Caracterização de cepas de plasmodium falciparum do Estado de Rondônia, Brasil, utilizando microtestes de sensibilidade aos antimaláricos, tipificação enzimática e anticorpos monoclonais

Santi, Sílvia Maria Di; Boulos, Marcos; Vasconcelos, Mayron Alves de; Oliveira, Salma Gomes de; Couto, Álvaro Augusto Ribeiro D'Almeida; Rosário, Virgílio Estólio do

doi:10.1590/s0036-46651987000300005

Cited by 9 publications

(1 citation statement)

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“…Plasmodium falciparum chloroquine-sensitive (3D7) [22] and chloroquine-resistant (S20) [23] strains were cultured in a candle jar as described elsewhere [24]. Briefly, P. falciparum infected-erythrocytes (Pf-iE) were cultivated in fresh-type O + human erythrocytes (UNICAMP, Blood Bank, Brazil) suspended at 4% final haematocrit in complete medium (RPMPI-1640 containing 10% homologous human plasma and 25 mM HEPES buffer, pH 7.4).…”

Section: Methodsmentioning

confidence: 99%

In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

Kayano

Lopes

Bueno

et al. 2011

Malar J

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BackgroundTo overcome the problem of increasing drug resistance, traditional medicines are an important source for potential new anti-malarials. Caesalpinia pluviosa, commonly named "sibipiruna", originates from Brazil and possess multiple therapeutic properties, including anti-malarial activity.MethodsCrude extract (CE) was obtained from stem bark by purification using different solvents, resulting in seven fractions. An MTT assay was performed to evaluate cytotoxicity in MCF-7 cells. The CE and its fractions were tested in vitro against chloroquine-sensitive (3D7) and -resistant (S20) strains of Plasmodium falciparum and in vivo in Plasmodium chabaudi-infected mice. In vitro interaction with artesunate and the active C. pluviosa fractions was assessed, and mass spectrometry analyses were conducted.ResultsAt non-toxic concentrations, the 100% ethanolic (F4) and 50% methanolic (F5) fractions possessed significant anti-malarial activity against both 3D7 and S20 strains. Drug interaction assays with artesunate showed a synergistic interaction with the F4. Four days of treatment with this fraction significantly inhibited parasitaemia in mice in a dose-dependent manner. Mass spectrometry analyses revealed the presence of an ion corresponding to m/z 303.0450, suggesting the presence of quercetin. However, a second set of analyses, with a quercetin standard, showed distinct ions of m/z 137 and 153.ConclusionsThe findings show that the F4 fraction of C. pluviosa exhibits anti-malarial activity in vitro at non-toxic concentrations, which was potentiated in the presence of artesunate. Moreover, this anti-malarial activity was also sustained in vivo after treatment of infected mice. Finally, mass spectrometry analyses suggest that a new compound, most likely an isomer of quercetin, is responsible for the anti-malarial activity of the F4.

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Section: Methodsmentioning

confidence: 99%

In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

Kayano

Lopes

Bueno

et al. 2011

Malar J

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Pfmdr1Asn1042AspandAsp1246TyrPolymorphisms, Thought to Be Associated with Chloroquine Resistance, Are Present in Chloroquine-Resistant and -Sensitive Brazilian Field Isolates ofPlasmodium falciparum

Póvoa

Adagu

Oliveira

et al. 1998

Experimental Parasitology

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Immunogenic properties of a recombinant fusion protein containing the C-terminal 19 kDa of Plasmodium falciparum merozoite surface protein-1 and the innate immunity agonist FliC flagellin of Salmonella Typhimurium

Bargieri

Leite

Lopes

et al. 2010

Vaccine

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In a recent study, we demonstrated the immunogenic properties of a new malaria vaccine polypeptide based on a 19 kDa C-terminal fragment of the merozoite surface protein-1 (MSP1(19)) from Plasmodium vivax and an innate immunity agonist, the Salmonella enterica serovar Typhimurium flagellin (FliC). Herein, we tested whether the same strategy, based on the MSP1(19) component of the deadly malaria parasite Plasmodium falciparum, could also generate a fusion polypeptide with enhanced immunogenicity. The His(6)FliC-MSP1(19) fusion protein was expressed from a recombinant Escherichia coli and showed preserved in vitro TLR5-binding activity. In contrast to animals injected with His(6)MSP1(19), mice subcutaneously immunised with the recombinant His(6)FliC-MSP1(19) developed strong MSP1(19)-specific systemic antibody responses with a prevailing IgG1 subclass. Incorporation of other adjuvants, such as CpG ODN 1826, complete and incomplete Freund's adjuvants or Quil-A, improved the IgG responses after the second, but not the third, immunising dose. It also resulted in a more balanced IgG subclass response, as evaluated by the IgG1/IgG2c ratio, and higher cell-mediated immune response, as determined by the detection of antigen-specific interferon-gamma secretion by immune spleen cells. MSP1(19)-specific antibodies recognised not only the recombinant protein, but also the native protein expressed on the surface of P. falciparum parasites. Finally, sera from rabbits immunised with the fusion protein alone inhibited the in vitro growth of three different P. falciparum strains. In summary, these results extend our previous observations and further demonstrate that fusion of the innate immunity agonist FliC to Plasmodium antigens is a promising alternative to improve their immunogenicity.

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Caracterização de cepas de plasmodium falciparum do Estado de Rondônia, Brasil, utilizando microtestes de sensibilidade aos antimaláricos, tipificação enzimática e anticorpos monoclonais

Cited by 9 publications

References 15 publications

In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

Pfmdr1Asn1042AspandAsp1246TyrPolymorphisms, Thought to Be Associated with Chloroquine Resistance, Are Present in Chloroquine-Resistant and -Sensitive Brazilian Field Isolates ofPlasmodium falciparum

Immunogenic properties of a recombinant fusion protein containing the C-terminal 19 kDa of Plasmodium falciparum merozoite surface protein-1 and the innate immunity agonist FliC flagellin of Salmonella Typhimurium

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