BackgroundLeishmaniasis includes a wide complex of diseases that affect humans and other mammals, and can range from a mild cutaneous form to a severe visceral type. The safety of the standard treatment using pentavalent antimony is a concern due to its toxic effects. The search for alternative, effective and less toxic treatments has led to the testing of natural products. The present study aimed to evaluate the cytotoxic, leishmanicidal and healing potential of Arrabidaea chica.MethodsThe crude ethanolic extract, as well as the chloroform, methanol and ethyl acetate fractions of A. chica were prepared and phytochemical analysis was performed. Cytotoxic evaluation was carried out through MTT colorimetric assay, and the 50 % cellular cytotoxicity was determined. After that, the effect of the extract and fractions against Leishmania amazonensis promastigotes, at intervals of 24, 48 and 72 h, was analyzed, and 50 % inhibitory concentration was determined. The healing effect of the plant was also tested in surgical lesions in Swiss mice skin.ResultsPhytochemical screening showed that the crude extracts contained flavonoids, tannins, anthocyanidins and chalcones. The leishmanicidal potential of A. chica produced satisfactory results in concentrations of between 60 and 155.9 μg/mL. Cytotoxic assay revealed a 50 % reduction in viable cells at a concentration of 189.9 μg/mL. The healing results indicated that the treated group exhibited more pronounced signs of lesion resolution in the early period, but this pattern did not persist throughout the treatment.ConclusionsThe results of the present study demonstrate that A. chica has cytotoxic and leishmanicidal potential but its healing effect must be better studied.

Leishmania amazonensis infection was studied in mice to evaluate the evolution of leishmaniasis. The association of different methods, such as lesion kinetics, limiting dilution analysis, and immunohistochemistry, established different levels of susceptibility and resistance. Mice were arranged in 3 groups: susceptible (C57BL/10 and CBA), relatively resistant (DBA/2), and resistant (C3H.He). The histopathological analysis of primary lesions and draining lymph nodes showed a predominance of eosinophils and mast cells in the initial phase of infection in all mice. However, the most susceptible mice presented a greater number of amastigotes and higher tissue damage. The immunoglobulin analysis showed that susceptible mice produced high levels of antibodies, whereas resistant and relatively resistant mice exhibited low production of antibodies. Resistant mice showed parasite persistency in the skin and lymph nodes, suggesting that the infection in these mice can be sustained through the infection of cells such as dendritic cells, fibroblasts, and other cells present in these organs.

The search for new immunopharmacological chemical agents to treat various diseases caused by bacteria, fungi, and protozoa, such as leishmaniasis, for example, has led to the exploration of potential products from plant species and their main active ingredients. Antimonial drugs are the current treatment for leishmaniasis. These drugs cause major side effects and frequent discontinuation of treatment. In this study, we evaluated the in vitro leishmanicidal activity of essential oil of Vanillosmopsis arborea (VAEO) and its major compound α-bisabolol against Leishmania amazonensis. The essential oil and α-bisabolol showed activity against promastigotes (IC50 7.35 and 4.95 μg/mL resp.) and intracellular amastigotes (IC50 12.58 and 10.70 μg/mL, resp.). Neither product showed any cytotoxicity on treated macrophages. The ultrastructural analysis of promastigotes incubated with VAEO or α-bisabolol at 30 μg/mL, showed morphological changes with the accumulation of vesicles electrodense lipid inclusions. The results give evidence that both VAEO and α-bisabolol have potential as new therapeutic agents against leishmaniasis.

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Morinda citrifolia, also known as noni, is commonly used in popular medicine in Brazil. Many parts of the noni tree are utilized in such practices, including the roots, leaves and seeds. Through a search of online databases, the present article reviews 92 research studies on the biological actions of M. citrifolia. The paper will discuss the therapeutic effects of noni and its compounds in a variety of forms of presentation, focusing on studies that support its traditional use. A large and diverse number of properties were identified, which were divided into immunostimulatory, antitumor, antidiabetic, anti-obesity, antibacterial and anti-septic, antifungal, antiviral, leishmanicidal, antiinflammatory, antinociceptive and analgesic, antioxidant, neuroprotective, wound healing, antiallergic, antiangiogenic, antiemetic and anti-nausea, anti-gastric ulcer and oesophagitis, anthelmintic, antimutagenic, antipsychotic, anxiolytic, photoprotective, anti-wrinkle and periodontal tissue regeneration activities. While it was concluded that although M. citrifolia is widely and successfully used for the treatment or prevention of various diseases, it should be consumed carefully, and only after exhaustive studies into its chemical constituents and mechanisms of action, both in in vitro and in vivo models, as well as clinical trials. Copyright © 2017 John Wiley & Sons, Ltd.