RESUMO
The aim of this study was to select different genotypes of Lippia sidoides with the highest activity against larvae and engorged females of the tick Rhipicephalus (Boophilus) microplus. The germplasms studied were LSID006, LSID102, LSID103 and LSID104. The LSID104 genotype, that presented carvacrol as a major constituent, was the germplasm with the worst larvicide effect (LC50 2.99 mg/mL). The LSID006 genotype was the least effective against engorged females (LC50 12.46 mg/mL), and it was chemically similar to the LSID102 genotype, which presented the highest acaricide activity (LC50 2.81 mg/mL). We conclude that chemical similarity of the germplasms was not correlated with acaricide activity against R. (B.) microplus. The essential oil of L. sidoides is a potent natural agent. However, the findings of this work provide a better understanding for product development based on this natural product, which must consider synergic effects or the action of minor compounds.
Assuntos
Acaricidas/farmacologia , Lippia/química , Rhipicephalus/efeitos dos fármacos , Animais , Feminino , Genótipo , Larva/efeitos dos fármacos , Lippia/genéticaRESUMO
Abstract The aim of this study was to select different genotypes of Lippia sidoides with the highest activity against larvae and engorged females of the tick Rhipicephalus (Boophilus) microplus. The germplasms studied were LSID006, LSID102, LSID103 and LSID104. The LSID104 genotype, that presented carvacrol as a major constituent, was the germplasm with the worst larvicide effect (LC50 2.99 mg/mL). The LSID006 genotype was the least effective against engorged females (LC50 12.46 mg/mL), and it was chemically similar to the LSID102 genotype, which presented the highest acaricide activity (LC50 2.81 mg/mL). We conclude that chemical similarity of the germplasms was not correlated with acaricide activity against R. (B.) microplus. The essential oil of L. sidoides is a potent natural agent. However, the findings of this work provide a better understanding for product development based on this natural product, which must consider synergic effects or the action of minor compounds.
Resumo O objetivo deste trabalho foi selecionar genótipos de Lippia sidoides que apresentem maiores atividades em larvas e fêmeas ingurgitadas do carrapato Rhipicephalus (Boophilus) microplus. Os genótipos estudados foram LSID006, LSID102, LSID103 e LSID104. O genótipo LSID104, o único a conter o monoterpeno carvacrol como um dos principais constituintes, foi o que apresentou o menor efeito larvicida (CL50 2,99 mg/mL). O genótipo LSID006 apresentou menor efeito sobre fêmeas ingurgitadas (CL50 12,46 mg/mL), entretanto foi quimicamente similar ao genótipo LSID102, que apresentou a maior atividade carrapaticida (CL50 2,81 mg/mL). Conclui-se que a semelhança química dos genótipos não se correlaciona com a atividade carrapaticida contra R. (B.) microplus. O óleo essencial de L. sidoides é um agente natural potente e os resultados deste trabalho proporcionam um melhor entendimento para o desenvolvimento de produtos com base neste produto natural, devendo ser considerado os efeitos sinérgicos ou a ação de compostos presentes em menores concentrações.
Assuntos
Animais , Feminino , Lippia/química , Rhipicephalus/efeitos dos fármacos , Acaricidas/farmacologia , Lippia/genética , Genótipo , Larva/efeitos dos fármacosRESUMO
Lippia gracilis, popularly known in Brazil as 'alecrim-de-tabuleiro', is used for many purposes, especially antimicrobial and antiseptic activities. The leaves of three L. gracilis genotypes, including LGRA-106, LGRA-109 and LGRA-110 were collected from the Active Germplasm Bank located in the "Campus Rural da UFS" research farm at the São Cristóvão country, Sergipe State, Brazil. The essential oils were obtained from leaves of L. gracilis plants by hydrodistillation. Chemical analysis of the essential oils was performed by gas chromatography-mass spectrometry (GC-MS). The susceptibility of Trichophyton rubrum strains, MYA3108 and TruMDR2, to the two L. gracilis genotypes (LGRA-106 and LGRA-109) essential oils was determined by the serial microdilution method. Leishmanicidal activity of essential oil from LGRA-106 and LGRA-110 was assayed by tetrazolium-dye (MTT) colorimetric method. The oxygenated monoterpene thymol was the main component of the essential oil from genotype LGRA-106, while Carvacrol was more abundant in LGRA-109 and LGRA-110. The concentrations of LGRA-106 and LGRA-109 essential oils that completely eliminate the fungi were determined and these concentrations were similar to those observed for fluconazole, a common antifungal drug. Among the genotype tested, LGRA-106 essential oil exhibited the best fungicidal activity at 46.87µgmL(-1). Regarding to leishmanicidal activity, the IC50, for LGRA-106 and LGRA-110, was 86.32 and 77.26µgmL(-1), respectively. The results showed that L. gracilis essential oil, rich in thymol and thymol itself presented best antidermatophytic activity, while the best leishmanicidal activity was obtained with essential oil from genotype rich in Carvacrol and Carvacrol itself.
