Plant toxins like ricin, abrin, and gelonin are discussed as potential bioterrorism agents. Ricin comes from castor beans and is lethal even in small doses if inhaled, ingested, or injected. It causes pulmonary edema or organ failure. Abrin comes from abrus precatorius and similarly causes respiratory distress or organ damage depending on route of exposure. Gelonin inhibits protein synthesis. All are highly toxic with no available treatments other than supportive care. Their widespread availability, stability, and lethality in small doses make these plant toxins concerning for bioterrorism.

2. Why plant toxins are used in
Bioterrorism?
• Biotoxins of plant origin attract terrorists as
they are:
_ Difficult to detect
_ Difficult to control

3. • There are a huge variety of plant poisons
and it is difficult to organize the myriad
plant toxins in an understandable manner.
• Among known plant toxins, few of which
may be worthy of special attention in
context of bioterrorism.
1. Ricin
2. Abrin
3. Gelonin
4. Lectin
5. Curare
6. Modeccin

4. Ricin
• Castor plant - Ricinus communis
– From processing waste
• Castor beans for oil
– Very stable
– In several forms
• Powder, mist, pellet, dissolved
in water or weak acid
– Irreversibly blocks protein synthesis
– Potential medical uses

5. Ricin

6. History
• World War I
– Considered for use as weapon by US
• 1978: London
– Assassination of Bulgarian exile, Georgi Markov
• 1991: Minnesota
– Patriot’s Council plot to kill US Marshal
• Iran-Iraq war
– Reports of ricin use
– Found in Al Qaeda caves in Afghanistan

7. Transmission
• Three routes
– Inhalation
– Ingestion
– Injection
• Person-to-person transmission does not
occur.

8. Signs and Symptoms
• Inhalation
– Incubation less than 8 hours
– Cough, weakness, fever, nausea, muscle
aches, chest pain and cyanosis
– Pulmonary edema, 18-24 hours after inhalation
– Severe respiratory distress
– Death from hypoxemia, 36-72 hours

9. Pulmonary edema

10. • Ingestion
– Least toxic form
– Less toxic if castor
beans swallowed whole
– Severe GI symptoms, 1-2 hours
– Rapid heartbeat
– Internal bleeding
– Vascular collapse
– Death occurs in 3 days or more

11. • Injection
– Local pain and necrosis at site of injection
– Systemic signs similar to those of ingestion

12. Treatment
• No treatment, vaccine or antisera
currently available
• Avoid ricin exposure
• Supportive care
– Dependent on route of exposure
– Ventilator
– Gastric lavage or cathartics

13. Ricin as biological weapon
•
•
•
•
Extreme ease of production
Widely available
Relatively high toxicity
Currently no treatment
– Supportive care only

14. Abrin
• Jequirity pea - Abrus precatorius
_ Very stable
_ In several forms
_ Powder, mist, pellet, dissolved in
water
_ Blocks protein synthesis
_ Potential medical use

15. Abrus plant

16. Toxicity
• Abrin works by
_ penetrating the cells of the body
_ inhibiting cell protein synthesis
• The severity of the effects of abrin
poisoning vary on the means of exposure
to the substance (whether
inhaled, ingested, or injected).

17. Transmission
• Three routes
_ Inhalation
_ Ingestion
_ Absorption

18. Signs and Symptoms
• Inhalation
– Respiratory distress, fever, cough, nausea, and
tightness in the chest.
– Heavy sweating may follow as well as pulmonary
edema.
– Skin might turn blue
– Low blood pressure
– Respiratory failure that ultimately lead to death

19. Cyanosis

20. • Ingestion
If a person swallows a small amount:
_
Vomiting, diarrhea, hallucination, seizures
and blood in the urine.
_ Severe dehydration followed by low
blood pressure.
_ Within several days, the
person’s liver, spleen and kidney might
stop working, and the person will die.

21. • Absorption
In powder or mist form abrin can cause
_ Redness of skin and eyes
_ pain
• Death from abrin poisoning could take
place within 36 to 72 hours of exposure.

22. Treatment
•
•
•
•
No treatment or antidote
Avoid abrin exposure
Getting the abrin off or out of body
Supportive care
_ Dependent on route of exposure
_ Flushing stomach with activated
charcoal

23. GELONIN
• Himalayan plant - Gelonium
multiflorum
• Inhibits protein synthesis
_ by cleaving N-glycosidic bond of
specific adenine.