Precatory Bean

Scientific Name(s): Abrus precatorius L.
Common Name(s): Bead vine, Black-eyed Susan, Buddhist rosary bead, Crab's eye, Jequirity seed, John Crow beads, Love bean, Lucky bean, Prayer beads, Precatory bean, Rosary pea, Weather plant

Medically reviewed by Drugs.com. Last updated on Jan 31, 2022.

Clinical Overview

Use

The precatory bean has experienced some success as an analgesic in terminally ill patients.

Dosing

Precatory bean is a dangerous poison; one seed if thoroughly chewed has been claimed to be fatal to a child, however the tough, impermeable seed coat reduces its toxic potential.

Contraindications

No longer considered safe.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking. Avoid use.

Interactions

None well documented.

Adverse Reactions

Because of the irritant effects of abrin on the GI mucosa, ingestion of precatory beans causes severe stomach cramping accompanied by nausea, vomiting, severe diarrhea, cold sweat, and fast pulse. Coma, circulatory collapse, acute renal failure, and hepatotoxicity also have been reported.

Toxicology

Precatory bean is highly toxic. Onset of toxicity usually occurs in 1 to 3 days. It is most commonly ingested accidentally by children.

Scientific Family

• Fabaceae (pea)
• Leguminosae (bean)

Botany

A. precatorius is native to southeast Asia and is now found in other tropical and subtropical regions. It is commonly found in Florida and Hawaii where it grows as a slender vine generally supported by other plants or a fence. The plant has clusters of pink flowers, and its compound leaves are sensitive to light, drooping at night and on cloudy days. The fruit splits open as it dries to reveal 3 to 5 hard-coated, brilliant scarlet (or rarely white) seeds with a small black spot at the point of attachment. This spot helps identify the seeds, which are sometimes confused with Rhynchosia, in which the black and red colors are reversed. Seeds of A. precatorius may also be confused with those of Ormosia, also a toxic member of the Fabaceae.Chevallier 2001, Garaniya 2014, Quattrocchi 2012, USDA 2016 A synonym is Abrus abrus L.

History

The precatory bean has found widespread use as an art object and ornament. The colorful, hard beans have been used as pendants, rosaries, rattles, necklaces, and in toys such as noise shakers.Fernando 2001

All parts of the plant have been used in traditional medicine. Dilute infusions have been used in South American and African folk medicine for the treatment of ophthalmic inflammations such as conjunctivitis. Precatory beans have been used medicinally to hasten labor, stimulate abortion, and also have found some use as an oral contraceptive in traditional medicine. The seeds also have been used to treat fever in Chinese medicine. The leaves and roots of the plant have been used in Ayurvedic medicine for treatment of asthma, bronchitis, and other respiratory conditions.Chevallier 2001, Evans 1989, Garaniya 2014

Because of the great potential for toxicity, the use of this plant is not recommended.

Chemistry

Several indole alkaloids (eg, abrin, hyaphorine, precatorine), triterpenoids, and glycosides have been isolated from the plant.Evans 1989, Garaniya 2014, Kim 2002, Yadava 2002

The protein abrin has been isolated from the seed and is respon...