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Nonspecific hypergammaglobulinemia (HGG) occurs in symptomatic human visceral leishmaniasis (VL) caused by L. L. infantum. This study assessed this finding in experimental infection in hamsters and natural infection in dogs. The serum concentration of proteins, albumin and globulins was determined through the biuret and bromocresol green reaction, where the HGG was better expressed through the albumin/globulin (A/G) ratio. HGG was associated with a higher concentration of specific anti-glycan antibodies (BSA-G)/promastigote soluble extract (PSE) and the presence of circulating immune complexes (IC) by dissociative enzyme-linked immunoassay (ELISA). The study found monovalent IC in 37.9% (PSE) and 50% (BSA-G) of sera from infected hamsters, with increased frequency as the disease progressed. HGG was found in >60% of the samples in dogs with VL, associated with higher levels of specific immunoglobulin (Ig)A and IgM, but not IgG, determined using the PSE and BSA-G ELISA. HGG was associated with the presence of monovalent IC in 58.9% (PSE) and 63.4% (BSA-G) positive dog samples. HGG may result not only from the nonspecific activation of B cells, with greater production of specific and nonspecific antibodies, but also due to lower IgG excretion due to the presence of soluble monovalent IC. HGG correlates to the progression of VL and may be a marker for manifested disease.

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In Central America, Leishmania (L.) infantum chagasi infection causes visceral leishmaniasis (VL) and non-ulcerated cutaneous leishmaniasis (NUCL). The aim of the present study was to evaluate the course of an experimental infection in hamsters caused by L. (L.) infantum chagasi isolated from patients affected by NUCL compared with a strain isolated from a patient with VL. Stationary phase parasites in culture were inoculated through subcutaneous and intraperitoneal routes in hamsters. Following the post-infection times, a histopathological study, parasite load and cytokine determination in skin from the cutaneous inoculation site and viscera were performed. Animals subcutaneously infected with the different strains did not develop macroscopic lesions at the inoculation site, and the histopathological changes in the dermis were very slight. Regarding the histopathological study of the viscera, we observed the portal mononuclear inflammatory infiltrate, the presence of nodules in the hepatic parenchyma and the proliferation of macrophages in the spleen, which increased over the infection course. Overall, the parasite load in the liver and spleen and in the total IgG titres in the sera of infected hamster showed an increase with the time of infection, regardless of the route of inoculation. Regarding cellular immunity, we did not observe an increase or decrease in pro- and anti-inflammatory cytokines compared to the healthy control, except for IL-10, which was evident in the infected animals. The data showed that strains isolated from NUCL cause visceral lesions in the hamsters regardless of the route of inoculation, and they were similar to parasites isolated from VL humans.

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ABSTRACT Dogs are considered to be the main domestic reservoir associated with the transmission of Leishmania (L.) infantum chagasi to humans in endemic areas of visceral leishmaniasis in America. However, little is known about the role of canines as a source of infection in endemic areas of nonulcerated cutaneous leishmaniasis (NUCL). Therefore, the objective of the present study was to investigate the role of dogs as a possible reservoir of the parasite in Southern Honduras. Dogs (n = 107) living with individuals affected by NUCL were clinically examined and biological material was collected for parasitological and immunological diagnosis. Most animals showed a healthy appearance and a few presented slight weight loss (64%), alopecia (7%), onychogryphosis (5%) and skin lesions (1%). The overall seroprevalence of Leishmania infection based on the DDP ® quick test and/or in-house ELISA serological test was 41%. The presence of the parasite's DNA was confirmed in 94% of the dogs; however, the average parasite load in the buffy coat was low at 6.09 parasites/µL, ranging between 0.221 and 50.2. The skin of seropositive dogs examined by histopathology using paraffin sections stained by hematoxylin and immunohistochemistry did not show cutaneous lesions or parasite amastigotes. Based on the absence of parasites in the skin and the low parasite load detected in the buffy coat, it seems that the dog does not represent a good source of infection for the vector in the endemic area of NUCL transmission in Southern Honduras. Other domestic and/or wild animals should be investigated.

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This was an open cohort prospective study (2016−2018) that analyzed the prevalence and incidence rates of human Leishmania (L.) infantum chagasi-infection and the evolution of their clinical-immunological profiles in distinct urban and rural scenarios of American visceral leishmaniasis (AVL) in Pará State, in the Brazilian Amazon. These infection profiles were based on species-specific DTH/IFAT-IgG assays and clinical evaluation of infected individuals, comprising five profiles: three asymptomatic, Asymptomatic Infection [AI], Subclinical Resistant Infection [SRI], and Indeterminate Initial Infection [III]; and two symptomatic, Subclinical Oligosymptomatic Infection [SOI] and Symptomatic Infection [SI = AVL]. The two distinct scenarios (900 km away) were the urban area of Conceição do Araguaia municipality and the rural area of Bujaru municipality in the southeast and northeast of Pará State. Human populations were chosen based on a simple convenience sampling design (5−10% in each setting), with 1723 individuals (5.3%) of the population (32,464) in the urban area and 1568 individuals (8.9%) of the population (17,596) in the rural one. A serological survey (IFAT-IgG) of canine infection was also performed in both scenarios: 195 dogs in the urban area and 381 in the rural one. Prevalence and incidence rates of human infection were higher in the urban area (20.3% and 13.6/100 person-years [py]) than in the rural setting (14.1% and 6.8/100-py). The AI profile was the most prevalent and incident in both urban (13.4% and 8.1/100-py) and rural (8.3% and 4.2/100-py) scenarios, but with higher rates in the former. An III profile case evolved to SOI profile after four weeks of incubation and another to SI (=AVL) after six. The prevalence of canine infection in an urban setting (39.2%) was also higher (p < 0.05) than that (32%) in the rural zone. AVL urbanization in Pará State, in the Brazilian Amazon, has led to infection rates significantly higher than those in rural sites, requiring more intense control measures.

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As part of our continuous studies involving the prospection of natural products from Brazilian flora aiming at the discovery of prototypes for the development of new antiparasitic drugs, the present study describes the isolation of two natural acetylene acetogenins, (2S,3R,4R)-3-hydroxy-4-methyl-2-(n-eicos-11'-yn-19'-enyl)butanolide (1) and (2S,3R,4R)-3-hydroxy-4-methyl-2-(n-eicos-11'-ynyl)butanolide (2), from the seeds of Porcelia macrocarpa (Warm.) R.E. Fries (Annonaceae). Using an ex-vivo assay, compound 1 showed an IC50 value of 29.9 µM against the intracellular amastigote forms of Leishmania (L.) infantum, whereas compound 2 was inactive. These results suggested that the terminal double bond plays an important role in the activity. This effect was also observed for the semisynthetic acetylated (1a and 2a) and eliminated (1b and 2b) derivatives, since only compounds containing a double bond at C-19 displayed activity, resulting in IC50 values of 43.3 µM (1a) and 23.1 µM (1b). In order to evaluate the effect of the triple bond in the antileishmanial potential, the mixture of compounds 1 + 2 was subjected to catalytic hydrogenation to afford a compound 3 containing a saturated side chain. The antiparasitic assays performed with compound 3, acetylated (3a), and eliminated (3b) derivatives confirmed the lack of activity. Furthermore, an in-silico study using the SwissADME online platform was performed to bioactive compounds 1, 1a, and 1b in order to investigate their physicochemical parameters, pharmacokinetics, and drug-likeness. Despite the reduced effect against amastigote forms of the parasite to the purified compounds, different mixtures of compounds 1 + 2, 1a + 2a, and 1b + 2b were prepared and exhibited IC50 values ranging from 7.9 to 38.4 µM, with no toxicity for NCTC mammalian cells (CC50 > 200 µM). Selectivity indexes to these mixtures ranged from >5.2 to >25.3. The obtained results indicate that seeds of Porcelia macrocarpa are a promising source of interesting prototypes for further modifications aiming at the discovery of new antileishmanial drugs.

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Visceral leishmaniasis (VL), also known as kala-azar, is an anthropozoonotic disease affecting human populations on five continents. Aetiologic agents belong to the Leishmania (L.) donovani complex. Until the 1990s, three leishmanine parasites comprised this complex: L. (L.) donovani Laveran & Mesnil 1903, L. (L.) infantum Nicolle 1908, and L. (L.) chagasi Lainson & Shaw 1987 (=L. chagasi Cunha & Chagas 1937). The VL causal agent in the New World (NW) was previously identified as L. (L.) chagasi. After the development of molecular characterization, however, comparisons between L. (L.) chagasi and L. (L.) infantum showed high similarity, and L. (L.) chagasi was then regarded as synonymous with L. (L.) infantum. It was, therefore, suggested that L. (L.) chagasi was not native to the NW but had been introduced from the Old World by Iberian colonizers. However, in light of ecological evidence from the NW parasite's enzootic cycle involving a wild phlebotomine vector (Lutzomyia longipalpis) and a wild mammal reservoir (the fox, Cerdocyon thous), we have recently analyzed by molecular clock comparisons of the DNA polymerase alpha subunit gene the whole-genome sequence of L. (L.) infantum chagasi of the most prevalent clinical form, atypical dermal leishmaniasis (ADL), from Honduras (Central America) with that of the same parasite from Brazil (South America), as well as those of L. (L.) donovani (India) and L. (L.) infantum (Europe), which revealed that the Honduran parasite is older ancestry (382,800 ya) than the parasite from Brazil (143,300 ya), L. (L.) donovani (33,776 ya), or L. (L.) infantum (13,000 ya). In the present work, we have now amplified the genomic comparisons among these leishmanine parasites, exploring mainly the variations in the genome for each chromosome, and the number of genomic SNPs for each chromosome. Although the results of this new analysis have confirmed a high genomic similarity (~99%) among these parasites [except L. (L.) donovani], the Honduran parasite revealed a single structural variation on chromosome 17, and the highest frequency of genomic SNPs (more than twice the number seen in the Brazilian one), which together to its extraordinary ancestry (382,800 ya) represent strong evidence that L. (L.) chagasi/L. (L.) infantum chagasi is, in fact, native to the NW, and therefore with valid taxonomic status. Furthermore, the Honduran parasite, the most ancestral viscerotropic leishmanine parasite, showed genomic and clinical taxonomic characteristics compatible with a new Leishmania species causing ADL in Central America.

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Visceral leishmaniasis (VL) is a chronic and often fatal disease caused by protozoans of the genus Leishmania that affects millions of people worldwide. Patients with symptomatic VL have an impaired anti-Leishmania-specific CD4+ T-cell response, which is reversed after clinical cure. In contrast, the quality of the CD4+ and CD8+ T-cell responses involved in resistance and/or cure of VL relies on the capability of these cells to activate polyfunctional and memory responses, which are associated with the simultaneous production of three cytokines: IFN-γ, IL-2, and TNF-α. Models for the development of CD4 and CD8 T-cell quality in memory and protection to leishmaniasis have been described previously. We aimed to assess the functionality of the T cells involved in the recovery of the immune suppression throughout the VL treatment. Therefore, we cultured peripheral blood mononuclear cells (PBMCs) from VL patients and healthy controls in vitro with soluble Leishmania antigen (SLA). Cell surface markers and intracellular cytokine production were determined on days 7, 14, 21, 30, 60, 90, and 180 after the beginning of chemotherapy. We observed that the frequencies of CD4+TNF-α+IFN-γ+ and the multifunctional CD4+IL-2+TNF-α+IFN-γ+, together with CD4+TNF-α+ and CD4+IFN-γ+ T cells, increased throughout and at the end of the treatment, respectively. In addition, enhanced frequencies of CD8+IL-2+TNF-α+IFN-γ+ and CD8+TNF-α+IFN-γ T cells were also relevant in the healing process. Noteworthy, the frequencies of the CD4+ and CD8 central-memory T cells, which produce IL-2, TNF-α, and IFN-γ and ensure the memory response against parasite reinfection, are significantly enhanced in cured patients. In addition, the subset of the non-functional CD8Low population is predominant in VL untreated patients and decreases along the chemotherapy treatment. In contrast, a CD8High subset increased towards the cure. Furthermore, the cure due to treatment with meglumine antimoniate or with liposomal amphotericin B was associated with the recovery of the T-cell immune responses. We described the evolution and participation of functional T cells during the treatment of patients with VL. Our results disclosed that the clinical improvement of patients is significantly associated with the participation of the CD4+ and CD8+ cytokine-secreting T cells.

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The clinical-immunological spectrum of human Leishmania (L.) infantum chagasi-infections in the Brazilian Amazon has been defined using DTH/IFAT-IgG immune assays and the clinical statuses of infected individuals, revealing five profiles: three asymptomatic [Asymptomatic Infection (AI), Subclinical Resistant Infection (SRI), and Indeterminate Initial Infection (III)], and two symptomatic profiles [Subclinical Oligosymptomatic Infection (SOI) and Symptomatic Infection (SI = American visceral leishmaniasis/AVL)]. We evaluated the diagnostic potential of urine qPCR over the entire spectrum of infection. Resine Instagene Matrix® was used for DNA extraction from urinary sediment, with amplification carried out using SYBR® Green Taq with the RV1 and RV2 primers. We examined urine samples from 151 individuals from an endemic area of AVL in Pará State in the Brazilian Amazon, including: 91 (60.3%) with diagnoses of previous infections [13 (14.3%) sharing the AI profile, 13 (14.3%) with the SRI profile, 43 (47.2%) with III, 12 (13.2%) with SI (treated AVL), and 10 (11%) with SI (untreated AVL)]; sixty (39.7%) were DTH(-)/IFAT-IgG(-) (the uninfected group). The urine qPCR was positive in 61.5% of both the AI and SRI profiles, 65% of the III profile, 50% of treated AVL, 100% of untreated AVL, and 6.7% of the uninfected group. Those results confirmed the urine qPCR diagnosis in 100% of untreated AVL cases as well as in more than 60% of the cases with asymptomatic AI, SRI, and III profiles - indicating it as a promising tool for monitoring the evolution of human L. (L.) infantum chagasi-infections in endemic areas.

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Although there is a great diversity of techniques and antigens used in the serodiagnosis of canine visceral leishmaniasis (CVL), total sensitivity and specificity have not yet been found. Since the use of amastigote forms in the indirect immunofluorescence assay has shown an improvement in the specificity of the test for the diagnosis of CVL, the performance of amastigotes forms of L. (L.) infantum chagasi as antigen source were evaluated in automatized ELISA test using crude antigen of axenic amastigote and purified amastigote from spleen of hamster chronically infected comparing with ELISA using total antigen produced with promastigote forms of L. (L.) infantum chagasi. One hundred and fifteen sera from dogs with positive parasitological diagnosis by PCR were used. The animals were classified into 2 groups: symptomatic (n = 67) and asymptomatic (n = 48) animals, in accordance with the clinical signs and laboratory tests were. As control, ninety-four sera from dogs with negative parasitological diagnosis were included. No significant difference was found in sensitivity, specificity, predictive values and accuracy between ELISA using whole antigens produced with both axenic and purified amastigotes in comparison with promastigotes forms. Correlation and concordance between the three total antigens tested in ELISA was observed. According to the similar performance among antigens, data pointed out to use antigen from promastigote forms for diagnosing canine leishmaniasis, especially due the easily in the production, lower cost and the abundance of correlative literature.

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Leishmania (Leishmania) infantum is the etiological agent of both American visceral leishmaniasis (AVL) and non-ulcerated cutaneous leishmaniasis (NUCL) in Honduras. Although AVL is the most severe clinical form of infection, recent studies have shown that human immune response to parasite infection can result in a clinical-immunological spectrum. The overall prevalence rate of infection and clinical-immunological profiles of the L. (L.) infantum infection in Amapala municipality, South Honduras was determined. We examined 576 individuals with diagnosis based on combined ELISA (IgG/IgM) and DTH assays. We also used genus-specific kDNA PCR and Hsp70 PCR-RFLP for NUCL cases. Clinical evaluation found 82% asymptomatic and 18% symptomatic individuals. All symptomatic cases (n = 104) showing NUCL were positive for parasites. We identified L. (L.) infantum species in 100% of the skin lesion scrapings and in 90% of the blood samples from NUCL cases studied. A total of 320 asymptomatic individuals were exposed (ELISA+ and/or DTH+), providing an overall L. (L.) infantum prevalence of 73.6%. Clinical, parasitological, and immunological evaluations suggest seven infection profiles, three asymptomatic and four symptomatic. This represents the first report on clinical and immunological features of human L. (L.) infantum-infection in Amapala municipality, Honduras.

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The clinical-immunological spectrum of human Leishmania (L.) infantum chagasi-infection in Amazonian Brazil has recently been reviewed based on the combined use of the delayed-type hypersensitivity (DTH) and indirect fluorescence antibody test (IFAT-IgG/IgM), both with homologous L. (L.) infantum chagasi-antigens, and associated with the clinical evaluation of infected individuals. This diagnostic approach has allowed to identify the broadest clinical-immunological spectrum of human L. (L.) infantum chagasi-infection composed by five clinical-immunological profiles of infection: three asymptomatic, 1) Asymptomatic Infection (AI) [DTH+/++++, IFAT-], 2) Subclinical Resistant Infection (SRI) [DTH+/++++, IFAT+/++], and 3) Indeterminate Initial Infection (III) [DTH-, IFAT+/++], and two symptomatic ones, 4) Symptomatic Infection (SI) [=American visceral leishmaniasis - AVL] and, 5) Subclinical Oligosymptomatic Infection (SOI), both with the same immune profile [DTH-, IFAT+++/++++]. Herein, we confirm for the third time the preclinical diagnosis of AVL through IgM-antibody response in an early asymptomatic case of infection (profile III), a 17-year-old boy who evolved to AVL (=profile SI) six weeks after the initial infection diagnosis, confirming that the combined use of DTH and IFAT-(IgG/IgM) assays associated with the clinical evaluation of infected individuals is potentially useful for monitoring human L. (L.) infantum chagasi-infection in endemic areas as well as optimizing AVL control.

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BACKGROUND: Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein. METHODS: The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells. RESULTS: The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide. CONCLUSION: This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.

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Background:Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein.Methods:The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells.Results:The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide.Conclusion:This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.(AU)

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Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein. Methods: The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells. Results: The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide. Conclusion: This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.(AU)

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In Honduras visceral leishmaniasis and non-ulcerated or atypical cutaneous leishmaniasis (NUCL) are caused by the species Leishmania (L.) infantum chagasi. NUCL is the most common clinical form in the southern regions of the country, mainly affecting the young. In view of the lack of knowledge about the pathogenesis of the disease pattern caused by L. (L) infantum chagasi in individuals affected by NUCL, the aim of the present study was to describe in detail the histopathological features of the skin lesion caused by the parasite. Biopsies from human NUCL lesions with a positive parasitological diagnosis were collected and processed using standard histological techniques. Paraffin sections stained by haematoxylin and eosin were used to examine the histopathological alterations seen in the skin. The lesions varied between 3 and 5 mm, and the majority of the patients (60%) had a single lesion. Lesions were more frequently seen in females (65%), with an average age of 33.4 years. Microscopically, the skin lesions were characterized by mononuclear inflammatory infiltrate in the dermis composed of lymphocytes, macrophages and a few plasma cells. The intensity of the infiltration varied from discrete to intense. In both cases, the parasitic infection was discrete. Granulomas were present in 60% of cases and were associated with intense inflammation. The data revealed by the histopathological alterations in the skin of individuals affected by NUCL suggest activation of a cellular immune response that potentially controls parasite spreading.

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BACKGROUND: The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (1-6) of bioactive extract from Nectandra leucantha (Lauraceae) twigs. METHODS: Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 1-6. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 1-6 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum. RESULTS: Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 1-6. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 µM, respectively), while compounds 1 and 3 were inactive. As neolignans 2-4 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 = 16.9 µM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity, suggesting that the formation of dimeric compounds by oxidative coupling is crucial for antiparasitic activity of dimeric compounds 2, 4 and 6. CONCLUSION: This study highlights compound 6 against L. (L.) infantum amastigotes as a scaffold for future design of new compounds for drug treatment of visceral leishmaniasis.

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Background:The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (1–6) of bioactive extract from Nectandra leucantha (Lauraceae) twigs.Methods:Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 1–6. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 1–6 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum.Results:Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 1–6. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 μM, respectively), while compounds 1 and 3 were inactive. As neolignans 2–4 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 =16.9 μM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity...(AU)

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Dogs are considered the main reservoirs of visceral leishmaniasis for humans, which also present a chronic and severe clinical picture when affected. The objective of the present report was to describe a canine visceral leishmaniasis case diagnosed in Londrina, an indene city, and its investigation. A street animal with extensive dermatological lesions, onychogryphosis, mild anemia and leukopenia was attended at a veterinary hospital in Londrina, where positivity was reported for Leishmania spp. in serological tests. Cytology was positive in bone marrow, PCR and parasite culture were positive in skin, spleen, liver, lymph node and bone marrow, and DNA sequencing confirmed the species of the parasite as L. (L.) infantum. The official diagnosis was made by the Central Laboratory of Paranل (LACEN), and through an official report, an investigation of the case was started for the confirmation of autochthony. An active search for the vector and other canine cases in the neighborhood was carried out along with a search for information on the origin of the animal in question. However, the species, Lutzomyia longipalpis, new canine cases, or origin of the sick animal were not identified. Although, the present case cannot be confirmed as autochthonous, we suggest that it is necessary to disseminate the present report to serve as a warning to veterinarians and other public health professionals in the northern region of Paranل to be attentive to suspicious cases and to not fail to investigate these cases to the end.(AU)

Os cمes sمo considerados os principais reservatَrios da leishmaniose visceral para os humanos e também apresentam quadro clيnico crônico e grave quando acometidos. O objetivo do presente relato foi descrever um caso de leishmaniose visceral canina diagnosticado em Londrina, um cidade indene, e sua investigaçمo. Um animal de rua com extensas lesُes dermatolَgicas, onicogrifose, anemia leve e leucopenia foi atendida em um hospital veterinلrio em Londrina, onde a positividade foi relatada para Leishmania spp. em testes sorolَgicos. A citologia foi positiva na medula َssea, a PCR e a cultura parasitلria foram positivas na pele, baço, fيgado, linfonodo e medula َssea. Com o sequenciamento de DNA confirmamos as espécies do parasita como L. (L.) infantum. O diagnَstico oficial foi feito pelo Laboratَrio Central do Paranل (LACEN) e, através de um relatَrio oficial, iniciou-se a investigaçمo do caso para a verificaçمo de autoctonia. Foi realizada uma busca ativa do vetor e outros casos caninos suspeitos no bairro, bem como a procura de informaçُes sobre a origem do animal doente. No entanto, a espécie Lutzomyia longipalpis nمo foi identificada, nem novos casos caninos foram identificados ou mesmo a origem do animal doente esclarecida. Embora o presente caso nمo possa ser confirmado como autَctone, sugerimos que seja necessلrio divulgar o presente relato para servir de aviso aos veterinلrios e outros profissionais de saْde pْblica na regiمo norte do Paranل para estarem atentos a casos suspeitos e nمo deixar de investigar esses casos até o fim.(AU)

Assuntos

RESUMO

Patients coinfected with Leishmania/HIV can develop atypical forms of visceral leishmaniasis (VL), making it indispensable to identify the etiological agent. We are presenting a post-mortem specie definition by ITS1-PCR-RFLP in a larynx tissue of a patient presented coinfection Leishmania/HIV. This patient was from a leishmaniasis endemic region in São Paulo (SP), Brazil, and was diagnosed clinically with mucocutaneous leishmaniasis. Before a rK39 immunochromatographic test positive, a tiny stored paraffin-embedded larynx tissue was obtained post-mortem and submitted to 3 conventional PCR assays: kDNA (K20/K22 and RV1/RV2), and ITS1 (LITSR/L5.8S). The last one was followed by RFLP (HaeIII) and analyzed by 4% Metaphor agarose gel electrophoresis. Leishmania genus and Leishmania (Leishmania) subgenus were defined by kDNA-PCR, with K20/K22 (120 bp) and RV1/RV2 (145 bp), respectively. ITS1-PCR-RFLP identified L. (L.) infantum chagasi species visualized by the restriction patterns of 180, 70 and 50 bp. This case draws attention to the necessity for a clear identification of the etiological agent causing infection, especially in endemic regions of cutaneous and visceral leishmaniasis, and particularly in patients with comorbidities who often present atypical forms of the disease. L. (L.) infantum chagasi, which is usually responsible for VL, had changed its clinical spectrum for mucocutaneous. Unequivocal identification was carried out by ITS-PCR-RFLP, therefore confirming rK39 result. These techniques, which complemented each other, have a convenient cost-benefit ratio that makes them suitable to be applied in developing countries.

RESUMO

Dogs are considered the main reservoirs of visceral leishmaniasis for humans, which also present a chronic and severe clinical picture when affected. The objective of the present report was to describe a canine visceral leishmaniasis case diagnosed in Londrina, an indene city, and its investigation. A street animal with extensive dermatological lesions, onychogryphosis, mild anemia and leukopenia was attended at a veterinary hospital in Londrina, where positivity was reported for Leishmania spp. in serological tests. Cytology was positive in bone marrow, PCR and parasite culture were positive in skin, spleen, liver, lymph node and bone marrow, and DNA sequencing confirmed the species of the parasite as L. (L.) infantum. The official diagnosis was made by the Central Laboratory of Paraná (LACEN), and through an official report, an investigation of the case was started for the confirmation of autochthony. An active search for the vector and other canine cases in the neighborhood was carried out along with a search for information on the origin of the animal in question. However, the species, Lutzomyia longipalpis, new canine cases, or origin of the sick animal were not identified. Although, the present case cannot be confirmed as autochthonous, we suggest that it is necessary to disseminate the present report to serve as a warning to veterinarians and other public health profess

Os cães são considerados os principais reservatórios da leishmaniose visceral para os humanos e também apresentam quadro clínico crônico e grave quando acometidos. O objetivo do presente relato foi descrever um caso de leishmaniose visceral canina diagnosticado em Londrina, um cidade indene, e sua investigação. Um animal de rua com extensas lesões dermatológicas, onicogrifose, anemia leve e leucopenia foi atendida em um hospital veterinário em Londrina, onde a positividade foi relatada para Leishmania spp. em testes sorológicos. A citologia foi positiva na medula óssea, a PCR e a cultura parasitária foram positivas na pele, baço, fígado, linfonodo e medula óssea. Com o sequenciamento de DNA confirmamos as espécies do parasita como L. (L.) infantum. O diagnóstico oficial foi feito pelo Laboratório Central do Paraná (LACEN) e, através de um relatório oficial, iniciou-se a investigação do caso para a verificação de autoctonia. Foi realizada uma busca ativa do vetor e outros casos caninos suspeitos no bairro, bem como a procura de informações sobre a origem do animal doente. No entanto, a espécie Lutzomyia longipalpis não foi identificada, nem novos casos caninos foram identificados ou mesmo a origem do animal doente esclarecida. Embora o presente caso não possa ser confirmado como autóctone, sugerimos que seja necessário divulgar o presente relato