Bio Assay of NAKE VENOMJ.S.K. NAGARAJAN,ASST. PROFESSOR,JSS UNIVERSITY,(OFF CAMPUS, JSS COLLEGE OFPHARMACY),OOTY- 643 001.email: firstname.lastname@example.orgPh: 09443149945
The VenomLD50 of 0.25- 10 to 15 mg is0.32 mg/kg deadly to a human adultOne bitedelivers 100- Contains120mg on Calciseptineaverage Toxin 1Maximum 400 Toxin Kmg
Toxins in VenomMost 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 ActionThese 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 JunctionVesicles containing Acetylcholine (ACh) ACh receptors Acetylcholinesterase (AChE)
VIPER VENOMViper Venom is the dried secretion obtainedfrom the poison glands of Viperae russelli andother species of Viperae.Ppn: Extraction Drying (freeze) Dissolving ( WFI) Filter(bacteria free)- STOCKSOLUTION Dilution (to give req. no. of Mouse unit/ml) Distributed in single dose. Dried and seal.NOTE: Mouse Unit/ml: Quantity in mg ofthe 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
AssayTest 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.