Volume 7, Issue 3, April 2016, Pages 427–432
Original article
- a Embrapa Pecuária Sudeste (CPPSE), Rod. Washington Luiz, Km 234, CP 339, CEP 13560-970 São Carlos, SP, Brazil
- b Embrapa Agroindústria de Alimentos, Av. das Américas, 29501, CEP 23020-470 Guaratiba, RJ, Brazil
- c Embrapa Amazônia Ocidental, Rod. AM-010, Km 29, CP 319, CEP 69010-970 Manaus, AM, Brazil
- Received 23 October 2015, Revised 4 January 2016, Accepted 4 January 2016, Available online 6 January 2016
Abstract
Herbal
extracts have been investigated as an alternative for parasite control,
aiming to slow the development of resistance and to obtain low-cost
biodegradable parasiticides. The goal of this study was to evaluate the
efficacy, in vitro, of 11 essential oils from Brazil on reproductive efficiency and lethality of the cattle tick Rhipicephalus (Boophilus) microplus. The effects of oils extracted from Curcuma longa, Zingiber officinale, Lippia alba, Lippia gracilis, Lippia origanoides, Lippia sidoides, Mentha arvensis, Mentha piperita, Croton cajucara (white and red), and Croton sacaquinha
on ticks were investigated by the Immersion Test with Engorged Females
(ITEF) and the modified Larval Packet Test (LPT). Distilled water and 2%
Tween 80 were used as control treatments. Chemical analysis of the oils
was done with gas chromatography coupled with mass spectrometry.
Analysis of the in vitro tests using Probit (SAS program)
allowed the calculation of lethal concentrations (LCs). Lower
reproductive efficiency indexes and higher efficacy percentages in the
ITEF were obtained with the oils extracted from C. longa (24 and 71%, respectively) and M. arvensis oils (27 and 73%, respectively). Lower LC50 was reached with C. longa (10.24 mg/mL), L. alba (10.78 mg/mL), M. arvensis (22.31 mg/mL), L. sidoides (27.67 mg/mL), and C. sacaquinha
(29.88 mg/mL) oils. In the LPT, species from Zingiberaceae and
Verbenaceae families caused 100% lethality at 25 mg/mL, except for L. sidoides. The most effective oils were from C. longa, L. gracilis, L. origanoides, L. alba, and Z. officinale. The LC50 and LC90
were, respectively: 0.54 and 1.80 mg/mL, 3.21 and 7.03 mg/mL, 3.10 and
8.44 mg/mL, 5.85 and 11.14 mg/mL, and 7.75 and 13.62 mg/mL. The efficacy
was directly related to the major components in each essential oil, and
the oils derived from Croton genus presented the worst performance, suggesting the absence of synergistic effect among its compounds. Since C. longa,
containing 62% turmerone, was the one most efficient against ticks,
this compound may be potentially used for tick control, but further
research is needed, especially to assess toxicity of these compounds to
the host. These new studies, together with the results presented here,
may provide a strong rationale for designing pre-clinical and clinical
studies with these agents.
Keywords
- Phytotherapy;
- Medicinal plants;
- Essential oils;
- Turmerone;
- Rhipicephalus (Boophilus) microplus;
- Tick control
Copyright © 2016 Elsevier GmbH. All rights reserved.
