Potencijalna primena etarskih ulja protiv gastrointestinalnih nematoda ovaca - perspektiva i barijere

Abstract

Ekonomski gubici koje gastrointestinalne nematode nanose modernom ovčarstvu postaju sve veći usled razvoja rezistencije na sintetske antihelmintike koji se koriste u svakodnevnoj kliničkoj praksi. Zbog toga, istraživači širom sveta, danas tragaju za alternativnim metodama u cilju kontrole ovih parazita. Kao moguća opcija su se zbog svojih osobina, nametnula etarska ulja i biljni proizvodi bogati različitim prirodno aktivnim jedinjenjima. Naime, prema dosadašnjim ispitivanjima, etarska ulja ispoljavaju visoku aktivnost protiv različitih razvojnih stadijuma nematoda, a uz pravilan način primene se generalno dobro tolerišu od strane sisara sa toksikološke strane gledišta. Do sada je dokazana visoka efikasnost velikog broja etarskih ulja protiv gastrointestinalnih nematoda ovaca (različite vrste eukaliptusa, limunske trave, mente, čajevca, timijana, cimeta, đumbira, lavande, crnog pelena i ruzmarina), njihovih aktivnih sastojaka (timol, karvakrol, karvon, anetol, mentol, cinamaldehid, cineol, linalol, vanilin, eugenol, limonen) kao i njihovih kombinacija (npr. cinamaldehid:karvakrol; anetol:karvon) u laboratorijskim uslovima. Međutim, glavno ograničenje za njihovu svakodnevnu primenu predstavlja još uvek nedovoljna efikasnost u terenskim uslovima, a koja potiče od anatomsko-fizioloških specifičnosti vezanih za preživare, kao i od farmakokinetičkih osobina pojedinih etarskih ulja. Ovaj problem bi se mogao prevazići odabirom odgovarajućih etarskih ulja uz adekvatno doziranje, način primene i formulaciju samih ulja, kombinovanom sinergističkom primenom više ulja ili njihovih sastojaka, kao i primenom nanotehnologije. Nevezano za ovaj problem, etarska ulja svakako imaju potencijal da uz kombinaciju sa drugim lekovima i merama, budu deo integrisanog pristupa, dizajniranog da se postigne održiva kontrola parazita u sistemima proizvodnje preživara. Potrebna su dodatna ispitivanja u ovoj oblasti, što se posebno odnosi na istraživanje efikasnosti u terenskim uslovima.

The economic losses caused by gastrointestinal nematodes to modern sheep farming are increasing due to the development of resistance to regular anthelmintics used in everyday clinical practice. Therefore, researchers around the world nowadays are looking for alternative methods to control these parasites. Essential oils, herbal products rich in various naturally active compounds, have become a viable option because of their properties. Namely, according to the previous research, essential oils show high activity against all nematode development stages and are generally well tolerated by mammals from the toxicological point of view. So far, high efficacy of a large number of essential oils against sheep gastrointestinal nematodes have been demonstrated (different species of eucalyptus, lemongrass, mint, tea tree, thyme, cinnamon, ginger, mugwort, rosemary etc), their active compounds (thymol, carvacrol, carvone, anethole, menthol, cinnamaldehyde, linalool, vanillin, eugenol, cineole, limonene) as well as their combinations (e.g. cinnamaldehyde:carvacrol; anethole:carvone). However, the main limitation for their everyday use is still insufficient efficacy in field conditions, which originates from the anatomical and physiological specificities associated with ruminants, as well as from the pharmacokinetic properties of certain essential oils. This problem could be overcomed by selecting the appropriate essential oils with adequate dosage, method of application and formulations of oils, by combined synergistic application of multiple oils or their ingredients, as well as the using of nanotechnology. Regardless of this problem, essential oils certainly have the potential to be, in combination with other drugs and measures, part of an integrated approach designed to achieve sustainable parasite control in ruminant production systems. Nevertheless, further examinations on this topic are needed, especially of testing efficacy in field conditions.