Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro

 


Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro

Abstract

The common krait (Bungarus caeruleus) and the endemic Sri Lankan krait (B. ceylonicus) are two species of krait responsible for envenomings in Sri Lanka that result in progressive neuromuscular paralysis. We characterised the in vitro neurotoxicity of B. ceylonicus and B. caeruleus venoms and studied their neutralisation by two commercially available Indian polyvalent antivenoms (i.e., VINS and BHARAT), Thai banded krait antivenom and Australian polyvalent antivenom using the chick biventer cervicis nerve-muscle preparation. Both venoms displayed concentration-dependent neurotoxicity, showing equipotent pre-synaptic neurotoxicity at 0.03 μg/mL. At a higher concentration (1 μg/mL), both venoms showed post-synaptic neurotoxicity, with B. ceylonicus venom being more potent. VINS was unable to neutralise the neurotoxicity of B. ceylonicus venom, but neutralised both pre- and post-synaptic neurotoxicity of B. caeruleus venom. BHARAT neutralised in vitro pre- and post-synaptic activity of both B. ceylonicus and B. caeruleus venoms. Banded krait antivenom and Australian polyvalent antivenoms were unable to fully neutralise the neurotoxicity of either venom at tested concentrations. In conclusion, B. ceylonicus venom shows pre- and post-synaptic neurotoxicity similar to B. caeruleus venom. BHARAT effectively neutralises both pre- and post-synaptic neurotoxicity of B. ceylonicus venom. Both Indian polyvalent antivenoms effectively neutralise neurotoxicity induced by B. caeruleus venom.

Galappaththige, J., Isbister, G. K., Maduwage, K., Hodgson, W. C., & Silva, A. (2025). Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro. Toxins, 17(9), 439. https://doi.org/10.3390/toxins17090439