Toxicity and treament of ricin poisoning:a review / 中国药理学与毒理学杂志

ABSTRACT

Ricin is a plant toxin isolated from the seed of the castor plant(Ricinus communis). As a typical II ribosome inactivating protein,ricin consists of two polypeptide chains named ricin toxin A chain(RTA)and ricin toxin B chain(RTB),linked via a disulfide bridge. RTB binds to both glycopro?tein and glycolipid at the surface of the target cell and mediates ricin to be endocytosed and transported retro?gradely to the endoplasmic reticulum. After being reduced and retrotranslocated to the cytosol,RTA mediates its toxicity due to its activity of a RNA N- glycosidases. Aside from its main toxic effect of protein synthesis inhibition,ricin also displays other properties that contribute to its toxicity such as inducing apoptosis,cytokine secreting and peroxidation. Ricin is stable and can be easily isolated. It has many routes of intoxication with no specific antidotes. Due to its natural abundance,remarkable toxicity,and the potential to be used in biological warfare as well as terrorist attacks,ricin has been classified as a Category B biothreat agent. Here we reviewed its history as a biothreat agent,constitu?tion,intoxication mechanism,detection methods and the development of specific antitodes.