title: Anti-Giardia activity of Syzygium aromaticum essential oil and eugenol: effects on growth, viability, adherence and ultrastructure.
abstract: The present work evaluates the anti-Giardia activity of Syzygium aromaticum and its major compound eugenol. The effects were evaluated on parasite growth, adherence, viability and ultrastructure. S. aromaticum essential oil (IC(50)=134 μg/ml) and eugenol (IC(50)=101 μg/ml) inhibited the growth of G. lamblia. The essential oil inhibited trophozoites adherence since the first hour of incubation and was able to kill almost 50% of the parasites population in a time dependent manner. The eugenol inhibited G. lamblia trophozoites adherence since the third hour and not induce cell lyses. The main morphological alterations were modifications on the cell shape, presence of precipitates in the cytoplasm, autophagic vesicles, internalization of flagella and ventral disc, membrane blebs, and intracellular and nuclear clearing. Taken together, our findings lead us to propose that eugenol was responsible for the anti-giardial activity of the S. aromaticum essential oil and both have potential for use as therapeutic agents against giardiasis.
authors.affiliation: Faculdade de Farmácia/CEF, Universidade de Coimbra, Azinhaga de Santa Comba, 3030-548 Coimbra, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Machado
authors.forename: A M
authors.initials: AM
authors.lastname: Dinis
authors.forename: L
authors.initials: L
authors.lastname: Salgueiro
authors.forename: José B A
authors.initials: JB
authors.lastname: Custódio
authors.forename: C
authors.initials: C
authors.lastname: Cavaleiro
authors.forename: M C
authors.initials: MC
authors.lastname: Sousa
mesh_terms: D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D005054:Eugenol / Q000494:pharmacology*; D016829:Giardia lamblia / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D006801:Humans; D020128:Inhibitory Concentration 50; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D027842:Syzygium / Q000737:chemistry*
chemical_list: D009822:Oils, Volatile; D010938:Plant Oils; D005054:Eugenol