Essential Oils as Novel Anthelmintic Drug Candidates

Abstract

Helminths, with an estimated 1.5 billion annual global infections, are one of the major health challenges worldwide. The current strategy of the World Health Organization to prevent helminth infection includes increasing hygienic awareness, providing better sanitation and preventative anthelmintic drug therapy in vulnerable populations. Nowadays, anthelmintic drugs are used heavily in livestock, both in case of infection and as a preventative measure. However, this has led to the development of resistance against several of the most common drugs, such as levamisole, ivermectin and thiabendazole. As many as 70% of the livestock in developed countries now has helminths that are drug resistant, and multiple resistance is common. Because of this, novel anthelmintics are urgently needed to help combat large-scale production losses. Prior to this review, no comprehensive review of the anthelmintic effects of essential oils and their components existed. Multiple review articles have been published on the uses of a single plant and its extracts that only briefly touch upon their anthelmintic activity. This review aims to provide a detailed overview of essential oils and their components as anthelmintic treatment against a wider variety of helminths.

Strongyloides infection screening in transplant candidates: What is the best strategy?

“…The application of empirical therapy with ivermectin, without diagnosis, should not be encouraged because the sensitivity of the techniques is limited in guaranteeing cure and also because of the possibility of developing resistance of these helminths to ivermectin, in the medium or long term, in a scenario of lack of good therapeutic options for strongyloidiasis. [17][18][19] In the present study, we used three parasitological techniques to evaluate only one fecal sample per patient: spontaneous sedimentation, the Baermann Modified technique, and culture on an agar plate. Evaluating the results of each one of them separately and the association between them, we obtained 10.0% positivity.…”

“…Thus, the diagnosis of S. stercoralis infection requires the search for more sensitive methods that can exclude the possibility of infection before patients who are candidates for transplants undergo more intense immunosuppression, including the chronic use of corticosteroids. The application of empirical therapy with ivermectin, without diagnosis, should not be encouraged because the sensitivity of the techniques is limited in guaranteeing cure and also because of the possibility of developing resistance of these helminths to ivermectin, in the medium or long term, in a scenario of lack of good therapeutic options for strongyloidiasis 17–19 …”

Medical management of cystic echinococcosis

“…Given the derivation of artesunate, the fastest acting antimalarial yet developed for human use, from the plant Artemisia annua , there is logic in exploring the activity of essential oils extracted from plants against helminths [12]. Essential oils are mixtures of low-molecular-weight hydrophobic metabolites and there are several compounds in each oil, including aromatic alcohols, acids, esters, phenolics, ketones, aldehydes and hydrocarbons.…”

Plant Essential Oils as a Tool in the Control of Bovine Mastitis: An Update

“…Essential oils are very complex natural mixtures that can contain 20-100 different plant secondary metabolites belonging to a variety of different chemical classes, like aromatic alcohols, acids, esters, ketones, phenolics, aldehydes, and hydrocarbons [61,62]. Essential oils are characterized by two or three major components, mainly terpenes, terpenoids, and phenylpropanoids, at rather higher (20-70%) concentrations than other components present in trace amounts [59].…”