title: In vitro activity of 'Mexican Arnica' Heterotheca inuloides Cass natural products and some derivatives against Giardia intestinalis.
abstract: Giardiasis is a gastrointestinal disease that affects humans and other animals caused by parasitic protists of the genus Giardia. Giardia intestinalis (Syn. Giardia lamblia; Giardia duodenalis) infections can cause acute or chronic diarrhoea, dehydration, abdominal discomfort and weight loss. Metronidazole is the most widely used drug for treating giardiasis. Although effective, metronidazol has undesirable secondary effects. Plants used in traditional medicine as antidiarrhoeals or antiparasitics may represent alternative sources for new compounds to treat giardiasis. Heterotheca inuloides Cass. (Asteraceae/Compositae) plant is widely used in Mexican traditional medicine. The following secondary metabolites were isolated from H. inuloides flowers: 7-hydroxy-3,4-dihydrocadalene (1), 7-hydroxycadalene (2), 3,7-dihydroxy-3(4H)-isocadalen-4-one (3), 1R,4R-hydroxy-1,2,3,4-tetrahydrocadalen-15-oic acid (4), quercetin (5), quercetin-3,7,3'-trimethyl ether (6), quercetin-3,7,3',4'-tetramethyl ether (7) and eriodictyol-7,4'-dimethyl ether (8). The activity of these compounds against Giardia intestinalis trophozoites was assessed in vitro as was the activity of the semisynthetic compounds 7-acetoxy-3,4-dihydrocadalene (9), 7-benzoxy-3,4-dihydrocadalene (10), 7-acetoxycadalene (11), 7-benzoxycadalene (12), quercetin pentaacetate (13) and 7-hydroxycalamenene (14). Among these, 7-hydroxy-3,4-dihydrocadalene (1) and 7-hydroxycalamenene (14) were the most active, whereas the remaining compounds showed moderate or no activity. The G. intestinalis trophozoites exposed to compound 1 showed marked changes in cellular architecture along with ultrastructural disorganization. The aim of this study was to evaluate the giardicidal activity of selected H. inuloides metabolites and some semisynthetic derivatives using an in vitro experimental model of giardiasis.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México,04510 México, D. F.,México.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rodríguez-Chávez
authors.affiliation: Laboratorio de Parasitología Experimental, Instituto Nacional de Pediatría,Insurgentes Sur 3700-C, 04530 México, D. F.,México.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Rufino-González
authors.affiliation: Laboratorio de Parasitología Experimental, Instituto Nacional de Pediatría,Insurgentes Sur 3700-C, 04530 México, D. F.,México.
authors.forename: Martha
authors.initials: M
authors.lastname: Ponce-Macotela
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México,04510 México, D. F.,México.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Delgado
mesh_terms: D000328:Adult; D019659:Asteraceae / Q000737:chemistry*; D001681:Biological Assay; D004951:Esterification; D035264:Flowers / Q000737:chemistry; D016829:Giardia lamblia / Q000187:drug effects* / Q000648:ultrastructure; D005873:Giardiasis / Q000188:drug therapy; D006801:Humans; D006865:Hydrogenation; D046529:Microscopy, Electron, Transmission; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology*; D053058:Trophozoites / Q000187:drug effects
chemical_list: C102244:7-hydroxy-3,4-dihydrocadalin; C520676:7-hydroxycalamenene; D010936:Plant Extracts; D012717:Sesquiterpenes
keywords: flavonoids