Low concentrations of acetylcarvacrol induce drastic morphological damages in ovaries of surviving Rhipicephalus sanguineus sensu lato ticks (Acari: Ixodidae)

Publication date: Available online 8 November 2019Source: MicronAuthor(s): Isaac Filipe Moreira Konig, Marcos Vinícius Silva de Oliveira, Raquel Romano Palmeira Gonçalves, Ana Paula Peconick, Sérgio Scherrer Thomasi, Luís Adriano Anholeto, José Ribamar Lima-de-Souza, Maria Izabel Camargo-Mathias, Rafael Neodini RemedioAbstractRhipicephalus sanguineus sensu lato (s. l.) ticks are targets of acaricidal treatments due to their great veterinary and medical importance. Acetylcarvacrol stands out as a promising acaricidal substance for its increased biocidal activity and stability. Additionally, its toxicity to mammals is reduced when compared to the parent molecule, carvacrol. The present study aimed to evaluate the effects of acetylcarvacrol on the morphology of ovaries of engorged R. sanguineus s. l. ticks. The animals were subjected to the Adult Immersion Test to calculate the lethal concentrations (LC50 and LC90) of acetylcarvacrol. Subsequently, the surviving ticks were dissected for collection of the ovaries. The samples were processed through routine histological techniques. The histological sections were stained with hematoxylin and eosin, bromophenol blue (protein detection) and PAS (polysaccharide detection). The alterations found in the ovaries were evaluated by morphometric and semiquantitative analysis. The LC50 and LC90 were 17.805 and 26.164 µL/mL, respectively. The most severe morphological alterations were disappearance of the female germ cells (oocytes), ...
Source: Micron - Category: Biology Source Type: research