Anthelmintic Properties of Essential Oils to Control Gastrointestinal Nematodes in Sheep-In Vitro and In Vivo Studies.

Filip Štrbac,Antonio Bosco,Giuseppe Cringoli,Dragica Stojanović,Laura Rinaldi,Slobodan Krnjajić,Dejan Orčić,Nataša Simin,Smaragda Sotiraki,Radomir Ratajac,Giorgio Saralli,Ivan Pušić,Maria Paola Maurelli

doi:10.3390/vetsci9020093

Abstract

Herbal products such as essential oils may play a promising role in the treatment of infections caused by gastrointestinal nematodes (GINs). The aim of this study was to evaluate the in vitro potential of 11 essential oils (EOs) and one binary combination of isolated EO compounds, as well as the in vivo anthelmintic efficacy of two EO formulations. Four GIN genera were identified in the coproculture examination: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. The in vitro egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO, whereas in the in vivo faecal egg count reduction test (FECRT), each EO sample was diluted in sunflower oil and orally administrated at a dose of 100 mg/kg to the different group of animals. In the EHT, the EOs of Origanum vulgare, Foeniculum vulgare, Satureja montana, Satureja hortensis and two types of Thymus vulgaris were the most effective. The dominant compounds of these EOs were carvacrol, thymol, anethol, p-cymene and γ-terpinene, indicating their importance for the anthelmintic activity. In the FECRT, both T. vulgaris EO type 1 and linalool:estragole combination show an anthelmintic potential with a mean effect on FECR of approximately 25%. The results suggest the possible role of tested EOs as anthelmintic agents in sheep farms, although further in vivo tests are needed.

Highlights

Gastrointestinal nematodes (GINs) are still the most prevalent parasites that cause disease in grazing ruminants worldwide, in sheep and goats [1]
The gas chromatography-mass spectrometry (GC-MS) analyses performed in the present study showed that the presence of compounds such as carvacrol, anethole, thymol, p-cymen and y-terpinene was related to the heightened efficacy of tested samples, since the most effective essential oils (EOs) were composed of these ingredients
The present study demonstrated the high in vitro, and, to some extent, in vivo, anthelmintic potential of the tested natural-based formulations against sheep gastrointestinal nematodes (GINs)

Summary

Introduction

Gastrointestinal nematodes (GINs) are still the most prevalent parasites that cause disease in grazing ruminants worldwide, in sheep and goats [1]. Infections with these parasites manifest in the form of a subclinically impaired weight gain as well as an impaired yield of meat and milk, but can seriously endanger animal health and welfare by causing conditions such as diarrhoea, digestive problems, anorexia, anaemia, protein loss as well as reduced immunity, which can lead to death [1,4,7]. For these reasons, GINs are responsible for huge economic and productive losses around the world. These losses are difficult to estimate, it is regarded that they amount to 17.94% of the total economic cost in animals [8], or hundreds of millions of euros per year across Europe [9]

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