CHARACTERISATION OF ISOELEUTHERINE IN AQUEOUS EXTRACT OF ELEUTHERINE PLICATA HERB, IRIDACEAE, ACTIVE AGAINST ENTAMOEBA HYSTOLITICA/ ENTAMOEBA DISPAR IN-VITRO

Eleutherine plicata Herb., Iridaceae, is an herbaceous Iridaceae, vernacular marupazinho, largely used as tea, in the Amazonian popular phytotherapy, to treat diarrhoea alleged to amoeba infestation. To investigate the form of use of this medicinal plant andits alleged activity, and to perform a phytochemical analysis and an anti-amoebaean assay. Bulbs of the plant were dried, grinded and extracted in boiling water. After concentration the extract (AEEp) was analysed by LC-DAD and tested against trophozoitic forms of three strain of Entamoeba histolytica/Entamoeba dispar. A significant peak in the LC-DAD chromatogram of AEEp can be observed and attributed to isoeleutherine, a naphtoquinone also an antiamoebian activity was detected for this extract. Isoeleutherine would be one of the active substances responsible for the anti-amoebaean activity of Eleutherineplicata Herb., since naphtoquinone show anti-protozoal activity and the substance shows pro-oxidative properties. Noteworthy is the fact that the decoction shows 3.5mg dry residue/mL, 40% higher than the concentration of the extract used in the bioassay (2.5mg/mL). The detected antiamoebian activity for AEEp aligns to the popular attribution of its use and the presence of Isoleutherine can partially explain this observation.