Targeting Leishmania Promastigotes and Amastigotes Forms through Amino Acids and Peptides: A Promising Therapeutic Strategy.

Millions of people worldwide are affected by leishmaniasis, caused by the Leishmania parasite. Effective treatment is challenging due to the biological complexity of the parasite, drug toxicity, and increasing resistance to conventional drugs. To combat this disease, the development of specific strategies to target and selectively eliminate the parasite is crucial. This Review highlights the importance of amino acids in the developmental stages of Leishmania as a factor determining whether the infection progresses or is suppressed. It also explores the use of peptides as alternatives in parasite control and the development of novel targeted treatments. While these strategies show promise for more effective and targeted treatment, further studies to address the remaining challenges are imperative.

Lychnophora pinaster's effects on inflammation and pain in acute gout.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethanolic extract of aerial parts from Lychnophora pinaster Mart. are used in traditional Brazilian medicine for treating pain, rheumatism and inflammation. AIM OF THE STUDY: Drugs for the treatment of gout present severe adverse effects, justifying the need to search for new therapeutic options. The aim of the present study was to evaluate the effects of the ethanolic extract of L. pinaster and its main constituents in arthritis induced in mice by the injection of monosodium urate (MSU) crystals. MATERIALS AND METHODS: Antinociceptive effect was investigated using an electronic pressure-meter nociception paw test in C57BL/6 mice. Anti-gouty arthritis was investigated in mice induced with gout by the injection of MSU crystals into their femur-tibial tissue. Ethanolic extract of the aerial parts of Lychnophora pinaster and its main chemical constituents were evaluated as treatment. RESULTS: The ethanolic extract and their main chemical constituents inhibited neutrophil migration, reduced IL-1ß and TNF-α concentrations in the inflamed tissue and showed antinociceptive activity. CONCLUSIONS: Gouty arthritis effects of the ethanolic extract can be attached to a synergistic effect of terpenes, flavonoids and phenolic acids present in the extract. Results obtained support the use of this extract and its main chemical constituents in the treatment of gout, inflammation, and pain.

Antitumor effect of Cymbopogon densiflorus (Linneu) essential oil in bladder cancer cells.

The aim of this study was to analyse the antitumor effect of the Cymbopogon densiflorus essential oil in silico and in vitro on bladder cancer cells RT4 and T24, with different TP53 status. The oil was extracted by hydrodistillation and the gas chromatography coupled to the mass spectrometry was used for characterisation. In silico analysis was carried out by Pass online software. Cytotoxicity, cell proliferation, cell cycle progression, apoptosis and wound healing assays were performed. Five major compounds were identified. In silico analysis showed that major compounds present high potential for antitumor activities. The treatment with C. densiflorus essential oil reduced cell viability of bladder cancer cells. Only in wild-type cells, the increase of apoptosis rates and the decrease of cell migration were observed. In conclusion, the C. densiflorus essential oil presents antitumor effects on TP53 wild-type and mutated bladder cancer cells, however, the mechanism of action is TP53 status-dependent.[Figure: see text].

Anti-inflammatory activity of Protium spruceanum (Benth.) Engler is associated to immunomodulation and enzymes inhibition.

ETHNOPHARMACOLOGICAL RELEVANCE: Protium spruceanum (Burseraceae) is used in Brazilian traditional medicine as anti-inflammatory, but the factors involved in this activity were not yet characterized. AIMS OF THE STUDY: analyze the aspects involved in the anti-inflammatory activity of polar fractions obtained from extracts of leaves and branches. MATERIALS AND METHODS: Hydromethanolic fraction was obtained by liquid-liquid partition from crude ethanolic extract and its compounds were identified by LC-DAD-MS. Activity tests were performed using LPS + IFN-γ stimulated J774A.1 macrophages. Cytokines were evaluated by CBA kit, NO by Griess method, ROS by DCFH-DA, N-acetylglucosaminidase (NAG) activity by spectrophotometric method, matrix-metalloproteinase (MMP-9) activity by zymography, inducible nitric oxide synthase (iNOS) expression by immunofluorescence and cyclooxygenase (COX-2) expression by Western blot. RESULTS: Fractions induced an increase of IL-6 and IL-10 which leads to the control of pro-inflammatory cytokines levels. The treatment with the fractions also reduced NO production at all concentrations tested in all evaluated periods. ROS production by the macrophages was inhibited by the treatment and the leaves fraction showed the best results with a lower concentration than that observed for the branches. The enzymes assays showed that leaves fraction inhibited NAG and MMP-9 activities, as well as, iNOS and COX-2 expression. These activities can be associated with the presence of procyanidin, catechin, rutin, quercitrin, isoquercitrin and kaempferol-3-O-rhamnoside, major compounds that were identified in the fraction. CONCLUSIONS: Anti-inflammatory activity of P. spruceanum is associated to an immunomodulatory effect that leads to inhibition of ROS, NO, NAG, MMP-9, COX-2 and iNOS.