Bothrops jararaca snake venom: a reappraisal of its coagulant activity

Introduction: Bothrops jararaca snake venom (BjV) contains toxins that activate and inhibit blood coagulation, causing consumption coagulopathy, thrombocytopenia, endothelial dysfunction, and secondary fibrinolysis in human and animal victims of snakebites. Objectives: The objective of this work was to study the in vitro coagulant activity of BjV in human, mouse, and rat plasma. Methods: The coagulant activity of BjV was assessed in normal and coagulation-factor-deficient plasma from humans, rats, and mice (C57BL/6, F8^-/-, F9^-/-, Vwf^-/-, and pearl mice (Ap3b1^-/-)). The roles of calcium ions, phospholipids, and blood cells in the coagulant activity of BjV were evaluated. Pharmacological inhibitors were used to analyze the generation of factor Xa and/or thrombin and their contribution to the coagulant activity of BjV. Results: Human plasma showed greater sensitivity to BjV than rat and mouse plasma. Calcium ions and phospholipids influenced its coagulant activity. Pre-incubation with rivaraxoban and/or dabigatran showed that the coagulant activity of BjV in rodent plasmas primarily depends on prothrombin activation, whereas in human plasma, it involves both thrombin-like-enzymes and prothrombin activators. Conclusions: This study highlighted important differences in the coagulant activity of BjV in human and rodent plasmas, underscoring the need to consider these disparities in comparative envenomation studies using animal models.