2. POISON: “any substance which when ingested, inhaled or absorbed or when applied to,
injected into, developed within the body by its chemical action, may cause damage to
structure or disturbance of function”.
Poisons originating from plant are known as Plant Poisons. The toxins may be present in
any part of the plant like leaves, stem, seeds, roots, bark, etc.
Phytotoxicology is expression used to signify the study of plants that produce
deleterious effects on human.
01 Introduction
3. The plant kingdom contains
potentially 300,000 species,
and the toxic effects of plants
serve primarily as defense
mechanisms against natural
predators.
There are more than 4000
species of medicinal plants
growing as shrubs, herbs and
trees in India; many of which
are poisonous when
administered in large doses.
In India, it was
estimated that more
than 50,000 people die
every year from toxic
exposure which was
highest in the world.
4. Historical Aspects
# The ancient Indian text Rig Veda (12th century BC) also describes several plant poisons.
# Socrates (470–390 BC) was sentenced to death by hemlock. They were used mainly for
hunting. Some were used as ―ordeal poisons ex physostigmine from Physostigma
venenosum (Calabar bean), and amygdalin from peach pits.
#Dioscorides was a Greek army physician, classified poisons according to their origin
(animal, vegetable, or mineral) and his book De Materia Medica is one of the most
influential herbal books and is a precursor to all modern pharmacopeias.
# Indian surgeon Sushruta defined the stages of slow poisoning, antidotes and traditional
substance for treatment of poisoning.
5. Glycosides
Steroidal glycosides,
Flavonoid glycosides,
Anthraquinone glycosides,
Cyanophoric glycosides,
Alcohol glycosides, Lactone,
Aldehyde, Phenolic
Alkaloids
Pyridine-Piperidine
alkaloids, Tropane
alkaloids, Quinoline
alkaloids, Isoquinoline
alkaloids, Steroidal
alkaloids Purine bases
Toxic
Proteins
Toxalbumines
Resins/Juices/
oils/Plant
acids
Classification of poisonous plants
02
On the basis of
chemical
constituents:
6. Neurotoxic Poisons
01
e.g. Papaver somniferum, Dhatura
fastuosa, Cannabis sativa, Nux vomica,
Erythroxylon coca, Atropa belladonna
Irritants
02
e.g. Castor, Abrus precatorius,
Capsicum, Calotropis gigantea,
Calotropis procera, Cytisus laburnum,
Croton tiglium, Argemone mexicana
Hepatotoxic Poisons
03 e.g. Neem, ackee
Cardiotoxic Poisons
04 e.g. Oleander, Aconitum napellus,
Nicotiana tabacum, Digitalis
purpurea
Dermal Irritants
05 e.g. Mango
Classification of poisonous plants
02
02
On the basis of their effect on the body:
8. 3.1 Abrus precatorius (Abrus)
• a.k.a.- Rati, gunja, jequirity bean, Indian liquorice, Rosary pea,
crab’s eye
•It is found all over India, and belongs to Leguminosae family.
Toxic Part of Plant
• Seed • Root • Leaves
Toxic Principle
• Abrin
• Present in seed and is toxalbumin
Mechanism of Action
Abrin prevents protein synthesis by inactivating the 26S subunit
of the Ribosome, thereby causing cell death.
Sign and symptoms
1. Dermal manifestations: inflammation, swelling, ecchymoses
and
necrosis at the site.
2. Ocular exposure: redness, chemosis, swelling and
conjunctivitis.
3. Oral ingestion: pain in abdomen, vomiting, diarrhoea,
bleeding per rectum, cardiac arrhythmias, convulsions
and CNS depression. The symptoms resemble those of viper
snakebite.
9. Fatal Dose:1 to 2 crushed seeds( 90 to 120 mg of abrin) Fatal period: 3 to 5 days
Treatment
• Injection of anti-abrin. • Gastric lavage
• Convulsions can be controlled by diazepam/lorazepam • Supportive measures
• Local exposure should be treated with copious irrigation
with plain water
Postmortem Findings
• Fragments of needle may be found. Edema at the site of injection. • Cerebral edema
• GIT-shows edematous bowel with hemorrhage • Liver, spleen, kidneys — congested
Medicolegal Importance
1. Accidental poisoning
2. Homicide by sui prepared with abrin
3. Cattle poison.
4. Malingerers use powder of abrus seed to produce conjunctivitis.
5. When intact seeds are swallowed or when seeds are boiled or cooked, they are not poisonous.
Test for Abrus precatorius
1 Fast Blue B-Potassium Hydroxide Test: A red to orange colour is observed.
2 Marquis Reagent: A pink colour is formed.
3 Van Urk Reagent: A green colour changing to blue is observed.
10. 3.2 Ricinus communis (Castor)
Castor plants are tall plants and grow all over India.
Identification of Seeds
• Seeds are variable, smooth, flattened-oval, mottled with light and
dark brown markings, bright and polished.
• They are of 2 sizes, small and big.
• Small seeds are about 1.2 × 0.8 cm in dimensions and resemble
croton seeds.
Toxic part of plants: All parts of plant but seeds are more toxic
Toxic Principle: Ricin (toxalbumin)
Mechanism of Action
Ricin blocks protein synthesis through inhibition of RNA polymerase.
Signs and Symptoms
Dust of seeds may cause:
• Watering of eyes and conjunctivitis
• Acute nasal inflammation and sneezing
• Headache• Asthmatic bronchitis • Gastric upset • Dermatitis
11. On ingestion (seen within 10 h of ingestion)
• GIT: Burning pain in throat, colicky abdominal pain/cramping, nausea, thirst, vomiting and diarrhea (often
bloody).
• CNS: Vertigo, drowsiness, delirium, convulsions and coma.
• Uremia, jaundice, rapid feeble pulse, cold clammy skin, cramps and dehydration.
Consciousness is retained till death in some cases.
Fatal dose: 5 to 10 seeds(1 mg/kg body weight for Ricin) Fatal period: 2 to few days
Treatment
•No known antidote or other specific treatment • Gastric lavage and administer activated charcoal
•Supportive treatment
Postmortem Findings
• Mucosa of GIT may be inflamed with hemorrhages
• Crushed seeds with pericarp may be found in stomach • Hemorrhages in organs.
Medico-legal Aspects
Accidental poisoning may occur in children; rarely, powdered seeds are given for homicide. The powder of
seeds causes conjunctivitis when applied to the eye.
A Bulgarian umbrella case-assassination of the Bulgarian dissident writer Georgi Markov on 7 September
1978
12. 3.3 Croton tiglium (Jamalgota)
It grows all over India.
Identification of Seeds
• Seeds are 1.27 × 0.84 cm in dimensions.
• Oval or oval-oblong and odorless.
• Dark brown or brownish-gray shell.
• Resemble castor seeds, but they are not shiny and not
mottled.
Toxic Part of Plants
• Seed • Stem •
Leaves
Toxic Principle
• Crotin (toxalbumin)
• Crotonoside (glycoside)
Signs and Symptoms
• Pain in abdomen • Salivation
• Vomiting • Diarrhoea (watery)
• Vertigo • Circulatory
failure/shock
Fatal dose: 4 crushed seeds or 3 drops of oil (1.5 ml).
Fatal period: 6 h to 3 days.
Treatment:
• Gastric lavage • Symptomatic
Postmortem Findings
• Signs of inflammation in GIT
• Abdominal viscera congested
Medicolegal Importance
1. Accidental poisoning
2. Used to procure abortion
3. Seeds may be used for homicidal purpose
4. Used in quack medicine
5. Arrow poison
13. 1
2 ml. of concentrated extract of residue in ethanol is added to an equal volume of 40%
Sodium hydroxide solution in a small test tube. A brownish red or reddish violet ring is
developed at the junction of the two liquids. (The colour formation is rapid by
warming).
2
Test 1:
2 ml. of concentrated ether extract of residue is taken in a porcelain basin and the solvent is
evaporated off. To the residue, an alcoholic solution of 1% solution of p-dimethyl amino
benzaldehyde in rectified spirit acidified with 1 ml. of conc. Sulphuric Acid is added drop by
drop. A transient red colour is observed. On evaporating to dryness on hot water bath, the
residue becomes brownish red to purple in colour which changes to pale blue on adding an
excess of reagent.
Test 2:
Test for Croton tiglium
14. 3.4
Calotropis
(Madar, Akdo)
Toxic Principle
• Calotoxin • Calotropin
(glycoside) • Calactin
• Uscharin
Sign and symptoms
1. Dermal exposure: Application to skin causes
irritation, redness and vesication
2. Ocular exposure: Irritation, lacrimation,
conjunctivitis
3. Ingestion: Causes
• Acrid bitter taste •
Burning pain in mouth
• Vomiting
• Diarrhoea
Fatal dose: Uncertain.
Fatal period: About 12 h.
Treatment: The patient is treated
symptomatically
15. Postmortem Findings
• Froth at mouth and nostrils • Stomatitis
• Inflammation of GIT • Abdominal viscera — congested
• Vesication, inflammation and redness at the site of contact
Medicolegal Importance
1. Accidental poisoning
2. Used in folk medicine
3. Used to fabricate wounds — malingers may apply juice to produce artificial bruise or conjunctivitis
4. Used in abortion stick to procure criminal abortion
5. Infanticide
6. Cattle poison
7. Root of C. procera is poisonous to cobra snakes. Snake charmers use root to scare away snake or to
subdue them.
Colour Test for Calotropis species
1 Conc. Hydrochloric Acid:
To a small portion of residue of the extract, a few drops of conc. Hydrochloric Acid is added and slightly
warmed. A greenish-blue colour is formed.
2 Conc. Sulphuric Acid:
To a small portion of residue of the extract, a few drops of conc. Sulphuric Acid are added. A pink to purple
colour develops after a few minutes.
3 Frohde’s Reagent:
To a small portion of residue of the extract, 2 drops of Frohde‘s reagent is added. A deep green colour
changing to blue and finally to green colour develops.
16. 3.5 Dhatura (Thorn apple)
Toxic part: all parts are toxic but seeds are more toxic.
In ancient times it was used in Ayurveda as a medicine
Active Principle
• Hyoscine (scopolamine)
• Hyoscyamine
• Atropine
(Together referred as beladonna alkaloids)
Mechanism of Action
• The alkaloids competitively inhibit the muscarinic effects
of acetylcholine.
Majority of the CNS actions are due to blockage of
muscarinic receptors in the brain viz. vagal stimulation,
decrease in heart rate. High doses cause cortical
excitation, restlessness, disorientation, hallucinations and
delirium followed by respiratory depression and coma.
17. Sign and Symptoms
5
Fatal Dose: 50 to 100 seeds(10 to 100 mg of atropine)
Fatal period: 24 hours
Treatment
•Treat the patient in quiet and dark environment
• Gastric lavage with activated charcoal
•Monitor and regulate patient’s temperature
•Physostigmine is used as an antidote. Benzodiazepines
can be given to curb the patient's agitation, and supportive
care with oxygen, hydration, and symptomatic treatment is
often provided.
Postmortem Findings
•Signs of asphyxia
• Gastrointestinal tract shows inflammation
• Seeds or fragments may be found in stomach
• Pulmonary edema
Medicolegal Importance
1. Accidental
2. Suicide – rare
3. Homicide
4. Datura seeds are used as stupefying agent
5. Datura seeds are abused. The seeds are mixed with
cigarette
and belladonna and smoked as hallucinogen.
6. Datura seed resist putrefaction of body
7. Scopolamine is used as truth serum.
Test
1 Vitali’s Test:
A portion of residue of the extract is treated as above
when violet colour is produced which
immediately changes to red and then disappears. On
adding a few drops of alcoholic KOH,
the colour reappears.
18. 3.6 Yellow Oleander
Botanical name: Cerbera thevetia
Common name: Yellow oleander, pila Kaner, exile.
Toxic part of plant: all parts but seed and root are more
toxic.
Toxic Principles
• Thevetin
• Thevetoxin
• Cerberin
Mechanism of Action
The glycosides have digoxin like action and inhibit
sodiumpotassium ATPase
Fatal Dose: 8 to 10 seeds
Fatal period: 2 to 3 hours if powdered root taken.
Sign and Symptoms
The milky juice (sap) if applied to skin may cause
inflammation in sensitive individuals
• Numbness in mouth and tongue • Vomiting
• Diarrhea • Headache
• Loss of muscle power • Giddiness
• Tachycardia
19. Treatment
• Gastric lavage with multiple dose activated charcoal
•Molar solution of sodium lactate IV and 5% glucose
to combat acidosis.
• Atropine 1 mg, 2 ml of adrenaline 1:1000 and 2 mg of
noradrenaline (if blood pressure is low) to counteract heart
block.
• Symptomatic treatment.
Postmortem Findings
Non-specific.
i. Signs of GIT irritation may be seen.
ii. Stomach and duodenum may be congested and
may show fragments of seeds.
iii. Congestion of visceral organs are seen.
Medicolegal Importance
1. Root used for causing abortion
2. Accidental death occurs due to consumption of folk
medicine containing oleander
3. Cattle poison
4. Suicide
5. Homicide is rare
6. Common oleander resist decomposition
20. Botanical name: Strychnos nux vomica
Common name: Kuchila, dog buttons
Toxic parts of plant
• Leaves
• Fruits and seed
• Root and stem
• Bark.
Toxic principles
• Seed contains two active principle namely:
• Strychnine
• Brucine
Mechanism of Action
Strychnine competitively antagonizes the inhibitory
neurotransmitter glycine by blocking its post-synaptic
uptake by brainstem and spinal cord receptors
Sign and Symptoms
muscular convulsions and eventually death through
asphyxia, when inhaled, swallowed, or absorbed through
the eyes or mouth
There may be frothing at mouth and pupils are dilated.
3.7 Strychnine
21. Fatal dose
• Seeds — 1 to 2 crushed seeds
• Strychnine — 50 to 100 mg
Fatal period: 1 to 2 hour
Treatment
• Patient should be managed in calm environment.
• Emesis is contraindicated as the procedure may
precipitate
convulsions. However, cautiously gastric lavage may
be carried out after protecting air way. Activated
charcoal
should be administered and is considered as effective
• Management of convulsions is important and can be
treated by lorazepam or diazepam.
• Rest symptomatic measures.
Postmortem findings
• Rigor mortis— appear and disappear early
• Postmortem caloricity
• Signs of asphyxia
• Froth at mouth
• Serosal surface may show hemorrhagic areas
• Organs are congested.
Medicolegal importance
1. Accidental poisoning may occur in children who may
chew the seeds out of curiosity.
2. Accidental poisoning may occur in adults due to
consumption
of folk/indigenous medicinal preparation.
3. Accidental poisoning in adults may occur due to
strychnine
consumption as it is considered as aphrodisiac.
4. Homicide rare due to bitter taste and dramatic
appearance
of symptoms, however cases have been reported.5
5. Used to kill cattle.
22. REFERENCES
•Historical Note: Traditional Use of Legume Seeds for Weighing Gold in India
•Forensic Applications of Indian Traditional Toxic Plants and their Constituents-Vivek Kumar Gupta,
Bechan Sharma
•Rajesh Bardale-Principlesof forensic medicine and toxicology
•A systemic review of vegetable poisoning and challenges in management-Sukhdeep Singh1, Mahesh
Kumar2,*, Arvind Kumar3, Rishabh Kumar Singh4
•Epg-pathshala Forensic Toxicology MODULE No.7: Organic Poisons: Plant Poisons
•Forensic medicine and Toxicology-Gautam Biswas
•Bulgarian umbrella - Wikipedia