Tetradenia riparia leaves, flower buds, and stem essential oils to control of Aedes aegypti larvae

Abstract Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a species native to the African continent and used as an insect repellent. The objective of the study was to evaluate the larvicidal potential of essential oils (EOs) from the leaves, flower buds, and stem of T. riparia, collected in winter against Aedes aegypti larvae. The EOs were extracted by hydrodistillation (3 h) and identified by GC/MS. The EOs were tested against larvae of A. aegypti at concentrations ranging from 12500 to 1.5 µg/mL for 24 h. The insecticide activity was evaluated by probit analysis, and the anticholinesterase activity was determined by bioautographic method. The results of the class projection indicated sesquiterpenes as the majority class, corresponding to 60.66% (leaves), 64.70% (flower buds) and 83.99% (stem), and the bioassays on A. aegypti larvae indicated LC50 of 1590, 675 and 665 µg/mL, respectively. The anticholinesterase activity indicated that the EO of the leaves inhibited the enzyme at a concentration of 780 µg/mL, and those from the flower buds and stem inhibited up to 1560 µg/mL. The results indicated weak activity of essential oils against A. aegypti larvae.

Actividad antioxidante y antibacteriana del aceite esencial de hoja de Myrcianthes pungens / Antioxidant and antibacterial activity of Myrcianthes pungens leaf essential oil

Myrcianthes pungens (Myrtaceae) es un árbol nativo de Brasil conocido como guabijú. En nuestro estudio, describimos la composición química del aceite esencial de las hojas secas de M. pungens, la actividad antioxidante por diferentes métodos y la actividad antibacteriana contra Staphylococcus aureus, Bacillus cereus y Pseudomonas aeruginosa. La identificación química se realizó mediante un cromatógrafo de gases acoplado a un espectrómetro de masas y la actividad antibacteriana se evaluó mediante un método de microdilución en caldo. El aceite esencial de la hoja presentó sesquiterpenos de hidrocarburos (42,6%) como su principal clase química cuyos compuestos principales fueron ß-cariofileno (11,7%) y 1,8-cineol (10,1%). La mayor protección antioxidante fue de 57.5 a 63.3% de ß-caroteno. La mayor actividad antibacteriana fue contra S. aureus (MIC de 78.12 µg/mL). Este valor fue 2,56 veces menor que el control positivo de estreptomicina. M. pungens es una fuente prometedora de moléculas naturales con potencial estudio para el desarrollo de productos farmacológicos, cosméticos y alimenticios.

Myrcianthes pungens (Myrtaceae) is a native tree to Brazil known as guabijú. In our study, we described the chemical composition of the essential oil from M. pungens dried leaves, the antioxidant activity by different methods and antibacterial activity against Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa. The chemical identification was done by gas chromatograph coupled to mass spectrometer and antibacterial activity was evaluated by broth microdilution method. The leaf essential oil presented hydrocarbon sesquiterpenes (42.6%) as its main chemical class whose major compounds were ß-caryophyllene (11.7%) and 1,8-cineole (10.1%). The best antioxidant protection was from 57.5 to 63.3% of ß-carotene. The highest antibacterial activity was against S. aureus (MIC of 78.12 µg/mL). This value was 2.56-fold lower than the positive streptomycin control. M. pungens is a promising source of natural molecules with potential study for the development of pharmacological, cosmetic and food products.

Uso de complexo homeopático reduz o parasitismo por carrapatos e amplia o intervalo de tempo entre tratamentos com acaricidas / Homeopathic complex decreases tick parasitism and increases the interval between treatments with acaricides

O presente trabalho avaliou a segurança e eficácia de 2 formulações homeopáticas no tratamento populacional de bovinos naturalmente parasitados com carrapatos da espécie Rhipicephalus (Boophilus) microplus. Foram realizados 2 experimentos utilizando complexos homeopáticos distintos, ambos com 20 vacas adultas, raça holandesa, em diferentes estágios de lactação, distribuídas em grupo controle (n= 10) e grupo tratado (n= 10) num estudo randomizado com duplo cego. A contagem de carrapatos foi registrada nos dias 7, 14, 21 e 28 após o tratamento homeopático e, posteriormente, em intervalos de 15 dias até o dia 140 do Experimento 01 e o dia 197 do Experimento 02. A formulação homeopática utilizada no Experimento 01 apresentou eficácia de 21,1%, sendo necessária intervenção com tratamento convencional durante o período de 140 dias. A eficácia do complexo homeopático no Experimento 02 foi de 6,7%. Os resultados foram seguros e eficazes na terapia antiparasitária, tendo bons resultados quando complementados com o uso racional e correto de acaricidas. (AU)

In the present study evaluated the efficacy of 2 homeopathic formulas in the treatment of cattle naturally with Rhipicephalus (Boophilus) microplus ticks. Two experiments were carried out using different combinations of homeopathic medicines, with 20 adult Holstein cows, in different stages of lactation, allocated to the control (n= 10) and treated (n= 10) groups in a randomized double-blind placebo-controlled trial. Tick count was performed on days 7, 14, 21 and 28 after homeopathic treatment ,and then at 15-day intervals up to day 140 in Experiment 1 and day 197 in Experiment 2. Efficacy in Experiment 1 was 21.1%, while conventional intervention was required along the 140-day period. Efficacy in Experiment 2 was 6.7%. The results indicate that the tested homeopathic formulas were safe and efficacious, outcomes being satisfactory when homeopathic treatment was combined with rational and correct conventional treatment. (AU)

Efficiency of tick biotherapic on the control of infestation by rhipicephalus (boophilus) microplus in dutch dairy cows / Eficiência de bioterápico de carrapato no controle da infestação por rhipicephalus (boophilus) microplus em vacas leiteiras de raça holandesa / Eficiencia de bioterápico de garrapata para control de la infestación por Rhipicephalus (Boophilus) microplus en vacas lecheras de raza holandesa

Background: cattle tick Rhipicephalus (Boophilus) microplus poses serious problems for farmers in Brazil, especially because the parasite easily develops resistance to pesticide agents. For this reason, together with other factors including environmental, human and animal contamination and costs, alternative approaches have been sought for. Aims: this study sough to evaluate the efficiency of a tick biotherapic on tick-infested cows. Methods: 34 dairy Dutch cows were divided in 2 groups: one group received 100g/day of mineral salt supplement impregnated with tick biotherapic 12cH for 6 months, and then in alternate days with tick biotherapic 30cH to complete 28 months of treatment; the other group (control) received only the mineral salt supplement. After 28 months of treatment, engorged Rhipicephalus (boophilus) microplus females were collected in both groups, counted and weighed; in vitro tests were carried out to assess mass of ticks; egg mass; egg-hatching rate; and reproductive efficiency. Results: There was significant difference between both groups for all parameters evaluated; tick-mass (p = 0.0008); egg mass (p=0.0044); egg-hatching rate (p= 0.0017); and reproductive efficiency (p = 0.0044). Conclusion: treatment with tick biotherapic significantly decreased the mass of engorged females, deposition and hatching rate of eggs, resulting consequently in the decrease of the reproductive efficiency of ticks.

Introdução: os carrapatos do gado Rhipicephalus (Boophilus) microplus representam um sério problema para os criadores brasileiros, especialmente porque desenvolvem rapidamente resistência aos pesticidas. Por isso, junto a outros fatores incluindo contaminação ambiental, humana e animal, assim como os custos, têm sido procuradas abordagens alternativas. Objetivos: avaliar a eficiência de um bioterápico desenvolvido a partir de carrapatos em vacas infestadas. Métodos: 34 vacas leiteiras de raça holandesa foram divididas em 2 grupos; um recebeu 100 mg/dia de suplemento salino mineral impregnado com o bioterápico 12cH durante 6 meses e após 30cH em dias alternos até completar 28 meses de tratamento; o outro grupo (controle) recebeu só o suplemento mineral. Após 28 meses de tratamento foram coletadas fêmeas ingurgitadas do carrapato em ambos os grupos, contadas e pesadas, e foram realizados testes in vitro para determinar a massa de parasitas; massa de ovos; taxa de eclosão dos ovos; e eficiência reprodutiva. Resultados: houve diferença significativa entre ambos os grupos em todos os parâmetros avaliados ? massa de parasitas (p=0,0008); massa de ovos (p=0,0044); taxa de eclosão de ovos (p=0,0017) e eficácia reprodutiva (0,0044). Conclusão: o tratamento com bioterápico de carrapato diminuiu significativamente a massa de fêmeas ingurgitadas e a deposição e taxa de eclosão, resultando, consequentemente, na diminuição da eficiência reprodutiva dos carrapatos.

Introducción: la garrapata del ganado Rhipicephalus (Boophilus) microplus produce serios problemas a los hacenderos brasileños especialmente porque desarrolla rápidamente resistencia a los agentes pesticidas. Por este motivo, asociado a otros factores como contaminación ambiental, humana y animal y los costos, se buscan abordajes alternativos. Objetivos: este estudio buscó evaluar la eficiencia de un bioterápico preparado de garrapatas en vacas infestadas. Métodos: 34 vacas lecheras de raza holandesa fueron divididas en 2 grupos; uno recibió 100 mg/día de suplemento mineral impregnado con bioterápico 12cH durante 6 meses y después, en días alternados hasta completar 28 meses de tratamiento; el otro recibió apenas el suplemento mineral (control). Después de 28 meses de tratamiento, garrapatas hembra ingurgitadas fueron recogidas en ambos grupos, contadas y pesadas; fueron realizados pruebas in vitro para medir la masa de garrapatas; la masa de huevos, la tasa de eclosión de huevos y la eficiencia reproductiva. Resultados: hubo diferencias significativas entre los 2 grupos en todos los parámetros evaluados ? masa de garrapatas (p=0,0008), masa de huevos (p=0,0044), tasa de eclosión de huevos (p=0,0017) y eficiencia reproductiva (p=0,0044). Conclusión: el tratamiento con bioterápico de garrapata redujo significativamente la masa de hembras ingurgitadas y la deposición y eclosión de huevos, resultando en disminución de la eficacia reproductiva de las garrapatas.