What is Pyrrolizidine alkaloids used for?

Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores. More than 660 PAs and PA N-oxides have been identified in over 6,000 plants, and about half of them exhibit hepatotoxicity.

Are Pyrrolizidine alkaloids?

Pyrrolizidine alkaloids (PAs) are alkaloids that typically contain either a saturated or a 1,2-unsaturated necine base unit. PAs are generally classified into four types based on the necine bases that are present, i.e., platynecine, retronecine, heliotridine, and otonecine (Fig. 1).

What is the meaning of Pyrrolizidine alkaloids?

Wikipedia. License. Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores.

Can Pyrrolizidine alkaloids be absorbed through skin?

The PA lycopsamine (typical for the gender of comfrey) is poorly absorbed through human skin. Regulatory limits calculated for systemic exposure are not applicable to topical preparations. The low bioavailability of lycopsamine contributes to the safety of comfrey herb cream.

How is a presumptive diagnosis of pyrrolizidine alkaloids made?

An ELISA that recognizes riddelliine and closely related pyrrolizidine alkaloids present in whole blood has also been described but is not widely available. More commonly, a presumptive diagnosis is made based on clinical signs, compatible changes in biochemical parameters, and a history of exposure.

Is it possible to test whole blood for pyrrolizidine?

Chemical analysis of whole blood for toxic metabolites can confirm recent exposure but depends on the half-life of RBCs to which these pyrroles are bound. An ELISA that recognizes riddelliine and closely related pyrrolizidine alkaloids present in whole blood has also been described but is not widely available.

Can you use pyrrolizidine alkaloids in animal feed?

The German Federal Institute for Risk Assessment (BfR) has also reported the occurrence of pyrrolizidine alkaloids in pseudocereals in 2014. Pyrrolizidine alkaloids can also pose a serious problem in animal feed, especially in hay and silage, as the characteristic inherent odour of the specific plants is no longer noticeable for animals.

Is there a maximum level of pyrrolizidine in food?

By the end of June 2020, the Standing Committee of the EU Commission adopted a Draft Regulation setting maximum levels for pyrrolizidine alkaloids (PA) in foodstuffs. The new maximum levels will apply from July 2022 and will be included in the Annex of Regulation (EC) No 1881/2006 setting maximum levels for certain contaminants in foodstuffs.