Neutralizing potency of horse antibothropic Brazilian antivenom against Bothrops snake venoms from the Amazonian rain forest

Neutralization of lethal toxicity (50% effective dose; ED50), hemorrhagic ( minimum hemorrhagic dose; MHD) and hemolytic activity (PLA(2)) and levels o f antibodies, measured by enzyme-linked immunosorbent assay (ELISA), were i nvestigated to test the potency of horse antibothropic serum (ABS) against Bothrops venoms from the Amazonian rain forest. ABS neutralized the lethal activity with a potency (mg of venom neutralized per I mi of antivenom) of 5.5, 3.7, 1.6, 1.3 and 6.5, respectively, for B. jararaca (reference venom for assessing the ABS potency in Brazil), B. atrox, B. brazili, B. bilineat us smaragdinus and B. taeniatus venoms. The volume of antivenom (yl) that n eutralized one MHD of B. jararaca, B, atrox, B, brazili. B. bilineatus smar agdinus and B. taeniatus venoms was 5, 7.71, 7.76, 8.3 and 5, respectively. ABS neutralized the PLA(2) activity with a potency of 6.2, 3.2, 1.4, 2.6 a nd 5 respectively, for B. jararaca, B. atrox, B. brazili, B. bilineatus sma ragdinus and B. taeniatus venoms. ELISA reactivity of ABS against the separ ate venoms was found to be quite variable. The reactivity against B. jarara ca venom was higher than against other Bothrops venoms. In conclusion, the assays described here suggest that Brazilian Bothrops polyspecific antiveno m is not very efficient in neutralizing the effects of Venom from some Amaz onian Bothrops species. (C) 2000 Elsevier Science Ltd. All rights reserved.