title: In vitro and in vivo anti-malarial activity of plants from the Brazilian Amazon.
abstract: BACKGROUND
  The anti-malarials quinine and artemisinin were isolated from traditionally used plants (Cinchona spp. and Artemisia annua, respectively). The synthetic quinoline anti-malarials (e.g. chloroquine) and semi-synthetic artemisinin derivatives (e.g. artesunate) were developed based on these natural products. Malaria is endemic to the Amazon region where Plasmodium falciparum and Plasmodium vivax drug-resistance is of concern. There is an urgent need for new anti-malarials. Traditionally used Amazonian plants may provide new treatments for drug-resistant P. vivax and P. falciparum. Herein, the in vitro and in vivo antiplasmodial activity and cytotoxicity of medicinal plant extracts were investigated.
  
  
  METHODS
  Sixty-nine extracts from 11 plant species were prepared and screened for in vitro activity against P. falciparum K1 strain and for cytotoxicity against human fibroblasts and two melanoma cell lines. Median inhibitory concentrations (IC50) were established against chloroquine-resistant P. falciparum W2 clone using monoclonal anti-HRPII (histidine-rich protein II) antibodies in an enzyme-linked immunosorbent assay. Extracts were evaluated for toxicity against murine macrophages (IC50) and selectivity indices (SI) were determined. Three extracts were also evaluated orally in Plasmodium berghei-infected mice.
  
  
  RESULTS
  High in vitro antiplasmodial activity (IC50 = 6.4-9.9 µg/mL) was observed for Andropogon leucostachyus aerial part methanol extracts, Croton cajucara red variety leaf chloroform extracts, Miconia nervosa leaf methanol extracts, and Xylopia amazonica leaf chloroform and branch ethanol extracts. Paullinia cupana branch chloroform extracts and Croton cajucara red variety leaf ethanol extracts were toxic to fibroblasts and or melanoma cells. Xylopia amazonica branch ethanol extracts and Zanthoxylum djalma-batistae branch chloroform extracts were toxic to macrophages (IC50 = 6.9 and 24.7 µg/mL, respectively). Andropogon leucostachyus extracts were the most selective (SI >28.2) and the most active in vivo (at doses of 250 mg/kg, 71% suppression of P. berghei parasitaemia versus untreated controls).
  
  
  CONCLUSIONS
  Ethnobotanical or ethnopharmacological reports describe the anti-malarial use of these plants or the antiplasmodial activity of congeneric species. No antiplasmodial activity has been demonstrated previously for the extracts of these plants. Seven plants exhibit in vivo and or in vitro anti-malarial potential. Future work should aim to discover the anti-malarial substances present.
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. renatabsl@hotmail.com.|Programa de Pós-graduação em Biotecnologia, Universidade Federal do Amazonas, Avenida Gal. Rodrigo Otávio Jordão Ramos, 3000, Coroado I, Campus Universitário, Bloco M, Setor Sul, 69077-000, Manaus, Amazonas, Brazil. renatabsl@hotmail.com.|Centro Universitário do Norte, Rua Dez de Julho, 873, Centro, 69010-060, Manaus, Amazonas, Brazil. renatabsl@hotmail.com.
authors.forename: Renata B S
authors.initials: RB
authors.lastname: Lima
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. luizrocha_silva@hotmail.com.|Programa de Pós-graduação em Biotecnologia, Universidade Federal do Amazonas, Avenida Gal. Rodrigo Otávio Jordão Ramos, 3000, Coroado I, Campus Universitário, Bloco M, Setor Sul, 69077-000, Manaus, Amazonas, Brazil. luizrocha_silva@hotmail.com.|Centro Universitário do Norte, Rua Dez de Julho, 873, Centro, 69010-060, Manaus, Amazonas, Brazil. luizrocha_silva@hotmail.com.
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Rocha e Silva
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade Estadual do Amazonas, Avenida Carvalho Leal, 1777, Cachoeirinha, 69065-001, Manaus, Amazonas, Brazil. marciarubia.melo@gmail.com.
authors.forename: Marcia R S
authors.initials: MR
authors.lastname: Melo
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. jaquelinesc96@hotmail.com.
authors.forename: Jaqueline S
authors.initials: JS
authors.lastname: Costa
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. neilasp@hotmail.com.|Programa de Pós-graduação em Biotecnologia, Universidade Federal do Amazonas, Avenida Gal. Rodrigo Otávio Jordão Ramos, 3000, Coroado I, Campus Universitário, Bloco M, Setor Sul, 69077-000, Manaus, Amazonas, Brazil. neilasp@hotmail.com.
authors.forename: Neila S
authors.initials: NS
authors.lastname: Picanço
authors.affiliation: Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Rua Comendador Alexandre Amorim, 330, Aparecida, 69103-000, Manaus, Amazonas, Brazil. eslima@ufam.edu.br.
authors.forename: Emerson S
authors.initials: ES
authors.lastname: Lima
authors.affiliation: Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Rua Comendador Alexandre Amorim, 330, Aparecida, 69103-000, Manaus, Amazonas, Brazil. marne@ufam.edu.br.
authors.forename: Marne C
authors.initials: MC
authors.lastname: Vasconcellos
authors.affiliation: Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Rua Comendador Alexandre Amorim, 330, Aparecida, 69103-000, Manaus, Amazonas, Brazil. apboleti@yahoo.com.br.
authors.forename: Ana Paula A
authors.initials: AP
authors.lastname: Boleti
authors.affiliation: Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Rua Comendador Alexandre Amorim, 330, Aparecida, 69103-000, Manaus, Amazonas, Brazil. jakeline.pinheiro@hotmail.com.
authors.forename: Jakeline M P
authors.initials: JM
authors.lastname: Santos
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. rodrigoamorim_br@yahoo.com.br.
authors.forename: Rodrigo C N
authors.initials: RC
authors.lastname: Amorim
authors.affiliation: Embrapa Amazônia Ocidental, Rodovia AM-010, Km 29 (Estrada Manaus/Itacoatiara), Caixa Postal 319, 69010-970, Manaus, Amazonas, Brazil. celio.chaves@embrapa.br.
authors.forename: Francisco C M
authors.initials: FC
authors.lastname: Chaves
authors.affiliation: Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima, 1715, Barro Preto, 30190-002, Belo Horizonte, Minas Gerais, Brazil. juliapenna@cpqrr.fiocruz.br.
authors.forename: Julia P
authors.initials: JP
authors.lastname: Coutinho
authors.affiliation: Laboratório de Malária e Dengue, Coordenação de Sociedade, Ambiente e Saúde, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. wptadei@gmail.com.
authors.forename: Wanderli P
authors.initials: WP
authors.lastname: Tadei
authors.affiliation: Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima, 1715, Barro Preto, 30190-002, Belo Horizonte, Minas Gerais, Brazil. akrettli@cpqrr.fiocruz.br.
authors.forename: Antoniana U
authors.initials: AU
authors.lastname: Krettli
authors.affiliation: Laboratório de Princípios Ativos da Amazônia, Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, Petrópolis, 69067-375, Manaus, Amazonas, Brazil. ampohlit@gmail.com.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Pohlit
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D001938:Brazil; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D006801:Humans; D020128:Inhibitory Concentration 50; D008288:Malaria / Q000188:drug therapy; D008807:Mice, Inbred BALB C; D018512:Parasitemia / Q000188:drug therapy; D021261:Parasitic Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D010944:Plants / Q000737:chemistry*; D010962:Plasmodium berghei / Q000187:drug effects; D010963:Plasmodium falciparum / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D010936:Plant Extracts