Evaluation of the combined effect of thymol, carvacrol and (E)-cinnamaldehyde on Amblyomma sculptum (Acari: Ixodidae) and Dermacentor nitens (Acari: Ixodidae) larvae.
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.
Programa de Pós-graduação em Comportamento e Biologia Animal da Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n-Campus Universitário Bairro Martelos, 36036-330 Juiz de Fora, MG, Brazil. Electronic address: tatinovatojf@gmail.com.
Tatiane Pinheiro Lopes
TP
Novato
Programa de Pós-graduação em Comportamento e Biologia Animal da Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n-Campus Universitário Bairro Martelos, 36036-330 Juiz de Fora, MG, Brazil.
Laryssa Xavier
LX
Araújo
Programa de Pós-graduação em Comportamento e Biologia Animal da Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n-Campus Universitário Bairro Martelos, 36036-330 Juiz de Fora, MG, Brazil.
Caio Márcio Oliveira
CM
de Monteiro
Programa de Pós-graduação em Ciências Veterinárias da Universidade Federal Rural do Rio de Janeiro, BR-465, Km 7, Seropédica, Rio de Janeiro, Brazil.
Ralph
R
Maturano
Programa de Pós-graduação em Ciências Veterinárias da Universidade Federal Rural do Rio de Janeiro, BR-465, Km 7, Seropédica, Rio de Janeiro, Brazil.
Tatiane de Oliveira Souza
Tde O
Senra
Programa de Pós-graduação em Biologia Celular e Molecular da Universidade Estadual Paulista Júlio de Mesquita Filho. R. 10, 13505-470 Rio Claro, São Paulo, Brazil.
Renata
R
da Silva Matos
Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, BR-465, Km 7, Seropédica, Rio de Janeiro, Brazil.
Geovany Amorim
GA
Gomes
Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, BR-465, Km 7, Seropédica, Rio de Janeiro, Brazil.
Mario Geraldo
MG
de Carvalho
Programa de Pós-graduação em Comportamento e Biologia Animal da Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n-Campus Universitário Bairro Martelos, 36036-330 Juiz de Fora, MG, Brazil.
Erik
E
Daemon
D000171:Acrolein / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000081007:Cymenes; D004359:Drug Therapy, Combination; D026863:Ixodidae / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D039821:Monoterpenes / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D009822:Oils, Volatile / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D013943:Thymol / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*
D000081007:Cymenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D013943:Thymol; D000171:Acrolein; C073316:carvacrol; C012843:cinnamaldehyde
Monoterpene; Phenylpropanoid; Synergism; Tick