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PRESENTED BY GUIDED BY
Namrata Singh Prof. Prafulla Kumar Mohanty
M.Sc. Semester II P.G.Department of Zoology
Roll number -15 ZOO 016 Utkal University, Vani Vihar
Bhubaneswar- 751 004.
1
VENOM OF SNAKES

CONTENTS
1. Introduction
2. Taxonomic position
3. History
4. Chemistry
5. Types of venom
6. Lethal dose
7. Anti-venom
8. Uses of anti-venom
9. Conclusion
10. References.
2

INTRODUCTION
1. The term ’venom’, is derived from Latin word
venenum, meaning poison.
2. Venom system are important adaptations that have
evolved in different animals for certain reasons. Of
all venomous animals, snakes are the most well
known because of their medical importance.
3. There are over 3000 species of snakes, but only 15%
are considered to be dangerous.
4. Snakes are found in every continent except Arctic
and Antarctica.
3

TAXONOMY OF SNAKES
KINGDOM : Animalia
PHYLUM : Chordata
SUB-PHYLUM : Vertebrata
CLASS : Reptilia
ORDER : Squamata
4

SNAKE VENOM
Snake venoms are a cocktail of simple to complex
secretion of bioactive proteins produced in a
specialized gland that is typically delivered via
specialized envenomation systems.
5

HISTORY
Charles Lucien
Bonaparte was the
first to establish
the proteinaceous
nature of snake
venom in 1843.
Fig. 01 Charles Lucien Bonaparte.
6

Fig. 02 Morphology of the cephalic region of a venomous snake.
7

Fig.03 Difference between venomous and non-venomous
snake.
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ROUNDED HEAD
TRIANGULAR HEAD

9
Fig.04 Bite marks of venomous and non-venomous snake.

10Fig.05 Venomous snakes of India.

THE VENOM APPARATUS
1. A venomous animal is equipped with a set of
apparatus namely
(a) Venom gland and
(b) Fangs.
2. Venomous snakes use their venom apparatus to
rapidly kill their prey and secondarily in defense
from their own enemies.
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VENOM GLANDS
1. The glands which secrete the venom are a
modification of parotid salivary gland and are
situated on either sides of the head, below and
behind the eye encapsulated in a muscular sheath.
2. The glands have large alveoli in which venom is
stored before being conveyed by the duct to the
tubular hollow fangs through which it is ejected.
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FANGS – DESIGNED FOR THE CURSE
1. The fangs are the
deadly features of the
snake which are
designed elegantly to
inject venom in the
prey.
2. Snakes possess a
natural disadvantage
of being limbless so
they are provided with
these apparatus to
help snakes survive. Fig.06 Structure of a fang.
13

Fig. 07 Venom glands and fangs of venomous snake. 14

CHEMISTRY OF SNAKE VENOM
CHEMICAL PROPERTIES
1. Acidic.
2. Specific gravity: 1.030 – 1.070.
3. Soluble in water.
COMPOSITION
Snake venom is composed of
proteins and enzymes like
fasciculins, dendrotoxins, α-
neurotoxins, phospholipases,
cardiotoxins, etc.
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TYPES OF VENOM
1. Neurotoxic
2. Cytotoxic
3. Hemotoxic
4. Myotoxic.
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NEUROTOXIC VENOM
1. This type of venom attacks nervous system.
2. This mainly includes fasciculins, dendrotoxins, alpha
neurotoxins.
3. Fasciculins are toxins that attack cholinergic neurons by
destroying acetylcholinesterase (AChE) so ACh cannot be
broken down and stays in the receptor.
4. Dendrotoxins are found in the venom of Black Mamba snake,
which interferes with voltage-gated K
+
channels. Tubocurarine,
cobrotoxin, bungarotoxin block the acetylcholine receptor or
prevent the opening of ion channel. By blocking signals from
nerves to muscles these toxins cause paralysis and possibly
death.
Example- Venom of Cobras, Kraits etc.
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MECHANISM OF ACTION
1. It takes about 10 minutes for the venom to affect
the nervous system.
2. Most neurotoxins are too large to cross the blood-
brain barrier, and so they usually exert their effects
on peripheral nervous system rather than directly
on brain and spinal cord.
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19
Fig.08 Action of neurotoxins.

SYMPTOMS OF NEUROTOXIC VENOM
1. Respiratory arrests
2. Prolonged unconsciousness
3. Dizziness
4. Tunnel vision
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CYTOTOXIC VENOM
1. Cytotoxins involve phospholipases, cardiotoxins.
2. Phospholipases helps to split cell membrane and
helps to digest and subdue prey.
3. Causes localized symptoms, like blue black spots on
the site of bite due to limited blood circulation.
4. Example – Venom of Puff Adder (Bitis arietans)
21

Fig.09 Action of cytotoxic venom.
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HEMOTOXIC VENOM
1. These venoms causes hemolysis or induce blood
coagulation.
2. It attacks cardiovascular system, circulatory system
and muscle tissues thus directly leading to heart
failure.
Symptoms are:
1. Lethargy
2. Headache
3. Nausea
4. Vomiting
Example- Venom of Crotalus (Rattle Snake).
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MYOTOXIC VENOM
1. The venom contains peptides that destroy the
muscle fibre proteins and results in myonecrosis.
Example- the venom of Brazilian Lancehead snake.
2. Symptoms include-
(a) dry throat
(b) thirst
(c) muscular spasm
(d) drooping eyelids
(e) blackish brown urine discharge.
24

Fig.10 Action of myotoxic venom on neuromuscular junction.
25

LETHAL DOSE (LD50)
The toxicity of snake venom is assessed by a
toxicological test called the median lethal dose, LD50,
which determines the concentration of a toxin
required to kill half the members of a tested
population of animals.
Fig.11 Lethal dose activity.
26

ANTI-VENOM
1. Anti-venom ( anti- opposite
of; venom L. venenin –
poison).
2. The only available treatment
against snake bite is the usage
of anti-venom.
3. The first anti-venom for
snakes was developed by
Alberte Calmette against the
Indian cobra (Naja naja).
Fig.12 Alberte Calmette.
27

The Snake’s head is grasped between the index finger
and thumb.
Application of pressure on snake’s jaw.
The fangs are pushed through a plastic/parafilm
membrane.
The venom is squeezed out and collected.
MILKING OF SNAKE VENOM
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Fig.13 Milking of snakes for venom.
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PRODUCTION OF ANTIVENOM
A mixture of venoms from different species of venomous snakes are injected
into the body of horse or goat or sheep.
The blood with antibodies are collected.
Antivenom
30

SNAKE ANTI-VENOM IN INDIA
1. Now a days, Polyvalent snake anti-venom are
being produced in our country.
31Fig.14 Polyvalent Antivenin.

MANUFACTURERS OF SNAKE ANTI-VENOM IN INDIA
1. Serum Institute of India, Pune.
2. Haffkine Institute, Mumbai.
32

33
Irula Snake catchers Industrial Cooperative Society at
the Madras Crocodile Bank Trust, Centre for
Herpetology on Chennai’s East Coast Road.
Madras Crocodile BankTrust.

34
Photograph of Irula Snake catchers extracting venom.

1. Medicines derived from neurotoxins are used to
treat brain injuries, strokes.
2. Hemotoxin are used to treat heart attacks and
blood disorders.
3. ANTI-CANCER ACTIVITIES: Snake venom also
lowers down the activity of cancer cell by
apoptogenic effect.
4. Anticoagulant properties: Snake venom enzymes
remove fibrinogen from the circulation without
converting it to fibrin. Venoms with anticoagulant
properties are extensively studied for possible
medical applications.
USES OF ANTI-VENOM
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SIDE EFFECTS OF ANTI-VENOM
1. Anaphylactic reactions such as difficulty in
breathing, reddening of skin, swelling of eyes and
face, fever, etc.
2. Inflammation of joints.
3. Enlargement of lymph glands.
36

CONCLUSION
Snake Venom is the stuff of nightmares
for some, the light at the end of the
tunnel for others. It is a killer as well as a
saviour.
37

REFERENCES
Goswami PK, Samant M and Srivastava RS (2014) Snake
venom, anti-snake venom and potential of snake
venom. International Journal of Pharmacy and
Pharmaceutical Sciences;6(5):4-7
Mackessy SP(2010) Handbook of venoms and toxins of
reptiles. CRC Press Taylor & Francis Group,London.
pp 6-19
Nelson DL, Cox MM(2013) Lehninger Principles of
Biochemistry. Sixth Edition. W.H. Freeman and
Company, New York, pp 424-426
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VENOM OF SNAKES . By - Namrata Singh

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VENOM OF SNAKES . By - Namrata Singh