Antiplasmodial and GABA(A)-benzodiazepine receptor binding activities of five plants used in traditional medicine in Mali, West Africa.
ABSTRACT Extracts of five medicinal plants: Boscia angustifolia, Cissus quadrangularis, Securidaca longipedunculata, Stylosanthes erecta and Trichilia emetica, used traditionally in Malian traditional medicine were screened for in vitro antiplasmodial activity and GABA(A)-benzodiazepine receptor binding activity. Four extracts showed significant antiplasmodial activities, with the dichloromethane extract of leaf of Securidaca longipedunculata being the most active (IC(50) of 7 microg/ml [95% CI: 5-9]). The dichloromethane extract of leaf of Trichilia emetica, in addition to its antiplasmodial activity (IC(50): 12 microg/ml [95% CI: 12-14]), exhibited a good binding activity to the GABA(A)-benzodiazepine receptor, while water and methanol extracts of the same plant did not show any activity. A strong GABA(A)-receptor complex binding activity was observed in the methanol extract of aerial part of Stylosanthes erecta. The results in this study justify some of the traditional indications of the plants investigated and may thus be candidates for Improved Traditional Medicines in Mali.
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ABSTRACT: Falcipain-2, a cysteine protease and essential hemoglobinase of Plasmodium falciparum, is a potential antimalarial drug target. We compared the falcipain-2 sequences and sensitivities to cysteine protease inhibitors of five parasite strains that differ markedly in sensitivity to established antimalarial drugs. The sequence of falcipain-2 was highly conserved, and the sensitivities of all of the strains to falcipain-2 inhibitors were very similar. Thus, cross-resistance between cysteine protease inhibitors and other antimalarial agents is not expected in parasites that are now circulating and falcipain-2 remains a promising chemotherapeutic target.Antimicrobial Agents and Chemotherapy 04/2001; 45(3):949-51. · 4.57 Impact Factor
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ABSTRACT: One hundred and twenty-five extracts of 122 different plant species traditionally used by the Tacana, a native community living in lowland forest at the base of the last foothills of the Cordillera Oriental of the Bolivian Andes, were screened for antimalarial activity in vitro on Plasmodium falciparum chloroquine resistant (D2) and sensitive strains (F32), and were evaluated in vivo on rodent malaria Plasmodium berghei. Five ethanolic stembark extracts showed marked activity either in vitro or in vivo, and only one of them, Bowdichia virgilioides being traditionally used against malaria, was active in vitro (IC50=1 microg/ml on both strains) and in vivo (51% at 100 mg/kg). Other active extracts were from Caesalpinia pluviosa bark displaying activity in vitro against chloroquine resistant strain (IC50 8.3 microg/ml), traditionally used against dysentery; two Lauraceae bark extracts, Nectandra aff. hihua and Licaria canella respectively used for construction purposes and against stomach ache, both displaying activity in vitro against P. falciparum sensible and resistant strains (IC50 around 4 microg/ml); finally, the bark of a strongly aromatic Burseraceae, Protium glabrescens exuding an anti-inflammatory and analgesic resin, was active in vivo only (61% at 100 mg/kg). Results are discussed in relation with Tacana traditional medicine.Journal of Ethnopharmacology 10/2001; 77(1):91-8. · 2.76 Impact Factor
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ABSTRACT: Fourteen Ghanaian plants used in folk medicine to treat fever/malaria were screened for activity against Plasmodium falciparum (strain K1) and were tested for general toxicity to the brine shrimp. Extracts from three of the plants, Pleiocarpa mutica, Cleistopholis patens and Uvaria chamae were found to have significant antiplasmodial activity. The extract of U. chamae was toxic to brine shrimps. These findings lend support to the use of these plants in traditional medicine. Possible toxicity due to U. chamae is a cause for concern. Five known alkaloids, pleiocarpine (1), kopsinine (2), pleiocarpamine (3), eburnamine (4) and pleiomutinine (5) were isolated from the roots of P. mutica. This is the first report of the occurrence of (4) in P. mutica. Compound (5) was the most active against P. falciparum (IC50 = 5 microM). Although (1) was inactive against malaria parasites in vitro, it was moderately active against P. berghei in mice (25 mg kg(-1) daily for 4 days reduced parasitaemia by 28.5% compared to untreated controls).Journal of Ethnopharmacology 07/2001; 76(1):99-103. · 2.76 Impact Factor