title: Antiplasmodial studies of Eurycoma longifolia Jack using the lactate dehydrogenase assay of Plasmodium falciparum.
abstract: The roots of Eurycoma longifolia Jack have been used as traditional medicine to treat malaria. A systematic bioactivity-guided fractionation of this plant was conducted involving the determination of the effect of its various extracts and their chemical constituents on the lactate dehydrogenase activity of in vitro chloroquine-resistant Gombak A isolate and chloroquine-sensitive D10 strain of Plasmodium falciparum parasites. Their antiplasmodial activity was also compared with their known in vitro cytotoxicity against KB cells. Four quassinoids, eurycomanone (1), 13,21-dihydroeurycomanone (3), 13 alpha(21)-epoxyeurycomanone (4), eurycomalactone (6) and an alkaloid, 9-methoxycanthin-6-one (7), displayed higher antiplasmodial activity against Gombak A isolate but were less active against the D10 strain when compared with chloroquine. Amongst the compounds tested, 1 and 3 showed higher selectivity indices obtained for the cytotoxicity to antiplasmodial activity ratio than 14,15 beta-dihydroxyklaineanone (2), eurycomanol (5), 6 and 7.
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia. klchan@usm.my
authors.forename: Kit-Lam
authors.initials: KL
authors.lastname: Chan
authors.forename: Chee-Yan
authors.initials: CY
authors.lastname: Choo
authors.forename: Noor Rain
authors.initials: NR
authors.lastname: Abdullah
authors.forename: Zakiah
authors.initials: Z
authors.lastname: Ismail
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002738:Chloroquine / Q000494:pharmacology; D035701:Eurycoma / Q000737:chemistry*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008296:Malaysia; D015394:Molecular Structure; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D010963:Plasmodium falciparum / Q000187:drug effects*; D036702:Quassins / Q000302:isolation & purification / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000962:Antimalarials; D010936:Plant Extracts; D036702:Quassins; D002738:Chloroquine; D007770:L-Lactate Dehydrogenase