Composição química de extratos vegetais e sua eficácia no controle in vitro de parasitos adultos de Fasciola hepatica

Abstract

Fasciolosis is a disease caused by the parasite Fasciola hepatica, a platelmint of the family Fasciolidae that affects the bile ducts and liver of several species, the most common being ruminants. The control of fasciolosis is difficult, since the great majority of the medicines indicated for the treatment of the disease reach only the parasite in the adult form. The search for alternative treatments with the use of natural products that can have an efficient action in both forms, eggs and adults, has been the target of studies in regions where the disease is endemic. Thereby the use of medicinal plants has been a great alternative to the treatment of fasciolosis. The objective of this work was to find plants with fasciolicidal activity that could become new alternatives in the treatment of adults of this parasite. To evaluate the activity of the extracts solutions were prepared at concentrations of 0,1%, 0,25% and 0,5% of each selected plant and these were applied in samples of 5 parasites in triplicate petri dish and observed the mortality of the same time in the period of 3, 12 and 15 hours of evaluation. For phytochemistry, the tests described by Matos (2009) and Wagner (1984) were used. The histological analysis was performed with the production of the paraffin blocks with the cuts of the reserved samples after the test of fasciolicidal activity. The blocks were cut at 3µm, applied to the slides, and stained with hematoxylin and eosin. Statistical analysis was performed using a completely randomized design (DIC), in a factorial scheme, with the extracts, time and concentration factors being 5% probability by the Newman-Keuls test. After performing the evaluations it was concluded that the best extracts activity time was 12 hours, the extracts with better activity were shells Stryphnodendron adstringens, the Psidium guajava leaves, Guapira graciliflora leaves, the Guapira noxia leaves, the Momordica charantia leaves and roots of Harpagophytum procumbens at 0,5% concentration. It was also in this concentration that histological alterations were found such as the absence of spines and cellular deposition in the parasite’s tegument. It is probable that the fasciolicidal activity of these extracts may be from the activity of steroidal terpenes, tannins or phenolic compounds.