14 research outputs found
Anti-snake venom effect of secodolastane diterpenes isolated from Brazilian marine brown alga Canistrocarpus cervicornis against Lachesis muta venom
Medicina transfusional brasileira: o resgate de uma história: Brazilian transfusion medicine: the rescue of a history
A hemoterapia é uma área em constante evolução, exigindo que os profissionais atuantes estejam em constante aprendizado. Nesse sentido, o conhecimento histórico torna-se uma importante base de dados, que permite o aprendizado. No que se refere à hemoterapia brasileira há poucos documentos atualizados que se comprometam a relatar os principais avanços realizados no Brasil, desde sua colonização, sendo, portanto, o objetivo deste artigo realizar uma revisão bibliográfica sobre os avanços da medicina transfusional brasileira de 1500 até 2020. Para atingir esse objetivo, pesquisamos nas plataformas NCBI (National Center of Biotechnology Information), LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde), SCIELO (Scientific Eletronic Library Online), BVS (Biblioteca Virtual em Saúde) e Google Scholar (Google Acadêmico), as palavras chaves “Hemoterapia História”, “Hemoterapia brasileira”, “transfusão Brasil” e “Sangue Brasil Colonial”. A análise da literatura mostrou que o principal incentivo dos avanços na medicina brasileira foram os conflitos políticos e sociais, além da vinda da corte portuguesa ao Brasil, o que permitiu a organização dos cirurgiões, sangradores e a criação de faculdades de Medicina. Os investimentos em pesquisa, ensino e saúde permitiram que a primeira transfusão brasileira fosse realizada em 1879, enquanto as mudanças políticas internas e externas ao País promoveram investimentos na modernização e organização da hemoterapia. A partir de 1980, houve uma forte restruturação nas políticas nacionais, que findou as doações pagas, construiu o SUS e estabeleceram os critérios para o tratamento do sangue, seguindo o fluxo dos avanços. O Brasil se dedicou a produção de kits de testes diagnósticos próprios para utilização na hemorede, com adaptação de suas diretrizes frente a situações de epidemias e pandemias e atualizações em seus regimentos que são seguidos até hoje e seguem em aperfeiçoamento
Inhibitory effect of a Brazilian marine brown alga Spatoglossum schröederi on biological activities of Lachesis muta snake venom
Inhibitory Effect of Plant Manilkara subsericea against Biological Activities of Lachesis muta Snake Venom
Snake venom is composed of a mixture of substances that caused in victims a variety of pathophysiological effects. Besides antivenom, literature has described plants able to inhibit injuries and lethal activities induced by snake venoms. This work describes the inhibitory potential of ethanol, hexane, ethyl acetate, or dichloromethane extracts and fractions from stem and leaves of Manilkara subsericea against in vivo (hemorrhagic and edema) and in vitro (clotting, hemolysis, and proteolysis) activities caused by Lachesis muta venom. All the tested activities were totally or at least partially reduced by M. subsericea. However, when L. muta venom was injected into mice 15 min first or after the materials, hemorrhage and edema were not inhibited. Thus, M. subsericea could be used as antivenom in snakebites of L. muta. And, this work also highlights Brazilian flora as a rich source of molecules with antivenom properties
Effect of Diterpenes Isolated of the Marine Alga Canistrocarpus cervicornis against Some Toxic Effects of the Venom of the Bothrops jararaca Snake
Snake venoms are composed of a complex mixture of active proteins and peptides which induce a wide range of toxic effects. Envenomation by Bothrops jararaca venom results in hemorrhage, edema, pain, tissue necrosis and hemolysis. In this work, the effect of a mixture of two secodolastane diterpenes (linearol/isolinearol), previously isolated from the Brazilian marine brown alga, Canistrocarpus cervicornis, was evaluated against some of the toxic effects induced by B. jararaca venom. The mixture of diterpenes was dissolved in dimethylsulfoxide and incubated with venom for 30 min at room temperature, and then several in vivo (hemorrhage, edema and lethality) and in vitro (hemolysis, plasma clotting and proteolysis) assays were performed. The diterpenes inhibited hemolysis, proteolysis and hemorrhage, but failed to inhibit clotting and edema induced by B. jararaca venom. Moreover, diterpenes partially protected mice from lethality caused by B. jararaca venom. The search for natural inhibitors of B. jararaca venom in C. cervicornis algae is a relevant subject, since seaweeds are a rich and powerful source of active molecules which are as yet but poorly explored. Our results suggest that these diterpenes have the potential to be used against Bothropic envenomation accidents or to improve traditional treatments for snake bites
The red seaweed Plocamium brasiliense shows anti-snake venom toxic effects
Background Snakebite is considered a neglected tropical disease by the World Health Organization. In Brazil, about 70% of the envenomation cases are caused by Bothrops snakes. Its venom may provoke hemorrhage, pain, necrosis, hemolysis, renal or cardiac failure and even death in victims. Since commercial antivenom does not efficiently neutralize the local toxic effects of venoms, natural products have been tested in order to provide alternative or complementary treatment to serum therapy. Therefore, the present study aimed to evaluate the ability of the seaweed Plocamium brasiliense and its active derivatives to neutralize hemorrhagic, edematogenic, hemolytic, coagulant and proteolytic activities of B. jararaca venom. Methods Specimens of P. brasiliense were collected in Rio de Janeiro state, Brazil, dried and submitted to oil extraction using four solvents of increasing polarities, n-hexane (HEX), dichloromethane (DCM), ethyl acetate (ETA) and hydroalcoholic solution (HYD). The solvents were evaporated, yielding HEX, DCM, ETA and HYD extracts. Further, all extracts were dissolved in dimethylsulfoxide. In addition, two monoterpenes (8-bromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene and 1,8-dibromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene) and a cholesterol fraction were isolated from the extract of P. brasiliense prepared in hexane. Algal samples were incubated for 30 minutes with B. jararaca venom, and then tested for lethality; hemorrhagic, edematogenic, hemolytic, coagulant and proteolytic effects. Results Most of the algal extracts inhibited the toxic effects with different potencies. The DCM extract was the most effective, since it inhibited all types of toxic activity. On the other hand, the HYD extract failed to inhibit any effect. Moreover, the isolated products inhibited proteolysis and protected mice from hemorrhage in 30% of the cases, whereas 8-bromo-3,4,7-trichloro-3,7-dimethyl-1E, 5E-octadiene inhibited 100% and 20% of the hemorrhagic and proteolytic activities, respectively. None of the algal products were toxic to mice. Conclusion Seaweeds may be a promising source of inhibitors against toxic effects caused by B. jararacaenvenomation, which may contribute to antivenom treatment
Sulfated Galactan from Palisada flagellifera Inhibits Toxic Effects of Lachesis muta Snake Venom
In Brazil, snakebites are a public health problem and accidents caused by Lachesis muta have the highest mortality index. Envenomation by L. muta is characterized by systemic (hypotension, bleeding and renal failure) and local effects (necrosis, pain and edema). The treatment to reverse the evolution of all the toxic effects is performed by injection of antivenom. However, such therapy does not effectively neutralize tissue damage or any other local effect, since in most cases victims delay seeking appropriate medical care. In this way, alternative therapies are in demand, and molecules from natural sources have been exhaustively tested. In this paper, we analyzed the inhibitory effect of a sulfated galactan obtained from the red seaweed Palisada flagellifera against some toxic activities of L. muta venom. Incubation of sulfated galactan with venom resulted in inhibition of hemolysis, coagulation, proteolysis, edema and hemorrhage. Neutralization of hemorrhage was also observed when the galactan was administered after or before the venom injection; thus mimicking a real in vivo situation. Moreover, the galactan blocked the edema caused by a phospholipase A2 isolated from the same venom. Therefore, the galactan from P. flagellifera may represent a promising tool to treat envenomation by L. muta as a coadjuvant for the conventional antivenom