Actividad insecticida de aceites esenciales sobre Blatella germanica (Linneaus, 1767) (Dictyoptera: Blattellidae) / nsecticidal activity of essential oils against Blatella germanica (Linneaus, 1767) (Dictyoptera: Blattellidae)

Blattella germanica (Linneaus, 1767) es una especie de cucaracha considerada plaga de la salud pública por estar asociada a gran número de microorganismos causantes de enfermedades al hombre. Para su control se utilizan diferentes tipos de formulaciones a base de insecticidas sintéticos a los cuales en su gran mayoría es resistente. En este contexto existe un interés creciente por los insecticidas botánicos. En el siguiente trabajo se evaluaron los aceites de Citrus aurantium (L.,1753), Ocimum basilicum (L.,1753), Piper aduncum subsp ossanum (C.DC. Saralegui) y Eucalyptus globulus (Labill, 1800) mediante aplicación tópica de un microlitro en el primer esternito abdominal de los individuos. Los cuatro aceites mostraron actividad insecticida sobre adultos de B. germanica con CL50 que oscilaron entre 58 µg/µL para O. basilicum y 250 µg/µL para P. aduncum(AU)´

Blattella germanica (Linneaus, 1767) is a cockroach species considered a public health pest, since it is associated with a great number of disease-causing microorganisms in humans. For its control, different types of synthetic-based insecticidal formulations are used, to which it is mostly resistant. In this context, there is a growing interest in botanical insecticides. In this research, oils from Citrus aurantium (L., 1753), Ocimum basilicum (L., 1753), Piper aduncum subsp. ossanum (C.DC. Saralegui), and Eucalyptus globulus (Labill, 1800) were evaluated by topical application of 1 µL to the first abdominal sternum of the individuals. The four essential oils evaluated showed insecticidal activity against adult B. germanica with LC50 ranging from 58µg/µL for O. basilicum to 250µg/µL for P. aduncum(AU)´

Chemistry, cytotoxicity and antileishmanial activity of the essential oil from Piper auritum

Leishmaniasis is one of the most important parasitic infections, but current treatments are unsatisfactory due to their toxicity, cost and resistance. Therefore, the development of new antileishmanial compounds is imperative. Many people who live in endemic areas use plants as an alternative to treat the disease. In this paper, we characterised the essential oil from Piper auritum, evaluated its cytotoxicity and determined its antileishmanial activity. The chromatogram obtained by gas chromatography revealed 60 peaks and we found that safrole was the most abundant compound, composing 87 percent of the oil. The oil was active against the promastigotes of Leishmania major, Leishmania mexicana, Leishmania braziliensis and Leishmania donovani with a favourable selectivity index against peritoneal macrophages from BALB/c mice. The Piper-oil inhibited the growing of intracellular amastigotes of L. donovani with an IC50 value of 22.3 ± 1.8 ìg/mL. This study demonstrates the usefulness of the essential oils as a promising alternative to treat leishmaniasis.

Utilización de aceites esenciales de pinaceas endémicas como una alternativa en el control del Aedes aegypti / Use of essential oils from endemic pinaceae as an alternative for Aedes aegypti control

INTRODUCCIÓN: Pinus caribaea y Pinus tropicalis son especies de plantas endémicas de Cuba y en su composición química presentan estructuras que se reportan en otras especies de plantas con fuerte actividad insecticida. OBJETIVO: evaluar el efecto larvicida de dos Pinaceas y sus derivados (aceites de trementina) en, Aedes aegypti, además de determinar el efecto ovicida de estos últimos en huevos de esta especie. MÉTODOS: se utilizó una cepa susceptible de referencia Rockefeller, suministrada por el Centro de Control de Enfermedades de San Juan de Puerto Rico y los bioensayos se realizaron según metodología de la Organización Mundial de la Salud para determinar resistencia y(o) susceptibilidad a insecticidas en mosquitos. El aceite de Pinus tropicalis fue obtenido por hidrodestilación y el aceite de Pinus caribaea se obtuvo por arrastre al vapor. El aceite de trementina (AT01) fue obtenido destilando la resina de pinos y una parte de este fue sometido a un tratamiento fotoquímico (AT02) de izomerización del a-pineno y b-pineno como componentes mayoritarios. RESULTADOS: el aceite de P. tropicalis mostró una concentración letal CL50= 42 mg/L y una CL95= 57 mg/L, y para P. caribaea la CL50= 51 mg/L y CL95= 181 mg/L. Los 2 aceites de trementina utilizados AT01 y AT02 mostraron alta acción larvicida al obtenerse las CL50 más bajas de este estudio (21,4 mg/L y 23,9 mg/L). El mayor efecto ovicida se mostró con la dosis diagnóstico del aceite de trementina AT02, con 94 % de no eclosión. CONCLUSIONES: los aceites foliales y sus derivados son candidatos para el control de esta especie de insecto, tanto por actividad insecticida como por su factibilidad, extracción y escalado.

INTRODUCTION: Pinus caribaea and Pinus tropicalis are endemic plants of Cuba and their chemical composition exhibits structures similar to those reported in other plant species with strong insecticidal action. OBJECTIVE: to evaluate the larvicidal effect of two pinaceae and their derivatives (turpentine oils) on Aedes aegypti in addition to determine the ovicidal effect of the latter on this species' eggs. METHODS: a reference susceptible strain called Rockefeller supplied by the Center of Disease Control in San Juan, Porto Rico was the choice whereas bioassays were conducted according to the World Health Organization methodology to ascertain resistance and (or) susceptibility of mosquitoes to insecticides. Water distillation allowed obtaining Pinus tropicalis oil and vapour dragging. Turpentine oil (AT01) was obtained by distilling pine resin and one part of it (AT02) underwent photochemical treatment of izomerization of a-pinen y b-pinen as main components. RESULTS: P. tropicalis showed lethal concentration LC50= 42 mg/L and LC95= 57 mg/L, and for P. caribaea, LC50= 51 mg/L and LC95= 181 mg/L. The two turpentine oils AT01 and AT02 exhibited high larvicidal action since they recorded the lowest LC50 of this study (21,4 mg/L and 23,9 mg/L). The greatest ovicidal effect went to diagnostic dose of AT02 turpentine oil, with 94% of hatching-deterrent action. CONCLUSIONS: leaf oils and their derivatives are candidates for the control of this species, because of their insecticidal action and also their feasibility, extraction and scaling.

Actividad insecticida de aceites esenciales de plantas en larvas de Aedes aegypti (Diptera: Culicidae) / Insecticidal effect of essential oils from plants in Aedes aegypti larvae (Diptera: Culicidae)

Introducción: la búsqueda de nuevas alternativas y compuestos ambientalmente inocuos y que generen mínima resistencia, como los productos naturales y metabolitos de origen vegetal, constituye una importante línea de investigación en el control integrado de plagas y vectores. Objetivos: evaluar la acción insecticida de aceites esenciales de las plantas Curcuma longa, Melaleuca leucadendron, Artemisia abrotanum en Aedes aegypti. Métodos: para los bioensayos se utilizó una cepa de Aedes aegypti de referencia susceptible a insecticidas y estabilizada en el laboratorio nombrada Rockfeller. Los bioensayos se realizaron según la metodología de la OMS. Resultados: se obtuvieron las dosificaciones y mortalidades obtenidas para el aceite de Curcuma longa. Resultaron la CL50= 0,0025 por ciento(concentración letal que provoca 50 por ciento de mortalidad) y la CL95= 0,0044 por ciento (concentración letal que provoca 95 por ciento de mortalidad) y su línea de regresión Y= 5,56 + 6,60X. Para Melaleuca leucadendron resultó ser CL50= 0,0041 por ciento y la CL95= 0,0051 por ciento y la ecuación de su recta fue Y= 5,20 + 13,90X. El aceite de Artemisia abrotamum mostró una CL50= 0,0193 por ciento y la CL95= 0,0272 por ciento y su línea de regresión fue Y= 5,22 + 11,19X. Conclusiones: con este estudio se comprobó la acción insecticida de estos aceites en larvas de Ae. aegypti, por lo que se recomienda una dosis diagnóstico para Curcuma longa de 113 mg/L= 0,0113 por ciento, para Melaleuca leucadendron una dosis diagnóstico de 120 mg/L= 0,0120 por ciento y para Artemisia abrotamum 620 mg/L= 0,062 por ciento.

Introduction: The search for new alternatives and environmentally-friendly compounds that generate minimal resistance such as natural products and metabolites of vegetal origin constitutes an important research line included in the comprehensive management of plagues and vectors. Objective: To evaluate the insecticidal activity of essential oils from Curcuma longa, Melaleuca leucadendron, Artemisia abrotanum against Aedes aegypti mosquitoes. Methods: An Aedes aegypti reference strain, susceptible to insecticides and stabilized at the laboratory, was used for the bioassays. It was known as Rockefeller. The bioassays were performed following the WHO methodology. Results: Dosing and mortality indexes were obtained for the three essential oils. For Curcuma longa oil, LC50= 0.0025 (lethal concentration that causes 50 percent mortality), LC95= 0.0044 percent (lethal concentration that causes 95 percent mortality) and regression line Y= 5.56 + 6.60X. For Melaleuca leucadendron oil, LC50= 0.0041 percent, LC95= 0.0051 percent and the regression line was Y= 5.20 + 13.90X. Artemisia abrotamun oil showed LC50= 0.0193 percent, LC95m= 0.0272 percent and the regression line was Y= 5.22 + 11.19X. Conclusions: This study verified the insecticidal action of these oils on Aedes aegypti larvae and recommended diagnosis doses of 113 mg/L= 0.0113 percet for Curcuma longa, 120 mg/L= 0.0120 percent for Melaleuca leucadendron, and 620mg/L= 0.062 percent for Artemisia abrotamum.

Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis

To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against promastigotes of Leishmania amazonensis. However, an indifferent effect has been found for combinations of meglumine antimoniate or amphotericin B and the essential oil.

Até hoje não temos vacina contra a Leishmania e a quimioterapia é a indicação para o controle desta doença. Os remédios que hoje utilizamos são tóxicos e muito caros e além disso o resultado não é sempre o desejado. Por isso, uma terapia de combinação é a melhor opção. Este trabalho mostra que o óleo de essência de C. ambrosioides tem atividade sinérgica junto com a pentamidina sobre os promastigotas de L. amazonensis, diferente do resultado da combinação de antimônio de meglumine e anfotericina B e o óleo de essência.