Canadian team develops ricin antidote

Canadian scientists recently published a study detailing their successful efforts to develop an antidote for ricin poisoning.

The team from Defense Research and Development Canada created four ricin-resistant hybridoma clones that secrete antiricin monoclonal antibodies with ricin-neutralizing capabilities. Their effectiveness was determined through an in vitro neutralization assay that showed success in mice subjects against multiple ricin challenges.

One of the experimental antidotes, called mAb D9 in the study, proved exceptionally effective against the toxin. When administered up to six weeks before or six weeks after a ricin challenge, it successfully protected or rescued all of the mice used in the trial.

The team, led by Dr. Wei-Gang Hu, said that mAb D9 has excellent potential for further development into a potent antidote against ricin poisoning as both a prophylactic and a therapy. They hope to humanize the antidote in further research.

Ricin is considered to be a major potential weapon of bioterror. It is extremely lethal, easily produced and relatively stable. It is made by processing the castor bean, which is generally available worldwide. The U.S. Centers for Disease Control and Prevention lists ricin as a Category B threat agent. There is currently no approved antidote against the toxin.