Action of andiroba oil and permethrin on the central nervous and reproductive systems of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks females. A confocal study Gislaine Cristina Roma ⇑ , Maria Cláudia Ramalho Vendramini, Maria Izabel Camargo-Mathias, Pablo Henrique Nunes, Adriano Uemura de Faria, Gervásio Henrique Bechara UNESP – Universidade Estadual Paulista, SP, Brazil article info Article history: Received 8 February 2013 Accepted 6 June 2013 Available online xxxx Keywords: Natural product Synthetic product Synganglion Ovary Nuclear changes Cell death abstract Research for acaricides with lower toxicity and impact on the environment has been intensified. An alter- native would be the use of natural compounds or of synthetic products in lower concentrations than the ones sold commercially. Thus, this study describes the action of andiroba seed oil on the nuclei of the ovary and synganglion cells of Rhipicephalus sanguineus, and presents an analysis of the nuclear morphol- ogy of the nervous system cells of this tick species when exposed to permethrin. The results obtained showed that, although no changes have been observed in the genetic material of the ovary cells exposed to the andiroba oil, this compound, as well as permethrin, has neurotoxic action on the females of this species. The damages caused to the physiology of the synganglion, due to the loss of integrity of the genetic material, would result in the impairment of the metabolism of other systems of R. sanguineus ticks. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Ticks are considered one of the most important parasites among arthropods, as they are obligatory hematophagous and vectors for several biopathogens. The species Rhipicephalus sanguineus is con- sidered an urban plague of great medical-veterinary importance (Walker, 1994). Besides being the dog its main host (Rey, 1973; Walker, 1994), this tick can also parasitize other mammals, includ- ing humans (Venzal et al., 2003; Nebreda-Mayoral et al., 2004; Louly et al., 2006). The use of synthetic acaricides is the most efficient method of tick control. However, it presents inconveniences, such as the high cost of the chemical products, development of tick resistance and damages to the environment and public health due to their resid- ual toxic effects (Freitas et al., 2005). Thus, the search for affordable new acaricides that are less toxic and have low impact on the environment has been intensified. One example of this is the andiroba (Carapa guianensis Aubl.) seed oil, which contains compounds that are repellent or lethal to many Arthropoda (Farias et al., 2007, 2009), but it also has beneficial medicinal properties in humans (Martinez, 2002). Another alternative is the use of synthetic products in lower concentrations than the ones commercially sold. According to Roma et al. (2009), the permethrin, a synthetic pyrethroid widely used to control R. sanguineus, when applied in much lower concen- trations than the one used in commercial products (approximately 100 times), is efficient to eliminate this species. However, this process would be slower, taking more than seven days to cause the death of the ectoparasite on the host. The application of lower dosages of synthetic acaricides is advantageous to the host and the environment, due to low toxicity risks. The integrity of the genetic material is crucial for the cellular viability and its functional activity. However, the cellular genomes are constantly subject to chemical agents that can cause changes in the vital genetic information (Castro, 2004). If this happens, all the metabolic functions of the organism would be impaired, compro- mising the animal survival. Thus, this study aimed to analyze, for the first time, the action of sub-lethal concentrations of andiroba seed oil (natural product) and permethrin (synthetic chemical product) on the genetic mate- rial of the synganglion of R. sanguineus semi-engorged females, through laser scanning confocal microscopy. The action of andiroba oil on the nuclei of the reproductive system cells of this species is also analyzed. 0034-5288/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.rvsc.2013.06.009 ⇑ Corresponding author. Address: UNESP – Universidade Estadual Paulista, Instituto de Biociências, Departamento de Biologia, Avenida 24 A, 1515, Bela Vista, Rio Claro, SP CEP: 13506-900, Brazil. Tel.: +55 19 35264135; fax: +55 19 35340009. E-mail address: gislaineroma@yahoo.com.br (G.C. Roma). Research in Veterinary Science xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc Please cite this article in press as: Roma, G.C., et al. Action of andiroba oil and permethrin on the central nervous and reproductive systems of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks females. A confocal study. Res. Vet. Sci. (2013), http://dx.doi.org/10.1016/j.rvsc.2013.06.009