Topical tamoxifen in the therapy of cutaneous leishmaniasis.

The aims of the present work were to test the effect of tamoxifen administered topically and the therapeutic efficacy of tamoxifen and pentavalent antimonial combinations in an experimental model of cutaneous leishmaniasis. BALB/c mice infected with a luciferase expressing line of Leishmania amazonensis were treated with topical tamoxifen in two different formulations (ethanol or oil-free cream) as monotherapy or in co-administration with pentavalent antimonial. Treatment efficacy was evaluated by lesion size and parasite burden, quantified through luminescence, at the end of treatment and 4 weeks later. Topical tamoxifen, formulated in ethanol or as a cream, was shown to be effective. The interaction between tamoxifen and pentavalent antimonial was additive in vitro. Treatment with combined schemes containing tamoxifen and pentavalent antimonial was effective in reducing lesion size and parasite burden. Co-administration of tamoxifen and pentavalent antimonial was superior to monotherapy with antimonial.

Efficacy of tamoxifen and miltefosine combined therapy for cutaneous leishmaniasis in the murine model of infection with Leishmania amazonensis.

OBJECTIVES: The objective of this study was to characterize in vitro interactions and evaluate the antileishmanial activity of tamoxifen and miltefosine combinations. METHODS: Interactions between drugs were evaluated in vitro against Leishmania amazonensis promastigotes and intracellular amastigotes by a modified isobologram method. Four different drug ratios were used to calculate the FIC index (FICI) and the mean sum of FICI. Treatment of L. amazonensis-infected BALB/c mice was initiated 4 weeks post-infection. Mice were treated with the half-maximal effective dose (ED50) or half the ED50 of tamoxifen and miltefosine orally for 15 days. Efficacy was evaluated by lesion growth and parasite burden measured through luciferase detection at the end of treatment and 30 days later. Characterization of growth curves and stepwise increase in drug concentrations in vitro were used to measure survival and resistance selection of parasite populations submitted to combination treatment. RESULTS: No in vitro interactions between tamoxifen and miltefosine were found. In infected mice, the combination of tamoxifen and miltefosine at doses corresponding to half the ED50 was more effective than monotherapy with either tamoxifen or miltefosine. When the ED50 was employed, the efficacy of the combination was equivalent to miltefosine monotherapy. In vitro, tamoxifen was able to retard or suppress the growth of parasites treated with miltefosine. CONCLUSIONS: In vitro and in vivo studies revealed no interaction between tamoxifen and miltefosine. Tamoxifen was able to hinder the emergence of miltefosine resistance.

Combination therapy with tamoxifen and amphotericin B in experimental cutaneous leishmaniasis.

Leishmaniasis chemotherapy remains very challenging. The high cost of active drugs, along with the severity of their side effects and the increasing failure rate of the current therapeutic schemes, calls for the discovery of new active drugs and schemes of treatment. The use of combination therapy has gained much attention in recent years as a possible strategy for overcoming the various shortcomings in the present arsenal. We recently described the effectiveness of tamoxifen in murine models of leishmaniasis, and here, we investigated the interactions between tamoxifen and amphotericin B, one of the most potent drugs used in leishmaniasis treatment. The in vitro interactions were indifferent for the association of tamoxifen and amphotericin B. The association was also assayed in vivo in Leishmania amazonensis-infected BALB/c mice and was found to yield at least additive effects at low doses of both drugs.

Effectiveness of liposomal buparvaquone in an experimental hamster model of Leishmania (L.) infantum chagasi.

The objective of this study was to develop a novel liposomal formulation, containing phosphatidylserine (PS), of buparvaquone (BPQ) and to evaluate its in vivo effectiveness in Leishmania (L.) infantum chagasi-infected hamsters. The activity of BPQ was evaluated against both the promastigote forms of different Leishmania species and the intracellular amastigotes of L. (L.) infantum chagasi. Buparvaquone was entrapped in PS-liposomes (BPQ-PS-LP), and the drug was quantified by ultra-high-performance liquid chromatography. The treatment was quantified by detecting the RNA of the living amastigotes in the spleen and the liver by real-time PCR. In vitro assays with L. (L.) infantum chagasi intracellular amastigotes were performed in peritoneal macrophages for the evaluation of the 50% inhibitory concentration (IC(50)). BPQ-PS-LP at 0.33 mg/kg/day for eight consecutive days reduced the number of amastigotes by 89.4% (P<0.05) in the spleen and by 67.2% (P>0.05) in the liver, compared to 84.3% (P<0.05) and 99.7% (P<0.05), respectively, following Glucantime® treatment at 50 mg/kg/day. Free BPQ at 20 mg/kg/day failed to treat the hamsters when compared to the untreated group. BPQ was significantly (P<0.05) selective against L. (L.) infantum chagasi intracellular amastigotes, with an IC(50) value of 1.5 µM; no in vitro mammalian cytotoxicity could be detected. Other cutaneous species were also susceptible to BPQ, with IC(50) values in the range 1-4 µM. BPQ-PS-LP caused a significant reduction in the parasite burden at a 60-fold lower dose than did the free BPQ. These results show the potential of PS-liposome formulations for the successful targeted delivery of BPQ in visceral leishmaniasis.

In vitro antileishmanial and antitrypanosomal activities of flavanones from Baccharis retusa DC. (Asteraceae).

Leishmaniasis and Chagas' are parasitic protozoan diseases that affect the poorest population in the world, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, novel, safe and more efficacious drugs are essential. In this work, the CH(2)Cl(2) phase from MeOH extract from the leaves of Baccharis retusa DC. (Asteraceae) was fractioned to afford two flavonoids: naringenin (1) and sakuranetin (2). These compounds were in vitro tested against Leishmania spp. promastigotes and amastigotes and Trypanosoma cruzi trypomastigotes and amastigotes. Compound 2 presented activity against Leishmania (L.) amazonensis, Leishmania (V.) braziliensis, Leishmania (L.) major, and Leishmania (L.) chagasi with IC(50) values in the range between 43 and 52 µg/mL and against T. cruzi trypomastigotes (IC(50)=20.17 µg/mL). Despite of the chemical similarity, compound 1 did not show antiparasitic activity. Additionally, compound 2 was subjected to a methylation procedure to give sakuranetin-4'-methyl ether (3), which resulted in an inactive compound against both Leishmania spp. and T. cruzi. The obtained results indicated that the presence of one hydroxyl group at C-4' associated to one methoxyl group at C-7 is important to the antiparasitic activity. Further drug design studies aiming derivatives could be a promising tool for the development of new therapeutic agents for Leishmaniasis and Chagas' disease.

Anti-malarial, anti-trypanosomal, and anti-leishmanial activities of jacaranone isolated from Pentacalia desiderabilis (Vell.) Cuatrec. (Asteraceae).

Leishmaniasis, Chagas disease, and malaria affect the poorest population around the world, with an elevated mortality and morbidity. In addition, the therapeutic alternatives are usually toxic or ineffective drugs especially those against the trypanosomatids. In the course of selection of new anti-protozoal compounds from Brazilian flora, the CH(2)C(l2) phase from MeOH extract obtained from the leaves of Pentacalia desiderabilis (Vell.) Cuatrec. (Asteraceae) showed in vitro anti-leishmanial, anti-malarial, and anti-trypanosomal activities. The chromatographic fractionation of the CH(2)Cl(2) phase led to the isolation of the bioactive compound, which was characterized as jacaranone [methyl (1-hydroxy-4-oxo-2,5-cyclohexandienyl)acetate], by spectroscopic methods. This compound showed activity against promastigotes of Leishmania (L.) chagasi, Leishmania (V.) braziliensis, and Leishmania (L.). amazonensis showing an IC(50) of 17.22, 12.93, and 11.86 µg/mL, respectively. Jacaranone was also tested in vitro against the Trypanosoma cruzi trypomastigotes and Plasmodium falciparum chloroquine-resistant parasites (K1 strain) showing an IC(50) of 13 and 7.82 µg/mL, respectively, and was 3.5-fold more effective than benznidazole in anti-Trypanosoma cruzi assay. However, despite of the potential against promatigotes forms, this compound was not effective against amastigotes of L. (L.) chagasi and T. cruzi. The cytotoxicity study using Kidney Rhesus monkey cells, demonstrated that jacaranone showed selectivity against P. falciparum (21.75 µg/mL) and a selectivity index of 3. The obtained results suggested that jacaranone, as other similar secondary metabolites or synthetic analogs, might be useful tolls for drug design for in vivo studies against protozoan diseases.

In vitro and experimental therapeutic studies of the calcium channel blocker bepridil: detection of viable Leishmania (L.) chagasi by real-time PCR.

The need for novel and efficacious drugs against neglected parasitic diseases, such as Leishmaniasis and American Trypanosomiasis, is certainly apparent. In this work, we evaluated the in vitro potential of the calcium channel blocker bepridil against Leishmania spp. and Trypanosoma cruzi parasites and exploited an experimental assay using a hamster model with Leishmania (L.) chagasi, with a real-time PCR method for therapeutic evaluation. Bepridil was in vitro effective against promastigotes and intracellular amastigotes of L. (L.) chagasi, with 50% inhibitory concentration (IC(50)) values of 3.81 and 21.55 µM, respectively. Leishmania (L.) amazonensis, L. (L.) major and L. (V.) braziliensis promastigotes and T. cruzi trypomastigotes were also susceptible to bepridil, with in vitro selectivity toward parasites and IC(50) values in the range of 3 to 7 µM. The mammalian cytotoxicity using LLC-MK2 cells resulted in an IC(50) value of 62.67 µM. However, bepridil showed lack of activity at 12 mg/kg in the experimental hamster model infected with L. (L.) chagasi parasites. However, the real-time PCR was a promising tool for the accurate and fast quantification of RNA of living parasites in the liver and spleen of infected hamsters after treatment, eliminating time-consuming light microscopy evaluations.

Anti-leishmanial and anti-trypanosomal potential of polygodial isolated from stem barks of Drimys brasiliensis Miers (Winteraceae).

Parasitic protozoan diseases affect the poorest population in developing countries. Leishmaniasis and Chagas disease have been included among the most important threats for public health in Central and South American continent, with few therapeutic alternatives and highly toxic drugs. In the course of selection of novel drug candidates, we studied the anti-protozoal potential of Drimys brasiliensis. Thus, the crude hexane extract from stem bark as well as its main derivative, the sesquiterpene polygodial, were tested using in vitro assays. The crude hexane extract and polygodial showed activity against Leishmania spp. in the range between 22 and 62 µg/mL, but polygodial demonstrated high parasite selectivity towards Trypanosoma cruzi trypomastigotes (2 µg/mL), with a selectivity index of 19. Finally, polygodial showed a leishmanicidal effect, inducing intense ultrastructural damages in Leishmania in short-time incubation. The obtained results suggested that polygodial could be used as a tool for drug design studies against protozoan diseases and as a candidate molecule for further in vivo studies against T. cruzi.

Anti-leishmanial and anti-trypanosomal activities of 1,4-dihydropyridines: In vitro evaluation and structure-activity relationship study.

Leishmaniasis and Chagas' disease constitute a relevant health and socio-economic problem in Latin America, Africa, and Asia. The therapeutic interventions rely on inefficient and highly toxic drugs with systemic side effects in patients. Considering the multiple biological activities of the calcium channel blockers and the high versatility of 1,4-dihydropyridines, eight clinically used 1,4-dihydropyridines (azelnidipine, amlodipine, cilnidipine, lercanidipine, nicardipine, nifedipine, nimodipine and nitrendipine) were in vitro tested against Leishmania and Trypanosoma cruzi parasites, and their cytotoxicity was tested against mammalian cells. In addition, a QSAR study was performed in order to delineate further structural requirements for the anti-protozoan activity and to predict the biological potency of 1,4-dihydropyridines. The tested compounds were effective against Leishmania (L.) amazonensis, Leishmania (V.)braziliensis, Leishmania (L.) chagasi, and Leishmania (L.) major promastigotes, L. (L.) chagasi intracellular amastigotes and T. cruzi trypomastigotes with 50% inhibitory concentration (IC(50)) values in the range of 2.6-181µM. The QSAR provided useful information about the structural features of the anti-protozoan activities, including diphenylpropyl and diphenylmethylazetidin groups at position 4 of the 1,4-dihydropyridine ring, allowing the prediction of two novel potential anti-protozoan analogs.

Isolation of an antileishmanial and antitrypanosomal flavanone from the leaves of Baccharis retusa DC. (Asteraceae).

In the course of selection of new bioactive compounds from Brazilian flora, the crude MeOH extract from the leaves of Baccharis retusa DC. (Asteraceae) showed potential against Leishmania sp. and Trypanosoma cruzi. Chromatographic fractionation of the dichloromethane phase from MeOH extract yielded great amounts of the bioactive derivative, which was characterized as 5,6,7-trihydroxy-4'-methoxyflavanone. The structure of this compound was established on the basis of spectroscopic data analysis, mainly nuclear magnetic resonance and mass spectrometry.

The preclinical discovery and development of oral miltefosine for the treatment of visceral leishmaniasis: a case history.

INTRODUCTION: Visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania donovani or Leishmania infantum. Closely related to poverty, VL is fatal and represents one of the main burdens on public health in developing countries. Treatment of VL relies exclusively on chemotherapy, a strategy still experiencing numerous limitations. Miltefosine (MF) has been used in the chemotherapy of VL in some endemic areas, and has been expanded to other regions, being considered crucial in eradication programs. AREAS COVERED: This article reviews the most relevant preclinical and clinical aspects of MF, its mechanism of action and resistance to Leishmania parasites, as well as its limitations. The authors also give their perspectives on the treatment of VL. EXPERT OPINION: The discovery of MF represented an enormous advance in the chemotherapy of VL, since it was the first oral drug for this neglected disease. Beyond selection of resistant parasites due to drug pressure, several other factors can lead to treatment failure such as, for example, factors intrinsic to the host, parasite and the drug itself. Although its efficacy as a monotherapy has reduced over recent years, MF is still an important alternative in VL chemotherapy, especially when used in combination with other drugs.

Dehydrodieugenol B derivatives as antiparasitic agents: Synthesis and biological activity against Trypanosoma cruzi.

Chagas disease is a neglected protozoan disease that affects more than eight million people in developing countries. Due to the limited number and toxicity profiles of therapies in current use, new drugs are urgently needed. In previous studies, we reported the isolation of two related antitrypanosomal neolignans from Nectandra leucantha (Lauraceae). In this work, a semi-synthetic library of twenty-three neolignan derivatives was prepared to explore synthetically accessible structure activity relationships (SAR) against Trypanosoma cruzi. Five compounds demonstrated activity against trypomastigotes (IC50 values from 8 to 64 µM) and eight showed activity against intracellular amastigotes (IC50 values from 7 to 16 µM). Eighteen derivatives demonstrated no mammalian cytotoxicity up to 200 µM. The phenolic acetate derivative of natural dehydrodieugenol B was effective against both parasite forms and eliminated 100% of amastigotes inside macrophages. This compound caused rapid and intense depolarization of the mitochondrial membrane potential, with decreased levels of intracellular reactive oxygen species being observed. Fluorescence assays demonstrated that this derivative affected neither the permeability nor the electric potential of the parasitic plasma membrane, an effect also corroborated by scanning electron microscopy studies. Structure-activity relationship studies (SARs) demonstrated that the presence of at least one allyl side chain on the biaryl ether core was important for antitrypanosomal activity, and that the free phenol is not essential. This set of neolignan derivatives represents a promising starting point for future Chagas disease drug discovery studies.

A Luciferase-Expressing Leishmania braziliensis Line That Leads to Sustained Skin Lesions in BALB/c Mice and Allows Monitoring of Miltefosine Treatment Outcome.

BACKGROUND: Leishmania braziliensis is the most prevalent species isolated from patients displaying cutaneous and muco-cutaneous leishmaniasis in South America. However, there are difficulties for studying L. braziliensis pathogenesis or response to chemotherapy in vivo due to the natural resistance of most mouse strains to infection with these parasites. The aim of this work was to develop an experimental set up that could be used to assess drug efficacy against L. braziliensis. The model was tested using miltefosine. METHODOLOGY/PRINCIPAL FINDINGS: A L. braziliensis line, originally isolated from a cutaneous leishmaniasis patient, was passaged repeatedly in laboratory rodents and further genetically manipulated to express luciferase. Once collected from a culture of parasites freshly transformed from amastigotes, 106 wild type or luciferase-expressing stationary phase promastigotes were inoculated subcutaneously in young BALB/c mice or golden hamsters. In both groups, sustained cutaneous lesions developed at the site of inoculation, no spontaneous self- healing being observed 4 months post-inoculation, if left untreated. Compared to the wild type line features, no difference was noted for the luciferase-transgenic line. Infected animals were treated with 5 or 15 mg/kg/day miltefosine orally for 15 days. At the end of treatment, lesions had regressed and parasites were not detected. However, relapses were observed in animals treated with both doses of miltefosine. CONCLUSIONS/SIGNIFICANCE: Here we described experimental settings for a late-healing model of cutaneous leishmaniasis upon inoculation of a luciferase-expressing L. braziliensis line that can be applied to drug development projects. These settings allowed the monitoring of the transient efficacy of a short-term miltefosine administration.

Generation of luciferase-expressing Leishmania infantum chagasi and assessment of miltefosine efficacy in infected hamsters through bioimaging.

BACKGROUND: The only oral drug available for the treatment of leishmaniasis is miltefosine, described and approved for visceral leishmaniasis in India. Miltefosine is under evaluation for the treatment of cutaneous leishmaniasis in the Americas although its efficacy for the treatment of human visceral leishmaniasis caused by Leishmania infantum chagasi has not been described. Drug efficacy for visceral leishmaniasis is ideally tested in hamsters, an experimental model that mimics human disease. Luciferase has been validated as a quantitative tool for the determination of parasite burden in experimental leishmaniasis. However, there are no reports of luciferase detection in the model of progressive visceral leishmaniasis in hamsters. Therefore, the aims of this study were to generate recombinant Leishmania infantum chagasi expressing the luciferase gene (Lc-LUC), characterize the biological properties of this transgenic line as compared with the wild-type parasites and evaluate miltefosine effectiveness in Lc-LUC infected hamsters. METHODOLOGY/PRINCIPAL FINDINGS: A transgenic line containing a luciferase encoding gene integrated into the ribosomal DNA locus was obtained and shown to produce bioluminescence which correlated with the number of parasites. Lc-LUC growth curves and susceptibility to pentavalent antimony and miltefosine in vitro were indistinguishable from the wild-type parasites. The effectiveness of pentavalent antimony was evaluated in Lc-LUC infected hamsters through bioimaging and determination of Leishman Donovan Units. Both methods showed concordant results. Miltefosine was effective in the treatment of Lc-LUC-infected hamsters, as demonstrated by the reduction in parasite burden in a dose-dependent manner and by prolongation of animal survival. CONCLUSIONS/SIGNIFICANCE: Luciferase expressing parasites are a reliable alternative for parasite burden quantification in hamsters with advantages such as the possibility of estimating parasite load before drug treatment and therefore allowing distribution of animals in groups with equivalent mean parasite burden. Miltefosine was effective in vivo in an L. infantum chagasi experimental model of infection.

Combination therapy with nitazoxanide and amphotericin B, Glucantime®, miltefosine and sitamaquine against Leishmania (Leishmania) infantum intracellular amastigotes.

Leishmaniasis is a neglected disease that affects poorest population mainly in developing countries, representing one of the major causes of mortality and morbidity. Therefore, efforts to find new chemotherapeutics for leishmaniasis remain a priority. Previous reports demonstrated the in vitro and in vivo antileishmanial activity of nitazoxanide, an antiprotozoan agent used in the treatment of infectious diarrhea. The present work was carried out to determine the effect of nitazoxanide in combination with current antileishmanial drugs. Mouse peritoneal macrophages were infected with Leishmania (Leishmania) infantum amastigotes in order to calculate the 50% and 90% inhibitory concentration values. Drug interactions were assessed with fixed ratio isobologram method and fractional inhibitory concentrations (FIC50 and FIC90); sum of FIC (ΣFIC50 and ΣFIC90) and overall mean ΣFIC (xΣFIC50 and xΣFIC90) were calculated for each combination. The nature of interactions was classified according to the xΣFIC50 and xΣFIC90. The combination between nitazoxanide and amphotericin B, Glucantime(®), miltefosine and sitamaquine showed xΣFIC50 values of 1.13, 0.83, 1.06 and 0.94, respectively, indicating additive interaction. Considering the in vitro activity of nitazoxanide and the obtained results, further in vivo studies may be considered to evaluate possible drug interactions in visceral leishmaniasis.

Antileishmanial activity of the estrogen receptor modulator raloxifene.

BACKGROUND: The treatment of leishmaniasis relies mostly on parenteral drugs with potentially serious adverse effects. Additionally, parasite resistance in the treatment of leishmaniasis has been demonstrated for the majority of drugs available, making the search for more effective and less toxic drugs and treatment regimens a priority for the control of leishmaniasis. The aims of this study were to evaluate the antileishmanial activity of raloxifene in vitro and in vivo and to investigate its mechanism of action against Leishmania amazonensis. METHODOLOGY/PRINCIPAL FINDINGS: Raloxifene was shown to possess antileishmanial activity in vitro against several species with EC50 values ranging from 30.2 to 38.0 µM against promastigotes and from 8.8 to 16.2 µM against intracellular amastigotes. Raloxifene's mechanism of action was investigated through transmission electron microscopy and labeling with propidium iodide, DiSBAC2(3), rhodamine 123 and monodansylcadaverine. Microscopic examinations showed that raloxifene treated parasites displayed autophagosomes and mitochondrial damage while the plasma membrane remained continuous. Nonetheless, plasma membrane potential was rapidly altered upon raloxifene treatment with initial hyperpolarization followed by depolarization. Loss of mitochondrial membrane potential was also verified. Treatment of L. amazonensis-infected BALB/c mice with raloxifene led to significant decrease in lesion size and parasite burden. CONCLUSIONS/SIGNIFICANCE: The results of this work extend the investigation of selective estrogen receptor modulators as potential candidates for leishmaniasis treatment. The antileishmanial activity of raloxifene was demonstrated in vitro and in vivo. Raloxifene produces functional disorder on the plasma membrane of L. amazonensis promastigotes and leads to functional and morphological disruption of mitochondria, which culminate in cell death.

Dehydrodieugenol B derivatives as antiparasitic agents: Synthesis and biological activity against Trypanosoma cruzi

Chagas disease is a neglected protozoan disease that affects more than eight million people in developing countries. Due to the limited number and toxicity profiles of therapies in current use, new drugs are urgently needed. In previous studies, we reported the isolation of two related antitrypanosomal neo- lignans from Nectandra leucantha (Lauraceae). In this work, a semi-synthetic library of twenty-three neolignan derivatives was prepared to explore synthetically accessible structure activity relationships (SAR) against Trypanosoma cruzi. Five compounds demonstrated activity against trypomastigotes (IC50 values from 8 to 64 mM) and eight showed activity against intracellular amastigotes (IC50 values from 7 to 16 mM). Eighteen derivatives demonstrated no mammalian cytotoxicity up to 200 mM. The phenolic ac- etate derivative of natural dehydrodieugenol

Parasite burden in Leishmania (Leishmania) amazonensis-infected mice: validation of luciferase as a quantitative tool.

Given the lack of effective and safe alternatives to the drugs already in use, considerable efforts are being applied to the search of new therapeutic options to treat leishmaniasis. A necessary step in the discovery of antileishmanial drugs is the validation of drug candidates in mouse models. The standard methods to quantify the parasite burden in animal models, mainly culture-based, are time consuming and expensive. In recent years, in vivo imaging systems have been proposed as a tool to overcome these problems, allowing parasite detection in living organisms. Here we compared different treatment efficacy evaluation approaches. Recombinant Leishmania (L.) amazonensis lines expressing the luciferase gene (La-LUC) were obtained and characterized for biological properties as compared with the wild type (WT) parental line. Bioluminescence generated by La-LUC was shown to correlate with the number of promastigotes in vitro. La-LUC promastigotes and intracellular amastigotes were equally sensitive to amphotericin B (AmB) as the WT parasites. The clinical pattern of lesion development upon infection with the transgenic lines was similar to lesions observed after infection with the WT strain. The half maximal effective dose (ED50) of AmB was determined in La-LUC infected mice through quantification of bioluminescence in vivo and ex vivo, by limiting dilution and using clinical parameters. There was agreement in the ED50 determined by all methods. Quantification of bioluminescence in vivo and/or ex vivo was elected as the best tool for determining parasite burden to assess drug efficacy in infected mice. Furthermore, the detailed analysis of AmB effectiveness in this model generated useful data to be used in drug combination experiments.

Antiparasitic, antineuroinflammatory, and cytotoxic polyketides from the marine sponge Plakortis angulospiculatus collected in Brazil.

Investigation of the bioactive crude extract from the sponge Plakortis angulospiculatus from Brazil led to the isolation of plakortenone ( 1) as a new polyketide, along with five known polyketides ( 2- 6) previously isolated from other Plakortis sponges. The known polyketides were tested in antileishmanial, antitrypanosomal, antineuroinflammatory, and cytotoxicity assays. The results show that plakortide P ( 3) is a potent antiparasitic compound, against both Leishmania chagasi and Trypanosona cruzi, and exhibited antineuroinflammatory activity. The known polyketides 2- 6 were tested for cytotoxicity against four human cancer cell lines, but displayed only moderate cytotoxic activity.

Chemical constituents of the volatile oil from leaves of Annona coriacea and in vitro antiprotozoal activity

The essential oil of the leaves from Annona coriacea Mart., Annonaceae, was extracted by hydrodistillation in a Clevenger apparatus and analyzed by GC/MS and GC/FID. The oil yield was 0.05 percent m/m. Sixty compounds were identified, in a complex mixture of sesquiterpenes (76.7 percent), monoterpenes (20.0 percent) and other constituents (3.3 percent). Bicyclogermacrene was its major compound (39.8 percent) followed by other sesquiterpenes. Most of the monoterpenes were in low concentration (<1 percent). Only β-pinene and pseudolimonene presented the highest level of 1.6 percent. The volatile oil presented anti-leishmanial and trypanocidal activity against promastigotes of four species of Leishmania and trypomastigotes of Trypanosoma cruzi, showing to be more active against Leishmania (L.) chagasi (IC50 39.93 µ g/mL) (95 percent CI 28.00-56.95 µ g/mL).