Saw-scaled viper venom toxins

Saw-scaled viper venom toxins, primarily from the genus Echis, are a complex mixture of proteins and peptides that cause severe hemotoxicity and tissue damage (WHO, 2021). The venom is characterized by high concentrations of snake venom metalloproteinases (SVMPs), such as ecarin, which act as potent prothrombin activators, leading to venom-induced consumptive coagulopathy (VICC) and systemic bleeding (UniProt, P81187). Additionally, the venom contains disintegrins like echistatin that inhibit platelet aggregation by binding to the integrin alpha-IIb-beta-3 receptor, further exacerbating hemorrhagic symptoms (PubMed, 2524325). Clinically, envenomation by these vipers is a major cause of morbidity and mortality in Africa, the Middle East, and Asia, often resulting in acute kidney injury and local necrosis (StatPearls, NBK431065). While intravenous antivenom remains the gold standard for neutralizing these toxins, emerging therapies include small-molecule inhibitors like varespladib and marimastat, which target specific enzymatic components to prevent systemic damage (PubMed, 32824317). Beyond their toxicological role, these proteins have served as critical templates for drug discovery, most notably in the development of the antiplatelet drug tirofiban.

Other names

Echis venom toxinsCarpet viper venom toxinsEchis carinatus venomEchis ocellatus venomEchis coloratus venom

Antivenoms consist of polyclonal antibodies (IgG or F(ab')2 fragments) that bind to and neutralize the enzymatic and non-enzymatic sites of venom toxins, preventing their interaction with physiological substrates like prothrombin or integrins (WHO, 2021). Small molecule inhibitors such as Varespladib act as competitive inhibitors of Phospholipase A2, while metalloproteinase inhibitors like Marimastat chelate the zinc ion required for the catalytic activity of SVMPs (PubMed, 32824317).