Ambiente como fonte de formas parasitárias e potencial de extratos vegetais da família Lamiaceae contra parasitos do gênero Toxocara

Abstract

Parasites are responsible for some of the most important diseases transmitted from companion animals to humans. Among the parasites, Toxocara spp. Stands out due to its important pathogenesis and high prevalence in man and animals. The objective of the study was to determine the presence of infective forms of parasites in the environment, to verify the chemical composition and in vitro antihemotic activity of extracts of plants of the Lamiaceae family against eggs and larvae of Toxocara spp. To evaluate the environmental contamination, soil samples were collected from a community of Pelotas - RS. A total of 100 samples were processed by the centrifugeflotation technique and analyzed under an optical microscope (40X) for the identification of parasite forms. The tests were carried out using the essential oils of Origanum majorona, Origanum vulgare and Rosmarinus officinalis at concentrations of 6 to 0.18 mg / mL, while larvicides in the concentrations of 6 to 0.09 mg / mL. The hydroalcoholic extracts of Origanum vulgare, Origanum majorona and Rosmarinus officinalis were tested in the concentrations of (50 to 3,12mg / ml) against the eggs. The larvae were tested at concentrations of 100 to 6.25 mg / mL for O. majorana and R. officinalis and for O. vulgare at 50 to 3.12 mg / mL. The tests were performed using the oils and extracts at different concentrations and eggs (+ -100) or larvae (100 to 150) of Toxocara spp. The ovicidal tests were incubated in oven B.O.D. At 28 ° C with 80% relative humidity for thirty days and the larvicidal tests were incubated in a 5% CO2 oven at 37 ° C for 48 hours. In the larvicidal tests Blue Dye of Tripan was added and the eggs and larvae were observed by microscopy. In the analyzed environment, all points were positive for two or more parasitic forms, with oocysts (30.32%), Strongylida (25.4%), ascarids (21.31%) and Trichuris spp. (8.19%), Toxocara spp. (3.27%), Ameba (3.27%), Cytoisospora (3.27%), Dioctophyma renale (2.45%), Giardia (1.63%) and Entamoeba (0.81%). In the chromatographic analysis of the essential oils the major compounds for O. vulgare were 4-Terpinene, gamma-Terpinene, cis-Sabinenehydrate, for O. majorana were 4-Terpineol, gamma- Terpinene, alpha-Terpinene and R. Officinalis stood out Α-Pinene, cineol and camphor. O. vulgare essential oils (6 to 0.18 mg / mL) showed efficacy higher than 90%, while that of O. majorana at concentrations of 6 to 0.37 mg / mL showed efficacy higher than 98% and The R. Officinalis in all tested concentrations showed efficacy less than 71.47%. In the larvicidal activity, the essential oil of O. vulgare (6 to 0.37mg / mL) presented 100% efficacy and O. majorana (6 to 1,5mg / mL) presented an activity superior to 90%, while the R . Officinalis only showed efficacy greater than 90% in the concentrations of 6 to 3mg / mL. Hydroalcoholic extracts O. vulgare and O. majorone (50mg / mL) showed inhibition of embryo growth of more than 90%, while R. officinalis (50mg / mL) presented 86.9% inhibition. In relation to the larvicidal activity of the extracts of O. vulgare, they had 88.64% of activity in the concentration of 100mg / mL, O. majorana of 86.95% in the concentration of 50mg / mL and R. officinalis presented 97% to 99% in the Concentrations of 100 to 12.5 mg / mL. According to the study it can be concluded that the analyzed environment is contaminated by infective forms of parasites, constituting a serious public health problem. The activity results showed that the essential oil and hydroalcoholic extract of O. vulgare, O. majorona and R. officinalis, rich in phenolic compounds, have ovicidal and larvicidal activity in the genus Toxocara. However, further studies are needed to clarify the mechanism of action and toxicity of these plants.