title: Antiamoebic activity of iridoids from Morinda morindoides leaves.
abstract: An aqueous decoction (dried extract), an 80 % methanolic extract from Morinda morindoides (Rubiaceae) leaves, and five iridoids isolated from the 80 % methanolic extract were evaluated in vitro for their activity against Entamoeba histolytica and their cytotoxicity. The aqueous decoction and the 80 % methanolic extract exhibited a promising antiamoebic activity with IC (50) values of 3.1 +/- 1.7 and 1.7 +/- 0.6 microg/mL, respectively. All tested iridoids displayed antiamoebic activity, the most active being epoxygaertneroside (IC (50): 1.3 +/- 0.4 microg/mL) and methoxygaertneroside (IC (50): 2.3 +/- 0.7 microg/mL) followed by gaertneroside, acetylgaertneroside and gaertneric acid with IC (50) values of 4.3 +/- 1.8, 5.4 +/- 1.4 and 7.1 +/- 1.4 microg/mL, respectively. Synergistic effects between the iridoids tested, or with other constituents, may explain the high activity of the extracts. All extracts and iridoids were devoid of any cytotoxic effect against MT-4 cells at the highest test concentration of 250 microg/mL. These findings support at least in part the traditional use of Morinda morindoides leaves for the treatment of amoebiasis in the Democratic Republic of Congo.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Kanyanga
authors.initials: K
authors.lastname: Cimanga
authors.forename: Kabangu
authors.initials: K
authors.lastname: Kambu
authors.forename: Lutete
authors.initials: L
authors.lastname: Tona
authors.forename: Nina
authors.initials: N
authors.lastname: Hermans
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.forename: Jozef
authors.initials: J
authors.lastname: Totté
authors.forename: Luc
authors.initials: L
authors.lastname: Pieters
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Vlietinck
mesh_terms: D000562:Amebiasis / Q000188:drug therapy; D000563:Amebicides / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000656:Amoeba / Q000187:drug effects*; D000818:Animals; D006801:Humans; D032066:Morinda; D021261:Parasitic Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves
chemical_list: D000563:Amebicides; D010936:Plant Extracts