Unveiling the nanotoxicology of snake venoms through functional and biochemical characterization of extracellular vesicles from Naja naja and Daboia russelii.

Snake venom is a complex biochemical arsenal that exerts multifaceted effects on host physiology, primarily targeting the hemostatic, cellular, and metabolic systems. Recent attention has turned to venom-derived extracellular vesicles (EVs) as active carriers of toxin components. The current study comparatively evaluates the hematological and enzymatic effects of crude venoms and EVs from Naja naja and Daboia russelii across key physiological parameters: prothrombin time (PT), activated partial thromboplastin time (aPTT), red blood cell hemolysis, and purinergic enzyme activity (ATPase and ADPase). Both venoms and their EVs caused dose-dependent alterations in coagulation, with EVs significantly prolonging aPTT and PT, indicating intrinsic and extrinsic pathway inhibition. Hemolysis assays revealed sex-specific erythrocyte susceptibility, with higher rates observed in female samples. Additionally, venom-derived EVs modulated ATPase and ADPase activity, interfering with cellular energy metabolism and thromboregulation. Our findings establish venom EVs as potent functional units that replicate and amplify native venom toxicity. These results underscore the importance of targeting EV-associated toxins in antivenom development and highlight the evolving complexity of venom systems biology. This study broadens our understanding of venom pathophysiology and identifies novel diagnostic and therapeutic avenues against snakebite envenomation.