238 research outputs found

    Copaiba Oil: An Alternative to Development of New Drugs against Leishmaniasis

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    Leishmaniasis is a neglected disease that is increasing globally at an alarming rate. Glucantime has been the therapy of choice for more than 50 years. A recent study reported the antileishmanial activity of copaiba oil against Leishmania amazonensis. These results led us to investigate morphological and ultrastructural changes in L. amazonensis treated with copaiba oil, using electron microscopy and flow cytometry to assess specific organelles as targets for copaiba oil. In the promastigote and axenic amastigote forms, this copaiba oil caused notable morphological and ultrastructural changes, including extensive mitochondrial damage and denaturation of the plasma membrane. Copaiba oil treatment also induced a decrease in Rh123 fluorescence, suggesting interference with the mitochondrial membrane potential and loss of cell viability with an increase in plasma membrane permeability, as observed by flow cytometry after staining with propidium iodide. In conclusion, copaiba oil could be exploited for the development of new antileishmanial drugs

    Effect of 1-(phenyl)-N’-(4-methoxybenzylidene)-9H-pyrido[3,4-b]indole-3-carbohydrazide on in vitropoliovirus replication

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    The effect of the alkaloid, 1-(phenyl)-N’-(4-methoxybenzylidene)-9H-pyrido[3,4-b]indole-3-carbohydrazide (PMC)on poliovirus (PV) replication cycle in Vero cells was assayed by inhibition of the cytopathic effect (CPE) and inhibition of plaque forming units (PFU). Both methodologies suggested that the mode of action was avoidance of infection progression in the host cell. The compound was able to prevent CPE and PFU formation when the cells were pretreated with PMC for 24 h prior to PV infection. In addition, when the alkaloid was continuously maintained in the infected cultures, the spread of PV to adjacent cells was impaired. The pre-exposure and post-exposure prophylactic applications are possible situations in which an anti-PV drug might be used. Future studies are needed to elucidate the PMC mode of action and verify the feasibility of PMC use of in vivo. No antipicornavirus agent is currently approved for clinical use

    The structure design of biotransformed unsymmetrical nitro-contained 1,5-diaryl-3-oxo-1,4-pentadienyls for the anti-parasitic activities

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    AbstractTwo 1,5-diaryl-3-oxo-1,4-pentadienyls (1 and 2) having nitro group attached exhibited potent anti-parasitic activity when evaluated against Trypanosoma cruzi and Leishmania amazonensis. In the present work, metabolomic analysis revealed that enzymatic action of T. cruzi reduces the CC bonds and let the nitro groups intact. Further, these two reduced compounds along with six other congeners were produced by chemical or microbiological methods and evaluated against T. cruzi. All reduced compounds showed less potency than compounds 1 and 2, proving the importance of unsaturated moieties for activity. This investigation provides insight into the mechanism of action of nitro unsaturated diarylpentadienones reinforcing previous studies showing their interference in the redox metabolism of T. cruzi. In the result increase in reactive oxygen and nitrogen species occurs, altering mitochondrial function and depleting the whole antioxidant system, which ultimately causes parasite death. Docking studies using trypanothione oxy-reductase as target helped understanding the activities. The present investigation confirms that enzymes play a pivotal role in drug activation

    Acyclic Sesquiterpenes from the Fruit Pericarp of Sapindus saponaria

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    Previous studies reported antiprotozoal activities of Sapindus saponaria L. The aim of this work was the evaluation of antileishmanial activity and mechanism of action of extract and fractions of S. saponaria L. Hydroethanolic extract (EHA) obtained from fruit pericarps was fractionated using solid-phase extraction in a reversed phase, resulting in fractions enriched with saponins (SAP fraction) and acyclic sesquiterpene oligoglycosides (OGSA fraction). The activities of EHA, SAP, and OGSA were evaluated by antiproliferative assays with promastigote and intracellular amastigote forms. Cytotoxicity on macrophages and hemolytic activity were also analyzed. Morphological and ultrastructural changes in Leishmania amazonensis promastigotes were evaluated by electron microscopy. Flow cytometry was used to investigate mitochondrial dysfunction and phosphatidylserine exposure. OGSA was more selective for parasites than mammalian J774A1 macrophage cells, with selectivity indices of 3.79 and 7.35, respectively. Our results showed that only the OGSA fraction did not present hemolytic activity at its IC50 for promastigote growth. Electron microscopy revealed changes in parasite flagellum, cell body shape, and organelle size, mainly mitochondria. Flow cytometry analysis indicated mitochondrial membrane and cell membrane dysfunction. OGSA showed antileishmanial activity, resulting in several changes to protozoa cells, including mitochondrial depolarization and early phosphatidylserine exposure, suggesting a possible apoptotic induction

    Atividades antioxidante e antifúngica de extratos e taninos condensados de Stryphnodendron obovatum Benth.

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    The antioxidant activity of stem-bark extracts from Stryphnodendron obovatum Benth., including fractions and isolated compounds, was evaluated by DPPH in thin-layer chromatography. All the fractions and isolated compounds showed antioxidant activity. Antifungal activity was determined by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) against the yeasts Candida albicans, Candida parapsilosis, Candida krusei and Candida tropicalis. All extracts (CE, EtOAc and FW), subfractions (F1-F12) and the compounds I, II and III were inactive against the yeasts. Against C. parapsilosis and C. albicans, fractions F13-15 and F20 showed moderate antifungal activity, and fractions F16-19 and F21-22 showed good activity. Chemical isolation of the ethyl-acetate fraction resulted in the identification of three compounds: epigallocatechin, gallocatechin and epigallocatechin-(4;b®;8)-gallocatechin.Atividade antioxidante de extrato, frações, subfrações e substâncias isoladas das cascas de Stryphnodendron obovatum Benth. foi avaliada através da redução do radical 1,1-difenil-2-picrilhidrazila (método DDPH·) em cromatografia em camada delgada. O extrato bruto (CE, acetona:água), as frações acetato de etila (EtOAc) e aquosa (FW), as subfrações (F1-F12) e as substâncias isoladas I, II e III apresentaram a capacidade de reduzir o radical DDPH·. A atividade antifúngica foi determinada pela concentração inibitória mínima (CIM) e concentração fungicida mínima (CFM) frente às amostras de leveduras Candida albicans, Candida parapsilosis, Candida krusei e Candida tropicalis. O extrato bruto (CE), as frações (EtOAC e FW), e os compostos isolados I, II e III, como também as subfrações cromatográficas (F1-F12) foram inativos frente a todas as leveduras testadas. Por outro lado, as subfrações cromatográficas F13-15 e F20 apresentaram atividade antifúngica moderada. Já as subfrações F16-19 e F21-22 mostraram boa atividade antifúngica frente às cepas de C. albicans e C. parapsilosis. As substâncias I, II, e III, isoladas da fração EtOAc por cromatografia e recromatografia em coluna de Sephadex® LH-20, foram identificadas como sendo os monômeros de flavan-3-ol, epigalocatequina e galocatequina, e um dímero, epigalocatequina-(4;b®;8)-galocatequina, respectivamente

    The Effects of N

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    Leishmaniasis is a disease that affects millions of people worldwide. The drugs that are available for the treatment of this infection exhibit high toxicity and various side effects. Several studies have focused on the development of new chemotherapeutic agents that are less toxic and more effective against trypanosomatids. We investigated the effects of N-butyl-1-(4-dimethylamino)phenyl-1,2,3,4-tetrahydro-β-carboline-3-carboxamide (C4) and its possible targets against L. amazonensis. The results showed morphological and ultrastructural alterations, depolarization of the mitochondrial membrane, the loss of cell membrane integrity, and an increase in the formation of mitochondrial superoxide anions in L. amazonensis treated with C4. Our results indicate that C4 is a selective antileishmanial agent, and its effects appear to be mediated by mitochondrial dysfunction

    Studies on effectiveness of Tanacetum parthenium against Leishmania amazonensis

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    Summary. We assessed the biological activity of a plant powder, crude extracts, and several fractions obtained from Tanacetum parthenium on Leishmania amazonensis. The medicinal plant T. parthenium is indicated for prevention of migraine headache crises, and several investigations have already demonstrated its anti-inflammatory activity. This study included the extraction process and bioassay-guided fractionation by the adsorption chromatography method. A progressive increase in the antileishmanial effect was observed in the course of the purification process. The plant powder (PTP) had a 50% inhibitory concentration (IC 50 ) at 490 µg/ml, whereas the dichloromethane fraction (DF) showed an IC 50 of 3.6 µg/ml against the growth of promastigote forms after 48 h of culturing. In axenic amastigote forms, the IC 50 of the PTP and DF were 74.8 µg/ml and 2.7 µg/ml, respectively. Cytotoxicity analysis indicated that the toxic concentrations of the PTP, ethyl-acetate crude extract (ECE), and DF were much higher for J774G8 macrophages than for the protozoans. Haemolytic experiments were performed, and the ECE and DF did not cause lysis at concentrations higher than the IC 50 for promastigotes

    n vitro Antileishmanial Activity of Hydroalcoholic Extract, Fractions, and Compounds Isolated from Leaves of Piper ovatum Vahl against Leishmania amazonensis

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    We assessed the biological activity of a crude extract, a mixture of several fractions, and a pure compound obtained from Piper ovatum Vahl against promastigote and amastigote forms of Leishmania amazonensis. The medicinal plant P. ovatum is used popularly as an anesthetic and anti-inflammatory. This study included the extraction process and bioassay-guided fractionation by the adsorption chromatography and Sephadex LH-20 method. A progressive increase in the antileishmanial effect was observed in the course of fractionation. The 50% inhibitory concentration (IC50) for dichloromethane-ethyl acetate (1:1 v/v) fraction was 2.1 μg/ml and 24 μg/ml; mixture of piperovatine: piperlongumune (2:3) 0.9 μg/ml and 24 μg/ml; piperovatine (1) 9.5 μg/ml and 10 μg/ml; and piperlonguminine (2) 2.5 μg/ml and 9.0 μg/ml, for promastigote and amastigote forms, respectively. Cytotoxicity analysis indicated that these toxic concentrations were much higher for J774G8 macrophages and Vero cells than for the protozoans. The mixture of piperovatine: piperlongumune (2:3) showed important antiprotozoal activity against the amastigote and promastigote forms of L. amazonensis, and it produced morphological changes in promastigotes and amastigotes at 0.9 μg/ml and 24 μg/ml (50% growth inhibition concentration), respectively, including intense cytoplasmic vacuolization, mitochondrial swelling, and mitochondrial damage, as revealed by transmission electron microscopy

    Análise por CG-EM do óleo essencial de Calendula officinalis cultivado no Brasil utilizando-se três diferentes processos de extração

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    Terpenos e aromas voláteis das flores de Calendula officinalis cultivados no sudoeste do Brasil foram isolados por arraste a vapor (SD), dedo frio (HS-CF) e micro extração em fase sólida (HS-SPME) acoplada à espectrometria de massas. As flores secas da C. officinalis contêm 0,1% de óleo essencial e foram identificadas 27 substâncias químicas através do cálculo do índice de Kováts e interpretação dos espectros de massas. As substâncias majoritárias presentes no óleo essencial das flores de C. officinalis, obtido por SD, HS-SPME e HS-CF foram δ-cadinene (22,5; 22,1 e 18,4 %) γ-cadinene (8,9, 25,4 e 24,9 %) e 20.4 % de α-cadinol foi observado apenas na extração por arraste a vapor.Terpenes and aroma volatiles from flowers of Calendula officinalis cultivated in southeastern Brazil were obtained by steam distillation (SD), headspace-cold finger (HS-CF) extraction and headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography and mass spectrometric analysis. The dried flowers contained 0.1% oil. Kovats indices and mass spectra were used to identify 27 individual components in the various volatile fractions. The main components present in the volatile fractions of the C. officinalis flowers, obtained by SD, HS-SPME, and HS-CF, were δ-cadinene (22.5, 22.1, and 18.4 %) and γ-cadinene (8.9, 25.4, and 24.9 %) while 20.4 % of α-cadinol was seen only after SD extraction

    Growth inhibition and ultrastructural alterations induced by Δ24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms

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    <p>Abstract</p> <p>Background</p> <p>Although <it>Candida </it>species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment.</p> <p>The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ<sup>24(25)</sup>-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of <it>Candida </it>spp., analysing the ultrastructural changes.</p> <p>Results</p> <p>AZA and EIL were found to be potent growth inhibitors of <it>Candida </it>spp. isolates. The median MIC<sub>50 </sub>was 0.5 μg.ml<sup>-1 </sup>for AZA and 2 μg.ml<sup>-1 </sup>for EIL, and the MIC<sub>90 </sub>was 2 μg.ml<sup>-1 </sup>for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were <it>Candida </it>non-<it>albicans </it>(CNA) species, but several of them, such as <it>C. guilliermondii, C. zeylanoides</it>, and <it>C. lipolytica</it>, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain <it>C. krusei </it>(ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay.</p> <p>Conclusion</p> <p>Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control <it>Candida </it>spp. infections, including those caused by azole-resistant strains.</p
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