ANA PAULA LOPES LIMA
Abstract:
Leishmaniasis is a disease transmitted by protozoan-infected sandflies of the genus Leishmania, whose cutaneous form is the most common with 50 to 75% of new cases reported. It is a non-contagious disease of chronic evolution, considered stigmatizing and neglected, affecting about 500,000 people in the world. Most drugs used in pharmacological treatment are potentially toxic and require patient hospitalization for administration, which raises costs and discourages the needy population from adhering to treatment. In this scenario, herbal medicines are inserted as an alternative because of their proven efficacy and because they cause fewer undesirable effects. The objective of the present study was to evaluate the leishmanicidal potential and the in vitro cell viability of Siparuna guianensis (SG) and α- Bisabolol (AB) isolated essential oils of Siparuna guianensis (SG) on Vero cells and Leishmania amazonensis promastigotes using the method colorimetric resazurin salt (Alamar Blue®) as an indicator of cellular metabolism. Cell invasion was also performed with the parasites previously treated with the IC50 obtained for AB and SG obtained in the cell viability test, in order to test the effect of the compounds on the infection capacity of the parasites. The results were analyzed using the program GraphPad Prism version 6.01. For analysis of the IC50, the non-linear regression tests were used. The tested compounds demonstrated viability on Vero basal cells and leishmanicidal activity: SG IC50 131.5 μg/mL and 2.59 μg/mL respectively. For α-Bisabolol the concentrations obtained were 103.8 μg/mL and 6.394 μg/mL and for SG were 94.61 μg/mL and 7.84 μg/mL, respectively. This is the first report of a cell invasion assay made with S. guianensis and α-Bisabolol alone, in which inhibition of 98.4% infective capacity of L. amazonensis promastigotes treated with SG at 131,5 μg/mL and inhibition of 95.4% of the infective capacity of the same AB-treated parasite at a concentration of 95.4 μg/mL, which are close to the value obtained by the conventional drug in a similar in vitro assay. which suggests a refinement of the technique and in vivo assays to determine the action of S. guianensis and α-Bisabolol from the concentrations obtained in this research.
