ABSTRACT
Toxic Principle and Mechanism of Action Only the seeds of the rosary pea are toxic as they contain potent lectins (toxalbumins) called abrin I and II that are toxic to all animals including humans. Abrin is very similar to ricin, the lectin found in castor beans, and consists of 2 polypeptide chains (A and B), cross-linked by a disulfide bond that is a potent ribosomal inhibitor.1,2 The B chain binds to carbohydrate receptors on cell surfaces, facilitating the entry of the A chain into the cell where it inhibits initiation and elongation of peptides within ribosomes. Rapidly growing and dividing cells such as those of the intestines are most severely affected. The lethal dose (LD50) of abrin is in the range of 0.1-0.2 micrograms/kg body weight.2 Each gram of seed contains approximately 0.5mg of abrin.2
