Tropane alkaloids (from Datura sp.) as undesirable substances in animal feed - Scientific Opinion of the Panel on Contaminants in the Food Chain

Abstract

SUMMARYThe term tropane alkaloids refers to a group of more than 200 compounds best known for their occurrence in the family Solanaceae comprising over 100 genera and 3000 plant species. They have in common a two-ringed structure characterized by a pyrrolidine and a piperidine ring sharing a single nitrogen atom and two carbons atoms. The nitrogen atom at the end of the molecule, which characterizes the compounds as alkaloids, is in this group characteristically methylated. The most important natural tropane alkaloids are (-)-hyoscyamine and (-)-scopolamine (also known as hyoscine). High concentrations of these alkaloids have been found particularly in Datura stramonium and Datura ferox, as well as in Datura innoxia. The pattern of tropane alkaloids differs significantly and in Datura stramonium (also known as thorn apple or Jimson weed) hyoscyamine prevails in most parts of the plant, whereas in Datura ferox scopolamine is the major alkaloid Tropane alkaloids as undesirable substances in animal feedThe EFSA Journal (2008) 691, 2-55 produced. Datura plants are toxic for animals if ingested in larger amounts. Their seeds, which contain significant amounts of hyoscyamine and scopolamine, can be found as botanical impurities in feed materials, particularly in soybean and linseed products.Very little information on the actual contamination of feed materials is available, and previous reports on adverse health effects in animals refer in most cases to accidental intoxications following the consumption of Datura plants rather than to the contamination of linseed and sobean contaning feed materials. Hence no conclusive exposure assessment could be presented for farm animals.Overall, pigs have been shown to be among the most sensitive species to Datura poisoning. A worst case exposure estimate indicated that adverse pharmacological effects in pigs following exposure to Datura ferox seeds, mainly containing scopolamine, can not be entirely excluded at the current statutory limits of 3000 mg/kg feed. However, the limited data also suggested that it is not likely that the presence of Datura stramonium impurities in animals feed up to the current statutory level of 1000 mg/kg would present a risk to animal health.The mechanism of action of tropane alkaloids relates to their competitive antagonism at muscarinic acetylcholine receptors, preventing the binding of acetylcholine. According to the specificity and selectivity of muscarinergic acetylcholine receptors in different organs, the functions of smooth muscles and exocrine gland cells, as well as the heart rate, respiration and functions in the central nervous system are modulated. Certain tropanes such as atropine (the racemic mixture of (-)-and (+)hyoscyamine) as well as scopolamine (mainly as butylscopolamine bromide) are used in human and veterinary therapy for a variety of related indications. Reports of poisoning of livestock and experimental feeding studies describe as most common symptoms associated with tropane alkaloids exposure dryness of the mucosa in the uppe...

Occurrence and Chemistry of Tropane Alkaloids in Foods, with a Focus on Sample Analysis Methods: A Review on Recent Trends and Technological Advances

“…This is because cattle generally do not consume plants that contain TAs, since they tend to have an unpleasant taste that makes animals avoid it. Only when the amount of available grass is restricted are cattle likely to consume these plants [3]. Therefore, exposure to these toxins is usually mainly through feed contaminated with TAs or through waters contaminated with TA drugs that end up in rivers and are consumed by animals [30].…”

“…Tropane alkaloids (TAs) are secondary metabolites produced by various plant species, mainly belonging to the Solanaceae family, in addition to a variety of other families (Brassicaceae, Erythroxylaceae, Euphorbiaceae, Convulvulaceae) [1][2][3]. There are more than 200 different TAs identified, and they can be found anywhere in the plant, including seeds, fruits, flowers, leaves and stems [2,4].…”

“…In addition, these alkaloids are found in all parts of TA-producing plants, so cross-contamination especially with seeds but also with leaves, roots, fruits and flowers is frequent due to fast and mechanical harvesting. The seeds of Datura stramonium (jimson weed or thorn apple), widely distributed in all the warm regions of the world, along with other Datura spp., such as D. ferox are the ones that appear the most in foods [3]. D. stramonium produces numerous seeds that are encapsulated in a kind of apple-shaped fruit, hence its name thorn apple.…”