Do combinations of fipronil, eugenol and carvacrol have synergistic effects against Rhipicephalus sanguineus?

Autor: Miranda FR; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Avelar BR; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., de Jesus ILR; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Guimarães BG; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Bonfim IV; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Alves MCC; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Ferreira TP; Animal Parasitology Department, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Azevedo TRC; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil.; Animal Parasitology Department, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Cid YP; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil. yaracid@ufrrj.br.; Pharmaceutical Science Department, Health and Biological Science Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil. yaracid@ufrrj.br., Scott FB; Postgraduate Veterinary Sciences Program, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil.; Animal Parasitology Department, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil.
Jazyk: angličtina
Zdroj: Parasitology research [Parasitol Res] 2023 Dec 14; Vol. 123 (1), pp. 48. Date of Electronic Publication: 2023 Dec 14.
DOI: 10.1007/s00436-023-08037-5
Abstrakt: The tick Rhipicephalus sanguineus is one of the main ectoparasites that affects dogs, causing direct and indirect damage to parasitized animals. Currently, infestation control is mainly carried out by using synthetic acaricidal drugs. However, a decrease in efficacy and an increase in resistance to the main therapeutic protocols against tick infestations have been increasingly reported and confirmed, a factor that has driven research into the potential acaricide activity of natural compounds, including in association with synthetic molecules. The aim of this work was to evaluate whether the combinations of fipronil (FIP) and eugenol (EUG), FIP and carvacrol (CAR), and EUG and CAR would have synergistic effects against immature and unfed adult stages of R. sanguineus through in vitro bioassays. Bioassays were carried out using the larval packet test (FAO 2004) adapted for nymphs and adults. The synergistic activity was explored by combining each solution, based on the estimated LC 50 , in a 1:1 ratio (FIP: EUG, FIP: CAR and EUG: CAR). CompuSyn software was used to evaluate the various pairwise combinations of FIP, EUG and CAR, checking if there was synergism or antagonism between them. FIP and EUG and FIP and CAR showed combination index (CIn) values above 1.45, indicating antagonism. The synergistic activity between EUG and CAR was verified against all unfed phases of R. sanguineus, since the CIn was below 0.70, a value that indicates synergism. The combination of fipronil with either eugenol or carvacrol presented antagonistic effects against R. sanguineus larvae. On the other hand, carvacrol and eugenol had excellent pharmacological synergism against all tick stages with mortality values in the range of 80 to 100%, including the adult stage, which is less susceptible than immature stages.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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