Evaluation of the combined effect of thymol, carvacrol and (E)-cinnamaldehyde on Amblyomma sculptum (Acari: Ixodidae) and Dermacentor nitens (Acari: Ixodidae) larvae
Data
2015-09-15
Autores
Lopes Novato, Tatiane Pinheiro
Araujo, Laryssa Xavier
Oliveira de Monteiro, Caio Marcio
Maturano, Ralph
Souza Senra, Tatiane de Oliveira
Matos, Renata da Silva [UNESP]
Gomes, Geovany Amorim
Carvalho, Mario Geraldo de
Daemon, Erik
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier B.V.
Resumo
This study aimed at assessing the combined effect of thymol, carvacrol and (E)-cinnamaldehyde on Amblyomma sculptum and Dermacentor nitens larvae. The effects resulting from treatments were evaluated by means of the modified larval packet test. In order to determine the LC50, components of essential oils, the monoterpenes thymol, carvacrol and phenylpropanoid (E)-cinnamaldehyde were individually tested at different concentrations. After determining the LC50, each essential oil component was separately evaluated and then combined with another substance at a 1:1 proportion at the LC50 concentration and at 1/2 and 1/4 of the LC50. For A. sculptum, the lowest LC50 value was obtained for (E)-cinnamaldehyde (1.40 mg/ml), followed by thymol (2.04 mg/ml) and carvacrol (3.49 mg/ml). The same order of effectiveness was observed for D. nitens, with values of 1.68, 2.17 and 3.33 mg/ml, respectively. In the evaluation of component associations of essential oils against A. sculptum larvae, only the combinations between carvacrol and thymol (LC50) and carvacrol and (E)-cinnamaldehyde (1/4 LC50) presented a moderate synergetic effect. In turn, for D. nitens larvae, the combinations between thymol and carvacrol (LC50 and 1/2 LC50) presented a synergetic effect, while the others presented an additive or antagonistic effect. Therefore, it can be concluded that the combination of thymol and carvacrol (LC50) has a moderate synergetic effect against A. sculptum larvae, while thymol, combined with carvacrol (LC50 and 1/2 LC50), has a synergetic effect against D. nitens larvae. (C) 2015 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
Tick, Monoterpene, Phenylpropanoid, Synergism
Como citar
Veterinary Parasitology. Amsterdam: Elsevier Science Bv, v. 212, n. 3-4, p. 331-335, 2015.