title: Cytotoxicity and in vitro susceptibility of Entamoeba histolytica to Morinda morindoides leaf extracts and its isolated constituents.
abstract: An aqueous decotion (dried extract), an 80% MeOH extract from Morinda morindoides leaves, and 10 flavonoids and 4 iridoids isolated from the 80% MeOH extract were evaluated in vitro for their potential antiamoebic activity and their cytotoxic effect against MT-4 cells. Results indicated that the aqueous decoction and the 80% MeOH extract exhibited an interesting antiamoebic activity with IC(50) values of 3.1 +/- 1.7 and 1.7 +/- 0.6 microg/ml, respectively. Apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited a moderate antiamoebic activity with IC(50) values of 22.3 +/- 3.2 and 37.4 +/- 2.7 microg/ml, respectively. Kaempferol (IC(50) = 10.3 +/- 2.3 microg/ml), apigenin (IC(50) = 12.7 +/- 4.3 microg/ml), and luteolin (IC(50) = 17.8 +/- 4.3 microg/ml) showed a more pronounced activity than their corresponding glycosides. All tested iridoids displayed a very good activity with IC(50) values less than 10 microg/ml. The most active iridoids were epoxygaertneroside (IC(50) = 1.3 +/- 0.4 microg/ml) and methoxygaertneroside (IC(50) = 2.3. +/- 0.7), followed by gaertneroside and gaertneric acid with IC(50) values of 4.3 +/- 1.8 and 7.1 +/- 1.4 microg/ml, respectively. Except quercetin and quercetin-7,4'-dimethylether which have shown a cytotoxic effect with IC(50) ranging from 14 to 22 microg/ml. No correlation could be deduced between the observed antiamoebic and cytotoxic activity of these tested samples. A structure-activity relationship for isolated compounds is discussed. These findings support the medicinal report for the traditional use of Morinda morindoides leaves for the treatment of amoebiasis.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp (UA), Belgium. kanyanga.cimanga@ua.ac.be
authors.forename: R K
authors.initials: RK
authors.lastname: Cimanga
authors.forename: K
authors.initials: K
authors.lastname: Kambu
authors.forename: L
authors.initials: L
authors.lastname: Tona
authors.forename: N
authors.initials: N
authors.lastname: Hermans
authors.forename: S
authors.initials: S
authors.lastname: Apers
authors.forename: J
authors.initials: J
authors.lastname: Totté
authors.forename: L
authors.initials: L
authors.lastname: Pieters
authors.forename: A J
authors.initials: AJ
authors.lastname: Vlietinck
mesh_terms: D000563:Amebicides / Q000494:pharmacology*; D000818:Animals; D004748:Entamoeba histolytica / Q000187:drug effects*; D032066:Morinda / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*
chemical_list: D000563:Amebicides; D010936:Plant Extracts