title: The antiplasmodial activity of isolates from Ajuga remota.
abstract: Ajuga remota is the most frequently used medicinal herb for malaria treatment in Kenya. Its two known isolates ajugarin-1 (1) and ergosterol-5,8-endoperoxide (3) and a new isolate 8-O-acetylharpagide (2) were evaluated for their in vitro antiplasmodial activity. Ajugarin-1 was moderately active, with an IC(50) of 23.0 +/- 3.0 microM, as compared to chloroquine (IC(50) = 0.041 +/- 0.003 microM) against the chloroquine-sensitive (FCA 20/GHA) strain of Plasmodium falciparum. Ergosterol-5,8-endoperoxide was about 3x as potent (IC(50) = 8.2 +/- 1.1 microM), while 8-O-acetylharpagide, whose structure was established by spectroscopic evidence, was inactive. Both ajugarin-1 and ergosterol-5,8-endoperoxide did not exhibit cytotoxicity against A431 (skin carcinoma) cell line, but 8-O-acetylharpagide was significantly cytotoxic. This iridoid glucoside, which has been formerly isolated from Ajuga decumbens, was identified in A. remota for the first time.
authors.affiliation: Faculty of Pharmacy, University of Nairobi, P.O. Box 19676, Nairobi, Kenya.
authors.forename: Kimani A M
authors.initials: KA
authors.lastname: Kuria
authors.forename: Hezekiah
authors.initials: H
authors.lastname: Chepkwony
authors.forename: Cindy
authors.initials: C
authors.lastname: Govaerts
authors.forename: Eugene
authors.initials: E
authors.lastname: Roets
authors.forename: Roger
authors.initials: R
authors.lastname: Busson
authors.forename: Peter
authors.initials: P
authors.lastname: De Witte
authors.forename: Istvan
authors.initials: I
authors.lastname: Zupko
authors.forename: Georges
authors.initials: G
authors.lastname: Hoornaert
authors.forename: Ludo
authors.initials: L
authors.lastname: Quirynen
authors.forename: Louis
authors.initials: L
authors.lastname: Maes
authors.forename: Leen
authors.initials: L
authors.lastname: Janssens
authors.forename: Jos
authors.initials: J
authors.lastname: Hoogmartens
authors.forename: Gert
authors.initials: G
authors.lastname: Laekeman
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology; D002855:Chromatography, Thin Layer; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000502:physiology; D004354:Drug Screening Assays, Antitumor; D004875:Ergosterol / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D007630:Kenya; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019686:Lamiaceae / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D012878:Skin Neoplasms; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000962:Antimalarials; D000970:Antineoplastic Agents; D004224:Diterpenes; C092328:ajugarin I; D002738:Chloroquine; D007770:L-Lactate Dehydrogenase; D005472:Fluorouracil; C036071:ergosterol-5,8-peroxide; D004875:Ergosterol