Venomics and Cellular Toxicity of Thai Pit Vipers (Trimeresurus macrops and T. hageni).

The two venomous pit vipers, and , are distributed throughout Thailand, although their abundance varies among different areas. No species-specific antivenom is available for their bite victims, and the only recorded treatment method is a horse antivenom raised against crude venom. To facilitate assessment of the cross-reactivity of heterologous antivenoms, protein profiles of and venoms were explored using mass-spectrometry-based proteomics. The results show that 185 and 216 proteins were identified from and venoms, respectively. Two major protein components in and venoms were snake venom serine protease and metalloproteinase. The toxicity of the venoms on human monocytes and skin fibroblasts was analyzed, and both showed a greater cytotoxic effect on fibroblasts than monocytic cells, with toxicity occurring in a dose-dependent rather than a time-dependent manner. Exploring the protein composition of snake venom leads to a better understanding of the envenoming of prey. Moreover, knowledge of pit viper venomics facilitates the selection of the optimum heterologous antivenoms for treating bite victims.