Effects of the Hyptis martiusii Benth. leaf essential oil and 1,8-cineole (eucalyptol) on the central nervous system of mice.

The aim of this study was to characterize the central effects of the Hyptis martiusii leaf essential oil (OEHM) and 1,8-cineole (eucalyptol) using behavioral animal models. Gas chromatography coupled to mass spectrometry (GC/MS) was used to characterize the chemical compounds present in the OEHM. For the behavioral tests, female Swiss mice treated with the OEHM (25, 50, 100 and 200 mg/kg, i.p.) and 1,8-cineole (50 mg/kg, i.p.) were used and subjected to the following tests: open field, elevated cross maze, rotarod, sodium pentobarbital- or ethyl ether-induced sleep time, pentylenetetrazol-induced convulsions, haloperidol-induced catalepsy, and ketamine-induced hyperkinesia. GC/MS analysis identified 20 constituents with the majority of them being monoterpenes and sesquiterpenes, with eucalyptol (1,8-cineol), the major sample compound (25.93%), standing out. The results showed the OEHM (25, 50 100 and 200 mg/kg, i.p.) and its major compound (50 mg/kg, i.p.) reduced animal motility in the open field test, increased pentobarbital- and ethyl ether-induced sleep time, as well as death latency in the pentylenetetrazole-induced convulsion model. However, the tested compounds were devoid of anxiolytic-like and myorelaxant activity. In addition, the OEHM (100 and 200 mg/kg, i.p.) and 1,8-cineole (50 mg/kg, i.p.) potentiated haloperidol-induced catalepsy and reduced ketamine-induced hyperkinesia. Taken together, the results suggest the OEHM has important hypnotic-sedative and antipsychotic-like effects, which appear to be due to the monoterpene 1,8-cineole, the major compound identified in the essential oil.

Avaliação da atividade moduladora e citotóxica do óleo essencial das folhas de Hyptis martiusii Benth / Evaluación de la actividad moduladora y citotóxica del aceite esencial de las hojas de Hyptis martiusii Benth / Assessment of Modulatory and Cytotoxic Activity of the Essential Oil in Hyptis Martiusii Benth Leaves

Resumo Introdução: a espécie Hyptis martiusii Benth, comumente chamada de "cidrera del campo", têm múltiplas propriedades biológicas, como ser inseticida, antifúngica e anti-inflamatória. O objetivo deste estudo foi investigar a atividade moduladora do óleo essencial das folhas frescas de Hyptis martiusii em associação com diferentes antibióticos contra as bactérias Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, e avaliar a atividade citotóxica da espécie. Materiais e métodos: o estudo utilizou a concentração inibitória mínima (CIM) como uma forma de avaliar a modulação com uma inoculação de 100 microlitros de cada estirpe bacteriana. As provas de citotoxicidade se realizaram mediante cultivo in vitro de células do tecido conectivo de camundongo (fibroblastos de mamíferos). Resultados: a pesquisa demonstrou que o óleo essencial das folhas de Hyptis martiusii Benth (OEHM) apresenta sinergismo só em associação com os antibióticos gentamicina e imipenem contra as bactérias Pseudomonas aeruginosa e Escherichia coli. No entanto, apresenta antagonismo em associação com amicacina, gentamicina e imipenem contra as três bactérias estudadas. Para além da ciprofloxacina não demonstrou resultados relevantes. Em relação com a atividade citotóxica, a concentração letal média (LC50) expôs um valor de 263,12 [ig/ml. Conclusão: finalmente, revelou-se que a H. martiusii apresenta atividade citotóxica sinérgica contra as bactérias avaliadas.

Resumen Introducción: la especie Hyptis martiusii Benth, comúnmente llamada "cidreira do campo", tiene múltiples propiedades biológicas, como ser insecticida, antifúngica y antiinflamatoria. El objetivo de este estudio fue investigar la actividad moduladora del aceite esencial de las hojas frescas de Hyptis martiusii en asociación con diferentes antibióticos contra las bacterias Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosa, y evaluar la actividad citotóxica de la especie. Materiales y métodos: el estudio utilizó la concentración mínima inhibitoria (CMI) como una forma de evaluar la modulación con una inoculación de 100 microlitros de cada cepa bacteriana. Las pruebas de citotoxicidad se realizaron mediante cultivo in vitro de células de tejido conectivo de ratón (fibroblastos de mamíferos). Resultados: la investigación demostró que el aceite esencial de las hojas de Hyptis martiusii Benth (OEHM) presenta sinergismo solo en asociación con los antibióticos gentamicina e imipenem contra las bacterias Pseudomonas aeruginosa y Escherichia coli. Sin embargo, presenta antagonismo en asociación con amikacina, gentamicina e imipenem contra las tres bacterias estudiadas. Además de la ciprofloxacina, no demostró resultados relevantes. En relación con la actividad citotóxica, la concentración letal media (CL50) exhibió un valor de 263,12 [ig/ml. Conclusión: finalmente, se reveló que la H. martiusii presenta actividad citotóxica sinérgica contra las bacterias evaluadas.

Abstract Introduction: The species Hyptis martiusii Benth. commonly called "cidreira do campo" has multiple biological properties, such as antifungal, anti-inflammatory, and insecticide. The aim of this study was to investigate the modulating activity of the essential oil of the fresh leaves of Hyptis martiusii in association with different antibiotics against the bacteria Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, as also the cytotoxic activity of this species. Materials and methods: The study used the MIC (minimum inhibitory concentration) as a way of assessing the modulation using an inoculation of 100 microliters of each bacterial strain. The cytotoxicity tests were conducted using in vitro culture of mouse connective tissue cells (fibroblasts of mammals). Results: The research demonstrated that the essential oil from leaves of Hyptis martiusii Benth (OEHM) presented synergism only when associated with the antibiotics gentamicin and imipenem against the bacteria Pseudomonas aeruginosa and Escherichia coli. However, it presented antagonism in association with amikacin, gentamicin and imipenem against the three studied bacteria. In addition to the ciprofloxacin showed no relevant results. In relation to the cytotoxic activity the lethal concentration (LC50) exhibited a value of 263.12 [ig/ml. Conclusion: Ultimately it was established, that H. Martiusii presents a synergistic cytotoxic activity against the evaluated bacteria.