A novel effect of aqueous extract of Pimpinella anisum seeds on ticks of domestic dogs (Canis lupus familiaris)

Abstract

Synthetic pesticides used to combat ticks lose their effectiveness against certain species and can affect human health. The present study evaluated in vitro and in vivo the effect of the aqueous extract of Pimpinella anisum (P. anisum) seeds against Rhipicephalus sanguineus and Ixodes affinis, domestic dog ticks. In the in vitro evaluations, concentrations of 1.25, 2.5, 5, 10, 25, 50, 75 and 100 % of the aqueous extract of P. anisum were applied directly to ticks. The concentrations that had the highest effectiveness in immobilization were 50 %, 75 % and 100 %, but the latter caused immobilization for a longer time (55.89 ± 0.16 min). In the in vivo evaluation, the concentrated aqueous extract was applied to ticks attached to the skin of domestic dogs. Amitraz, a commercial tickicide, was used as a positive control. Both the concentrated aqueous extract and Amitraz caused 100 % of tick detaching. Nonetheless, concentrated aqueous extract of P. anisum seeds was more effective in reducing the average time of tick detaching (60.81 ± 3.17 min) compared to the commercial tickicide Amitraz (145.12 ± 15.97 min). This research suggests that the p-anisaldehyde identified in the aqueous extract could be linked to the immobilization and detaching of R. sanguineus and I. affinis from domestic dogs, suggesting that this extract could be used as a biopesticide to control ticks in domestic dogs.