bioassay of venom by JSK NAGARAJAN

							             Bio Assay of
            NAKE VENOM


J.S.K. NAGARAJAN,
ASST. PROFESSOR,
JSS UNIVERSITY,
(OFF CAMPUS, JSS COLLEGE OF PHARMACY),
OOTY- 643 001.
email: nagasaki2001@rediffmail.com
Ph: 09443149945
         The Venom

 LD50 of 0.25-        10 to 15 mg is
  0.32 mg/kg           deadly to a human
 One bite delivers    adult
  100-120mg on         Contains
  average
                        Calciseptine
Maximum 400            Toxin 1
 mg
                        Toxin K
      Toxins in Venom
 Most snakes have multiple types of
                 venom.
• Cobras have both a short and long
  neurotoxin as well as a cardiotoxin.
• Kraits: 3 different types of neurotoxins.
• Sea snakes: Neurotoxin as well as 2
  Blood toxins (one causes lysis blood
  cells, the other is an anti-coagulant).
• Mambas have only Fasciculin.
        Mode of Action
These snake neurotoxins act on the
  neuromuscular junction (next slide) and
  block neuromuscular transmission.

• Fasciculin interferes with this process by
  binding to Acetylcholinesterase (AChE).

• Cobratoxin binds to the Acetylcholine
  receptors on the muscle cell.

• Result: “Death by respiratory paralysis”.
   Neuromuscular Junction




Vesicles containing
 Acetylcholine (ACh)
 ACh receptors
 Acetylcholinesterase (AChE)
              VIPER VENOM

Viper Venom is the dried secretion obtained
from the poison glands of Viperae russelli and
other species of Viperae.

Ppn: Extraction
      Drying (freeze)
      Dissolving ( WFI)
      Filter(bacteria free)- STOCK SOLUTION
      Dilution (to give req. no. of Mouse unit/ml)
      Distributed in single dose.
      Dried and seal.

NOTE: Mouse Unit/ml: Quantity in mg of the
venom which will kill in 2-24hrs NLT 3 & NMT
8 mice.
   Anti Snake Venom
• ASV is prepared by hyperimmunising
  horses against venoms of snake.



• It neutralises the free, unbound
  venom & to some extent also
  dissociates the bound toxin
      1 ml of ASV neutralises


•   Cobra – 0.6 mg
•   Common krait – 0.45mg
•   Russels viper – 0.6 mg
•   Saw scaled viper – 0.45 mg
                    Assay
Test Animals: 10 Mice ( 18- 20g)

Dissolve(Equiv. 50 Mouse Unit)25 ml of Saline

        Inject 0.5 ml IV into each mice

      Observe the animals for 24 hours.

Result: NLT 3 & NMT 8 mice die in 2 - 24 hrs.

If the number of deaths is not within the range

   Change the dilution of the venom suitably.

  Express result in terms of Number of Mouse
                    Units/mg.
THE END