Abrus Precatorius - Toxin

Toxin

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. Once inside the cell, the A chain prevents protein synthesis by inactivating the 26S subunit of the ribosome. One molecule of abrin will inactivate up to 1,500 ribosomes per second.

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.Abrin has an estimated human fatal dose of 0.1-1 ug/kg. Ingesting the intact seeds typically results in no clinical findings, as they pass through the gastrointestinal tract due to their hard shell.

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 it toxicity.

In March 2012 a recall was issued for bracelets made using Jequirity Beans sold by the Eden Project and other outlets in the UK.

This plant is also poisonous to horses.

Read more about this topic:  Abrus Precatorius