Biological activities of phosphodiesterase from Crotalus durissus terrificus venom

Phosphodiesterases (PDEs) are an enzymes family that hydrolyze phosphodiester bonds sequentially from the 3´ terminus of polynucleotides to produce 5’-mononucleotides. Historically, snake venom PDEs have been widely used in sequencing and structural studies of nucleic acids. In contrast, the potential pharmacological activities of these enzymes are poorly understood and their role in envenomation remains unclear. Previosuly, we isolated and preliminary characterized a PDE from C. d. terrificus (CDT) venom, demonstrating that is capable of hidrolizing ATP, ADP, AMP and DNA. Here, we evaluated the edema-forming activity and locomotory behavior induced by CDT-PDE. The enzyme was purified through two chromatographic steps (Sephadex G-75 and HiTrap Q-FF). The CDT-PDE activity was tested by chromogenic reaction with sodium salt of bis (p-nitrophenyl phosphate). Groups of five mice were subplantar injected in the right hind foot with 1 µg of purified PDE or a mixture of PDE (1 μg) and ADP (50 nmol) that was co-injected or adenosine (50 nmol) or ADP (50 nmol) or PBS. Edema was measured as the increase in paw thickness using low-pressure spring calipers at various intervals (0.5, 1, 3, and 6 h). At the end of the experiment, the hind feet were removed and processed for histological analysis. Locomotory behavior was assessed in an open-field test Each mouse (n=6) received an i.p. injection of PDE or PBS. Mice not injected with PDE or PBS were used as controls. The results indicate that PDE from CDT venom from northeastern Argentina is edematogenic and causes an inflammatory infiltrate. Besides, PDE-CDT reduced the locomotor activity in the initial minutes after injection. Results all indicate that PDE exhibits pharmacological activities that they deserve to be studied in further detail. Further investigations are required to assess the contribution of this enzyme to the systemic manifestations associated with envenomation by this species.