Izabel Cristina Piloto Ferreira

Antifungal activity of the extracts and saponins from Sapindus saponaria L.

Extracts from the dried pericarp of Sapindus saponaria L. (Sapindaceae) fruits were investigated for their antifungal activity against clinical isolates of yeasts Candida albicans and C. non-albicans from vaginal secretions of women with Vulvovaginal Candidiasis. Four clinical isolates of C. albicans, a single clinical isolated of each of the species C. parapsilosis, C. glabrata, C. tropicalis, and the strain of C. albicans ATCC 90028 were used. The hydroalcoholic extract was bioactivity-directed against a clinical isolate of C. parapsilosis, and showed strong activity. The n-BuOH extract and one fraction showed strong activity against all isolates tested. Further column-chromatography on silica gel separation of this fraction afforded two pure triterpene acetylated saponins: 3-O-(4-acetyl-beta-D-xylopyranosyl)-(1->3)-alpha-L-rhamnopyranosyl-(1->2)-alpha-L-arabinopyranosyl-hederagenin (1) and 3-O-(3,4-di-acetyl-beta-D-xylopyranosyl)-(1->3)-alpha-L-rhamnopyranosyl-(1->2)-alpha-L-arabynopyranosyl-hederagenin (2). The structures of the compounds were based on spectral data ((1)H and 13C NMR, HSQC, HMBC and MS), and on with literature. The saponins isolated showed strong activity against C. parapsilosis.

Anti-leishmanial activity of alkaloidal extract from Aspidosperma ramiflorum

Infections due to protozoa of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials (SbV), which present renal and cardiac toxicity. Besides, the precise chemical structure and mechanism of action of these drugs are unknown up to date. In order to find new drugs against leishmaniasis, we have been studying extracts of Brazilian trees. In the present study, we have evaluated the effectiveness of an alkaloid extract of Aspidosperma ramiflorum Muell. Arg. (Apocynaceae), against the extracellular forms promastigotes of L. (L.) amazonensis and L. (V.) braziliensis. The alkaloid extract of A. ramiflorum was much more effective against L. (L.) amazonensis (LD50 < 47 microg/ml) than L. (V.) braziliensis. Based on these in vitro results against L. (L.) amazonensis new studies should be made to find the compounds with anti-leishmanial activity.

Effect of HIV protease inhibitors on New World Leishmania

The incidence of HIV/Leishmania co-infection decreases after antiretroviral drug therapy; therefore, the in vitro and in vivo activity of three antiretroviral drugs against Leishmania (Viannia) braziliensis and L. (L.) amazonensis was evaluated. Different concentrations of indinavir (IDV), atazanavir (ATV), and ritonavir (RTV) were added to promastigote cultures, and the 50% inhibitory concentration (IC50) was determined. IDV and RTV were also evaluated against intracellular amastigotes, and the Infection Index determined. BALB/c mice, infected with L. (L.) amazonensis in the left footpad, were treated orally with IDV and RTV for 30 days, and monitored by measuring the footpad thickness and parasite load of regional lymph nodes and spleen. For promastigotes, IDV exhibited an IC50 value of 100 μM against L.(L.) amazonensis. The RTV IC50 for L. (L.) amazonensis and L. (V.) braziliensis were 40 and 2.3 μM, respectively, and the ATV IC50 for L. (V.) braziliensis was 266 μM. For intracellular amastigotes, IDV (25, 50, and 100 μM) significantly decreased the Infection Index of L. (L.) amazonensis (56.8%, 47.9%, and 65.0%) and L. (V.) braziliensis (37.8%, 48.7%, and 43.2%). RTV (12.5, 25, and 50 μM) decreased the infection index of L. (L.) amazonensis by 26.3%, 42.4%, and 44.0%, and that of L. (V.) braziliensis by 27.6%, 37.3%, and 39.2%. Antiretroviral-treated mice had a significant reduction in footpad thickness after the third week of IDV and after the fifth week of RTV treatment. However, there was no reduction in parasite load. These results suggest that IDV and RTV have anti-Leishmania activity, but only in higher concentrations.

Antileishmanial activity of a guaianolide from Tanacetum parthenium (L.) Schultz Bip.

Leishmaniasis is one of the major infectious diseases affecting the poorest regions of the world. The present study evaluated the antileishmanial activity of a guaianolide purified from the hydroalcoholic extract of aerial parts of Tanacetum parthenium (L.) Schultz Bip. The isolated compound showed activity against the promastigote form of Leishmania amazonensis, with 50% inhibition (IC(50)) of cell growth at a concentration of 2.6 μg/ml. For the intracellular amastigote form, this guaianolide reduced by 10% the survival index of parasites in macrophages when it was used at 20.0 μg/ml. The selective index (SI) ratio (CC(50) for J774G8 cells/IC(50) for protozoans) was 385, showing that it is more selective against the parasite than mammalian cells. Morphological alterations of protozoans treated with IC(50) included changes in size, shape, and structure (more than one nucleus and flagellum) under both light and scanning electron microscopies.

Trypanocidal activity of guaianolide obtained from Tanacetum parthenium (L.) Schultz-Bip. and its combinational effect with benznidazole.

In the present study, we evaluated the in vitro antiprotozoal activity of a guaianolide (11,13-dehydrocompressanolide) isolated from Tanacetum parthenium against Trypanosoma cruzi and investigated the possible combinational effect of guaianolide and benznidazole. The isolated compound was shown to be effective against T. cruzi, with IC₅₀ values of 18.1±0.8 and 66.6±1.3 μM against the multiplicative epimastigote and amastigote forms, respectively. The best results were obtained against trypomastigotes, with an EC₅₀ of 5.7±0.7 μM. The guaianolide presented no toxicity in LLCMK₂ cells (CC₅₀ of 93.5 μM) and was 16.4-fold more selective for trypomastigotes. The study of the combinational effect of benznidazole and guaianolide revealed the presence of a synergistic effect against the epimastigote form and marginal additive effect against the trypomastigote form. Striking morphological changes were observed in epimastigotes treated with guaianolide, such as thinning and stretching of the cell body and flagellum and changes in the format of the cell body with apparent leakage of the cytoplasmic content in trypomastigote forms. The ultrastructural analysis of epimastigotes revealed the presence of membranes that involved organelles and formation of myelin-like figures. Flow cytometry revealed a cell volume reduction and decrease in mitochondrial membrane potential. However, no major changes in cell membrane integrity were found in the epimastigote form treated with guaianolide.

Activity of Extracts and Coumarins from the Leaves of Calophyllum brasiliense. on Leishmania braziliensis.

Abstract In the current study, we evaluated the activity of extracts and (-)mammea A/BB from the leaves of Calophyllum brasiliense. Camb. (Clusiaceae), against Leishmania braziliensis.. The dichloromethane extract and the coumarin (-)mammea A/BB showed significant activity against the promastigote forms of L. braziliensis., with a 50% lethal dose (LD50) at concentrations of 60 and 23.2 μ g/mL, respectively. However, the aqueous extract from the leaves and amentoflavone showed no activity against promastigote forms. For the intracellular amastigote form, the dichloromethane extract and the coumarin (-)mammea A/BB reduced by 50% the infection index of parasites in macrophages at concentrations of 22 and 29 μ g/mL, respectively. In addition, the dichloromethane extract did not show cytotoxic effects against mouse peritoneal macrophages at concentration up to 1000 μ g/mL. On the other hand, the coumarin (-)mammea A/BB showed more cytotoxicity than the dichloromethane extract. The compounds were characterized by one and two-dimensional 1H and 13C NMR analyses, and LC/UV/MS was used to identify (-)mammea A/BB and amentoflavone in the dichloromethane extract. These results provide new perspectives on the development of novel drugs with leishmanicidal activities obtained from natural products.

In vitro and in vivo antileishmania activity of sesquiterpene lactone-rich dichloromethane fraction obtained from Tanacetum parthenium (L.) Schultz-Bip

The discovery of new treatments for neglected diseases, including leishmaniasis, is a substantial challenge for scientific research. Plant extracts have shown potential in the selective treatment of tropical diseases. The present study evaluated the in vitro and in vivo antileishmania effects of a sesquiterpene lactone-rich dichloromethane fraction (DF) obtained from the aerial parts of Tanacetum parthenium (L.) Schultz-Bip. In vitro studies of the DF indicated an IC50 of 2.40±0.76 μg mL(-1) against the promastigote form and 1.76±0.25 μg mL(-1) against the axenic amastigote form of Leishmania amazonensis. In vivo intramuscular treatment with DF decreased the growth and size of footpad lesions in mice. The DF also significantly decreased the parasite population compared with animals that were treated with the reference drug. Plasma malondialdehyde levels were increased slightly by the DF, attributable to its parthenolide-rich composition that causes cellular apoptosis, compared with the control group, demonstrating treatment efficacy without toxicity or genotoxicity. Because the isolation and purification of plant compounds are costly and time-consuming and generate low yields, extract fractions, such as the DF studied herein, represent a promising alternative for the treatment of leishmaniasis.

Chemical Constituents from the Roots of Spathelia excelsa and their Antiprotozoal Activity

A investigacao fitoquimica das raizes de Spathelia excelsa levou ao isolamento das cromonas 10(2,3-epoxi-3-metilbutanil)spatheliacromeno e 10(2,3-diidroxi-3-metilbutanil) metoxispatheliacromeno (5-metoxispatheliabiscromeno); o limonoide desacetilspathelina e epimero C-21 do protolimonoide 3β-angeloiloxi-7α,24,25-triidroxi-21,23-oxido-14,18-cicloapotirucal-21hemiacetal; os alcaloides 7,8-dimetoxiflindersina, casimiroina e N-methyl-4,7,8-trimetoxiquinolino2(1H)-ona, alem da mistura de β-sitosterol e stigmasterol. Nos ensaios biologicos sobre a forma promastigosta de Leishmania braziliensis, desacetilspathelina apresentou atividade moderada e sobre a forma epimastigota de Trypanossoma cruzi, 10(2,3-epoxi-3-metilbutanil)spatheliacromeno apresentou atividade forte (IC 50 = 11 µg mL -1 ). Phytochemical investigation from roots of Spathelia excelsa yielded the chromones 10(2,3-epoxy-3-methylbutanyl)spatheliachromen and 10(2,3-dihydroxy-3-methylbutanyl) methoxyspatheliacromen (5-methoxyspatheliabischromen); limonoid deacetylspathelin and protolimonoid C-21-epimers 3β-angeloyloxy-7α,24,25-trihydroxy-21,23-oxide-14,18cycloapotirucall-21-hemiacetal; the alkaloids 7,8-dimethoxyflindersin, casimiroin and N-methyl4,7,8-trimethoxyquinolin-2(1H)-one, besides a mixture of β-sitosterol and stigmasterol. Assays on promastigote forms of Leishmania braziliensis, deacetylspathelin showed moderate activity; and on epimastigote forms of Trypanossoma cruzi, 10(2,3-epoxy-3-methylbutanyl)spatheliachromen exhibited strong activity (IC 50 = 11 µg mL -1

Active polyketides isolated from Penicillium herquei

In this work we are reporting the isolation by classical methods of chromatography of six polyketides from Penicillium herquei. The compounds citreorosein ( 1) , emodin ( 2) , janthinone ( 3) , citrinin ( 4) , citrinin H1 ( 5) and dicitrinol ( 6) were identified by spectral methods of 1D and 2D NMR and MS. Compounds 1, 2 and 3 were tested against promastigotes forms of Leishmania brasiliensis and 1 and 2 were also assayed against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis and showed good activity.

Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L.

Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis.