Toxicity of ricin present in castor bean seeds

The castor bean (Ricinus communis) is a bush from Euphorbiacea family cultivated for obtaining oil from the seeds. This oil has broad industrial employment, particularly for biodiesel. However, castor bean seeds exhibit a potent toxin, ricin. It is a glycoprotein with highly toxic action of inactivating ribosomes. The toxic action of ricin is due to inhibition of protein synthesis in eukaryotic cells, causing cell death. Only one molecule of ricin that enters the cytosol is able to inactivate ribosomes over 1500 per minute. Clinical signs associated with castor bean poisoning often occur in animals in a few hours after ingestion of the seeds. This paper reviews the literature on the toxic effects of ricin and techniques for preventing the poisoning.