Atividade antiparasitária de óleos essenciais de Pelargonium graveolens, Citrus aurantium e Cuminum cyminum em Fasciola hepatica

Abstract

Fasciola hepatica (Linnaeus, 1758) is a parasite that affects the liver and bile ducts of several species, commonly diagnosed in ruminants. Fasciolosis is one of the most important parasitic diseases in animal health, causing great economic losses in Brazil and worldwide. The reports of trematode resistance to the drugs used emphasize the need to search for alternative products for the treatment of this disease. Therefore, the present study aimed to evaluate the in vitro ovicidal and adulticidal activity of essential oils (EOs) from Citrus aurantium, Pelargonium graveoles and Cuminum cyminum in Fasciola hepatica. To carry out the experiment, adult trematodes were collected directly from the liver of positive bovines in the post-mortem examination. In the ovicidal test, eggs were obtained by immersing adults in saline solution and subsequently incubated together with the tested oils and the control groups: albendazole, nitroxinil, distilled water control and Tween® 80. The concentrations of essential oils for testing in eggs ranged from 4.5 to 0.03125 mg/ml. For the adulticidal test, the adult forms of F. hepatica were incubated with RPMI medium and essential oils under different concentrations, ranging from 0.0675 to 0.031125 mg/mL and then observed for 24h post-treatment, as well as the control groups: albendazole, nitroxinil, RPMI medium and Tween® 80. Subsequently, the adult specimens were fixed by immersion in a 10% buffered formalin solution for 24 hours to be processed for histology. The results showed the effectiveness of 100% of the essential oils on trematode eggs, at all concentrations tested in the hatching test. For adults, the EOs from P. graveolens and C. cyminum showed total efficacy (100%) in a shorter time compared to C. aurantium oil. In the histological analysis, different alterations were observed in the integument layers of adults treated with OEs, such as the modification and destruction of the spines. Based on the results obtained in this study, the essential oils of P. graveolens, C. aurantium and C. cyminum have a fasciocidal potential.