Estudo fitoquímico e análise leishimanicida in vitro do extrato bruto do fruto de Morinda citrifolia (Noni)

Abstract

The current forms of treatment of leishmaniasis induce strong side effects and several cases of resistance to the drugs used for treatment have been reported. In the search for new alternatives of treatment, the discovery of therapeutic properties of active substances present in plant extracts have attracted the interest of research into new treatment options for leishmaniasis using medicinal plants. Morinda citrifolia, commonly known as noni, stands out since it has several active substances that have antimicrobial, antiviral and antifungal and potential activity against protozoa such as the members of Leishmania genus. We carried out the phytochemical study and evaluated the antileishmanial activity and in vitro cytotoxicity of crude extract of M. citrifolia fruit. The crude extract showed a yield of 6.31%. The phytochemical screening showed the presence of anthraquinones, flavonoids, alkaloids, terpenoids, steroids, saponins, coumarins, phenolic compounds, tannins, anthocyanidins and chalcones. The high performance liquid chromatography with diode array detector and light scattering identified phenolics and aromatics compounds as its major constituents. The extract showed a dose-dependent activity, and IC50 of 204.1 µg/ml for promastigotes, 137.0 µmg/mL to axenic amastigotes, and 63.6 µg /mL against intracellular amastigotes of Leishmania amazonensis. Promastigotes forms treated for 24 hours with extract concentrations of 15 to 120 µg/mL and observed in transmission electron microscopy presented cytoplasmatic vacuolization, lipid inclusion and increased activity exocyted. The cytotoxicity assay showed that the activity of the extract is more specific for the protozoan and was not cytotoxic to the cell. The crude extract of M. citrifolia fruit is active against L. amazonensis in the in vitro model, and promising for further researches of new treatments for leishmaniasis.