Predicting the Efficacy of Antivenoms against African Vipers and Elapids by Using Immunoblotting and Cytotoxicity Neutralisation Assays

Abstract

Aim: Snakebite is an important public health problem especially in tropical and subtropical countries. Snake antivenom is the only specific treatment to save the lives. However, antivenoms are relatively expensive, have restricted efficacy to the species of snake whose venom was used to manufacture. Therefore, there is a compelling need to maximize the availability of antivenoms and to know the efficacy of different types of anitvenoms for various species of snakes. Study Design:  In-vitro experimental study. Place and Duration of Study: In the laboratory at the Medical Institution, between February to March 2014. Methodology: Venom extracted from the viper and elapid snakes and four different antivenoms, manufactured from Africa, Australia and Asia were used in this study. Sodium dodecyl sulfate (SDS) gel was used to fractionate the venom protein. Immunoblotting allowed the transfer of fractionated proteins from the SDS gel to the nitrocellulose absorbent membrane, and then incubated it in antivenom to observe the binding of all different antivenoms to specific proteins in the venoms of different snakes. Immortalized African green monkey kidney cells (VERO) were used in cell cytotoxicity assay provided a functional measure of antibody efficacy to neutralise the pathological effects of venom in its native state. Results: In immunoblotting assay, Ipser Afrique polyvalent and SAIMR antivenom exhibited the strong reactivity with elapid and viper venom proteins. In vitro cell cytotoxicity assay, Ipser Afrique polyvalent and SAIMR antivenoms were effective in neutralizing the toxicity of Echi ocellatus venom, meanwhile, Australian polyvalent and Banded Krait antivenoms were found to be ineffective for the same venom. Conclusion: Antivenoms from different geographical areas were found to be ineffective against African snakes in this study. Therefore, local pilot trials should be done to ensure the safety and efficacy of antivenoms when introduce to new geographic area.