Disease relevance of Pyrrolizidine alkaloids

• The toxicity of acutely administered (ip) PA was determined in another experiment [1].
• Rats fed a goats' milk diet for 180 days with a calculated total PA intake of 0.96 mg/rat had swollen hepatocytes of centrilobular distribution, and biliary hyperplasia, indicating PA involvement [2].
• The PA monocrotaline was nontoxic to guinea pigs at doses up to 1,000 mg/kg body weight, whereas jacobine and mixed SJPA were highly toxic at doses ranging from 100 to 150 mg/kg body weight [1].

High impact information on Pyrrolizidine alkaloids

• It remains open whether the duplicated DHS belonging to class 2 is involved in the biosynthesis of PAs [3].
• Pyrrolizidine alkaloids (PAs) were among the first naturally occurring carcinogens identified in plant products, and their presence in herbal teas is a matter of public health significance [4].
• We have undertaken metabolism and excretion studies of SEN in rats to provide data for comparison between PAs and to evaluate the potential role of metabolism and excretion in toxicity [5].
• Rats fed tansy ragwort at dietary levels of 1%, 0.1%, 0.01% and 0.001% (corresponding to PA intakes of 39.77, 5.04, 0.52, and 0.05 mg/rat) showed swollen hepatocytes, megalocytosis, biliary hyperplasia, and fibrosis [2].
• The moth Utetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae, Crotalaria spp.). We here show, in laboratory tests, that Utetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae [6].

Anatomical context of Pyrrolizidine alkaloids

• Catheterization of the portal vein via the right ruminal vein was done to separate the ruminal effects of toxin metabolism and absorption from the direct effects of PA on liver tissue [7].

References