Evaluation of the In Vitro Antiparasitic Effect of the Essential Oil of Cymbopogon winterianus and Its Chemical Composition Analysis.

Cymbopogon winterianus, known as "citronella grass", is an important aromatic and medicinal tropical herbaceous plant. The essential oil of C. winterianus (EOCw) is popularly used to play an important role in improving human health due to its potential as a bioactive component. The present study aimed to identify the components of the essential oil of C. winterianus and verify its leishmanicidal and trypanocidal potential, as well as the cytotoxicity in mammalian cells, in vitro. The EOCw had geraniol (42.13%), citronellal (17.31%), and citronellol (16.91%) as major constituents. The essential oil only exhibited significant cytotoxicity in mammalian fibroblasts at concentrations greater than 250 µg/mL, while regarding antipromastigote and antiepimastigote activities, they presented values considered clinically relevant, since both had LC50 < 62.5 µg/mL. It can be concluded that this is a pioneer study on the potential of the essential oil of C. winterianus and its use against the parasites T. cruzi and L. brasiliensis, and its importance is also based on this fact. Additionally, according to the results, C. winterianus was effective in presenting values of clinical relevance and low toxicity and, therefore, an indicator of popular use.

Cytotoxicity of Essential Oil Cordia verbenaceae against Leishmania brasiliensis and Trypanosoma cruzi.

The species Cordia verbenacea DC (Boraginaceae), known as the whaling herb and camaradinha, is a perennial shrub species native to the Atlantic Forest. Its leaves are used in folk medicine as an anti-inflammatory, analgesic, antiulcerogenic and curative agent, in the form of teas or infusions for internal or topical use. The present study aimed to verify the cytotoxicity of the essential oil and the leishmanicidal and trypanocidal potential of C. verbenacea. The essential oil was characterized by GC-MS. The in vitro biological activity was determined by anti-Leishmania and anti-Trypanosoma assays. The cytotoxixity was determined using mammalian fibroblasts. The C. verbenacea species presented α-pinene (45.71%), ß-caryophyllene (18.77%), tricyclo[2,2,1-(2.6)]heptane (12.56%) as their main compounds. The essential oil exhibited strong cytotoxicity at concentrations below 250 µg/mL (LC50 138.1 µg/mL) in mammalian fibroblasts. The potent anti-trypanosome and anti-promastigote activities occurred from the concentration of 62.5 µg/mL and was considered clinically relevant. The results also demonstrate that at low concentrations (<62.5 µg/mL), the essential oil of C. verbenacea managed to be lethal for these activities. This can be considered an indication of the power used in daily human consumption. Therefore, it can be concluded that the essential oil of C. verbenacea contains a compound with remarkable antiparasitic activities and requires further research.

Synthesis, trypanocidal and anti-leishmania activity of new triazole-lapachol and nor-lapachol hybrids.

A new library of twenty triazole-lapachol and nor-lapachol derivatives was synthesized. The compounds were evaluated against the epimastigotes form of Trypanosoma cruzi and promastigotes of Leishmania braziliensis and L. infantum. The cytotoxicity of the compounds was determined on murine fibroblasts and used to assess the selectivity index. The introduction of triazole rings in the naphthoquinone derivatives improved activity against the parasitic protozoa T. cruzi and Leishmania species. Some of the derivatives were three to six times more potent than benznidazole against T. cruzi, with similar or slightly better selectivity indexes. The results against L. braziliensis showed that the derivatives 5b and 5e were the most selective compounds. However, they were less selective than the reference compound, miltefosine. Among all products, the derivative 3a was the most selective compound against L. infantum. Nevertheless, it was less potent and less selective than miltefosine. Also, the minimum inhibitory concentration values of the derivatives against nine different bacteria were determined. Moderate antibacterial activity was observed for compound 5c against Staphylococcus aureus.

Engineering Oral and Parenteral Amorphous Amphotericin B Formulations against Experimental Trypanosoma cruzi Infections.

Chagas disease (CD) is a parasitic zoonosis endemic in most mainland countries of Central and South America affecting nearly 10 million people, with 100 million people at high risk of contracting the disease. Treatment is only effective if received at the early stages of the disease. Only two drugs (benznidazole and nifurtimox) have so far been marketed, and both share various limitations such as variable efficacy, many side effects, and long duration of treatment, thus reducing compliance. The in vitro and in vivo efficacy of poly-aggregated amphotericin B (AmB), encapsulated poly-aggregated AmB in albumin microspheres (AmB-AME), and dimeric AmB-sodium deoxycholate micelles (AmB-NaDC) was evaluated. Dimeric AmB-NaDC exhibited a promising selectivity index (SI = 3164) against amastigotes, which was much higher than those obtained for licensed drugs (benznidazole and nifurtimox). AmB-AME, but not AmB-NaDC, significantly reduced the parasitemia levels (3.6-fold) in comparison to the control group after parenteral administration at day 7 postinfection. However, the oral administration of AmB-NaDC (10-15 mg/kg/day for 10 days) resulted in a 75% reduction of parasitemia levels and prolonged the survival rate in 100% of the tested animals. Thus, the results presented here illustrate for the first time the oral efficacy of AmB in the treatment of trypanosomiasis. AmB-NaDC is an easily scalable, affordable formulation prepared from GRAS excipients, enabling treatment access worldwide, and therefore it can be regarded as a promising therapy for trypanosomiasis.

Antiprotozoal Activity of Triazole Derivatives of Dehydroabietic Acid and Oleanolic Acid.

Tropical parasitic diseases such as Chagas disease and leishmaniasis are considered a major public health problem affecting hundreds of millions of people worldwide. As the drugs currently used to treat these diseases have several disadvantages and side effects, there is an urgent need for new drugs with better selectivity and less toxicity. Structural modifications of naturally occurring and synthetic compounds using click chemistry have enabled access to derivatives with promising antiparasitic activity. The antiprotozoal activity of the terpenes dehydroabietic acid, dehydroabietinol, oleanolic acid, and 34 synthetic derivatives were evaluated against epimastigote forms of Trypanosoma cruzi and promastigotes of Leishmaniabraziliensis and Leishmania infantum. The cytotoxicity of the compounds was assessed on NCTC-Clone 929 cells. The activity of the compounds was moderate and the antiparasitic effect was associated with the linker length between the diterpene and the triazole in dehydroabietinol derivatives. For the oleanolic acid derivatives, a free carboxylic acid function led to better antiparasitic activity.

Multi-Anti-Parasitic Activity of Arylidene Ketones and Thiazolidene Hydrazines against Trypanosoma cruzi and Leishmania spp.

A series of fifty arylideneketones and thiazolidenehydrazines was evaluated against Leishmania infantum and Leishmania braziliensis. Furthermore, new simplified thiazolidenehydrazine derivatives were evaluated against Trypanosoma cruzi. The cytotoxicity of the active compounds on non-infected fibroblasts or macrophages was established in vitro to evaluate the selectivity of their anti-parasitic effects. Seven thiazolidenehydrazine derivatives and ten arylideneketones had good activity against the three parasites. The IC50 values for T. cruzi and Leishmania spp. ranged from 90 nM-25 µM. Eight compounds had multi-trypanocidal activity against T. cruzi and Leishmania spp. (the etiological agents of cutaneous and visceral forms). The selectivity of these active compounds was better than the three reference drugs: benznidazole, glucantime and miltefosine. They also had low toxicity when tested in vivo on zebrafish. Trying to understand the mechanism of action of these compounds, two possible molecular targets were investigated: triosephosphate isomerase and cruzipain. We also used a molecular stripping approach to elucidate the minimal structural requirements for their anti-T. cruzi activity.

Antiprotozoan lead discovery by aligning dry and wet screening: prediction, synthesis, and biological assay of novel quinoxalinones.

Protozoan parasites have been one of the most significant public health problems for centuries and several human infections caused by them have massive global impact. Most of the current drugs used to treat these illnesses have been used for decades and have many limitations such as the emergence of drug resistance, severe side-effects, low-to-medium drug efficacy, administration routes, cost, etc. These drugs have been largely neglected as models for drug development because they are majorly used in countries with limited resources and as a consequence with scarce marketing possibilities. Nowadays, there is a pressing need to identify and develop new drug-based antiprotozoan therapies. In an effort to overcome this problem, the main purpose of this study is to develop a QSARs-based ensemble classifier for antiprotozoan drug-like entities from a heterogeneous compounds collection. Here, we use some of the TOMOCOMD-CARDD molecular descriptors and linear discriminant analysis (LDA) to derive individual linear classification functions in order to discriminate between antiprotozoan and non-antiprotozoan compounds as a way to enable the computational screening of virtual combinatorial datasets and/or drugs already approved. Firstly, we construct a wide-spectrum benchmark database comprising of 680 organic chemicals with great structural variability (254 of them antiprotozoan agents and 426 to drugs having other clinical uses). This series of compounds was processed by a k-means cluster analysis in order to design training and predicting sets. In total, seven discriminant functions were obtained, by using the whole set of atom-based linear indices. All the LDA-based QSAR models show accuracies above 85% in the training set and values of Matthews correlation coefficients (C) vary from 0.70 to 0.86. The external validation set shows rather-good global classifications of around 80% (92.05% for best equation). Later, we developed a multi-agent QSAR classification system, in which the individual QSAR outputs are the inputs of the aforementioned fusion approach. Finally, the fusion model was used for the identification of a novel generation of lead-like antiprotozoan compounds by using ligand-based virtual screening of 'available' small molecules (with synthetic feasibility) in our 'in-house' library. A new molecular subsystem (quinoxalinones) was then theoretically selected as a promising lead series, and its derivatives subsequently synthesized, structurally characterized, and experimentally assayed by using in vitro screening that took into consideration a battery of five parasite-based assays. The chemicals 11(12) and 16 are the most active (hits) against apicomplexa (sporozoa) and mastigophora (flagellata) subphylum parasites, respectively. Both compounds depicted good activity in every protozoan in vitro panel and they did not show unspecific cytotoxicity on the host cells. The described technical framework seems to be a promising QSAR-classifier tool for the molecular discovery and development of novel classes of broad-antiprotozoan-spectrum drugs, which may meet the dual challenges posed by drug-resistant parasites and the rapid progression of protozoan illnesses.

Quality assurance of serologic testing for Chagas disease in a primary care setting of rural Paraguay.

The diagnosis of Chagas disease mostly relies on the use of multiple serologic tests that are often unavailable in many of the remote settings where the disease is highly prevalent. In the Teniente Irala Fernández Municipality, in central Paraguay, efforts have been made to increase the diagnostic capabilities of specific rural health centres, but no quality assurance of the results produced has been performed. We comparatively analysed the results obtained with 300 samples tested using a commercial rapid diagnostic test (RDT) and enzyme linked immunosorbent assays (ELISA) at the laboratory of the Teniente Irala Fernández Health Center (CSTIF) with those generated upon repeating the tests at an independent well-equipped research laboratory (CEDIC). A subgroup of 52 samples were further tested at Paraguay's Central Public Health Laboratory (LCSP) by means of a different technique to evaluate the diagnostic performance of the tests carried out at CSTIF. We observed an excellent agreement between the ELISA results obtained at CSTIF and CEDIC (kappa coefficients between 0.85 and 0.93 for every kit evaluated), and an overall good performance of the tests carried out at CSTIF. However, the sensitivity of one kit was lower at CSTIF (81.3 %) than at CEDIC (100 %). The individual use of an RDT to detect the infection at CSTIF showed a similar sensitivity to that obtained combining it to an ELISA test (92.3% vs 88.5, p = 1). Nonetheless, the generalizability of this result is yet limited and will require of further studies.

Phenol composition, cytotoxic and anti-kinetoplastidae activities of Lygodium venustum SW. (Lygodiaceae).

The search for new therapeutic agents has been a constant for the treatment of diseases such as leishmaniasis and Chagas disease. Most drugs used have side effects, justifying the need to evaluate the cytotoxicity of the tested products for candidates to new drugs. In this study, the bioactivity of Lygodium venustum, a cosmopolitan fern of Lygodiaceae, was assessed about their leishmanicidal and trypanocidal potential. The better activity was observed using methanol fraction, with inhibition percentage of 63% and 68% for promastigotes and epimastigotes, respectively, at a concentration of 500 µg/mL. The ethyl acetate and methanol fractions demonstrated a higher cytotoxic potential. This was the first report of leishmanicidal, trypanocidal and cytotoxic activities to L. venustum.

Anti-Trypanosoma cruzi and cytotoxic activities of Eugenia uniflora L.

Chagas disease is caused by Trypanosoma cruzi, being considered a public health problem. An alternative to combat this pathogen is the use of natural products isolated from fruits such as Eugenia uniflora, a plant used by traditional communities as food and medicine due to its antimicrobial and biological activities. Ethanolic extract from E. uniflora was used to evaluate in vitro anti-epimastigote and cytotoxic activity. This is the first record of anti-Trypanosoma activity of E. uniflora, demonstrating that a concentration presenting 50% of activity (EC(50)) was 62.76 µg/mL. Minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Our results indicate that E. uniflora could be a source of plant-derived natural products with anti-epimastigote activity with low toxicity.

Trypanocide, cytotoxic, and antifungal activities of Momordica charantia.

CONTEXT: Chagas disease, caused by Trypanosoma cruzi, is a public health problem. Currently, chemotherapy is the only available treatment for this disease, and the drugs used, nifurtimox and benzonidazol, present high toxicity levels. An alternative for replacing these drugs are natural extracts from Momordica charantia L. (Cucurbitaceae) used in traditional medicine because of their antimicrobial and biological activities. OBJECTIVE: In this study, we evaluated the extract of M. charantia for its antiepimastigote, antifungal, and cytotoxic activities. MATERIALS AND METHODS: An ethanol extract of leaves from M. charantia was prepared. To research in vitro antiepimastigote activity, T. cruzi CL-B5 clone was used. Epimastigotes were inoculated at a concentration of 1 × 10(5) cells/mL in 200 µl tryptose-liver infusion. For the cytotoxicity assay, J774 macrophages were used. The antifungal activity was evaluated by microdilution using strains of Candida albicans, Candida tropicalis, and Candida krusei. RESULTS: The effective concentration capable of killing 50% of parasites (IC(50)) was 46.06 µg/mL. The minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Metronidazole showed a potentiation of its antifungal effect when combined with an extract of M. charantia. CONCLUSIONS: Our results indicate that M. charantia could be a source of plant-derived natural products with antiepimastigote and antifungal-modifying activity with moderate toxicity.

First study of in vitro protective effect of Lepidium meyenii (Maca) on frozen-thawed bovine spermatozoa.

Background and Aim: Lepidium meyenii Walp (Maca) is an herbaceous plant that grows in the Peruvian Andes and it has been widely used as a nutritional supplement and fertility enhancer and has been used in the treatment of a variety of diseases, such as rheumatism, respiratory disorders, and anemia. The most notable feature of Maca is its potent antioxidant capacity, which helps in the scavenging of free radicals and protection of cells from oxidative stress. This study aimed to evaluate the in vitro effect of Maca extract on thawed sperm cells from bulls. Materials and Methods: Three dilutions of 1, 10, and 100 mg/mL of Maca extract were incubated with frozen-thawed bovine semen and analyzed at 1, 3, and 24 h of exposure time, evaluating the activity of the extract on the DNA, motility, morphology, viability, integrity of the membrane and acrosome of spermatozoa. Results: The Maca extract improved the studied sperm parameters of motility, acrosome integrity, vitality, and DNA integrity of sperm cells at a concentration of 10 mg/mL, and at 1 mg/mL, an improvement was observed in the morphology and integrity of the membrane. However, the best activity of the Maca extract was observed on the DNA integrity of the sperm, which was effective at the three concentrations evaluated after 24 h of incubation. Conclusion: The results indicate that L. meyenii can help in maintaining spermatozoa cellular integrity after the frozen-thaw process, especially in the protection against DNA fragmentation. Therefore, Maca would be a feasible supplementation to protect sperm to maintain their fertile ability after thawing.

Dynamics of Triatoma infestans populations in the Paraguayan Chaco: Population genetic analysis of household reinfestation following vector control.

BACKGROUND: Although domestic infestations by Triatoma infestans have been successfully controlled across Latin America, in areas of the Gran Chaco region, recurrent post-spraying house colonization continues to be a significant challenge, jeopardizing Chagas disease vector control and maintaining active Trypanosoma cruzi transmission. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the dynamics of triatomine reinfestation in a rural area of the Paraguayan Chaco, genetic characterization (based on 10 microsatellite loci and cytochrome B sequence polymorphisms) was performed on baseline and reinfestant T. infestans (n = 138) from four indigenous communities and adjacent sylvatic sites. House quality and basic economic activities were assessed across the four communities. Significant genetic differentiation was detected among all baseline triatomine populations. Faster reinfestation was observed in the communities with higher infestation rates pre-spraying. Baseline and reinfestant populations from the same communities were not genetically different, but two potentially distinct processes of reinfestation were evident. In Campo Largo, the reinfestant population was likely founded by domestic survivor foci, with reduced genetic diversity relative to the baseline population. However, in 12 de Junio, reinfestant bugs were likely derived from different sources, including survivors from the pre-spraying population and sympatric sylvatic bugs, indicative of gene-flow between these habitats, likely driven by high human mobility and economic activities in adjacent sylvatic areas. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that sylvatic T. infestans threatens vector control strategies, either as a reinfestation source or by providing a temporary refuge during insecticide spraying. Passive anthropogenic importation of T. infestans and active human interactions with neighboring forested areas also played a role in recolonization. Optimization of spraying, integrated community development and close monitoring of sylvatic areas should be considered when implementing vector control activities in the Gran Chaco.

Solid Nanomedicines of Nifurtimox and Benznidazole for the Oral Treatment of Chagas Disease.

Chagas disease (CD) is a parasitic zoonosis endemic in Central and South America affecting nearly 10 million people, with 100 million people at high risk of contracting the disease. Treatment is only effective when received at the early stages of the disease and it involved two drugs (nifurtimox (NFX) and benznidazole (BNZ)). Both treatments require multiple daily administrations of high doses, suffer from variable efficacy and insufficient efficacy in chronic CD, many side effects, and a very long duration of treatment that results in poor compliance, while combined available therapies that lead to reduced duration of treatment are not available and polypharmacy reduces compliance and increases the cost further. Here we present self-nanoemulsified drug delivery systems (SNEDDS) able to produce easily scalable combined formulations of NFX and BNZ that can allow for tailoring of the dose and can be easily converted to oral solid dosage form by impregnation on mesoporous silica particles. SNEDDS demonstrated an enhanced solubilisation capacity for both drugs as demonstrated by flow-through studies and in vitro lipolysis studies. High loading of SNEDDS to Syloid 244 and 3050 silicas (2:1 w/w) allowed clinically translatable amounts of both NFX and BNZ to be loaded. Tablets prepared from NFX-BNZ combined SNEDDS loaded on Syloid 3050 silicas demonstration near complete dissolution in the flow through cell apparatus compared to NFX and BNZ commercial tablets respectively (Lampit® and Rochagan®). NFX-BNZ-SNEDDS demonstrated nanomolar efficacy in epimastigotes and amastigotes of T. cruzi with acceptable selectivity indexes and demonstrated enhanced survival and reduced parasitaemia in acute murine experimental models of CD. Thus, the results presented here illustrate the ability for an easily scalable and personalised combination oral therapy prepared from GRAS excipients, enabling treatment access worldwide for the treatment of CD.

Sensitivity comparison for the Leishmania spp. detection in different canine tissues using PCR-HRM.

BACKGROUND: Leishmaniasis is a vector-borne disease caused by a parasite protozoon from the genus Leishmania. Among the molecular techniques applied for detecting these parasites, real-time PCR with High Resolution Melting (PCR-HRM) proved advantageous since it simultaneously determines both the presence and species of the pathogen in one step, through amplification and later analysis of curves generated by melting temperature. METHODS: Based on this molecular technique, the goal of this study was to estimate the PCR-HRM sensitivity for Leishmania spp. detection in different canine tissues by evaluating biological samples obtained from popliteal, submandibular, and pre-scapular lymph nodes, from bone marrow and ear pinnae of 28 stray dogs captured in the metropolitan area of Asunción (Paraguay). RESULTS: The rk39 immunochromatographic test showed that 25/28 tested dogs (89%) presented antibodies against L. infantum. In 20/25 dogs that tested positive for rk39 (80%), it was possible to detect Leishmania spp. by PCR-HRM and determine that the species corresponded entirely to L. infantum. Regarding the analysis of different tissues, the parasite was detected in all popliteal lymph node samples, followed by high detection in submandibular (at 95%) and pre-scapular lymph nodes (at 90%), bone marrow (at 85%), and ear pinnae (at 85%). CONCLUSIONS: This study demonstrated that the use of real-time PCR-HRM using the molecular marker hsp70 was a highly sensitive method for simultaneously detecting and identifying Leishmania species in different tissues taken from infected dogs. In addition, the usefulness of ear pinnae as easily accessible tissue for molecular diagnosis was emphasized.

Triazole-Resistance in Environmental Aspergillus fumigatus in Latin American and African Countries.

Triazole-resistance has been reported increasingly in Aspergillus fumigatus. An international expert team proposed to avoid triazole monotherapy for the initial treatment of invasive aspergillosis in regions with >10% environmental-resistance, but this prevalence is largely unknown for most American and African countries. Here, we screened 584 environmental samples (soil) from urban and rural locations in Mexico, Paraguay, and Peru in Latin America and Benin and Nigeria in Africa for triazole-resistant A. fumigatus. Samples were screened using triazole-containing agars and confirmed as triazole-resistant by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth dilution reference method. Isolates were further characterized by cyp51A sequencing and short-tandem repeat typing. Fungicide presence in samples was likewise determined. Among A. fumigatus positive samples, triazole-resistance was detected in 6.9% (7/102) of samples in Mexico, 8.3% (3/36) in Paraguay, 9.8% (6/61) in Peru, 2.2% (1/46) in Nigeria, and none in Benin. Cyp51A gene mutations were present in most of the triazole-resistant isolates (88%; 15/17). The environmentally-associated mutations TR34/L98H and TR46/Y121F/T289A were prevalent in Mexico and Peru, and isolates harboring these mutations were closely related. For the first time, triazole-resistant A. fumigatus was found in environmental samples in Mexico, Paraguay, Peru, and Nigeria with a prevalence of 7-10% in the Latin American countries. Our findings emphasize the need to establish triazole-resistance surveillance programs in these countries.

Chemical Constituents and Biological Activities of Croton heliotropiifolius Kunth.

Croton heliotropiifolius Kunth (Euphorbiaceae), whose occurrence has already been registered in the most varied Brazilian biomes, is commonly found in the Chapada do Araripe, Ceará. The species is traditionally used to treat fungal, parasitic, and degenerative diseases. This study investigated the chemical composition and pharmacological potential (antioxidant, antifungal, antiparasitic, and cytotoxic) of an aqueous extract obtained from the roots of C. heliotropiifolius. Following a qualitative phytochemical screening, the chemical constituents were identified by ultra-efficiency liquid chromatography coupled witha quadrupole/time-of-flight system (UPLC-QTOF). The antioxidant potential was verified by thin-layer chromatography (TLC). The direct and combined antifungal activity of the extract against opportunistic Candida strains was investigated using the microdilution method. The minimal fungicidal concentration (MFC) was determined by subculture, while the modulation of the morphological transition (fungal virulence) was evaluated by light microscopy. The in vitro antiparasitic activity was analyzed using epimastigotes of Trypanosoma cruzi and promastigotes of Leishmania braziliensis and Leishmania infantum, while cytotoxicity was determined in cultures of mouse fibroblasts. The phytochemical analysis identified the presence of acids, terpenes, flavonoids, lignans, and alkaloids. Among these constituents, the presence of polar and non-polar phenolic compounds with known antioxidant action was highlighted. While the extract showed clinically ineffective antifungal effects, it could enhance the effectiveness of fluconazole, in addition to inhibiting the morphological transition associated with increased virulence in Candida strains. Although the extract showed low cytotoxicity against fibroblasts, it also had weak antiparasitic effects. In conclusion, Croton heliotropiifolius is a source of natural products with antifungal and antioxidant potential.

Identification of bloodmeal sources of triatomines captured in the Paraguayan Chaco region of South America by means of molecular biology analysis.

The Paraguayan Chaco is an isolated environment with its own unique ecosystem. In this region, Chagas disease remains a health problem. Chagas disease is caused by the parasite Trypanosoma cruzi, and it is primarily transmitted by triatomines. In order to identify the blood meal sources of triatomines, specimens of the vector were collected in domestic and peridomestic areas and the PCR-RFLP method was implemented. Cytochrome b was amplified from the samples and later subjected to digestion with two restriction enzymes: Hae III and Xho I.It was possible to generate distinct restriction patterns on the amplified material to identify several blood meal sources for the vectors. We employed the blood from several species as positive controls: human, chicken, canine, feline, and armadillo blood. However, we identified only 3 sources for the blood meals of the insect vectors: human, chicken and canine blood. In total, 76 triatomines were captured. T. cruzi was not found in any of them. In 61% of the captured specimens, the blood meal sources for the vectors could be identified. In 30% of these cases, the presence of DNA from more than one vertebrate was detected in the same triatomine. The most common blood meal source found was chicken blood. The presence of human and chicken blood in triatomines captured in domestic and peridomestic areas strongly suggests that the parasite can freely move amongst both areas regardless of food availability. Free vector movement in these areas constitutes an epidemiological threat for the inhabitants of the community under study.

In vivo and in vitro anti-leishmanial activities of 4-nitro-N-pyrimidin- and N-pyrazin-2-ylbenzenesulfonamides, and N2-(4-nitrophenyl)-N1-propylglycinamide.

A series of compounds containing the nitrobenzene and sulfonamido moieties were synthesized and their leishmanicidal effect was assessed in vitro against Leishmaniainfantum promastigotes. Among the compounds evaluated, the p-nitrobenzenesulfonamides 4Aa and 4Ba, and the p-nitroaniline 5 showed significant activity with a good selectivity index. In a Balb/c mice model of L. Infantum, administration of compounds 4Aa, 4Ba or 5 (5mg/kg/day for 10 days, injected ip route) led to a clear-cut parasite burden reduction (ca. 99%). In an attempt to elucidate their mechanism of action, the DNA interaction of 4Aa and 5 was investigated by means of viscosity studies, thermal denaturation and nuclease activity assay. Both compounds showed nuclease activity in the presence of copper salt. The results suggest that compounds 4Aa, 4Ba and 5 represent possible candidates for drug development in the therapeutic control of leishmaniasis.

The efficacy of new 2,5-dihydroxybenzyl derivatives against Trypanosoma cruzi, Leishmania infantum and Leishmania braziliensis.

INTRODUCTION: Chagas disease and Leishmaniasis are among the most important parasitic diseases. They are considered to be within the most relevant group of neglected tropical diseases and have been included as priorities for searching new drugs due to their several treatment limitations. These parasitic diseases caused by flagellated protozoans affect more than 20 million people predominantly in developing countries. METHODOLOGY: In this study, we prepared a series of 2-substituted 1,4-benzenediols by an efficient, green, and lithium salt-free synthesis in water/ethanol as solvent to test their anti-parasitic activity. All 36 phenolic derivatives were evaluated in vitro for their activity against T. cruzi epimastigotes, L. infantum, and L. braziliensis promastigotes, as well as their cytotoxicity on macrophage and fibroblast cell lines. RESULTS: Based on the results obtained, the compounds that presented a methyl, trifluoromethyl or bromo group at the para-position of the second benzene ring were found the most active analogs, with higher selective index values on the three parasites assayed. CONCLUSION: This evidence suggests that the anti-parasitic activity observed in these analogs is affected by the size of the group at the 4-position of the second ring, but not related with electronic factors.This study identified hit compounds with the potential to target several kinetoplastid parasites.