title: In vitro antileishmanial activity and cytotoxicity of essential oil from Lippia sidoides Cham.
abstract: Leishmaniasis is a widespread tropical infection caused by different species of Leishmania protozoa. There is no vaccine available for Leishmania infections and conventional treatments are very toxic to the patients. Therefore, antileishmanial drugs are urgently needed. In this study we have analyzed the effects of essential oils from Lippia sidoides (LSEO) and its major compound thymol on the growth, viability and ultrastructure of Leishmania amazonensis. The essential oil and thymol showed significant activity against promastigote forms of L. amazonensis, with IC(50)/48 h of 44.38 and 19.47 μg/mL respectively. However, thymol showed toxicity against peritoneal macrophages and low selectivity against the promastigotes when compared with the crude LSEO. On the other hand, no cytotoxic effect was observed in macrophages treated with the crude essential oil. Incubation of L. amazonensis-infected macrophages with LSEO showed a marked reduction in amastigote survival within the macrophages. Significant morphological alterations as accumulation of large lipid droplets in the cytoplasm, disrupted membrane and wrinkled cells were usually seen in treated parasites. The LSEO's activity against both promastigote and the amstigote forms of L. amazonensis, together with its low toxicity to mammalian cells, point to LSEO as a promising agent for the treatment of cutaneous leishmaniasis.
authors.affiliation: Programa de Pós-graduação em Biotecnologia-RENORBIO, Universidade Federal do Piaui, Brazil.
authors.forename: Maria das Graças Freire
authors.initials: Md
authors.lastname: de Medeiros
authors.forename: Aline Caroline
authors.initials: AC
authors.lastname: da Silva
authors.forename: Antonia Maria das Graças Lopes
authors.initials: AM
authors.lastname: Citó
authors.forename: Andrezza Raposo
authors.initials: AR
authors.lastname: Borges
authors.forename: Sidney Gonçalo
authors.initials: SG
authors.lastname: de Lima
authors.forename: José Arimatéia Dantas
authors.initials: JA
authors.lastname: Lopes
authors.forename: Regina Celia Bressan Queiroz
authors.initials: RC
authors.lastname: Figueiredo
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D007891:Leishmania / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D007896:Leishmaniasis / Q000188:drug therapy*; D032411:Lippia / Q000737:chemistry*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D021261:Parasitic Sensitivity Tests; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D013943:Thymol / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000981:Antiprotozoal Agents; D009822:Oils, Volatile; D010936:Plant Extracts; D013943:Thymol