Pyrrolizidine alkaloid production of Jacobaea aquatica and contamination of forage in meadows of Northern Austria

Abstract

Jacobaea aquatica (=Senecio aquaticus, Asteraceae), marsh ragwort, grows regionally in low management intensity wet grasslands in various European countries. The plant can be regarded as a noxious weed as it contains pyrrolizidine alkaloids (PAs), which cause health problems in livestock. In the Waldviertel region of Northern Austria, marsh ragwort has established dense populations as the fertilizing and production intensity of the meadows changed during the last decades. Ragwort biomass production and alkaloid concentration in J. aquatica were recorded during three consecutive years at three sites to study the effects of two treatments: cutting twice a year either early in June plus September, or in July plus August, respectively. Six PAs (Z‐erucifoline > senecionine > integerrimine > seneciphylline > acetyl‐erucifoline and acetyl‐seneciphylline) were evaluated. The alkaloid contents were highest in July and August when 600–1,400 mg/kg dry matter (DM) total PAs occurred in most ragwort samples. Consequently, the forage can easily be contaminated with 40–80 mg/kg DM of PAs and may present a health risk for domestic animals and also affect human health as these alkaloids are transferred into milk.

Pyrrolizidine Alkaloids in the Food Chain: Is Horizontal Transfer of Natural Products of Relevance?

“…In particular, it has recently been observed that some species like S. jacobaea (syn. : Jacobaea vulgaris), Senecio aquaticus [38,39], or Senecio inaequidens (a neophyte to European areas) [40], may mass-infest pasture areas or public land (parks, greenery, nature preserves, and ancillary areas of transport routes/roadsides) [41]. Those cuttings and green wastes naturally contain a high load of toxic PAs and if used as organic fertilizers in non-PA-crops, these PAs could potentially be passed on via horizontal PA-transfer.…”

Is it possible to avoid pyrrolizidine alkaloid contamination in equine herb containing nutraceuticals?

“…For example, in areas with marsh ragwort a total PA content of 100 mg/kg is easily reached in forage cut in summer, which provides more than 1-3 mg PAs/kg body weight per day to horses (Chizzola et al 2019). This massively exceeds the recommended oral intake limit of 1 µg PA/kg bodyweight/ day.…”

“…Another important fact is, that the diet of horses mostly consists of forage, which, depending on the geographical location, the harvest date and the year, can be massively contaminated by ragwort (Jacobaea vulgaris, Senecio jacobaea) or marsh ragwort (Jacobaea aquatica) (Chizzola et al 2019).…”

Was genau sind Pyrrolizidinalkaloide und warum sind sie so gefährlich für Pferde?

“…Bei Heu hängt die Verunreinigung mit Kreuzkrautarten ( Senecio jacobaea, Jacobaea aquatica ) stark von der geografischen Lage und dem Erntezeitpunkt ab. Aber auch die klimatischen Bedingungen des jeweiligen Jahres spielen eine wichtige Rolle 9 .…”

“…Auch Verunreinigungen von Futter mit PA können für die Gesundheit von Pferden gefährlich werden. Dies betrifft sowohl Raufutter als auch Kraftfutter (wie Hafer oder kommerzielle Futtermischungen) und vermutlich auch Zusatzfuttermittel sowie Nutraceuticals 7 , 9 , 10 . Auch bei geringer täglicher PA-Belastung, aber langfristiger Verabreichung eines PA-belasteten Futtermittels, ist es aufgrund der kumulativen Schäden denkbar, dass sich dies für Pferde nachteilig auswirkt.…”