title: Anti-malarial activity of indole alkaloids isolated from Aspidosperma olivaceum.
abstract: BACKGROUND
  Several species of Aspidosperma (Apocynaceae) are used as treatments for human diseases in the tropics. Aspidosperma olivaceum, which is used to treat fevers in some regions of Brazil, contains the monoterpenoid indole alkaloids (MIAs) aspidoscarpine, uleine, apparicine, and N-methyl-tetrahydrolivacine. Using bio-guided fractionation and cytotoxicity testing in a human hepatoma cell line, several plant fractions and compounds purified from the bark and leaves of the plant were characterized for specific therapeutic activity (and selectivity index, SI) in vitro against the blood forms of Plasmodium falciparum.
  
  
  METHODS
  The activity of A. olivaceum extracts, fractions, and isolated compounds was evaluated against chloroquine (CQ)-resistant P. falciparum blood parasites by in vitro testing with radiolabelled [3H]-hypoxanthine and a monoclonal anti-histidine-rich protein (HRPII) antibody. The cytotoxicity of these fractions and compounds was evaluated in a human hepatoma cell line using a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, and the SI was calculated as the ratio between the toxicity and activity. Two leaf fractions were tested in mice with Plasmodium berghei.
  
  
  RESULTS
  All six fractions from the bark and leaf extracts were active in vitro at low doses (IC50 < 5.0 μg/mL) using the anti-HRPII test, and only two (the neutral and basic bark fractions) were toxic to a human cell line (HepG2). The most promising fractions were the crude leaf extract and its basic residue, which had SIs above 50. Among the four pure compounds evaluated, aspidoscarpine in the bark and leaf extracts showed the highest SI at 56; this compound, therefore, represents a possible anti-malarial drug that requires further study. The acidic leaf fraction administered by gavage to mice with blood-induced malaria was also active.
  
  
  CONCLUSIONS
  Using a bio-monitoring approach, it was possible to attribute the anti-P. falciparum activity of A. olivaceum to aspidoscarpine and, to a lesser extent, N-methyl-tetrahydrolivacine; other isolated MIA molecules were active but had lower SIs due to their higher toxicities. These results stood in contrast to previous work in which the anti-malarial activity of other Aspidosperma species was attributed to uleine.
authors.forename: Talita P C
authors.initials: TP
authors.lastname: Chierrito
authors.forename: Anna C C
authors.initials: AC
authors.lastname: Aguiar
authors.forename: Isabel M
authors.initials: IM
authors.lastname: de Andrade
authors.forename: Isabela P
authors.initials: IP
authors.lastname: Ceravolo
authors.forename: Regina A C
authors.initials: RA
authors.lastname: Gonçalves
authors.forename: Arildo J B
authors.initials: AJ
authors.lastname: de Oliveira
authors.affiliation: Faculdade de Medicina, Programa de Pós-Graduação em Medicina Molecular, Universidade Federal de Minas Gerais, Prof, Alfredo Balena, 190, 30130-100 Belo Horizonte, MG, Brazil. akrettli@cpqrr.fiocruz.br.
authors.forename: Antoniana U
authors.initials: AU
authors.lastname: Krettli
mesh_terms: D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D030009:Aspidosperma / Q000737:chemistry*; D001938:Brazil; D002470:Cell Survival / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects; D026121:Indole Alkaloids / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D021261:Parasitic Sensitivity Tests; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry; D010963:Plasmodium falciparum / Q000187:drug effects*
chemical_list: D000962:Antimalarials; D026121:Indole Alkaloids; D010936:Plant Extracts
references.citation: Antimicrob Agents Chemother. 1979 Dec;16(6):710-8
references.pmid: 394674
references.citation: J Ethnopharmacol. 2002 Jun;81(1):23-9
references.pmid: 12020924
references.citation: J Ethnopharmacol. 1997 Jul;57(2):131-8
references.pmid: 9254115
references.citation: An Acad Bras Cienc. 2012 Dec;84(4):899-910
references.pmid: 23207699
references.citation: Emerg Infect Dis. 2007 Jul;13(7):1125-6
references.pmid: 18214203
references.citation: Phytomedicine. 2011 Oct 15;18(13):1118-25
references.pmid: 21612900
references.citation: J Ethnopharmacol. 2007 Mar 1;110(1):165-70
references.pmid: 17097251
references.citation: Bioorg Med Chem Lett. 2004 Mar 8;14(5):1145-9
references.pmid: 14980653
references.citation: Exp Parasitol. 1965 Aug;17(1):80-9
references.pmid: 5843289
references.citation: J Parasitol. 1979 Jun;65(3):418-20
references.pmid: 383936
references.citation: N Engl J Med. 2009 Jul 30;361(5):455-67
references.pmid: 19641202
references.citation: Phytomedicine. 2012 Dec 15;20(1):71-6
references.pmid: 23092722
references.citation: Mem Inst Oswaldo Cruz. 2007 Jun;102(3):359-65
references.pmid: 17568942
references.citation: Malar J. 2013 Jul 03;12:226
references.pmid: 23819884
references.citation: J Immunol Methods. 1986 May 22;89(2):271-7
references.pmid: 3486233
references.citation: Phytomedicine. 2012 Mar 15;19(5):413-7
references.pmid: 22326547
references.citation: Science. 1976 Aug 20;193(4254):673-5
references.pmid: 781840
references.citation: Braz J Med Biol Res. 2006 Mar;39(3):387-91
references.pmid: 16501818
references.citation: Phytomedicine. 2002 Mar;9(2):142-5
references.pmid: 11995947
references.citation: J Ethnopharmacol. 2003 Aug;87(2-3):253-6
references.pmid: 12860318
references.citation: Exp Parasitol. 2002 Nov-Dec;102(3-4):157-63
references.pmid: 12856311
references.citation: Expert Opin Drug Discov. 2009 Feb;4(2):95-108
references.pmid: 23480511
references.citation: Mutat Res. 1975 Dec;31(6):347-64
references.pmid: 768755
references.citation: Curr Infect Dis Rep. 2010 May;12(3):165-73
references.pmid: 21308525
references.citation: Mem Inst Oswaldo Cruz. 2013 Dec;108(8):974-82
references.pmid: 24402150
references.citation: Lancet. 2014 Mar 22;383(9922):1049-58
references.pmid: 24360369
references.citation: Tetrahedron. 1965 May;21(5):1141-66
references.pmid: 5879346
references.citation: Curr Drug Targets. 2009 Mar;10(3):261-70
references.pmid: 19275562
references.citation: Antimicrob Agents Chemother. 2014;58(1):342-7
references.pmid: 24165179
references.citation: Molecules. 2013 May 29;18(6):6281-97
references.pmid: 23760029
references.citation: Braz J Med Biol Res. 1991;24(11):1113-23
references.pmid: 1823001