Volume 76, 15 December 2015, Pages 647–652
Anthelmintic activity in vitro of Citrus sinensis and Melaleuca quinquenervia essential oil from Cuba on Haemonchus contortus
Highlights
- •
- Citrus sinensis was five times more effective on Haemonchus contortus eggs than Melaleuca quinquenervia.
- •
- Limonene appears to inhibit embryogenesis of helminth eggs.
- •
- Melaleuca quinquenervia has a narrower and faster range of response on larvae.
- •
- This is the first report of anthelmintic activity of Melaleuca quinquenervia.
Abstract
Gastrointestinal
nematodes are an important problem in the small ruminant production and
their control nearly exclusively depends on commercial anthelmintics.
However, parasite resistance to those chemical formulations is an
increasing global problem, so new plant-derived compounds are being
studied for their potential use against gastrointestinal nematodes. Citrus sinensis and Melaleuca quinquenervia essential oils were evaluated against Haemonchus contortus
Embrapa2010 resistant isolate, through the egg hatch test (EHT) and
larval development test (LDT) at concentrations ranging from 0.02 mg/mL
to 50 mg/mL and from 0.04 mg/mL to 3.12 mg/mL, respectively. All
concentrations, positive controls (thiabendazole in EHT or ivermectin in
LDT), and negative controls (2% Tween 80 in EHT or 0.5% DMSO in LDT)
were performed in six replicates and in three independent experiments,
for a total of 18 repetitions involving approximately 1800 parasites per
treatment. Significant differences (P ≤ 0.01) of inhibition
percentages were identified by one-way analysis of variance followed by
the Tukey test. Inhibitory concentration values (IC50 and IC90) were analyzed by the Probit procedure of SAS. The essential oils evaluated showed that C. sinensis presented limonene as major component (96.0%), while M. quinquenervia contained longifolene (32.95%) and 1,8-cineole (25.43%) as major components. In the EHT, the IC50 and IC90 of the essential oils were respectively 0.27 and 0.99 mg/mL for C. sinensis and, 1.52 and 5.63 mg/mL for M. quinquenervia. In the LDT, the IC50 and IC90 were 0.97 and 2.32 mg/mL for C. sinensis and, 0.44 and 0.94 mg/mL for M. quinquenervia. C. sinensis was five times more effective on eggs than M. quinquenervia. However, it was twice more effective on larvae than C. sinensis,
indicating that bioactive essential oils have different modes of
action. The results suggest that these compounds are good candidates for
nematode control. However, alternative anthelmintics have to be safe to
the host, promote parasite control in vivo and not generate residues. So, all these key points need to be elucidated before using any plant extract and/or components.
Graphical abstract
Keywords
- Herbal medicine;
- Essential oils;
- Haemonchus contortus;
- Melaleuca quinquenervia;
- Citrus sinensis;
- Cuba
Copyright © 2015 Published by Elsevier B.V.