Amit Talukdar, Arpita Devi, Mandira Basumatary
Kraits are a group of medically important venomous snakes responsible for numerous snakebite cases annually leading to thousands of mortalities and associated co-morbidities in patients. The Sind krait (Bungarus sindanus) is an underexplored venomous elapid of South Asia distributed towards the North-western region of the Indian subcontinent. The cryptic natural history of the snake, geographically variable venom composition, and venom induced neurotoxicity pose a significant challenge for researchers and clinicians. This review integrates current knowledge on the distribution, ecology, and behaviour of the species across its distribution in Pakistan and north-western India. We critically evaluated venom composition studies that suggest plausible mechanisms of neurotoxicity with predominance of β-bungarotoxins or phospholipase A2s (PLA2s), and ancillary role of three-finger toxins (3FTxs), like κ- and α-neurotoxins depending on the region. Neutralization assays and limited clinical reports indicate reduced effectiveness of polyvalent "Big Four" antivenom against B. sindanus envenoming. We explored relevant strategies for the development of effective therapeutics against B. sindanus venom, including conventional, region-specific, next-generation antivenom and/or adjunct therapies. In this context, we explored the potential of recently developed broadly-neutralizing recombinant monoclonal antibodies to bind B. sindanus venom toxins across different populations and geographies using a hypothesis-driven in silico molecular docking and residue-interaction approach. Prioritized research agenda should explore the natural history and venom dynamics of this species to better understand the venom evolution, venom variation, clinical relevance, and antivenom neutralization, and utilize the learning for the development of safer and effective alternative therapeutic approaches.