Products
There are no medicines with ricin on the market. What is available is castor oil, but it is free of the toxin because of the manufacturing process. This remains in the remains of the seeds when pressed.
Structure and properties
Ricin is a natural toxin found in the seeds of the so-called miracle tree or castor tree of the spurge family. It is a heterodimeric protein and a lectin consisting of an A and B chain linked by a disulfide bridge (A-S-S-B). Both chains have a molecular weight of just over 30 kDa. A lectin is a protein that binds to carbohydrates.
Effects
Ricin is a potent poison that is lethal even in small amounts. For adults, the lethal dose is in the low milligram range. The B chain binds to the cell, resulting in endocytosis of the toxin. The A chain inhibits intracellular ribosomes, blocks protein synthesis, and induces cell death (cytotoxicity, apoptosis).
Indications for use
Currently, there are no medical indications for its use. Ricin has been studied as an anticancer drug.
Abuse
Ricin has been misused for various poisonous murders in the past. The most famous case is the elaborate murder of Bulgarian journalist Georgi Markov in 1978 on Waterloo Bridge in London, the so-called umbrella assassination. There are fears that ricin could be used for bioterrorist attacks in the future. Fortunately, however, it does not appear to be particularly well suited for this purpose. Ricin is most toxic when administered by inhalation or parenterally. Ingestion is less toxic, but can also be life-threatening. Eating a few ricin seeds can cause death. They are especially toxic when chewed.
Poisoning
Possible symptoms of poisoning include:
- Ingestion: nausea, vomiting, diarrhea, abdominal pain, liver and kidney dysfunction, death
- Inhalation: cough, respiratory dysfunction, joint pain, fever, respiratory distress, death.
- Injection: weakness, muscle pain, vomiting, fever, low blood pressure, multiple organ failure, death.
The symptoms occur within hours to days.
