Use of commercial tannic acid against the toxic effects of Bothrops jararacussu venom.

Abstract

Snakebite envenomation is a neglected public health issue affecting thousands of victims worldwide. In Brazil, the genus Bothrops is responsible for 88% of snakebites; bites from the species B. jararacussu present at a high frequency and are associated with high lethality and morbidity rates. B. jararacussu injects a large volume of venom, leading to massive tissue necrosis, hemorrhage, and eventually death. Antivenom is the only available treatment for neutralizing such toxic effects; it effectively prevents death but not the physical sequelae caused by muscle damage. Antivenom has other drawbacks, such as fever and anaphylactic reactions, high production costs, and the need for controlled storage temperatures. Thus, complementary treatments are sought to overcome these disadvantages of antivenoms. Here, we assessed the effects of commercial tannic acid on the major toxic activities of B. jararacussu venom, such as its proteolytic, plasma coagulation, edematogenic, hemorrhagic, and lethal effects. Overall, the incubation of tannic acid with B. jararacussu venom inhibited the venom's in vitro coagulant and proteolytic effects and in vivo hemorrhagic and edematogenic activities; however, it failed to prevent against lethality. Antibothropic serum protected mice from B. jararacussu venom-induced death and inhibited edema by approximately 45% but did not protect against hemorrhage. In conclusion, tannic acid efficiently neutralized the main toxic activities of B. jararacussu venom, which causes severe envenomation in some South American countries. Thus, tannic acid is a candidate for managing Bothrops snakebites and, alongside antivenom, may hasten and improve victim recovery.