Abrus precatorius, known commonly as jequirity, Gunj, Crab's eye, rosary pea, John Crow Bead, precatory bean, Indian licorice, Akar Saga, is a slender, perennial climber that twines around trees, shrubs, and hedges. It is a legume with long, pinnate-leafleted leaves. The plant is best known for its seeds, which are used as beads and in percussion instruments, and which are toxic due to the presence of abrin.
The plant is native to Indonesia and grows in tropical and subtropical areas of the world where it has been introduced. The toxin abrin is a dimer consisting of two protein subunits, termed A and B. The B chain facilitates abrin's entry into a cell by bonding to certain transport proteins on cell membranes, which then transport the toxin into the cell. Symptoms are identical to those of ricin, except abrin is more toxic by almost two orders of magnitude, the fatal dose of abrin is approximately 75 times smaller than the fatal dose of ricin. Abrin can kill with a circulating amount of less than 3 micrograms.
Abrus precatorius, called kudri mani in Tamil and guru ginja in Telugu, has been used in Siddha medicine for centuries. The Tamil Siddhars knew about the toxic effects in plants and suggested various methods which is called "suththi seythal" or purification. This is done by boiling the seeds in milk and then drying them. The protein is denatured when subjected to high temperatures which removes its toxicity. In Siddha medicine, the white variety is used to prepare oil that is claimed to be an aphrodisiac. A tea is made from the leaves and used to treat fevers, coughs and colds. Seeds are poisonous and therefore are used after mitigation. The plant is also used in Ayurveda.
The seeds of Abrus precatorius are much valued in native jewelry for their bright coloration. Most beans are black and red, suggesting a ladybug, though other colors are available. Jewelry-making with jequirity seeds is dangerous, and there have been cases of death by a finger-prick while boring the seeds for beadwork.