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Submitted by Daniella Santos (daniella.santos@ufma.br) on 2022-08-29T14:34:16Z No. of bitstreams: 1 EdileneRibeiro.pdf: 1011143 bytes, checksum: 2923ac2e8a2ca761ea117d38db63d40f (MD5) Made available in DSpace on 2022-08-29T14:34:16Z (GMT). No. of bitstreams: 1 EdileneRibeiro.pdf: 1011143 bytes, checksum: 2923ac2e8a2ca761ea117d38db63d40f (MD5) Previous issue date: 2021-05-25 CAPES FAPEMA The search for biologically active agents from plant species has enabled the discovery of extremely important substances in the control of various diseases. In view of the diversity of bioactive substances present in essential oils, as well as the epidemiological scenario of schistosomiasis, a neglected disease with a high social and economic impact in the world, this work aims to evaluate the molluscicidal activity of the essential oil (EO ) of Hyptis pectinata (sambacaitá ) and the monoterpenes camphor, 1,8-cineole, α pinene and thymol, against Biomphalaria glabrata snails. The EO was extracted from the leaves of H. pectinata by hydrodistillation. The chemical composition analysis of essential oil was carried out by gas chromatography with flame ionization detector and mass spectrometry. The camphor, 1,8-cineole, α-pinene and thymol monoterpenes were evaluated individually for the molluscicidal potential. Molluscicide tests, both for EO and monoterpenes, were performed according to the standard methodology of the World Health Organization. Toxicity to non-target organisms was evaluated in fish of the species Danio rerio, according to the methodology of the Brazilian Association of Technical Standards. The H. pectinata showed a 1.5% yield and 21 compounds were identified. The molluscicidal activity exhibited by the EO against B. glabrata was significant with LC90 63.02 μg ∙ mL-1. Regarding monoterpenes, camphor and 1,8- cineole did not induce snail mortality. Thymol and α-pinene were active against B. glabrata, causing mortality in concentration-dependent and LC90 7.11 μg ∙ mL-1 and 10.34 μg ∙ mL-1, respectively. The effect of thymol and α-pinene on inhibition of acetylcholinesterase (AChE) activity of B. glabrata was examined. This activity was determined according to the Ellman method. The results showed that thymol and α pinene are inhibitors of AChE of B. glabrata, but at higher concentrations than those used in the molluscicide test. The H. pectinata oil and the monoterpenes thymol and α pinene, showed low toxicity for D. rerio fish compared to the commercial molluscicide niclosamide. The knowledge of the toxicity of H. pectinata oil and of the monoterpenes thymol and α-pinene against B. glabrata contributes to its potential use in molluscicidal and alternative formulations in the control of schistosomiasis. A pesquisa por agentes biologicamente ativos oriundos de espécies vegetais tem possibilitado a descoberta de substâncias de extrema importância no controle de várias enfermidades. Diante da diversidade de substâncias bioativas presentes em óleos essenciais de espécies vegetais, bem como do cenário epidemiológico da esquistossomose, doença negligenciada de alto impacto social e econômico no mundo, este trabalho teve como objetivo avaliar o efeito moluscicida do óleo essencial (OE) de Hyptis pectinata (sambacaitá) e dos monoterpenos cânfora, 1,8-cineol, α-pineno e timol, contra caramujos Biomphalaria glabrata. O OE foi extraído de folhas de H. pectinata por hidrodestilação. A análise da composição química do óleo essencial foi realizada por cromatografia gasosa com detector de ionização de chama e espectrometria de massa. Os monoterpenos foram avaliados individualmente quanto ao potencial moluscicida. Os ensaios moluscicida, tanto do OE quanto dos monoterpenos, foram realizados conforme metodologia padrão da Organização Mundial da Saúde. A toxicidade a organismos não-alvo foi avaliada em peixes da espécie Danio rerio, conforme metodologia da Associação Brasileira de Normas Técnicas. O OE de H. pectinata apresentou rendimento de 1,5% e foram identificados 21 compostos. A atividade moluscicida exibida pelo OE contra B. glabrata foi significativa com CL90 63,02 μg∙mL -1 . Em relação aos monoterpenos, o cânfora e 1,8-cineol não induziram mortalidade dos caramujos. O timol e α-pineno foram ativos contra B. glabrata, induzindo mortalidade em padrões dependentes de concentração com CL90 7,11 μg∙mL -1 e 10,34 μg∙mL -1 , respectivamente. Foi examinado o efeito do timol e α-pineno sobre a inibição da atividade de acetilcolinesterase (AChE) de B. glabrata. Essa atividade foi determinada conforme método de Ellman. Os resultados mostraram que o timol e α- pineno são inibidores da AChE de B. glabrata, porém em concentrações superiores às utilizadas no teste moluscicida. O OE de H. pectinata e os monoterpenos timol e α- pineno apresentaram baixa toxicidade em peixes D. rerio comparado ao moluscicida comercial niclosamida. O conhecimento da toxicidade do óleo de H. pectinata e dos monoterpenos timol e α-pineno contra B. glabrata contribui para seu potencial uso em formulações moluscicidas e alternativas no controle da esquistossomose.

In tropical countries, arboviruses are public health threats, especially those transmitted by Aedes aegypti mosquitoes. The prevention of such diseases is based on vector control. However, the compounds currently used have disadvantages such toxicity to humans and environment, so larvicide plants is a promising alternative. The purpose of this study is to determine the best season to harvest aerial parts of Mesosphaerum suaveolens (L.) Kuntze to obtain its essential oil, and evaluate the effects of seasons on chemical composition, larvicidal activity against A. aegypti, and toxicology against Artemia salina and Danio rerio using such essential oils and its major compounds. The gas chromatography–mass spectrometry analysis of essential oil samples performed at different times during a year, showed qualitative and quantitative variation in the chemical composition. 1,8-Cineole is the major compound in all seasons. The dry season had a higher yield. The essential oils showed activity against A. aegypti larvae, with lethal concentrations varying from 90.8 to 135.2 μg/mL. Their major compounds present no activity up to the highest concentration tested (200 μg/mL). The toxicity for A. salina and D. rerio was lower than for A. aegypti larvae, ranging from 94.6 to 215.7 μg/mL. The results demonstrate potential of the essential oil of the aerial parts of M. suaveolens for the control of A. aegypti larvae, and evidence that the oil of the plant collected in the dry season is more promising for the control of the larvae and provides better yield.