Differential Hematotoxic Activity of Southeast Asian Pit Viper Venoms: The Cross-Neutralizing Effect of Available Antivenoms

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  Image Credit: Creative Commons (some rights reserved) CC BY-NC Photo 111998430, (c) Nicholas Hess Differential Hematotoxic Activity of Southeast Asian Pit Viper Venoms: The Cross-Neutralizing Effect of Available Antivenoms Abstract Background/Objectives : Pit vipers (subfamily Crotalinae) are responsible for a large proportion of snakebite envenoming cases in Southeast Asia. Envenomation by these snakes commonly causes hematotoxic effects, including platelet dysfunction and coagulation disturbances. Although antivenom remains the mainstay of treatment, species-specific antivenoms are not available for several regional pit viper species. This study evaluated the hematotoxic activities of selected Southeast Asian pit viper venoms and the cross-neutralizing capacity of commercially available antivenoms.  Methods : Venoms from five medically important pit viper species— Calloselasma rhodostoma ,  Trimeresurus albolabris ,  T. hageni ,  T. purpureomaculatus , ...

Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution

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Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution

Abstract

We searched for and compared venom phospholipase A2 (PLA2) sequences containing either Asn6 or Arg6 substitutions expressed in New World pitvipers and their Asian sister taxa within the genera Gloydius, Protobothrops, and Ovophis. Phylogenetic analyses based on 35 of these PLA2s, and multiple sequence alignments, revealed the independent evolution of three subtypes of N6-PLA2s and two distinct lineages of R6-PLA2s. The results help to pinpoint the most likely Asian sister lineages of present-day New-World pitvipers.
Tsai, I., & Tsai, T. (2026). Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution. Toxicon, 109051. https://doi.org/10.1016/j.toxicon.2026.109051