AVALIAÇÃO DA ATIVIDADE ANTI-LEISHMANIA DE EXTRATOS DE CATASETUM FIMBRIATUM (Morren) Lindl. (Orchidaceae)

Abstract

Leishmaniasis is a growing public health problem in Brazil, and is considered an endemic disease of priority concern, mainly present in countries with tropical and subtropical climates. There are two types of leishmaniasis that affect humans: cutaneous leishmaniasis, which manifests in mucous membranes and skin, and visceral leishmaniasis, which mainly affects organs such as the liver, spleen and bone marrow. In Brazil, the main causative agents of cutaneous leishmaniasis in humans are L. braziliensis and L. amazonensis. Available treatments are scarce, long, parenteral administration and have several toxic effects, which makes patient adherence difficult and allows the emergence of resistant strains. Therefore, research into new substances with antileishmanial activity is very necessary, and natural products offer a large source of secondary metabolites with diverse biological activities. The objective of this project was to evaluate the anti-leishmanial activity of the orchid species Catasetum fimbriatum, a native South American orchid that belongs to the Orchidaceae family. The evaluation of the anti-leishmanial activity of this orchid was performed through extracts from different parts of the plant, such as leaves, new and old pseudobulbs, nutritive roots and supporting roots, through in vitro assays using promastigote forms of Leishmania amazonensis, grown in Schneider culture medium. Its cytotoxicity to mammalian cells was evaluated in the NIH/3T3 fibroblast cell line. Most of the extracts tested reduced the viability of the promastigote forms at the concentrations tested, being little or not at all toxic to NIH/3T3 cells. Among the extracts tested, the nutritive root extract stood out, as it demonstrated greater potency and selectivity. These results open the possibility of future studies to track the molecules responsible for the observed antileishmanial activity, contributing to a greater knowledge of the potential biological activities of this orchid, as well as the possibility of obtaining new alternatives for the treatment of leishmaniasis.