Repellency effect of Pilocarpus spicatus A. St.-Hil essential oil and nanoemulsion against Rhipicephalus microplus larvae

Author(s):Show less -

Nogueira, Jeane A. P. ^{[1, 2]} ; Figueiredo, Amanda ^{[3, 4]} ; Duarte, Jonatas L. ^[5] ; de Almeida, Fernanda B. ^[5] ; Santos, Marcelo G. ^[6] ; Nascimento, Leonor M. ^{[1, 2]} ; Fernandes, Caio P. ^[5] ; Mourao, Samanta C. ^[2] ; Toscano, Joao Henrique B. ^[3] ; Rocha, Leandro M. ^{[1, 2]} ; Chagas, Ana Carolina S. ^[4]

Affiliation

^[1] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, RJ - Brazil

^[2] Univ Fed Fluminense UFF, Niteroi, RJ - Brazil

^[3] Univ Estadual Paulista, UNESP, Jaboticabal, SP - Brazil

^[4] Embrapa Pecuaria Sudeste CPPSE, Sao Carlos, SP - Brazil

^[5] Univ Fed Amapa UNIFAP, Macapa, AP - Brazil

^[6] Univ Estado Rio de Janeiro UERJ, Sao Goncalo, RJ - Brazil

• Document type: Journal article
• Source: Experimental Parasitology; v. 215, AUG 2020.
• Web of Science Citations: 0

Abstract

Rhipicephalus microplus, the cattle tick, is a major cause of economic losses in bovine production. Due to the widespread acaricidal resistance to commercially available products, as well as their toxicity and environmental impact, alternative control methods are required. Nanoformulations produced from plant extracts as bioactive substances are very promising as innovative acaricidal agents. Thus, the aim of this study was to evaluate the in vitro repellent activity of Pilocarpus spicatus essential oil and its nanoemulsion against R. microplus, using larval repellent test (RT). The essential oil was extracted by hydrodistillation, using a Clevenger-type apparatus. The nanoemulsion was prepared with 5% essential oil, 5% tween 80, and 90% water, using the phase inversion method (50 mg/mL). Limonene was the major component (46.8%) of the essential oil, as determined by gas chromatography-mass spectrometry (GC/MS) and confirmed by flame ionization detection (GC/FID). According to the RT results, the essential oil had a repellent activity greater than 69%, from concentrations of 3.12 mg/mL (69.81 +/- 10%) to 50 mg/mL (98.10 +/- 0.6%), whereas the nanoemulsion at 50 mg/mL presented repellent activities of 97.14 +/- 1.37% and 97.89 +/- 0.52% 6 and 10 h after treatment, respectively. These values regarding to total repellency were very close to those calculated for mortality corrected by Abbott's formula. The phase inversion method preserved the chemical and physical characteristics of the essential oil since both reached an equal repellent effect at the same concentration. Therefore, P. spicatus essential oil and nanoemulsion had excellent repellent activities against R. microplus larvae, demonstrating its potential for future use as an alternative for tick control. (AU)

• FAPESP's process: 17/00373-2 - Characterization of local immune responses associated with the parasitic resistance phenotype in morada nova lambs
• Grantee: João Henrique Barbosa Toscano
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 17/13249-8 - Nanotechnology applied to elaboration of synthetic acaricides associated with plant isolates for the control of Rhipicephalus (b.) microplus
• Grantee: Amanda Figueiredo
• Support Opportunities: Scholarships in Brazil - Doctorate