Programa de Pós-graduação em Comportamento e Biologia Animal, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário Bairro Martelos, 36036-330, Juiz de Fora, MG, Brazil,
Published: December 2014
AI Article Synopsis
Article Abstract
Thymol is a monoterpene with proven acaricide action for several tick species. In addition to killing these ectoparasites, thymol can also reduce oviposition and egg hatch rate. However, the effects of thymol on the morphophysiology of tick ovaries are still unknown. Thus, the aim of this study was to evaluate the morphophysiological changes caused by this active principle in ovaries of Rhipicephalus sanguineus after a 6-day feeding period, through the application of morphohistochemical techniques. After the feeding period, a total of 50 females were divided into five groups and immersed in the following solutions: (I) distilled water (control), (II) 30% ethanol (control), (III) 1.25 mg/mL thymol, (IV) 2.5 mg/mL thymol, and (V) 5.0 mg/mL thymol. The experimental groups were kept in a climatic chamber (27 ± 1 °C; RH 80 ± 10%) for 5 days. After this period, morphological (hematoxylin/eosin) and histochemical (von Kossa) techniques were applied after remotion of the ovaries. The morphological results revealed large vacuoles in germ cells at different developmental stages and invaginations that represent deformations in the chorionic membrane. From the results obtained in this study, it was concluded that thymol interfered with the development of oocytes, which showed degeneration signs. The treatment containing 5.0 mg/mL thymol affected more accentuately the morphological development. Moreover, thymol also altered the calcium content of yolk granules, which generally showed an intense staining for this element.
Essential oils are natural substances used as therapeutic agents and food preservatives to inhibit harmful microorganisms. This study aimed to assess the synergistic effect of Trachyspermum ammi essential oil and ampicillin on antibiotic-resistant gastrointestinal pathogens, including Escherichia coli, Enterococcus faecalis, Shigella flexneri, Salmonella typhimurium. Using gas chromatography-mass spectrometry (GC-MS), the main components of T.
Due to their effectiveness at low doses and relative safety for non-target species, plant essential oils (EOs) are considered ideal alternatives to conventional pesticides for pest control. In this study, the chemical composition of () EO was construed by Gas Chromatography-Mass Spectrometry (GC-MS), and its larvicidal and ovicidal activity against omnivorous pests () was assessed. The effects of EO on the activities of antioxidant detoxification enzymes were also measured.
* The study tested different commercial acaricides, disinfectants, and natural products for their ability to prevent tick eggs from hatching, finding that certain acaricides like chlorpyrifos and amitraz were particularly effective.
* In field tests, phoxim showed a 40% effectiveness in preventing hatching of tick eggs, while another acaricide, deltamethrin, was only 8.79% effective, highlighting the potential for specific chemicals and natural products to control tick populations.
* The study tested different concentrations of ivermectin and EOCs on Rhipicephalus annulatus tick isolates, finding that while all EOCs were toxic to the ticks, no true synergistic effect with ivermectin was identified despite some combinations showing increased mortality.
* The research suggests that combining ivermectin with certain EOCs, especially D-limonene and cinnamaldehyde, could enhance tick control methods, and further research is recommended to assess effectiveness in real-world scenarios.
Department of Pharmacology, Pharmacognosy & Botany, Faculty of Pharmacy, Complutense University of Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
This study determined the antioxidant and antibacterial activities of (Ts), (Rp), and (Js) from Addis Ababa against MDR-. Accordingly, had the highest total phenolic (TPC), flavonoid (TFC) and proanthocyanidin content. In Ts, the GC-MS analyses predicted 14 bioactive compounds.
