Abstract
The toxicity of plants containing certain pyrrolizidine alkaloids has long been recognized
in grazing animals and humans. Genotoxicity and carcinogenicity data from in vitro and in vivo (animal) studies were published over the last few decades for some of the 1,2-unsaturated
pyrrolizidine alkaloids, leading to regulatory action on herbal medicinal products
with pyrrolizidine alkaloid-containing plants more than 30 years ago. In recent years,
it has become evident that in addition to herbal medicinal products containing pyrrolizidine
alkaloid-containing plants, these products may also contain pyrrolizidine alkaloids
without actually including pyrrolizidine alkaloid-containing plants. This is explained
by contamination by accessory herbs (weeds). The national competent authorities of
the European member states and the European Medicines Agency, in this case, the Committee
on Herbal Medicinal Products, reacted to these findings by setting limits for all
herbal
medicinal products. This review article will briefly discuss the data leading
to the establishment of thresholds and the regulatory developments and consequences,
as well as the current discussions and research in this area.
Key words
pyrrolizidine alkaloids - herbal medicinal products - contamination - HMPC
