Neutralización de la actividad letal del veneno de serpiente Bothrops atrox por suero hiperinmune de llama (Lama glama) / Neutralization of the lethal activity from Bothrops atrox venom by hyperimune llama serum (Lama glama)

RESUMEN Objetivos: Evaluar la capacidad del suero hiperinmune de llama (Lama glama) para neutralizar la letalidad del veneno de la serpiente Bothrops atrox en ratones de laboratorio. Materiales y métodos: Se calculó la dosis letal media (DL50) de un pool de venenos de serpientes de Bothrops atrox de Perú, y se midieron los títulos de anticuerpos por ensayo ELISA; así como la potencia de neutralización del suero inmune por el cálculo de la dosis efectiva media (DE50) durante el periodo de inmunización. Resultados: La DL50 del veneno fue de 3,96 µg/g, similar a otros trabajos realizados en Bothrops atrox en Perú. Los títulos de anticuerpos contra el veneno se incrementan rápidamente en la llama mostrando una rápida respuesta inmune; sin embargo, la capacidad de neutralización se incrementa más lentamente y requiere de varias dosis y refuerzos de las inmunizaciones alcanzado una DE50 de 3,30 µL/g ratón y una potencia de neutralización 3,6 mg/mL después de 15 inmunizaciones. Conclusiones: El suero hiperinmune de llama es capaz de neutralizar la letalidad del veneno de la serpiente Bothrops atrox de Perú en ratones de laboratorio.

ABSTRACT Objectives: To evaluate the capacity of the hyperimmune llama serum (Lama glama) to neutralize the lethal activity of Bothrops atrox venom in laboratory mice. Materials and methods: Mean lethal dose (LD50) was calculated from a Bothrops atrox venom sample pool from Peru. The antibody titers were measured by ELISA assay; and the immune serum neutralization potency was measured by calculating the mean effective dose (ED50) during the immunization period. Results: The venom's LD50 was 3.96 μg/g; similar to what was found in other studies about Bothrops atrox carried out in Peru. The titers of antibodies against the venom increased rapidly in the llama, demonstrating a fast immune response; however, the neutralization capacity increased slowly and required several doses and immunization reinforcements, obtaining a ED50 of 3.30 μL/g mouse and a neutralization potency of 3.6 mg/mL after 15 immunizations. Conclusions: The hyperimmune llama serum is able to neutralize the lethality of the Bothrops atrox venom from Peru in laboratory mice.

Use of EDTA in the treatment of local tissue damage caused by the Bothrops alternatus venom / Utilização do EDTA no tratamento da lesão tecidual local causado pelo veneno de Bothrops alternatus

Twelve adult rabbits were distributed in three groups and received on the femoral biceps region, via intradermal injection (ID), 25µg of Bothrops alternatus venom dissolved in NaCl 0.9% and diluted in 0.25mL of phosphate buffered saline (PBS). Thirty minutes later, the group G1 received 0.25mL of phosphate buffered saline (PBS) ID while to G2 and G3 25mg of ethylenediamine tetraacetic acid (EDTA) dissolved in 0.25mL of PBS were administered via intramuscular (IM) and intravenous (IV) injection, respectively. Evaluations included local lesion and blood profile of all animals, before (time zero) and at 1, 2, 3, 4, 5, 6, 12, 18 and 24h after venom administration. All animal treated with PBS (G1) and EDTA IV (G3) presented increase of nociceptive stimuli at the site of inoculation of the venom, followed by moderate edema that persisted for 24h. Animals treated with IM EDTA (G2) only manifested increase of nociceptive stimuli at the site of injection 1h after treatment with discrete local edema between 12 and 24h. In relation to the local hemorrhagic halo no differences were found amongst the studied groups. Blood profile revealed significant decrease of segmented neutrophils in all groups. There was also increase in triglycerides and decrease in total protein and albumin in all groups. The local lesion was not altered by the treatments.(AU)

Doze coelhos adultos, distribuídos em três grupos, receberam, na região de bíceps femoral, por via intradérmica (ID), 25µg de veneno de Bothrops alternatus, dissolvidos em NaCl 09%, diluído em 0,25mL de tampão salina fosfato (PBS). Trinta minutos após o desafio, o grupo G1 recebeu 0,25mL de (PBS) ID, e os grupos G2 e G3 receberam 25mg de ácido etilenodiamino tetra-acético (EDTA), dissolvidos em mL de PBS por via intramuscular (IM) e intravenosa (IV), respectivamente. Foram avaliados lesão local e perfil sanguíneo de todos os animais, antes - tempo zero, e à uma, às duas, três, quatro, cinco, seis, 12, 18 e 24 horas após a injeção do veneno. Tanto os animais tratados com PBS (G1) como os animais tratados com EDTA IV (G3) apresentaram aumento do estímulo nociceptivo no local da administração do veneno, seguido por moderado edema, que perdurou por 24h. Os animais tratados com EDTA IM (G2) somente manifestaram aumento do estímulo nociceptivo local uma hora após tratamento e discreto edema local entre 12 e 24 horas. Em relação ao halo hemorrágico, não houve diferença entre os três grupos estudados. No perfil hematológico, observou-se diminuição significativa dos neutrófilos segmentados nos três grupos estudados. Da mesma forma, houve aumento dos triglicerídeos e diminuição da proteína total e albumina em todos os grupos. Conclui-se que a lesão local não foi alterada pelos tratamentos.(AU)

Clinical and immunological aspects of envenomations by Bothrops snakes: [review]

Accidents caused by snakes, especially in tropical and subtropical countries, still constitute a serious public health problem due to the lack of knowledge of health professionals and the precariousness of health systems in the regions where most accidents occur. Snake venoms contain a range of molecules that may provoke local swelling, pain, renal and respiratory insufficiencies. The study of the effects of each molecule on humans can help the development of complementary therapy. Similarly, the knowledge of clinical aspects of envenomations provides a better identification and implementation of appropriate treatment. In addition, to understand Bothrops envenomations and improve the therapeutic strategy, it is necessary to understand and study the role of important inflammatory mediators, particularly nitric oxide (NO), cytokines and the complement system.

Detection and neutralization of venom by ovine antiserum in experimental envenoming by Bothrops jararaca

In this study we optimized an enzyme-linked immunosorbent assay (ELISA) to evaluate bothropic venom levels in biological samples. These samples were obtained by two distinct protocols. In the first one, Swiss mice were injected with 1 LD50 of Bothrops jararaca (B. jararaca) venom and 15 minutes later, animals were treated with ovine antibothropic serum. Blood and spleen homogenate samples were obtained 6 hours after antiserum therapy. Ovine antibothropic serum significantly neutralized venom levels in serum and spleen. In the second protocol, BALB/c mice were injected with 1 LD50 of bothropic venom by either intraperitoneal (IP) or intradermal (ID) route and venom levels were evaluated 1, 3 and 6 hours after, in blood, spleen homogenates and urine. Serum and splenic venom levels were significantly higher in animals envenomed by IP route comparing with animals envenomed by ID route. Higher venom levels were also detected in urine samples from animals envenomed by IP route. However, these differences were not statistically significant. These results demonstrated that the optimized ELISA was adequate to quantify venom levels in different biological samples. This assay could, therefore, substitute the in vivo neutralizing assay and also be useful to evaluate the severity of human and experimental envenomations.

Treatment of Bothrops alternatus envenomation by Curcuma longa and Calendula officinalis extracts and ar-turmerone

Investigou-se a eficácia do extrato de plantas no tratamento local do envenenamento botrópico. Veneno de serpentes Bothrops alternatus (1,25µg) diluído em 100µl de solução salina estéril foi inoculado (via intradérmica) entre as escápulas de 30 coelhos. Os animais foram divididos em seis grupos (tratamentos): grupo I: tratamento subcutâneo com extrato de Curcuma longa; grupo II: tratamento tópico com extrato hidroalcoólico de Curcuma longa; grupo III: tratamento tópico com ar-turmerone em vaselina; grupo IV: tratamento tópico com extrato metanólico de Curcuma longa; grupo V: tratamento tópico com pomada de Calendula officinalis e grupo VI: aplicação tópica de solução salina a 0,9 por cento (Controle). Os tratamentos foram realizados 30 minutos, 2h, 4h, 24h e 72h após a inoculação do veneno. Foram avaliados intensidade de edema local (com paquímetro), halo hemorrágico (régua com gabaritos circulares) e presença de necrose. Sete dias após a inoculação do veneno botrópico (168h) foi coletado sangue do coração, com e sem EDTA, para realização de hemograma, dosagem plasmática de fibrinogênio e dosagens séricas de proteína total, uréia e creatinina. Após as coletas de sangue, todos os animais foram anestesiados, sacrificados com inalação pelo éter etílico e necropsiados. Fragmentos de pele foram retirados para avaliação histopatológica. Os resultados obtidos mostraram que o tratamento mais eficaz para inibição da evolução do edema, necrose e hemorragia local após envenenamento com Bothrops alternatus foi a aplicação tópica de ar-turmerone.

Effect of adjuvants on the antibody response of mice to Bothrops asper (Terciopelo) snake venom

The adjuvant of several immunostimulant molecules on the murine antibody response to Bothrops asper snake venom were evaluated. Mice receiving venom together with either sodium alginate, calcium alginate, aluminum hydroxide, muramyl dipeptide, killed Brucella abortus or B. abortus smooth lipopolysaccharide developed a similar antibody response. Despite the fact that in some cases animals injected with venom and Salmonella montevideo lipopolysaccharide developed a significantly higher antibody titer when compared to other experimental groups, no statistically significant differences were observed in most of the comparisons.