Action of Cannabis sativa (Linnaeus, 1753) extract and the acaricide fluralaner (active ingredient Bravecto) on the reproductive (ovary) and nervous systems (synganglion) of Rhipicephalus linnaei (Audouin, 1823) ticks

• Grant number: 25/01903-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2025
• End date: January 31, 2029
• Field of knowledge: Biological Sciences - Zoology - Applied Zoology
• Principal Investigator: Maria Izabel Souza Camargo
• Grantee: Melissa Carolina Pereira
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

Ticks are vectors of diseases that affect public health and livestock production, leading to the excessive and inappropriate use of acaricides, which can induce resistance. Fluralaner has demonstrated high efficacy in tick control, but its effects on ticks physiology are not well understood. On the other hand, the extract of Cannabis sativa has already been proven in human and veterinary medicine for its pharmacological properties, including antiparasitic and tick-killing actions. In light of this, the present project aims to compare the effects of fluralaner (synthetic acaricide) and C. sativa extract (natural bioactive) on the following biological parameters of the dog tick Rhipicephalus linnaei: egg-laying rate, larval hatching rate, occurrence of morphological alterations in eggs, and egg-laying outcome. A histological and ultrastructural study will also be conducted on the ovaries and the synganglion of semi-engorged female R. linnaei, comparing the alterations caused by each compound in these organs. Additionally, host model analyses will be performed to verify whether exposure to these compounds induces any changes in the kidneys, an essential organ for their survival. Thus, the expected results aim to assist in the search for new tick control strategies, illustrating how these chemicals affect the organs, tissues, and cells of ectoparasites, as well as vital organs in hosts.