Question
What is the name of the toxin found in this seed/bean and its mechanism of toxicity?
Answer
Name: Jequirity bean or rosary pea (Abrius precatorius)
Toxin: Abrin (toxalbumin)
Mechanism of toxicity:
- Abrin is a toxin that is similar to ricin in structure and mechanism.
- It is a dimer with A and B-chains.
- B-chain facilitates entry into the cell (via endocytosis)
- A-chain inhibit protein synthesis by inhibition of ribosome 60S
Exposure
- Ingestion (most common): The bean/pea must be chewed or grinded, which releases Abrin, to cause toxicity. Whole bean/pea ingestion without breaking its shell is non-toxic
- Injection (rare): potentially life-threatening.
Signs and symptoms of toxicity:
- GI: nausea, vomiting, abdominal pain, diarrhea (common) --> electrolyte abnormalities, hypovolemia, GI bleeding
- Severe toxicity: multiorgan failure, hypovolemic shock and death.
Treatment:
- Predominantly supportive measures/care.
- There is no “antidote” for Abrin or Ricin toxicity.
References
- Audi et al. Ricin poisoning: A comprehensive review. JAMA 2005 Nov 9;294(18):2342-51.
- Rinner GR et al. Fatal abrin poisoning by injection. CLin Toxicol (Phila). 2020 June 1;1-3. doi: 10.1080/15563650.2020.1771360.