Cytotoxic effects of Satureja montana L. essential oil on oocytes of engorged Rhipicephalus microplus female ticks (Acari: Ixodidae)

Abstract

In addition to pesticidal activity, the capacity of natural compounds to inhibit the reproduction of parasites emerge as an important alternative tick control method. In this context, Satureja spp. stand out due to their recognized pesticidal properties. Among parasites of veterinary importance, the cattle tick, Rhipicephalus microplus, is responsible for great economic losses in livestock and transmission of relevant pathogens. Thus, the aim of this study was to evaluate the effects of different concentrations of the essential oil of Satureja montana L. on the ovary morphology of R. microplus engorged females through histological and histochemical techniques. The most remarkable morphological changes found were: cytoplasmic vacuolation of germ cells, irregular and thicker chorion, irregular oocyte shape, ring‐shaped nucleolus, decrease in protein and carbohydrate content in oocytes, in addition to cellular changes in the oviduct and pedicel. All morphological changes were assessed using a semiquantitative method already established in the literature. Ticks exposed to 5.0 μl/ml of essential oil showed the most significant changes when compared to control groups. Thus, the essential oil of S. montana L. damaged the reproductive system of R. microplus, which may impair ticks' offspring production and promote a long‐term control of this species. Highlights The essential oil of Satureja montana L. affects the ovary morphology of the cattle tick. The main morphological alterations found were cytoplasmic vacuolation, irregular and thicker chorion and irregular oocyte shape. These alterations may impair the development of eggs.

Histopathological effects of the fruit extract of Citrullus colocynthis on the ovary of the tick Hyalomma dromedarii

“…Serial transverse sections were cut at 3 μm thick using a YD-335 computer microtome (Huran Kaida Scientific Instrument Comp., China), and stained with Mallory triple stain (MT) (Pantin 1946 ) or hematoxylin-eosin stain (HE) (Pears 1960 ), then photographed using a Samsung ES95 HD digital camera fixed on an Olympus microscope (Japan made).…”

The effect of salinity stress on germination parameters in Satureja thymbra L. (Lamiaceae)

“…The essential oil of S. thymbra contains important chemical components such as p-cymene, γ-terpinene, thymol, carvacrol, β-caryophyllen, α-humulene (Khalil et al, 2020). It has been stated in studies that the essential oil obtained from this species has antifungal effects against Mycogone perniciosa, acaricidal effects against Hyalomma marginatum, insecticidal effects against Culex pipiens, and antibacterial effects against Aeromonas salmonicida (Cetin et al, 2010;Dawood et al, 2021;Gea et al, 2021;Reis et al, 2021). It was emphasized that the essential oil of this species also showed an in vitro inhibitory effect against SARS-CoV and HSV-I replication (Khalil et al, 2020).…”