senecio oxyphyllus

“…is the main toxic plant in the western region of Uruguay as well (personal communication, Rivero, 2017). In recent years, levels of intoxication have grown exponentially to reach epidemic proportions, with 91 outbreaks of seneciosis in cattle registered between 1988 and 2016, 76% of which occurred between 2010 and 2016 (Dutra et al, 2016;García et al, 2018).…”

“…The outbreaks are spatially correlated, resulting in clusters of high incidence of seneciosis located in the northeast of Uruguay, close to the border with Brazil, and in contrast to the south and southeast of Uruguay, where there is a low incidence of poisoning of cattle by Senecio (Dutra et al, 2015. The significant increase in Senecio poisoning has been associated with a decrease in the sheep population in livestock systems, and the appearance or expansion of Senecio species that previously did not prevail nor did exist in the region (Dutra et al, 2016;García et al, 2018).…”

Estrés oxidativo inducido por extractos de plantas hepatotóxicas del género Senecio (“margarita de campo”, Asteraceae) sobre mitocondrias y microsomas de hepatocitos de ratas Wistar

“…;Cheng et al, 2011). A pesar de este abanico de AP presentes en las plantas, uno o algunos de ellos son dominantes en su concentración respecto a los demás, factor importante a tener en cuenta para considerar su identidad fitoquímica(Macel et al, 2004;Langel et al, 2011;García, 2017). Estas situaciones han permitido a diferentes autores realizar listados de especies de senecios, indicando su composición química prevalente de AP.…”