Morphophysiological study of the salivary glands, singanglium, Gené’s organ and ovaries of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) females treated with different concentrations of thymol

Author(s)

Renata da Silva Matos

• Document type: Doctoral Thesis
• Press: Rio Claro. 2018-10-31.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro
• Defense date: 2018-09-04
• Advisor: Maria Izabel Souza Camargo

Abstract

The results of this study demonstrated the acaricidal potential of thymol at the concentrations of 1. 25 ; 2. 5 ; 5. 0 , 10. 0 and 20. 0 mg/mL , once the product was capabl e of causing morphophysiological alterations in the synganglion, salivary glands, Gene’s organ and ovaries of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) female ticks . The synganglion of the exposed females presented cells with vacuolated cytopla sm and pyknotic nuclei in the cortex region. The salivary glands presented alterations as well, acini I presented enlarged lumen, and the cells of acini II and III displayed cytoplasmic vacuolation and fragmented nuclei. The engorged females that had the G ene’s organ analyzed and were exposed to diluted thymol at the concentrations of 10. 0 and 20. 0 mg/mL presented tubular accessory glands with cytoplasmic vacuolation and irregular nuclei, sometimes fragmented or with ruptured membrane . Some cells were rupt ured by the action of the product, probably after having undergone hypertrophy. When not ruptured, these cells presented invaginations both in the basal lamina and in the unstructured lateral membranes. Additionally, the thymol concentration of 20. 0 mg/mL caused an increase in caspase 3 and GST activities in the Gene’s organ. The oocytes of the engorged females showed severe damages after exposed to thymol, mainly at the concentrations of 10. 0 and 20. 0 mg/mL, displaying vacuolated cytoplasm, ruptured yolk g ranules and internally and externally altered mitochondria . The activity of the enzyme SOD in the groups exposed to ethanol 30%, and to thymol at 5. 0 , 10. 0 and 20. 0 was inhibited. The females exposed to the concentrations of 5. 0 and 10. 0 mg/mL showed incre ased GST enzyme activity. Caspase 3 activity was increased in the females exposed to 20. 0 mg/mL, which confirmed that thymol triggered the process of cell death in such germ cells. (AU)

• FAPESP's process: 14/13143-7 - Study morphophysiological salivary gland, singânglio, body of ovarian gene and engorged females of R. sanguineus (Latreille, 1806) (Acari: Ixodidae) treated with different concentrations thymol
• Grantee: Renata da Silva Matos
• Support Opportunities: Scholarships in Brazil - Doctorate