title: Counteraction of Bothrops snake venoms by Combretum leprosum root extract and arjunolic acid.
abstract: BACKGROUND
  Serotherapy against snakebite is often unavailable in some regions over Brazil, where people make use of plants from folk medicine to deal with ophidic accidents. About 10% of Combretum species have some ethnopharmacological use, including treatment of snakebites.
  
  
  METHODS
  We evaluated the ability of the extract of Combretum leprosum and its component arjunolic acid to reduce some in vivo and in vitro effects of Bothrops jararacussu and Bothrops jararaca venoms. The protocols investigated include phospholipase, proteolytic, collagenase, hyaluronidase, procoagulant, hemorrhagic, edematogenic, myotoxic and lethal activities induced by these venoms in Swiss mice.
  
  
  RESULTS
  Oral pre-treatment with arjunolic acid reduced the Bothrops jararacussu lethality in up to 75%, while preincubation prevented the death of all the animals. Hemoconcentration effect of Bothrops jararacussu venom was confirmed two hours after i.p. injection, while preincubation with arjunolic acid preserved the hematocrit levels. Both Combretum leprosum extract and arjunolic acid abolished the myotoxic action of Bothrops jararacussu venom. Preincubation of Bothrops jararacussu venom with the extract or arjunolic acid prevented the increase of plasma creatine kinase activity in mice. The hemorrhagic activity of Bothrops jararaca crude venom was reduced down to about 90% and completely inhibited by preincubation with 10 mg/kg or 100 mg/kg Combretum leprosum extract, respectively, while the preincubation and the pretreatment with 30 mg/kg of arjunolic acid reduced the venom hemorrhagic activity down to about 12% and 58%, respectively. The preincubation of the venom with both extract and 30 mg/kg arjunolic acid significantly reduced the bleeding amount induced by Bothrops jararacussu venom. The extract of Combretum leprosum decreased the edema formation induced by Bothrops jararacussu venom both in preincubation and pretreatment, but not in posttreatment. Similarly, arjunolic acid preincubated with the venom abolished edema formation, while pre- and posttreatment have been partially effective. Some enzymatic activities of Bothrops jararacussu and Bothrops jararaca venoms, i.e. phospholipase A2, collagenase, proteolytic and hyaluronidase activities, were to some extent inhibited by the extract and arjunolic acid in a concentration-dependent manner.
  
  
  CONCLUSIONS
  Altogether, our results show that Combretum leprosum extract can inhibit different activities of two important Brazilian snake venoms, giving support for its popular use in folk medicine in the management of venomous snakebites.
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Fabrício F A
authors: FF
authors: Fernandes
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Marcelo A
authors: MA
authors: Tomaz
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Camila Z
authors: CZ
authors: El-Kik
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Marcos
authors: M
authors: Monteiro-Machado
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Marcelo A
authors: MA
authors: Strauch
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Bruno L
authors: BL
authors: Cons
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Matheus S
authors: MS
authors: Tavares-Henriques
authors: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Adélia C O
authors: AC
authors: Cintra
authors: Departamento de Química - Universidade Federal de Rondônia, Porto Velho, RO, Brazil.
authors: Valdir A
authors: VA
authors: Facundo
authors: Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas - Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. Electronic address: melo.pa@gmail.com.
authors: Paulo A
authors: PA
authors: Melo
mesh_terms: D000818:Animals; D000997:Antivenins / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D017837:Bothrops; D001938:Brazil; D029765:Combretum / Q000737:chemistry*; D003435:Crotalid Venoms / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000188:drug therapy / Q000209:etiology; D020834:Ethnopharmacology; D006470:Hemorrhage / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008519:Medicine, Traditional; D051379:Mice; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018517:Plant Roots; D012909:Snake Bites / Q000188:drug therapy / Q000503:physiopathology; D014315:Triterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000997:Antivenins; D003435:Crotalid Venoms; D010936:Plant Extracts; D014315:Triterpenes; C061640:arjunolic acid
keywords: Antiophidic plants; Arjunolic acid; Combretum leprosum; Hemorrhage; Myotoxicity; Snake venoms