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Abrus precatorius, jequirity bean, rosary pea

Summary

Contains a very highly toxic substance but does not seem to have caused fatal poisonings in the past few decades. Its use in jewellery is, however, not very wise.

Blog Entries

Read more about Abrus precatorius, jequirity bean, rosary pea, in these blog entries (most recent first);
The problem of getting people to understand what you say (or write)
The Eden Project recalls bracelets made of rosary pea seeds.

Family

Fabaceae

Meaning of the Name

Arbus
Probably, from arbor, the Latin for tree or shrub.

precatorius
Relating to prayer, a probable reference to the use of the seeds to make rosaries.

Common Names and Synonyms

rosary pea, jequirity, jequirity bean, crab's eye, John Crow bead, precatory bean, Indian liquorice

How Poisonous, How Harmful?

Abrus precatorius contains the toxic lectin, or toxalbumin, abrin. Abrin is similar in structure to ricin the toxin in Ricinus communis. It is often described as deadly and some newspapers have claimed that it is twice as toxic as ricin. Occasionally, rosary pea and castor bean get confused and the impression is given that they are the same thing.

Abrus precatorius, jequirity bean, rosary pea

Abrus precatorius, jequirity bean, rosary pea
courtesy of the U.S. Geological Survey

Though abrin is believed to be present throughout the plant, the seeds attract the greatest attention. as is often the case, they have an indigestible outer casing and there have been reports of them passing through the digestive system without harm.

If chewed or crushed to release the abrin, poisoning can occur. Some say that one crushed seed is sufficient to cause death but the literature contains one paper detailing the case of an intended suicide who had thoroughly crushed a number of seeds and ingested the powder before thinking better of it and seeking medical care. The subject, a 27-year old male, suffered severe gastrointestinal symptoms but was fit for release from the emergency department after eight hours and a follow-up, one month later, showed no long-term effects.

It appears that abrin is only very slowly absorbed by the body and, therefore, swift action after ingestion should prevent severe consequences.

Incidents

The International Poisonous Plants Checklist gives twenty references to papers concerned with Abrus precatorius poisoning though only one, from 1969, is obviously about a human fatality involving a 2-year old child.

Abrus precatorius, jequirity bean, rosary pea

Abrus precatorius, jequirity bean, rosary pea
Courtesy of the US Department of Agriculture

A 1978 case is reported but appears to be a successful suicide rather than accidental ingestion.

There are reports of deaths in children in the 1940s, '50s and '60s in Florida where the plant can be found growing in the open but the absence of more recent fatalities may be the result of improved care.

The plant does not feature in any of the American Association of Poison Control Centers' (AAPCC) annual reports from the National Poison Data System (NPDS) since, at least, 2004.

A 2007 case report describes the death of a 30-year old woman who was believed to have chewed the seeds. Her death resulted from swelling of the brain and the paper states that this symptom had not been seen before with abrin poisoning.

A 2008 paper reported the case of a 27-year old male who chewed a number of seeds intending to commit suicide but then sought immediate medical help and survived after an very unpleasant gastrointestinal upset.

Also in 2008, a 19-year old in India attempted suicide using Abrus precatorius seeds. He suffered very severe poisoning but, again, survived partly because, following the 2007 case, he was given a brain scan. Another paper from India, in 2008, reported on two cases in one of which the subject died before medical support could be provided.

A 2010 paper gives another case, involving a 20-year old, but, in this incident, the young man refused to acknowledge that he had chewed and swallowed rosary pea seeds until his father brought the rest of pack to the hospital. Nonetheless, he recovered fully and suffered no long-term consequences.

Folklore and Facts

The reputation of rosary pea seems to come from the similarity in structure and action between ricin and abrin. It seems likely that, like ricin, the theoretical toxicity is much more significant than the actual harm caused. Certainly, given that the theoretical toxicity is very much higher than ricin, the dearth of fatal case reports supports this.

The seeds are an attractive red with a black spot on them and have been used for many years in South America to make necklaces and bracelets as well as, as the common name suggests, rosaries.

There are persistent reports that the workers who pierce the seeds in order to thread them onto a string suffer poisoning but there seems to be little evidence. An online search found 265 scientific papers referring to Abrus precatorius but not one of them dealt with occupational poisoning.

In December 2011, it emerged that the Eden Project, one of the UK's best known visitor attractions, had sold around 2,800 bracelets, over two years, made of Abrus precatorius seeds. Following the discovery, buyers were asked to return the bracelets for a full refund.