Fasciolosis has been diagnosed in cattle, goats, sheep and horses in southern and southeastern Brazil. Effective alternative treatments are the targets of study. One promising alternative is the use of plant extracts. The aim of this study was to perform phytochemical analysis of extracts of Eugenia uniflora L., Harpagophytum procumbens, Psidium guajava L. and Stryphnodendron adstringens, and to evaluate the in vitro efficacy of these extracts on ovicidal activity in Fasciola hepatica. Plant extracts were analyzed for phytochemical properties. F. hepatica eggs were collected directly from the gallbladders of animals diagnosed as positive for fasciolosis on post mortem examination. One hundred eggs were incubated with 3 ml of each extract at concentrations of 0.10%, 0.25% and 0.50%, albendazole 0.50% (positive control) or tap water (negative control). To determine anti larval efficacy of each plant extract, hatched eggs were counted and the averages were used. Phytochemical analysis revealed the presence of phenolic compounds, tannins and terpenes in most extracts. E. uniflora L. extract was 100% effective at 0.10%, H. procumbens was effective at 0.25% and P. guajava L. and S. adstringens extracts were 100% effective at all concentrations tested. Taken together, the data suggested that ovicidal activity in F. hepatica is due to the presence of these bioactive compounds.

A fasciolose é causada pelo trematódeo Fasciola hepatica, que se loja nos canais biliares de animais de sangue e ocasionalmente em humanos. Animais parasitados por F. hepatica apresentam retardo no desenvolvimento dentre outras enfermidades, gerando perdas econômicas consideráveis. O controle da fasciolose pode ser feito por meio do molusco hospedeiro ou por uso de fasciolicidas. No entanto, a terapêutica vigente ainda apresenta limitações de eficácia e alto custo de aquisição pelo produtor rural. Foram realizados testes in vitro com ± 100 ovos por placa e em triplicata com o extrato vegetal a 0,5% e encubados por 14 dias em BOD a 25ºC, e então, analisados sob a luz incandescente a cada hora por 3 horas. Dos sete extratos vegetais, as raízes de Harpagophytum procumbens, cascas de Uncaria tomentosa e folhas de Guapira graciliflora, Psidium guajava e de Momordica charantia apresentaram 100% de eficácia, já as folhas de G. noxia 62,2% e de Stryphnodendron adstringens teve 95,4% contra a eclosão dos miracídios de fascíolas.