Comparative characterization of Bothrops atrox venom compositional profiles and in vitro activities across distinct localities in the Brazilian Amazon.

Bothrops atrox is responsible for most of the snakebite accidents in the Brazilian Northen region. Understanding the intraspecific variability in the snake venom of this species contributes to a better understanding and treatment of snakebite symptoms. This study presents a descriptive comparative characterization of the individual venom composition and in vitro functional profiles of Bothrops atrox specimens from distinct localities across the Amazon Basin. Individual venoms were analyzed using reverse-phase high-performance liquid chromatography and evaluated for proteolytic, phospholipase-A2 and L-amino acid oxidase, and indirect hemolytic activities. Multivariate statistical approaches (Multiple Factor Analysis and Factor Analysis of Mixed Data followed by Hierarchical Clustering of Principal Components) were applied to explore variations across groups. L-amino-acid oxidase and indirect hemolytic activities, as well as chromatogram peaks within the 51-67 min retention window, were highlighted as possible markers in the grouping of these individuals in clusters located East and West of Amazon Basin. Also, to the best of our knowledge, this is the first compositional and functional assessment of individual Bothrops atrox venoms from the Amazon Basin in Acre and insular Pará. These markers can guide future characterization studies and support clinical understanding of envenomation in this region.