title: Giardia lamblia: the effects of extracts and fractions from Mentha x piperita Lin. (Lamiaceae) on trophozoites.
abstract: Giardia lamblia is a parasite that causes giardiasis in humans and other mammals. The common treatment includes different classes of drugs, which were described to produce unpleasant side effects. Mentha x piperita, popularly known as peppermint, is a plant that is frequently used in the popular medicine to treat gastrointestinal symptoms. We examined the effects of crude extracts and fractions from peppermint against G. lamblia (ATCC 30888) on the basis of trophozoite growth, morphology and adherence studies. The methanolic, dichloromethane and hexanic extracts presented IC(50) values of 0.8, 2.5 and 9.0microg/ml after 48h of incubation, respectively. The aqueous extract showed no effect against the trophozoites with an IC(50)>100microg/ml. The aqueous fraction presented a moderate activity with an IC(50) of 45.5microg/ml. The dichloromethane fraction showed the best antigiardial activity, with an IC(50) of 0.75microg/ml after 48h of incubation. The morphological and adhesion assays showed that this fraction caused several alterations on plasma membrane surface of the parasite and inhibited the adhesion of G. lamblia trophozoites. Cytotoxic assays showed that Mentha x piperita presented no toxic effects on the intestinal cell line IEC-6. Our results demonstrated antigiardial activity of Mentha x piperita, indicating its potential value as therapeutic agent against G. lamblia infections.
authors.affiliation: Department of Histology and Embryology, Laboratory of Microscopy and Image Processing, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 3 degrees andar, Maracanã, Rio de Janeiro, RJ 20550-170, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Vidal
authors.forename: J C
authors.initials: JC
authors.lastname: Vidal
authors.forename: A P R
authors.initials: AP
authors.lastname: Gadelha
authors.forename: C S
authors.initials: CS
authors.lastname: Lopes
authors.forename: M G P
authors.initials: MG
authors.lastname: Coelho
authors.forename: L H
authors.initials: LH
authors.lastname: Monteiro-Leal
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D016829:Giardia lamblia / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D020128:Inhibitory Concentration 50; D007422:Intestines / Q000166:cytology / Q000187:drug effects; D036142:Mentha piperita / Q000737:chemistry* / Q000633:toxicity; D046529:Microscopy, Electron, Transmission; D018715:Microscopy, Video; D010936:Plant Extracts / Q000494:pharmacology / Q000633:toxicity; D053058:Trophozoites / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D010936:Plant Extracts