Evaluation of indirect hemolysis induced by snake venoms and its neutralization by corresponding antivenoms: comparative study across five genera

Abstract

Hemolytic activity of snake venoms represents a toxic effect with significant biochemical complexity. In this study, we conducted a comprehensive comparative assessment of the indirect hemolytic activity (expressed as HD 50 ) of 25 medically important venom samples, encompassing five genera. Additionally, we evaluated the efficacy of commercial AV in neutralizing this activity (NHD 50 ). Elapidae venoms displayed the highest hemolytic potency (lowest HD 50 ), correlating with high phospholipase A 2 activity. Within the Bothrops genus, we observed wide variation in potency, with species like B. insularis and B. moojeni exhibiting high activity, while the venom of B. erythromelas consistently proved to be the most resistant to neutralization by antibothropic antivenom. The functional activity data were integrated with chromatographic profiles, enzymatic activities, and phylogenetic analyses, revealing that hemolytic potency is not solely determined by PLA 2 activity but also by its molecular context. Ancestral State Reconstruction suggests multiple events of gain and loss of hemolytic potency within the Bothrops clade. These findings highlight the need for improvements in anti-venom composition, especially for the treatment of envenoming caused by species whose venoms exhibit high resistance to neutralization.