Combating malaria in Africa

Trape, Jean François; Pison, Gilles; Spiegel, André; Enel, Catherine; Rogier, Christophe

doi:10.1016/s1471-4922(02)02249-3

Cited by 153 publications

(123 citation statements)

References 33 publications

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“…There are around 250 million clinical cases every year and almost one million deaths, mostly children, which are attributable to this disease 35 . The main reasons that explain this worsening situation are therapy problems 30 : resistance to the current antimalarial drugs 33 , unavailability and unaffordability of antimalarial drugs 4 and lack of new therapeutic targets 3 . These facts have led to searches for new antimalarial compounds.…”

Section: Introductionmentioning

confidence: 99%

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

Valdés

Martínez

Lizama

et al. 2010

Rev. Inst. Med. trop. S. Paulo

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SUMMARYTerrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC 50 values lower than 100 µg/mL against P. falciparum, four extracts were classified as marginally active (SI < 4), one as partially active (Parthenium hysterophorus) exhibiting SI equal to 6.2 and two extracts as active (Bambusa vulgaris and Punica granatum), showing SI > 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC 50 = 4.7 µg/mL, SI = 28.9). Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.

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Section: Introductionmentioning

confidence: 99%

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

Valdés

Martínez

Lizama

et al. 2010

Rev. Inst. Med. trop. S. Paulo

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“…Drug resistance has led to increased mortality in hyper and holoendemic areas and contributed to the appearance and spread of new focal areas of malaria caused by P. falciparum. Furthermore, resistance has been identified as a factor that economically compromises malaria control efforts (Trape et al 2002). Great effort and time have been dedicated to the in vitro reproduction of the erythrocytic stages of the Plasmodium life cycle as a fundamental tool for studying the mechanisms of susceptibility and resistance to drugs as well as screening for the identification of new drugs (Girard et al 2007).…”

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confidence: 99%

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Silva

Magalhães

Costa

et al. 2012

Mem. Inst. Oswaldo Cruz

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“…The emergence and spread of CQ-resistant strains of Plasmodium falciparum has been identified as a major factor responsible for the recent increases in malaria mortality and morbidity (1). In Africa alone, malaria-related mortality is estimated at a level of 0.5 to 2.0 million people per year, predominantly children under the age of five (2).…”

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confidence: 99%

Chloroquine Resistance Modulated in Vitro by Expression Levels of the Plasmodium falciparum Chloroquine Resistance Transporter

Waller

Muhle

Ursos

et al. 2003

Journal of Biological Chemistry

110

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Plasmodium falciparum malaria is increasingly difficult to treat and control due to the emergence of parasite resistance to the major antimalarials, notably chloroquine. Recent work has shown that the chloroquine resistance phenotype can be conferred by multiple amino acid mutations in the parasite digestive vacuole transmembrane protein PfCRT. Here, we have addressed whether chloroquine resistance can also be affected by changes in expression levels of this protein.Transient transfection reporter assays revealed that truncation of the pfcrt 3-untranslated region just prior to putative polyadenylation sites resulted in a 10-fold decrease in luciferase expression levels. Using allelic exchange on a chloroquine-resistant line (7G8 from Brazil), this truncated 3-untranslated region was inserted downstream of the pfcrt coding sequence, in the place of the endogenous 3-untranslated region. The resulting pfcrt-modified "knockdown" clones displayed a marked decrease in pfcrt transcription and an estimated 30 -40% decrease in PfCRT protein expression levels. [ 3 H]hypoxanthine incorporation assays demonstrated up to a 40% decrease in chloroquine with or without verapamil IC 50 levels of pfcrt knockdown clones, relative to the 7G8 parent. Single-cell photometric analyses were consistent with an altered intracellular pH in the knockdown clones, providing further evidence for a relationship between PfCRT, pH regulation, and chloroquine resistance. Genetic truncation of 3-untranslated regions provides a useful approach for assessing the impact of candidate genes on drug resistance or other quantifiable phenotypes in P. falciparum.

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Combating malaria in Africa

Cited by 153 publications

References 33 publications

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Chloroquine Resistance Modulated in Vitro by Expression Levels of the Plasmodium falciparum Chloroquine Resistance Transporter

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