Composition, pharmacology, and pathophysiology of the venom of monocled cobra (Naja kaouthia)- a medically crucial venomous snake of southeast Asia: An updated review

Abstract

The Monocled Cobra (Naja kaouthia), a category one medically significant snake from the Elapidae family, inflicts severe envenomation in South and Southeast Asian countries. N. kaouthia is distributed throughout the eastern and northeastern parts of India, Nepal, Bangladesh, Myanmar, Thailand, Vietnam, Malaysia, and southwestern China. Envenomation by N. kaouthia is a medical emergency, and the primary clinical symptoms are neurotoxicity and localized tissue destruction. Unfortunately, data on the actual magnitude of N. kaouthia envenomation is scarce due to poor record keeping, lack of diagnostic kits, and region-wise well-coordinated epidemiological surveys. The present review highlights the diversity in the composition of N. Kaouthia venom (NKV) across various geographical regions, as revealed through biochemical and proteomic analyses. The qualitative and quantitative differences in the toxin isoforms result in differences in lethality and pathophysiological manifestation that may limit the effectiveness of antivenom therapy. Studies on commercial polyvalent antivenom (PAV) effectiveness against distinct NKV samples have revealed varying toxicity and enzymatic activity neutralization. Additionally, the identification of snake venom's poorly immunogenic toxins by mass spectrometry, quantification of venom-specific antibodies, and implications for antivenom therapy against snakebites are highlighted. Future directions involve clinical studies on NK envenomation where the snake is frequently encountered and the correlation of this data with NKV composition in that region. For more efficient and superior hospital management of NK envenomation, research should enhance the current immunization procedure to boost the development of antibodies against less immunogenic venom components of this snake.