Leptodeira bakeri (Serpentes: Colubridae): a Venomous or Non-Venomous Snake?

Comparatively modest consideration has been given to the biological properties of venoms produced by opisthoglyphous colubrids. Leptodeira bakeri belongs to the Colubridae family, which includes well over half of the snake species on earth. Snakes in this family had been considered non-venomous. The purpose of this study was to investigate the diverse toxic activities of L. bakeri venom, a Venezuelan opisthoglyphous (rear-fanged) snake. Crude venom showed approximately 24 protein bands under reducing conditions on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Partial purification of venom fractions containing proteolytic activity was done by molecular exclusion chromatography (Superose 12). Five peaks (I – V) were obtained and SDS-PAGE for each peak was carried out. Peak II had hemorrhagic activity. Venom hemorrhagic activity on chicken embryos and mice, gelatinase activity and neurotoxic clinical manifestations were assayed. The LD 50 for L. bakeri venom was determined to be 1.35 mg/kg mouse body weight. Leptodeira bakeri venom confirmed to have proteolytic, hemorrhagic, and neurotoxic activities, which should be classified as a venomous Colubridae snake. Studying venoms from opisthoglyphous snakes has its difficulties since obtaining enough venom to carry out purification and performing multiple biological assays is not an easy task. This work offers additional evidence that colubrid venoms consist of numerous components which can exhibit a multiplicity of activities, some of which may be new, consequently emphasizing the basically unexploited potentials of colubrid snake venoms. To our knowledge, this is the first work in which neurotoxic and hemorrhagic signs and symptoms produced by L. bakeri venom have been reported.