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Snakes venom

Snakes venom

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Snakes venom

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

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

  3. 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

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

  5. 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

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

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

  8. ROUNDED HEAD TRIANGULAR HEAD Fig.03 Difference between venomous and non-venomous snake. 8

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

  10. Fig.05 Venomous snakes of India. 10

  11. 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. 11

  12. 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. 12

  13. 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

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

  15. 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. 15

  16. TYPES OF VENOM 1. Neurotoxic 2. Cytotoxic 3. Hemotoxic 4. Myotoxic. 16

  17. NEUROTOXIC VENOM 1. This type of venom attacks nervous system. 2. This mainly includes 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 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. fasciculins, dendrotoxins, alpha +channels. Tubocurarine, 17

  18. 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. 18

  19. Fig.08 Action of neurotoxins. 19

  20. SYMPTOMS OF NEUROTOXIC VENOM 1. Respiratory arrests 2. Prolonged unconsciousness 3. Dizziness 4. Tunnel vision 20

  21. 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

  22. Fig.09 Action of cytotoxic venom. 22

  23. 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). 23

  24. 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

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

  26. 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

  27. 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

  28. MILKING OF SNAKE VENOM 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. 28

  29. Fig.13 Milking of snakes for venom. 29

  30. 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

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

  32. 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. 33

  34. Photograph of Irula Snake catchers extracting venom. 34

  35. USES OF ANTI-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. 35

  36. 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

  37. 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

  38. 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 38

  39. THANK YOU 39

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