AUTHOR=Attarde Saurabh , Khochare Suyog , Iyer Ashwin , Dam Paulomi , Martin Gerard , Sunagar Kartik 

TITLE=Venomics of the Enigmatic Andaman Cobra (Naja sagittifera) and the Preclinical Failure of Indian Antivenoms in Andaman and Nicobar Islands

JOURNAL=Frontiers in Pharmacology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.768210

DOI=10.3389/fphar.2021.768210

ISSN=1663-9812

ABSTRACT=<p>The Andaman and Nicobar Islands are an abode to a diversity of flora and fauna, including the many endemic species of snakes, such as the elusive Andaman cobra (<italic>Naja sagittifera</italic>). However, the ecology and evolution of venomous snakes inhabiting these islands have remained entirely uninvestigated. This study aims to bridge this knowledge gap by investigating the evolutionary history of <italic>N. sagittifera</italic> and its venom proteomic, biochemical and toxicity profile. Phylogenetic reconstructions confirmed the close relationship between <italic>N. sagittifera</italic> and the Southeast Asian monocellate cobra (<italic>N. kaouthia</italic>). Overlooking this evolutionary history, a polyvalent antivenom manufactured using the venom of the spectacled cobra (<italic>N. naja</italic>) from mainland India is used for treating <italic>N. sagittifera</italic> envenomations. Comparative evaluation of venoms of these congeners revealed significant differences in their composition, functions and potencies. Given the close phylogenetic relatedness between <italic>N. sagittifera</italic> and <italic>N. kaouthia</italic>, we further assessed the cross-neutralising efficacy of Thai monovalent <italic>N. kaouthia</italic> antivenom against <italic>N. sagittifera</italic> venoms. Our findings revealed the inadequate preclinical performance of the Indian polyvalent and Thai monovalent antivenoms in neutralising <italic>N. sagittifera</italic> venoms. Moreover, the poor efficacy of the polyvalent antivenom against <italic>N. naja</italic> venom from southern India further revealed the critical need to manufacture region-specific Indian antivenoms.</p>