102 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

    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

    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

    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

    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

    Effects of medicinal plant extracts on growth of Leishmania (L.) amazonensis and Trypanosoma cruzi

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    Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L.) amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi.This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi

    Acute and Chronic Toxicity of an Aqueous Fraction of the Stem Bark of Stryphnodendron adstringens (Barbatimão) in Rodents

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    Stryphnodendron adstringens has a high tannin content and is used as an antiseptic and antimicrobial and in the treatment of leucorrhea, gonorrhea, wound healing, and gastritis. The present study evaluated the toxic effects of the heptamer prodelphinidin (F2) from the stem bark of S. adstringens in rodents. In the acute toxicity test, the mice that received oral doses exhibited reversible effects, with an LD 50 of 3.015 mg ⋅ kg −1 . In the chronic toxicity test at 90 days, Wistar rats were treated with different doses of F2 (10, 100, and 200 mg ⋅ kg −1 ). In the biochemical, hematological, and histopathological examinations and open-field test, the different dose groups did not exhibit significant differences compared with controls. The present results indicate that F2 from the stem bark of S. adstringens caused no toxicity with acute and chronic oral treatment in rodents at the doses administered

    Biological activities of essential oil obtained from Cymbopogon citratus on Crithidia deanei

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    Summary. We report the effect of the essential oil extracted from Cymbopogon citratus on endosymbiont-harbouring and endosymbiontfree strains of the insect trypanosomatid Crithidia deanei grown at 28°C in a chemically defined medium. A dose-dependent antiprotozoan effect of the essential oil of C. citratus could be observed on both strains of C. deanei. The IC 50 values (50% inhibitory concentration) for symbiont-bearing and symbiont-free strains were 120 and 60 µg/ml, respectively. The viability assay showed that the symbiont-free strain is more sensitive to the presence of the essential oil, because lysed cells were observed after 2 h of exposure at higher concentrations. In addition, alterations in the ultrastructure and in the detection of cell-surface carbohydrate residues in both strains of C. deanei after treatment with the essential oil were also evaluated. Both strains showed ultrastructural alterations in the cellular and flagellar pocket membranes, as revealed by transmission electron microscopy. In the lectin assay, the essential oil influenced the expression of carbohydrates in symbiont-free C. deanei, as evidenced by a reduction of sialic acid residues on the cell surface

    Proanthocyanidin Polymer-Rich Fraction of Stryphnodendron adstringens Promotes in Vitro and in Vivo Cancer Cell Death via Oxidative Stress

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    Cervical cancer is the fourth most common cancer that affects women, mainly through human papilloma virus (HPV) infection with high-risk HPV16 and HPV18. The present study investigated the in vitro anticancer activity and mechanism of action of a proanthocyanidin polymer-rich fraction of Stryphnodendron adstringens (F2) in cervical cancer cell lines, including HeLa (HPV18-positive), SiHa (HPV16-positive), and C33A (HPV-negative) cells, and also evaluated in vivo anticancer activity. In vitro, cell viability was determined by the MTT assay. Cell migration was determined by the wound healing assay. The mechanism of action was investigated by performing ultrastructural analysis and evaluating reactive oxygen species (ROS) production, mitochondrial metabolism, lipoperoxidation, BCL-2 family expression, caspase expression, and DNA and cell membrane integrity. In vivo activity was evaluated using the murine Ehrlich solid tumor model. F2 time- and dose-dependently reduced cell viability and significantly inhibited the migration of cervical cancer cells. HeLa and SiHa cells treated with F2 (IC50) exhibited intense oxidative stress (i.e., increase in ROS and decrease in antioxidant species) and mitochondrial damage (i.e., mitochondrial membrane potential depolarization and a reduction of intracellular levels of adenosine triphosphate). Increases in the Bax/BCL-2 ratio and caspase 9 and caspase 3 expression, were observed, with DNA damage that was sufficient to trigger mitochondria-dependent apoptosis. Cell membrane disruption was observed in C33A cells (IC50 and IC90) and HeLa and SiHa cells (IC90), indicating progress to late apoptosis/necrosis. The inhibition of ROS production by N-acetylcysteine significantly suppressed oxidative stress in all three cell lines. In vivo, F2 significantly reduced tumor volume and weight of the Ehrlich solid tumor, and significantly increased lipoperoxidation, indicating that F2 also induces oxidative stress in the in vivo model. These findings indicate that the proanthocyanidin polymer-rich fraction of S. adstringens may be a potential chemotherapeutic candidate for cancer treatment
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