title: Effects of Croton rhamnifolioides essential oil on Aedes aegypti oviposition, larval toxicity and trypsin activity.
abstract: Although numerous reports are available concerning the larvicidal potential of essential oils, very few investigations have focused on their mechanisms of action. In the present study, we have investigated the chemical composition of the leaf oil of Croton rhamnifolioides during storage and its effects on oviposition and survival of larvae of the dengue fever mosquito Aedes aegypti. In addition, we have established a possible mechanism of action for the larvicidal activity of the essential oil. GC-MS analyses revealed marked differences in the composition of oil that had been freshly isolated and that of a sample that had been stored in a sealed amber-glass vial under refrigeration for three years. However, both fresh and stored oil exhibited substantial larvicidal activities with LC50 values of 122.35 and 89.03 ppm, respectively, and oviposition deterrent effects against gravid females at concentrations of 50 and 100 µg·mL-1. These results demonstrate that the larvicidal effect of the essential oil was unchanged during three years of storage even though its chemical composition altered. Hence, the essential oil could be used in the preparation of commercial products. In addition, we observed that the trypsin-like activity of mosquito larvae was inhibited in vitro by the essential oil of C. rhamnifolioides, suggesting that the larvicidal effect may be associated with inhibition of this enzyme.
authors.affiliation: Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Geanne K N
authors.initials: GK
authors.lastname: Santos
authors.affiliation: Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Kamilla A
authors.initials: KA
authors.lastname: Dutra
authors.affiliation: Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Camila S
authors.initials: CS
authors.lastname: Lira
authors.affiliation: Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Bheatriz N
authors.initials: BN
authors.lastname: Lima
authors.affiliation: Laboratório de Glicoproteínas, Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-420 Recife, PE, Brazil.
authors.forename: Thiago H
authors.initials: TH
authors.lastname: Napoleão
authors.affiliation: Laboratório de Glicoproteínas, Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-420 Recife, PE, Brazil.
authors.forename: Patrícia M G
authors.initials: PM
authors.lastname: Paiva
authors.affiliation: Laboratório de Pesquisa e Desenvolvimento de Produtos Tecnológicos, Instituto Federal de Educação, Ciência e Tecnologia de Pernambuco, 50740-540 Recife, PE, Brazil.
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Maranhão
authors.affiliation: Laboratório de Pesquisa e Desenvolvimento de Produtos Tecnológicos, Instituto Federal de Educação, Ciência e Tecnologia de Pernambuco, 50740-540 Recife, PE, Brazil.
authors.forename: Sofia S F
authors.initials: SS
authors.lastname: Brandão
authors.affiliation: Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil. dmafn@ufpe.br.
authors.forename: Daniela M A F
authors.initials: DM
authors.lastname: Navarro
mesh_terms: D000330:Aedes / Q000033:anatomy & histology* / Q000187:drug effects; D000818:Animals; D029802:Croton / Q000737:chemistry*; D003436:Croton Oil / Q000494:pharmacology; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D007814:Larva / Q000187:drug effects; D009822:Oils, Volatile / Q000494:pharmacology*; D010058:Oviposition / Q000187:drug effects*; D018515:Plant Leaves / Q000737:chemistry; D014357:Trypsin / Q000378:metabolism*
chemical_list: D009822:Oils, Volatile; D003436:Croton Oil; D014357:Trypsin