'Suicide tree' toxin is 'perfect' murder weapon

* 27 November 2004
* From New Scientist Print Edition. Subscribe and get 4 free issues.
* James Randerson

A PLANT dubbed the suicide tree kills many more people in Indian communities than was previously thought. The warning comes from forensic toxicologists in India and France who have conducted a review of deaths caused by plant-derived poisons.

Cerbera odollam, which grows across India and south-east Asia, is used by more people to commit suicide than any other plant, the toxicologists say. But they also warn that doctors, pathologists and coroners are failing to detect how often it is used to murder people.

A team led by Yvan Gaillard of the Laboratory of Analytical Toxicology in La Voulte-sur-Rhône, France, documented more than 500 cases of fatal Cerbera poisoning between 1989 and 1999 in the south-west Indian state of Kerala alone. Half of Kerala's plant poisoning deaths, and 1 in 10 of all fatal poisonings, are put down to Cerbera.

But the true number of deaths due to Cerbera poisoning in Kerala could be twice that, the team estimates, as poisonings are difficult to identify by conventional means. Using high-performance liquid chromatography coupled with mass spectrometry to examine autopsy tissues for traces of the plant, the team uncovered a number of homicides that would otherwise have gone unnoticed (Journal of Ethnopharmacology, vol 95, p 123). This also suggests that some cases put down to suicide may actually have been murders, they say.

Although the kernels of the tree have a bitter taste, this can be disguised if they are crushed and mixed with spicy food. They contain a potent heart toxin called cerberin, similar in structure to digoxin, found in the foxglove. Digoxin kills by blocking calcium ion channels in heart muscles, which disrupts the heartbeat. But while foxglove poisoning is well known to western toxicologists, Gaillard says pathologists would not be able to identify Cerbera poisoning unless there is evidence the victim had eaten the plant. "It is the perfect murder," he says.

Three-quarters of Cerbera victims are women. The team says that this may mean the plant is being used to kill young wives who do not meet the exacting standards of some Indian families. It is also likely that many cases of homicide using the plant go unnoticed in countries where it does not grow naturally.
From issue 2475 of New Scientist magazine, 27 November 2004, page 15
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This could be quite interesting/handy.

Nice article, I was just looking for plant toxins...

I have attached the complete article in pdf, here is a small piece about the 'local use':
To commit suicide, people remove the green fibrous husk
of the seed, take the white fleshy kernel out and mash it with
jaggery (gur) and consume it as a sweet. For homicide, a few
kernels are mixed with food containing plenty of chillies to
cover the bitter taste of the poison. Death is likely to occur
3–6 h after ingestion.

Nowadays, HPLC-MS is not a very rare technique, but still expensive. It will although be hard to get the seeds of the tree...is (in)famous for it's toxicity, ordering it would raise eyebrows...
Extraction seems to be rather easy, just make an alcohol extract.

It will although be hard to get the seeds of the tree...is (in)famous for it's toxicity, ordering it would raise eyebrows...

I would assume, as well, that ordering this plant would raise some eyebrows, however, researching this very plant and it's toxic properties for a book plot in development it seems that it can be easily ordered over the internet.


***Found in: http://toptropicals.com/catalog/uid/cerbera_odollam.htm


"It can be grown in a small pot to show on office desk or everywhere you want for decoration."


Item Size Availability
2470 Cerbera odollam - nut
Chiute, Sea Mango. You can grow this plant from seed as a "Lucky Bean" in a pot or plant it on top of a ground, it will sprout and you will have a nice bushy tree in no time. White fragrant flowers, similar to Plumeria. See picture of the seed and picture of bonsai-1, picture of bonsai-2.
2-3" nut (seed)
Price ($) BACKORDER


2339 Cerbera odollam - plant
Chiute, Sea Mango. Endemic to the Mariana Islands. This is a small to medium-sized tree with dark foliage and showy, white fragrant flowers, similar to Plumeria, but the leaves are smaller.
These are sprouted seeds - picture of plant for sale-1, picture of plant for sale-2.1 gal pot
Price ($) 29.95


The fact this site describes it as an easy to grow plant (Lucky Bean) and aesthetically appealing plant for decoration for use in an office etc, it seems as if this plant can go overlooked. The "Lucky Bean" reference is, for me, the most interesting. They're almost marketing this plant as fun to grow. Kind of makes me remember a class project in elementary school where we would grow a bean sprout. Makes me wonder if this is part of a primary school child's curriculum in India, using this particular plant. ;)

Remarkable.

Does anybody have a link to a comprehensive listing of plant toxins?

Google (for the first time) has let me down, giving me only

http://amby.com/cat_site/plants.html

But in itself it looks like there might be a few useful links there.

According to the german wikipedia, the main toxin of the plant is cerberine, a cardioglycoside similar to the toxins of oleander.

http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Cerberin.svg/200px-Cerberin.svg.png

Does anybody have a link to a comprehensive listing of plant toxins?

I'd be interested also. I've had a bit of luck doing internet research, but the data is scattered everywhere. Can anyone recommend a comprehensive book on poisonous plants?


Rogue Science Forum post with lots of information on poisonous plants:
http://www.roguesci.org/theforum/battlefield-chemistry/1561-foxglove-digitalis.html

Cornell University Poisonous Plants: http://www.ansci.cornell.edu/plants/

Poisonous Plants and Plant Parts: http://plantanswers.tamu.edu/publications/poison/poison.html

UK site re poisonous plants: http://www.powen.freeserve.co.uk/Reference/Poisonous/poison%20index.htm

Dr. Duke's Phytochemical and Ethnobotanical Databases: http://www.ars-grin.gov/duke/farmacy.html


The toxic chemicals in most plants are either saponins (steroidal glycosides) or alkaloids.

For example:

Digitalis species (Foxglove) contains the saponin digoxin (20830-75-5), which has an oral LD50 of ~20 mg/kg in rodents and <1 mg/kg in cats (similar to methyl mercury or sodium azide).

Conium Maculatum (Hemlock) contains the alkaloid coniine (458-88-8). can't find an LD50 for this one, but doses of as little as 5 mg/kg have been fatal in mammals. Coniine can also be synthesised fairly easily: http://www.chm.bris.ac.uk/motm/hemlock/synthesis.htm

Atropa belladonna (deadly nightshade) contains a mix of alkaloids, and the extract has an (ip injection) LD50 of around 20 mg/kg. Here's a page on extracting alkaloids: http://home.conceptsfa.nl/~boogaar1/ganeralalkaloidextraction.htm


Other common plants that are listed as toxic (although in some cases this may just man that you'll vomit if you eat them by the handful)

Azalia
Cherry tree
Autumn crocus
Cyclamen
Monteray cyprus
Daphne
Delphinium
Flax
Geranium
Heather
Ivy
Lupine
Morning glory
Oleander
Peony
Rhododendron
St Johns Wort
Wisteria
Yew

The toxic chemicals in most plants are either saponins (steroidal glycosides) or alkaloids.

For example:

Digitalis species (Foxglove) contains the saponin digoxin (20830-75-5), which has an oral LD50 of ~20 mg/kg in rodents and <1 mg/kg in cats (similar to methyl mercury or sodium azide).

Conium Maculatum (Hemlock) contains the alkaloid coniine (458-88-8). can't find an LD50 for this one,

The substances you mention are not saponins. They are cardiac glykosides. Both groups (saponins and cardiac glykosides) are of glykosidic nature, all cardiac glykosides have a steroidal aglycone in molecule, while some (not all) saponins have also a steroidal aglycone in their structure. The difference between the two groups is in their physiological action: while cardiac glykosides (digoxin, gitoxin, oleandrin, adonitoxin, convallatoxin, ouabain etc.) are acting mainly on the Na+/K+/ATPase of myocardial cells, the saponins (like digitonin and sapotoxin) are changing the surface tension and are dispersing lipoid matters, damaging cell membrane, like tensides.

LD50 for coniine (mice, p.o.) is 100 mg/kg.


Atropa belladonna (deadly nightshade) contains a mix of alkaloids, and the extract has an (ip injection) LD50 of around 20 mg/kg.

Which species is that LD50 value reffered for?

Thanks for clearing that up regarding saponins. I was incorrectly assuming that saponin was a generic term for a large number of plant glycosides.


The LD50 for belladonna is from RTECS, and is fairly ancient:

LD50 - Lethal dose, 50 percent kill
Intraperitoneal
Rodent - mouse
22 mg/kg
Details of toxic effects not reported other than lethal dose value
RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,272,1970

The LD50 for belladonna is from RTECS, and is fairly ancient:

LD50 - Lethal dose, 50 percent kill
Intraperitoneal
Rodent - mouse
22 mg/kg
Details of toxic effects not reported other than lethal dose value
RPOBAR Research Progress in Organic-Biological and Medicinal Chemistry. (New York, NY) V.1-3, 1964-72. Discontinued. Volume(issue)/page/year: 2,272,1970

This seems highly doubtful to me, because rodents (mice, rats, rabbits etc.) are specifically resistent towards the toxic action of solanaceae tropane alkaloids (atropine, scopolamine, hyoscyamine), due to fast hepatic metabolism of these alkaloids. This paradox (LD50 (rat, i.p.) beeing over 600 mg/kg atropine sulfate vs. circa 1-5mg/kg by human) is well-known in the toxicological community and toxicology students are faced with it quite early in colloqiums for the reason not to neglect high human toxicity of these very common alkaloids due to their low acute toxicities in rodents. As I'm not aware of any other important toxins of belladona, I assume, there is some inaccuracy in this particular value, maybe it was 20mg per mouse, or 200 (2.000?) mg/kg...

Cerbera Odollam- Perfect murder weapon with some disadvantages.

In study in article which Child-of-bodom attached, it says, that only 1 of 6 people, who were poisoned by cerbera odollam's kernel, died. It also says, that there were no correlation between the amount of kernel consumed and the mortality rate. This sounds like a big disadvantage, if one would intent to use it, as silent poison. Maybe if alcoholic extract would be made, larger dose of cerberin would hit the blood at the same time and befor stomach starts to "turning around" and vomiting begins. This could raise mortality ratio ;).

Here we come across secon diasadvatage- symptoms. "Heart attack" is desired symptom, but others like nausea and vomiting are not so welcomed, if one want represent death as a heart attack.

Any corrections or additional information are highly appreciated.

The addition of an anti-emetic (such as cannabinoids) would be called for then, to suppress the vomiting, and to aid retention of the poison in the stomach longer.

Though nausea and vomiting are common symptoms of a major coronary event. :)

Also, being a plant poison, the concentration of active ingredient will vary with season and location. Extraction and qualitative analysis of the ingredient would be necessary to accurately predict a lethal dose.

Yes, antiemetics would help to retain stomach content for a longer time (so more of active substance can absorb), but the victim will probably start to vomit sooner or later.

Very detailed symptoms of Cerbera Tanghin, which is close relative to Cerbera Odllam (it also contains cerberin) can be seen at http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1319007 .