title: Activity of selected phytochemicals against Plasmodium falciparum.
abstract: According to the WHO, in 2008, there were 247 million reported cases of malaria and nearly one million deaths from the disease. Parasite resistance against first-line drugs, including artemisinin and mefloquine, is increasing. In this study the plant-derived compounds aglafolin, rocaglamid, kokusaginine, arborine, arborinine and tuberostemonine were investigated for their anti-plasmodial activity in vitro. Fresh Plasmodium falciparum isolates were taken from patients in the area of Mae Sot, north-western Thailand in 2008 and the inhibition of schizont maturation was determined for the respective compounds. With inhibitory concentrations effecting 50%, 90% and 99% inhibition (IC(50), IC(90) and IC(99)) of 60.95 nM, 854.41 nM and 7351.49 nM, respectively, rocaglamid was the most active of the substances, closely followed by aglafoline with 53.49 nM, 864.55 nM and 8354.20 nM. The activity was significantly below that of artemisinin, but moderately higher than that of quinine. Arborine, arborinine, tuberostemonine and kokusaginine showed only marginal activity against P. falciparum characterized by IC(50) and IC(99) values higher than 350 nM and 180 μM, respectively, and regressions with relatively shallow slopes S>14.38. Analogues of rocaglamid and aglafoline merit further exploration of their anti-plasmodial activity.
authors.affiliation: Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Astelbauer
authors.forename: Maria
authors.initials: M
authors.lastname: Gruber
authors.forename: Brigitte
authors.initials: B
authors.lastname: Brem
authors.forename: Harald
authors.initials: H
authors.lastname: Greger
authors.forename: Andreas
authors.initials: A
authors.lastname: Obwaller
authors.forename: Gunther
authors.initials: G
authors.lastname: Wernsdorfer
authors.forename: Kanungnit
authors.initials: K
authors.lastname: Congpuong
authors.forename: Walther H
authors.initials: WH
authors.lastname: Wernsdorfer
authors.forename: Julia
authors.initials: J
authors.lastname: Walochnik
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D001572:Benzofurans / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D016778:Malaria, Falciparum / Q000469:parasitology; D021261:Parasitic Sensitivity Tests; D008517:Phytotherapy / Q000379:methods; D010936:Plant Extracts / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000302:isolation & purification; D013785:Thailand
chemical_list: D000962:Antimalarials; D001572:Benzofurans; D010936:Plant Extracts; C077355:aglafoline