Precatory Bean

Scientific Name(S): Abrus precatorius L. Family: Leguminosae (Fabaceae)

Common Name(S): Precatory bean, love bean, rosary pea, crab's eye, jequirity seed, bead vine, black-eyed Susan, prayer beads and numerous other locally used common names.

Botany: The plant originated in southeast Asia and is now found in other tropical and subtropical regions. It is found commonly in Florida and Hawaii where it grows as a slender vine generally supported by other plants or a fence. The leaves are sensitive to light, drooping at night and on cloudy days. The fruit splits open as it dries to reveal three to five hard coated, brilliant scarlet 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 Leguminosae.

History: The rosary pea has found widespread use as an art object and ornament. The colorful, hard beans have been used as pendants, rosaries, necklaces and in toys such as noise shakers. 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. They have been used to hasten labor, stimulate abortion and have also found some use as an oral contraceptive in traditional medicine. Because of the great potential for toxicity, the use of this plant should not be recommended.

Uses of Precatory Bean:

The precatory bean has experienced some success as an analgesic in terminally ill patients and evaluated in the treatment of experimental cancers.

Side Effects of Precatory Bean:

The precatory bean is highly toxic and has been known to cause severe stomach cramping, nausea, severe diarrhea, cold sweat, fast pulse, coma, and circulatory collapse.

Toxicology: Fatal poisoning in children has been reported after the thorough chewing of one seed. Ingestion of jequirity seeds causes severe stomach cramping accompanied by nausea, severe diarrhea, cold sweat, fast pulse, coma and circulatory collapse. The onset of toxicity usually occurs in 1 to 3 days. The seeds must be chewed thoroughly; unchewed or intact seeds remain impervious to gastric fluid and pose less of a toxicologic potential. Gastric lavage or emesis should be followed by measures to maintain circulation including the correction of hypovolemia and electrolyte disturbances. Alkalinization of the urine to control uremia and enhance toxin excretion has been recommended. Necklaces made of the pierced seeds have been reported to induce dermatitis.

A radioimmunoassay has been developed for abrin.

The LD50 of abrin given IP to mice is 0.04 mcg; 5 mg of the alkaloid abrine is reported to be toxic to humans. In goats, ground seeds administered at a dose of 1 and 2 g/kg/day caused death in 2 to 5 days.

Summary: Phytotoxin poisoning from Abrus represents a rare but extremely dangerous and potentially fatal hazard, especially to the young. Prompt emesis followed by supportive therapy may result in uncomplicated recovery from poisoning. While rosary peas generally have little exposure in American culture, health professionals should remain aware of their potential danger.