title: Antimicrobial activity of euplotin C, the sesquiterpene taxonomic marker from the marine ciliate Euplotes crassus.
abstract: Strains of the marine ciliate protist Euplotes crassus produce exclusive terpenoids called euplotins that play an ecological role. Among these derivatives, euplotin C is the main of four secondary metabolites isolated from cultures of this protozoon and represents the sesquiterpene taxonomic marker from E. crassus. Because different terpenoid metabolites of plant origin showed a certain antimicrobial activity, we assessed the compound euplotin C, purified by high-pressure liquid chromatography and solubilized in two solubility enhancers, against the protozoa Leishmania major and Leishmani infantum, the fungus Candida albicans, and nine strains of gram-positive and gram-negative microorganisms. An activity of euplotin C against Leishmania promastigotes was demonstrated (50% lethal doses were 4.6 or 8.1 microg/ml depending on the agent used to solubilize the compound), while the effect was less evident on Candida and nearly absent on bacteria. A nonsignificant cytotoxicity (50% lethal dose, >200 microg/ml) against the J774 cell line was observed. A leishmanicidal activity was also shown by the living, euplotin-producing cells of E. crassus cultured together with promastigotes; this activity increased with time from 10 min to 6 h of incubation. This study provides an initial rationale for the evaluation of euplotin C and other similar natural products as alternative or possibly synergistic compounds for current antiprotozoon chemotherapeutics.
authors.affiliation: University of Turin, Department of Clinical and Biological Sciences, S. Luigi Gonzaga Hospital, Orbassano (TO) 10043, Italy. dianella.savoia@unito.it
authors.forename: Dianella
authors.initials: D
authors.lastname: Savoia
authors.forename: Claudio
authors.initials: C
authors.lastname: Avanzini
authors.forename: Tiziano
authors.initials: T
authors.lastname: Allice
authors.forename: Emanuela
authors.initials: E
authors.lastname: Callone
authors.forename: Graziano
authors.initials: G
authors.lastname: Guella
authors.forename: Fernando
authors.initials: F
authors.lastname: Dini
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry; D015415:Biomarkers; D002176:Candida albicans / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D016812:Euplotes / Q000737:chemistry* / Q000145:classification*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007700:Kinetics; D018314:Leishmania infantum / Q000187:drug effects; D018320:Leishmania major / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D015415:Biomarkers; D012717:Sesquiterpenes; C493253:euplotin C