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ABSTRACT: The introduction of highly active antiretroviral therapy (HAART) has caused a marked reduction in the occurrence and severity of parasitic infections, including the toxoplasmic encephalitis (TE). These changes have been attributed to the restoration of cell-mediated immunity. This study was developed to examine the activity of six antiretroviral protease inhibitors (API) on Toxoplasma gondii tachyzoites. The six API showed anti-Toxoplasma activity, with IC50 value between 1.4 and 6.6 µg/mL. Further studies at the molecular level should be performed to clarify if the use of API could be beneficial or not for AIDS patients with TE.
Revista do Instituto de Medicina Tropical de São Paulo 02/2013; 55(1):65-67. · 1.00 Impact Factor
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ABSTRACT: Propolis is a resinous mixture of different plant exudates collected by honeybees. Currently, propolis is widely used as a food supplement and in folk medicine. We have evaluated 20 Cuban propolis extracts of different chemical types, brown (BCP), red and yellow (YCP), with respect to their in vitro antibacterial, antifungal and antiprotozoal properties. The extracts inhibited the growth of Staphylococcus aureus and Trichophyton rubrum at low μg/mL concentrations,
whereas they were not active against Escherichia coli and Candida albicans. The major activity of the extracts was found against the protozoa Leishmania, Trypanosoma and Plasmodium, although cytotoxicity against MRC-5 cells was also observed. The BCP-3, YCP-39 and YCP-60 extracts showed the highest activity against P. falciparum, with 50% of microbial growth (IC50) values of 0.2 μg/mL. A positive correlation between the biological activity and the chemical composition was observed for YCP extracts. The most promising antimicrobial activity corresponds to YCP subtype B, which contains acetyl triterpenes as the main constituents. The present in vitro study highlights the potential of propolis against protozoa, but further research is needed to increase selectivity towards the parasite. The observed chemical composition-activity relationship of propolis can contribute to the identification
of the active principles and standardisation of this bee product.
Memórias do Instituto Oswaldo Cruz 12/2012; 107(8):978-984. · 2.15 Impact Factor
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ABSTRACT: Propolis is a resinous mixture of different plant exudates collected by honeybees. Currently, propolis is widely used as a food supplement and in folk medicine. We have evaluated 20 Cuban propolis extracts of different chemical types, brown (BCP), red and yellow (YCP), with respect to their in vitro antibacterial, antifungal and antiprotozoal properties. The extracts inhibited the growth of Staphylococcus aureus and Trichophyton rubrum at low µg/mL concentrations, whereas they were not active against Escherichia coli and Candida albicans. The major activity of the extracts was found against the protozoa Leishmania, Trypanosoma and Plasmodium, although cytotoxicity against MRC-5 cells was also observed. The BCP-3, YCP-39 and YCP-60 extracts showed the highest activity against P. falciparum, with 50% of microbial growth (IC50) values of 0.2 µg/mL. A positive correlation between the biological activity and the chemical composition was observed for YCP extracts. The most promising antimicrobial activity corresponds to YCP subtype B, which contains acetyl triterpenes as the main constituents. The present in vitro study highlights the potential of propolis against protozoa, but further research is needed to increase selectivity towards the parasite. The observed chemical composition-activity relationship of propolis can contribute to the identification of the active principles and standardisation of this bee product.
Memórias do Instituto Oswaldo Cruz 12/2012; 107(8):978-84. · 2.15 Impact Factor
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ABSTRACT: Trichomonas vaginalis infection is associated with important problems of public health, including the spreading of other sexual transmitted infections. The existence of clinical resistant isolates to metronidazole and tinidazole, the drugs approved for the treatment of trichomoniasis, points to the necessity of continue searching for trichomonicidal substances. Here we optimize a colorimetric assay with MTT for assess trichomonas viability. The absence of ascorbic acid and cysteine in the culture medium was indispensable to perform the assay, as these compounds spontaneously reduce the MTT. Linearity of absorbance was verified versus trichomonas counts. Medium inhibitory concentration of metronidazole was determined using the sigmoidal Emax model, by comparison the absorbance of test cultures with controls. The obtained value was in the range of published data. The test would be use for the evaluation of trichomonicidal activity of chemical compounds and natural products.
Current clinical pharmacology. 11/2012;
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ABSTRACT: The marine organisms are a rich source of varied natural products with unique functionality. A variety of natural products of new molecular structures with diverse biological activities have been reported from marine flora and fauna for treatment and/or prevention of human diseases. The present review briefly illustrates current status of marine products as antiprotozoal agents. The in vitro and in vivo studies of marine algae, invertebrates and micoorganisms against different protozoa parasites are included. The marine products studied, according international criterions to selection of more promisory products in the differents models reported, demonstrated their potentialities as antiprozoal agents. Herein, the interest of scientific community to search new alternatives from marine environment has been demonstrated.
Current clinical pharmacology. 11/2012;
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ABSTRACT: Bursera graveolens is a wild tree of commercial importance native to the Neotropics, which has been widely used in folk medicine. In the present study, the chemical composition and anti-proliferative properties of the essential oil from B. graveolens were assayed. The chemical composition of the essential oil, determined by GC-MS, was complex and dominated by limonene (26.5%). Bursera oil inhibited the growth of MCF-7 breast tumor cells as well as amastigotes of L. amazonensis, with IC50 values of 48.9 +/- 4.3 and 36.7 +/- 4.7 microg/mL, respectively. In addition, the cytotoxicity of the oil was 103.9 +/- 7.2 microg/mL against peritoneal macrophages from BALB/c mice. These results demonstrate that the essential oil from B. graveolens is a promissory antiproliferative product.
Natural product communications 11/2012; 7(11):1531-4. · 1.24 Impact Factor
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ABSTRACT: Introduction: leishmaniasis is a disease caused by several species from
Leishmania genus, which has been increasingly reported in the last few years.
Several genetic, immunological factors and others related to this parasite have
been associated to the outcome of the infection, and the occurrence of illness in
varied clinical forms. All the aforementioned has an impact on the diagnostic
method that should be used.
Methods: a basic and recent literature review was made, mainly focused on
general aspects of leishmaniasis as epidemiological situation of disease, life cycle
and transmission, vectors, clinical presentation and diagnosis; the latter shows
information about the main methods used at present. The procedure followed by
the Leishmania group at "Pedro Kourí" Institute of Tropical Medicine to support the
diagnostic activities was presented as well.
Results: updated practical information about the chosen topics was presented,
with a practical guiding approach aimed at the health personnel that must face
suspected leishmaniasis cases. Tables and figures summarized relevant aspects in
an organized form, as well as the working algorithm of Institute concerning
diagnosis was presented. The application of molecular diagnosis by this working
team was particularly underlined.
Conclusions: as leishmaniasis is still out of control, opportune diagnosis remains a
must. All the methods provide useful information for taking decisions on clinical
management, treatment and epidemiology of this parasitosis; hence, a working
algorithm was submitted in our lab based on the most useful methods under our
present conditions and experience.
Revista Cubana de Medicina Tropical 09/2012; 64(2):108-131.
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ABSTRACT: Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Leishmania amazonensis. Furthermore, their toxicity was assayed against murine macrophage. The three most potent extracts against the amastigote stage of Leishmania amazonensis were from Hura crepitans, Bambusa vulgaris, and Simarouba glauca.
ISRN pharmacology. 01/2012; 2012:104540.
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ABSTRACT: To evaluate the antileishmanial activity of different extracts from three Cuban Pluchea species.
In in vitro assays the IC(50) was calculated in the promastigotes and amastigotes forms as cytotoxicity in murine macrophages. In leishmaniasis cutanea experiment, mortality, weight loss, lesion size and burden parasite were measured.
Extracts evaluated showed inhibitive effect on growing of promastigote form; however, active extracts caused a high toxicity. Ethanol and n-hexane extracts demonstrated specific antileishmanial activity. Ethanol and n-hexane extracts from Pluchea carolinensis (P. carolinensis) caused similar inhibition against amastigote form. The intraperitoneal administration of the ethanol extract of P. carolinensis at 100 mg/kg prevented lesion development compared with control groups.
The antileishmanial experiment suggests that ethanol extracts from P. carolinensis is the most promising. Further studies are still needed to evaluate the potential of this plant as a source of new antileishmanial agents.
Asian Pacific Journal of Tropical Medicine 10/2011; 4(10):836-40. · 0.37 Impact Factor
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ABSTRACT: Surfacen® is an exogenous natural lung surfactant, composed by phospholipids and hydrophobic proteins, which is applied successfully in Newborn Respiratory Distress Syndrome. In this paper, in vitro activity of Surfacen® against Leishmania amazonensis is described. The product showed activity against the amastigote form found in peritoneal macrophages from BALB/c mice, with an IC50 value of 17.9 ± 3.0 µg/mL; while no toxic effect on host cell was observed up to 200 µg/mL. This is the first report about the antileishmanial activity of Surfacen®.
Revista do Instituto de Medicina Tropical de São Paulo 08/2011; 53(4):235-8. · 1.00 Impact Factor
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ABSTRACT: Malaria is one of the major threats concerning world public health. Resistance to the current antimalarial drugs has led to searches for new antimalarial compounds. Acridinone derivatives have recently demonstrated to be active against malaria parasite. We focused our attention on synthesized new acridinone derivatives, some of them resulting with high antiviral and trypanocidal activity. In this study new derivatives of 10-alyl-, 10-(3-methyl-2-butenyl)- and 10-(1,2-propadienyl)-9(10H)-acridinone were evaluated for their antimalarial activity against Plasmodium falciparum. To assess the selectivity, cytotoxicity was assessed in parallel against human MRC-5 cells. Inhibition of β-hematin formation was determined using a spectrophotometric assay. Mitochondrial bc(1) complexes were isolated from yeast and bovine heart cells to test acridinone inhibitory activity. This study resulted in the identification of three compounds with submicromolar efficacy against P. falciparum and without cytotoxic effects on human cellular line. One compound, IIa (1-fluoro-10-(3-methyl-2-butenyl)-9(10H)-acridinone), can be classified as hit for antimalarial drug development exhibiting IC(50) less than 0.2 μg/mL with SI greater than 100. In molecular tests, no relevant inhibitory activity was obtained for our compounds. The mechanism of acridinones antimalarial action remains unclear.
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 05/2011; 65(3):210-4. · 2.24 Impact Factor
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ABSTRACT: In countries where leishmaniasis is endemic, there are not very many treatment alternatives and most options have problems associated with their use. Plants and their natural products constitute good sources of interesting lead compounds that could be potentially active against Leishmania. Chenopodium ambrosioides is a plant that is widely used in popular medicine and its antiparasitic effects have been documented, including the antileishmanial potentialities of Chenopodium oil. The objective of this study was to determine the chemical composition, in-vitro cytotoxicity and antileishmanial activity of essential oils extracted from C. ambrosioides, which received different treatments prior to extraction. The chemical characterization by GC-MS of the three essential oil samples showed similar composition and the major components were alpha-terpinene (17.0-20.7%), p-cymene (20.2-21.1%) and ascaridole (30.5-47.1%). The essential oils exhibited similar antileishmanial activities against intracellular amastigote form, with IC50 values between 4.7 and 12.4 microg/mL. However, a lower cytotoxicity was displayed by the essential oil extracted from fresh green vegetable material, which was statistically different (P < 0.05) from the other samples. This study demonstrated that the prior treatment of plant material did not interfere with the antiparasitic activity of essential oils from C. ambrosioides but did change their cytotoxicity, which should be taken into account in further studies.
Natural product communications 02/2011; 6(2):281-6. · 1.24 Impact Factor
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Lianet Monzote
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ABSTRACT: The World Health Organization has classified the leishmaniasis as a major tropical disease. An effective vaccine is not available and the chemotherapy is the only effective way to treat all forms of disease. Currently, the therapy is toxic, expensive and the resistance has emerged as a serious problem, which has compelled the search for new antileishmanial agents. The aim of this article is to review the recent advances in antileishmanial drugs. In addition, patents from 01/1969 to 12/2009 were analyzed. After initial review, 867 patents were classified as vaccines, immunomodulators and drugs. Among them, the major percent was reached by the drugs, accounting for 68% of the patents. In this review, 580 patents were listed, reviewed and classified according the approach of the inventors in the expansion of antileishmanial drug discovery. In this moment, the scenario of leishmaniasis chemotherapy is more promising than ever. Nevertheless, advances in the understanding of new metabolic pathways and drug targets in the parasite could offer new alternatives to treatment of leishmaniasis.
Recent Patents on Anti-Infective Drug Discovery 01/2011; 6(1):1-26.
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ABSTRACT: The diseases caused by protozoan parasite are responsible for considerable mortality and morbidity, affecting more than 500 million of people in the world. The epidemiological control of protozoan is unsatisfactory due to difficulties of vector and reservoir control; while the progress in the development of vaccine tends to be slow and arduous. Currently, the chemotherapy remains essential component of both clinical management and disease control programmer in endemic areas. The drugs in use as anti-protozoan agents were discovered over 50 years and a number of factors limit their utility such as: high cost, poor compliance, drug resistance, low efficacy and poor safety. In the recent years, the searches about the development of new drugs against protozoa parasite have been increased. This special issue of The Open Medicinal Chemistry Journal will present some of developments in this field with the aim to shown the significant advances in the discovery of new anti-protozoan drugs.
The Open Medicinal Chemistry Journal 01/2011; 5:1-3.
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ABSTRACT: The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites.
The Open Medicinal Chemistry Journal 01/2011; 5:40-50.
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ABSTRACT: In the present study, an activity of Bixa orellana extract against Leishmania amazonensis was demonstrated.
Experimentally infected BALB/c mice were treated with B. orellana extract which showed a significant activity against promastigote and amastigote forms of L. amazonensis.
This study supports the importance of natural sources as antileishmanial drugs.
Forschende Komplementärmedizin / Research in Complementary Medicine 01/2011; 18(6):351-3. · 1.65 Impact Factor
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ABSTRACT: Leishmaniasis is a widespread tropical infection caused by different species of Leishmania protozoa. There is no immunoprophylaxis (vaccination) available for Leishmania infections and conventional treatments are unsatisfactory; therefore antileishmanial drugs are urgently needed. Natural products are attractive due to their structural diversity.
The present work investigated the antileishmanial action of 21 species of plants.
Plants were collected and their hydroalcoholic extracts were screened against promastigotes and amastigotes of L. amazonensis. Their toxicity was also assayed against peritoneal macrophages from BALB/c mice.
Five extracts showed significant growth inhibitory activity against promastigote form. Only the extracts from Bidens pilosa L. (Asteraceae) and Punica granatum L. (Punicaceae) inhibited the growth of intracellular amastigotes, with IC(50) values of 42.6 and 69.6 microg/mL, respectively. In addition, a low toxicity on macrophage from BALB/c mice was observed.
The antiparasitic activities of B. pilosa and P. granatum have been reported against other parasitic agents and their actions can be the results of flavonoids present in the extracts.
This study supports the importance of natural products as potential sources in the search for new antileishmanial drugs.
Pharmaceutical Biology 09/2010; 48(9):1053-8. · 0.88 Impact Factor
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ABSTRACT: Diseases caused by parasitic infections are responsible for considerable morbidity and mortality. The progress in the development of vaccines against parasite infections tends to be slow and the epidemiological control of diseases is unsatisfactory. Currently, chemotherapy remains an essential component of clinical management and disease control programs. In the past 20 years, there was a significant increase in our basic knowledge about structure and biochemical functions of parasites. Several studies to identify unique metabolic pathways and key enzymes for parasite survival are in progress, which may support the development of novel target-based drugs. The mitochondrial respiratory chain of parasites typically shows greater diversity compared with host animals; including the electron transport complexes and their related enzymes; tRNA import, as well as the synthesis of fatty acids, pyrimidines and ubiquinones. These unique aspects may represent promising targets for chemotherapy. This review presents a compilation about the knowledge and understanding of the action of therapeutic agents on mitochondria from parasites and their future perspectives.
Current clinical pharmacology. 03/2010; 5(1):55-60.
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ABSTRACT: Leishmaniasis is one of the most important parasitic infections, but current treatments are unsatisfactory due to their toxicity, cost and resistance. Therefore, the development of new antileishmanial compounds is imperative. Many people who live in endemic areas use plants as an alternative to treat the disease. In this paper, we characterised the essential oil from Piper auritum, evaluated its cytotoxicity and determined its antileishmanial activity. The chromatogram obtained by gas chromatography revealed 60 peaks and we found that safrole was the most abundant compound, composing 87% of the oil. The oil was active against the promastigotes of Leishmania major, Leishmania mexicana, Leishmania braziliensis and Leishmania donovani with a favourable selectivity index against peritoneal macrophages from BALB/c mice. The Piper-oil inhibited the growing of intracellular amastigotes of L. donovani with an IC50 value of 22.3 +/- 1.8 microg/mL. This study demonstrates the usefulness of the essential oils as a promising alternative to treat leishmaniasis.
Memórias do Instituto Oswaldo Cruz 03/2010; 105(2):168-73. · 2.15 Impact Factor
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BMC Pharmacology. 01/2010;
