Abrin

Abrin is a natural poison that is found in the seeds of a plant called the rosary pea or jequirity pea. Abrin is similar to ricin, a toxin that is found in the seeds of the castor oil plant.

Physical Properties
Abrin can be made in the form of a powder, a mist, a pellet, or it can be dissolved in water. Powdered abrin is yellowish-white in colour. Abrin is a stable substance, meaning that it can last for a long time in the environment despite extreme conditions such as very hot or very cold temperatures.

Use
Abrin is not known to have been used as a biological weapon. The rosary pea, which is the source of abrin, is common to many tropical areas throughout the world and is sometimes used as an herbal remedy. The seeds of the rosary pea have been used to make beaded jewelry, which can lead to abrin poisoning if the seeds are chewed and swallowed. The outer shell of the seed protects the contents from the stomachs of most mammals. Abrin has some potential medical uses, such as in treatment to kill cancer cells.

Toxicity
Abrin works by getting inside the cells of a person’s body and preventing the cells from making the proteins they need. Without the proteins, cells die. Eventually this is harmful to the whole body, and death may occur. Effects of abrin poisoning depend on whether abrin was inhaled, ingested, or injected.

Signs and symptoms of abrin exposure
The major symptoms of abrin poisoning depend on the route of exposure and the dose received, though many organs may be affected in severe cases. Initial symptoms of abrin poisoning by inhalation may occur within 8 hours of exposure. Following ingestion of abrin, initial symptoms may occur in less than 6 hours but usually are delayed for 1 to 3 days.

Inhalation
Within a few hours of inhaling significant amounts of abrin, the likely symptoms would be respiratory distress (difficulty breathing), fever, cough, nausea, and tightness in the chest. Heavy sweating may follow as well as fluid building up in the lungs (pulmonary edema). This would make breathing even more difficult, and the skin might turn blue. Excess fluid in the lungs would be diagnosed by x-ray or by listening to the chest with a stethoscope. Finally, low blood pressure and respiratory failure may occur, leading to death.

Ingestion
If someone swallows a significant amount of abrin, he or she would develop vomiting and diarrhea that may become bloody. Severe dehydration may be the result, followed by low blood pressure. Other signs or symptoms may include hallucinations, seizures, and blood in the urine. Within several days, the person’s liver, spleen, and kidneys might stop working, and the person could die.

Absorption
Abrin in the powder or mist form can cause redness and pain of the skin and the eyes. Death from abrin poisoning could take place within 36 to 72 hours of exposure, depending on the route of exposure (inhalation, ingestion, or injection) and the dose received. If death has not occurred in 3 to 5 days, the victim usually recovers.

Treatment
Because no antidote exists for abrin, the most important factor is avoiding abrin exposure in the first place. If exposure cannot be avoided, the most important factor is then getting the abrin off or out of the body as quickly as possible. Abrin poisoning is treated by giving victims supportive medical care to minimize the effects of the poisoning. The types of supportive medical care would depend on several factors, such as the route by which victims were poisoned (that is, whether poisoning was by inhalation, ingestion, or skin or eye exposure). Care could include such measures as helping victims breathe, giving them intravenous fluids (fluids given through a needle inserted into a vein), giving them medications to treat conditions such as seizure and low blood pressure, flushing their stomachs with activated charcoal (if the abrin has been very recently ingested), or washing out their eyes with water if their eyes are irritated.