July 14, 2003: What is the toxicity of mole beans?

The Poison Center received a call about two children who had ingested “mole beans.”  These plants are popular in Tennessee.  But, mole beans contain ricin.

Ricin is one of the most toxic substances known and the most toxic substance of plant origin.  Ricin is a glycoprotein, which interferes with protein synthesis.  The majority of the information about ricin toxicity comes from reports of castor bean ingestion.  Castor beans are used in making ornamental necklaces.  

The degree of mastication is a vital factor in releasing the toxin (whole beans traverse the GI tract intact) and probably accounts for the varying degree of reported toxicity.  Clinically, biphasic toxicity is described consisting of acute gastroenteritis followed by damage to viscera several days later.  Nausea, vomiting, diarrhea, abdominal pain GI hemorrhage, dehydration, and shock occur initially.  Damage to live, kidneys, and pancreas occur several days after ingestion.

Treatment is supportive and symptomatic.  There is no indication for emesis, gastric lavage, or charcoal.  Since delayed toxicity can occur, it is prudent to monitor these patients a few days following the ingestion.

In two weeks:

What is the role of Ricin as a Weapon of Mass Destruction?   

As always, if there are any questions, call the MTPC.

I am interested in any questions that you would like answered in “Question of the Week.”  Please e-mail me with any suggestions at donna.seger@Vanderbilt.edu

Donna Seger, M.D.
Medical Director, Middle Tennessee Poison Center