Castor beans ingestion

Palatnick, W, Tenenbein, M. Hepatotoxicity from Castor Bean Ingestion in a Child. Journal of Toxicology Chnical Toxicology, 38(l) 67-69, 2000... 

Palatnick, W. and Tenenbein, M. (2000) Hepatotoxicity from castor bean ingestion in a child. J Toxicol Clin Toxicol, 38, 67-69. 

In a series of ten paediatric castor bean ingestions, seven had transient ECG abnormalities, including QT interval prolongation (in five cases), intraventricular conduction disturbance and repolarization changes. The authors suggested that these changes were probably secondary to metabolic disturbances (Kaszds and Papp, 1960). It is possible that these abnormalities may have resulted from ricin-induced apoptosis of key elements of the cardiac conduction system. Such an effect of ricin has been noted in vivo in rats (Leek, 1989). 

Patients who receive prompt symptomatic and supportive care following castor bean ingestion are likely to survive, with a fatality rate for treated patients of approximately 2% (Rauber and Heard, 1985). In fatal cases, death usually occurs on the third day or later and is due to multi-organ failure (Franz and Jaax, 1997). The most common findings at autopsy are ulceration of the mucosa of the stomach and small intestine, necrosis of mesenteric lymph nodes, hepatic necrosis and nephritis (Franz and Jaax, 1977). 

Hamelin, E.I., Johnson, R.C., Osterloh, J.D., Howard, D.J., Thomas, J.D., 2012. Evaluation of rid-nine, a ricin biomarker, from a non-lethal castor bean ingestion. J. Anal. Toxicol. 36, 660-662. 

ECG abnormalities in children who ingested castor beans have been noted by Kaszas and Papp (1960). These include QT interval lengthening, repolarization changes, and intraventricular conduction disturbances. Crompton (1980) later reported on experiments on pigs that experienced hemorrhagic lesions and an abnormal ECG due to ricin. At the present time, no antidotes or effective therapy are available to counteract the effects of ricin. 

Gastrointestinal effects usually develop in under 6 h, but vomiting can begin in 1 to 3 h post-ingestion of castor beans (Kopferschmitt et al, 1983 Spyker et al, 1982). In some cases, signs may be delayed for several days. The cytotoxic effects on the liver, CNS, kidney, and adrenal glands may not occur for 2 to 5 days post-exposure. With an inhalation exposure symptoms begin within 8 h. Death occurs about 48 h after a parenteral or oral exposure (Budavari, 2000). 

The observation that the duck is the most hkely to ingest castor beans provides evidence that castor beans could be used by terrorists against wild ducks. 

Transdermal exposure to ricin is not serious, since it is not well absorbed through the skin. Oral exposure, for example by ingestion of castor beans, can cause severe gastroenteritis, gastrointestinal hemorrhage, and death due to circulatory collapse. Parenteral injection of ricin is rapidly fatal, as is aerosol exposure the lethal dose by these routes is 5-10 micrograms/kg (8). 

Ingestion is the most common route, but ocular and dermatologic exposures to castor bean powder have been reported. 

It is is the third most toxic substance known after plutonium and botulism it is a protein toxin that is extracted from the castor bean (Ricinus communis). The USA Centers for Disease Control (CDC) considers 500 pg to be the lethal dose of ricin in humans if exposure is from injection or inhalation. Ricin is poisonous if inhaled, injected, or ingested, acting by the inhibition of protein synthesis. While there is no known antidote, the US military has developed a vaccine. 

There is normally a delay of several hours between the exposure to ricin and the onset of clinical symptoms, but the cytotoxic effects may not occur until two to five days after ingestion. In contrast, certain individuals may display allergic reactions almost immediately after exposure, and this is presumed to be related to the glycoproteins that the beans contain. Episodes of asthma have been linked to the inhalation of ricin dust at castor bean mills — in one incident in 1952 at Bauru in Brazil, 150 people living close to a bean mill were affected by sudden asthma attacks. 

If a suspected ingestion of the beans has occurred then it is vital to determine whether or not the beans were chewed before swallowing or if the outer coat had been removed in some other way. Anyone handling the beans should wear protective gloves. It should be remembered that the castor beans contain a number of allergenic glycoproteins which can produce skin reations and even anaphylaxis. 

The two articles on ricin at the end of this article tell of survival by accidental ingestion by adults of castor bean dust or of children who live after swallowing a few beans. But when relatively pure ricin is administered on purpose when the victim breathes it ir), gets it under the skin, or swallows it, he is doomed. There is no known antidote... 

Activated charcoal lavage may be helpful immediately after ingestion of castor beans or ricin, but ricin acts rapidly and irreversibly, which makes treatment very difficult after signs and symptoms appear. Symptomatic care is the only intervention presently available to clinicians treating aerosol ricin poisoning. Additional information on ricin may be found in Franz and Jaax (1997). 

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