Cutaneous leishmaniasis

N-Pyrazolyl- and N-Triazolylamines and -Ureas as Antileishmanial and Antitrypanosomal Drugs

Three types of modifications of antileishmanial pyrazole lead compounds 7 and 8 were conducted to expand understanding of the relationships between structural features and antileishmanial/antitrypanosomal activity: (1) the pyrazole core was retained or replaced by a 1,2,4-triazole ring; (2) various aryl moieties including 2-fluorophenyl, pyridin-3-yl and pyrazin-2-yl rings were attached at 3-position of the core azole; (3) either arylmethylamino or ureido substituents were introduced at 5-position of the azole core. The synthesis followed established routes starting with esters 9 or 15 and anhydride 21. The synthesized 3-arylpyrazoles and 3-aryl-1,2,4-triazoles had only very low antileishmanial activity. The 2-fluorophenyl-substituted pyrazole 18c revealed the highest antileishmanial activity of this series of compounds, but its IC50 value (20 μM) still indicates low activity. However, low micromolar antitrypanosomal activity was detected for the pyridin-3-yl-substituted pyrazoles 12b (IC50=4.7 μM) and 14a (IC50=2.1 μM). Their IC50 values are comparable with the IC50 values of the reference compounds benznidazole and nifurtimox. Whereas only low unspecific cytotoxicity at the primary peritoneal mouse macrophages (PMM) was detected, considerable cytotoxicity at MRC-5 human fibroblast cells was found for both pyrazoles 12b an 14a. The activity of pyrazole 12b against T. cruzi is 4-fold higher than its unspecific MRC-5 cytotoxicity.

Failure to Detect Leishmania in the Blood of Patients with Old-World Cutaneous Leishmaniasis: Implications for Blood Donation

Cutaneous leishmaniasis (CL) is endemic in Israel, caused mainly by Leishmania major (L. major) and L. tropica. In addition, returning travelers import another leishmanial species such as L. braziliensis. Although we are dealing with a skin disease, the blood bank in Israel does not accept blood donations from people infected with CL in cases of multiple lesions due to the possibility of transfusion. Our purpose was to investigate the prevalence of Leishmania in the blood of patients with active or previous CL. This pilot study screened patients with active or previous CL for parasites in their blood. All patients were infected in Israel or were returning travelers with leishmaniasis acquired in Latin America. Patients were seen at the Sheba Medical Center. In addition, patients were seen at their homes in L. tropica and L. major endemic regions in Israel. Blood samples were taken from each patient for culture and polymerase chain reaction (PCR). Altogether 62 blood samples were examined (L. tropica = 26, L. major = 33, and L. braziliensis = 3). Twenty-seven patients had an active disease and 35 were recovered. All blood cultures and PCR were negative for parasites except one blood sample that was PCR positive for L. braziliensis. The findings of our study, although a small sample, suggest that people with active or recent CL caused by L. major and L. tropica, do not harbor parasites in their blood. Thus, their exclusion from blood donation should be revisited. Further studies are needed with larger sample size and highly sensitive tests.

Evaluation of photodynamic therapy against Leishmania tropica promastigotes using different photosensitizers

BACKGROUND

Photodynamic therapy is a two-step procedure, involving the use of photosensitizing agents followed by selective illumination of the target lesion with visible light. Photodynamic therapy has been described recently as a promising strategy for treatment of leishmaniasis. This study aims to evaluate the in vitro phototoxic, morphological, and apoptotic effect of methylene blue, toluidine blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy on the viability of Leishmania tropica promastigotes.

METHODS

Parasites were treated with methylene blue, toluidine blue, chloro-aluminum phthalocyanine, and pheophorbide a or/and methylene blue, toluidine blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy, and cell proliferation, morphological changes, and apoptosis were evaluated by XTT, giemsa staining, DAPI staining, and DNA fragmentation, respectively.

RESULTS

Parasite viability was significantly different in between the groups treated with methylene blue, toluidine blue, and pheophorbide a, with or without irradiation. chloro-aluminum phthalocyanine treatment did not lead to any alterations in cell viability in Leishmania tropica promastigotes with or without irradiation. DAPI staining results indicated that apoptotic bodies and nucleus fragmentation started to be visible in methylene blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy groups. DNA ladder pattern which is used to define apoptosis was observed in irradiated methylene blue, chloro-aluminum phthalocyanine, and pheophorbide a groups.

CONCLUSIONS

The results revealed that apoptosis-induced cell death was observed in Leishmania tropica promastigotes after the application of photosensitizers in combination with light irradiation.

Ultrasound patterns of localized cutaneous leishmaniasis and clinical correlations

A single-center retrospective study reviewed the following sonographic features of 18 confirmed cases of localized cutaneous leishmaniasis to identify shared presentation patterns: echotexture, lesion borders, hypodermal involvement, soft-tissue changes, and vascular pattern. A second objective was to correlate these patterns with clinical characteristics, including sex, age, anatomical location, nodule vs. plaque presentation, raised borders, granulation tissue, swelling, hyperkeratotic crusting, disease onset, and healing time. Two main patterns were identified with high-frequency ultrasonography. The first pattern was characterized by a high level of inflammation and deep hypodermal involvement, while the second variant showed involvement limited to the dermis, with minimal inflammation. The "inflammatory pattern" showed ill-defined borders, mixed echotexture, prominent vascularity with central distribution, and was correlated with clinical signs of ulceration, granulation tissue, raised borders, and longer healing time (p < 0.05). The "pauci-inflammatory pattern" presented a well-defined structure with decreased echogenicity, reduced or absent vascularity with minimal soft-tissue changes, and was associated with a shorter healing time (p < 0.05).

Efficacy of Systemic Treatment for Leishmania tropica Cutaneous Leishmaniasis

The effectiveness of systemic treatment for Leishmania tropica cutaneous leishmaniasis remains unclear. The purpose of the study is to evaluate the efficacy and safety of systemic treatments for L. tropica cutaneous leishmaniasis. This retrospective study was performed in 114 patients. Systemic treatments included liposomal amphotericin B and sodium stibogluconate. All patients underwent systemic treatment for L. tropica cutaneous leishmaniasis. Favourable treatment responses were recorded in 72.5% and 70.2% of the patients in the liposomal amphotericin B and sodium stibogluconate groups, respectively; 25.3% and 46% of those in the liposomal amphotericin B and sodium stibogluconate groups respectively, experienced at least one adverse effect. Lesions in cartilaginous areas were associated with higher treatment failure. Prior topical or systemic treatment increased the chance of future systemic treatment success. Liposomal amphotericin B was associated with a shorter intravenous treatment duration and better safety profile. Thus, liposomal amphotericin B is the treatment of choice for L. tropica cutaneous leishmaniasis.

Efficacy of topical Miltefosine formulations in an experimental model of cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in ~ 90 countries, with an increasing incidence. Presently available pharmacotherapy implies the systemic administration of moderately/very toxic drugs. Miltefosine (Milt) is the only FDA-approved drug to treat CL via the oral route (Impavido®). It produces side effects; in particular, teratogenic effects are of concern. A topical treatment would have the great advantage of minimising the systemic circulation of the drug, preventing side effects. We prepared dispersions containing Milt and liposomes of different compositions to enhance/modulate trans-epidermal penetration and evaluated in vitro and in vivo efficacy and toxicity, in vitro release rate of the drug and particles size stability with time. Treatments were topically administered to BALB/c mice infected with Leishmania (Leishmania) amazonensis. The dispersions containing 0.5% Milt eliminated 99% of the parasites and cured the lesions with a complete re-epithelisation, no visible scar and re-growth of hair. Fluid liposomes decreased the time to heal the lesion and the time needed to eliminate viable amastigotes from the lesion site. Relapse of the infection was not found 1 month after treatment in any case. Ultraflexible liposomes on the other hand had no significant in vitro effect but decreased in vivo efficacy. A topical Milt formulation including fluid liposomes seems a promising treatment against CL.

Treating pediatric cutaneous Leishmania tropica with systemic liposomal amphotericin B: A retrospective, single-center study

Leishmania tropica (L. tropica) cutaneous leishmaniasis (CL) is associated with high morbidity and low response rate to therapy, especially in pediatric patients. Intravenous (IV) liposomal amphotericin B (LAmB) has been used off-label as a treatment for L. tropica CL for many years. However, data regarding its efficacy and safety in children is lacking. In order to evaluate the efficacy and safety of IV LAmB for treating pediatric patients with L. tropica, we retrospectively reviewed electronic medical records of 24 children who were diagnosed with L. tropica CL and treated with IV LAmB during 2014-2020, at a tertiary medical center in Israel. Fourteen (58%) completed the treatment protocol and 10 (42%) experienced an infusion-related adverse event (IRAE) leading to treatment termination. Complete response was noted in 6/14 (43%) patients, while 8/14 (57%) failed to respond. Lower response rate was noted in lesions involving the mid-facial area. The relatively low response rate is speculated to result from a low dose of LAmB, short follow-up period, and difficult to treat anatomic locations. The observation of a lower response rate for mid-facial lesions should be validated in larger cohorts. The highrisk of IRAE should be considered in physician decisions regarding this treatment.

[Cutaneous leishmaniasis in Germany-still a travel-related disease]

Cutaneous leishmaniasis is an infectious disease caused by several Leishmania species. It is transmitted to humans by the bite of the infected female phlebotomus sandfly. Today, more than 1 billion people in leishmaniasis endemic areas are at risk of infection. More than 1.5 million new cases of cutaneous leishmaniasis occur every year. On the basis of two cases, we show that cutaneous leishmaniasis is still an imported tropical disease in Germany. However, due to the increasing intercontinental travel, cases may increase. Therefore, cutaneous leishmaniasis should be considered in the differential diagnosis in patients with nonhealing wounds, ulcers, papules or nodules and the corresponding travel history.

Therapeutic Potential of Green Synthesized Copper Nanoparticles Alone or Combined with Meglumine Antimoniate (Glucantime®) in Cutaneous Leishmaniasis

Background: In recent years, the focus on nanotechnological methods in medicine, especially in the treatment of microbial infections, has increased rapidly. Aim: The present study aims to evaluate in vitro and in vivo antileishmanial effects of copper nanoparticles (CuNPs) green synthesized by Capparis spinosa fruit extract alone and combined with meglumine antimoniate (MA). Methods: CuNPs were green synthesized by C. spinosa methanolic extract. The in vitro antileishmanial activity of CuNPs (10–200 µg/mL) or MA alone (10–200 µg/mL), and various concentrations of MA (10–200 μg/mL) along with 20 μg/mL of CuNPs, was assessed against the Leishmania major (MRHO/IR/75/ER) amastigote forms and, then tested on cutaneous leishmaniasis induced in male BALB/c mice by L. major. Moreover, infectivity rate, nitric oxide (NO) production, and cytotoxic effects of CuNPs on J774-A1 cells were evaluated. Results: Scanning electron microscopy showed that the particle size of CuNPs was 17 to 41 nm. The results demonstrated that CuNPs, especially combined with MA, significantly (p < 0.001) inhibited the growth rate of L. major amastigotes and triggered the production of NO (p < 0.05) in a dose-dependent manner. CuNPs also had no significant cytotoxicity in J774 cells. The mean number of parasites was significantly (p < 0.05) reduced in the infected mice treated with CuNPs, especially combined with MA in a dose-dependent response. The mean diameter of the lesions decreased by 43 and 58 mm after the treatment with concentrations of 100 and 200 mg/mL of CuNPs, respectively. Conclusion: The findings of the present study demonstrated the high potency and synergistic effect of CuNPs alone and combined with MA in inhibiting the growth of amastigote forms of L. major, as well as recovery and improving cutaneous leishmaniasis (CL) induced by L. major in BALB/c mice. Additionally, supplementary studies, especially in clinical settings, are required.

Albalawi A, Alanazi AD, Baharvand P, Moghaddam A, Mahmoudvand H. Chitosan-Based Nanomaterials as Valuable Sources of Anti-Leishmanial Agents: A Systematic Review

BACKGROUND

The current chemotherapy agents against various forms of leishmaniasis have some problems and side effects, including high toxicity, high cost, and the emergence of resistant strains. Here, we aimed to review the preclinical studies (in vitro and in vivo) on the anti-leishmanial activity of chitosan and chitosan-based particles against Leishmania spp.

METHODS

This study was conducted based on the 06-PRISMA guidelines and registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. Various English databases such as PubMed, Google Scholar, Web of Science, EBSCO, ScienceDirect, and Scopus were used to find the publications related to the anti-leishmanial effects of chitosan and its derivatives and other pharmaceutical formulations, without a date limitation, to find all the published articles. The keywords included "chitosan", "chitosan nanoparticles", "anti-leishmanial", "Leishmania", "leishmaniasis", "cutaneous leishmaniasis", "visceral leishmaniasis", "in vitro", and "in vivo". The language for data collection were limited to English.

RESULTS

Of 2669 papers, 25 papers, including 7 in vitro (28.0%), 7 in vivo (28.0%), and 11 in vitro/in vivo (44.0%) studies conducted up to 2020 met the inclusion criteria for discussion in this systematic review. The most common species of Leishmania used in these studies were L. major (12, 48.0%), L. donovani (7, 28.0%), and L. amazonensis (4, 16.80%). In vivo, the most used animals were BALB/c mice (11, 61.1%) followed by hamsters (6, 33.3%) and Wistar rats (1, 5.5%), respectively. In vitro, the most used Leishmania form was amastigote (8, 44.4%), followed by promastigote (4, 22.2%), and both forms promastigote/amastigote (6, 33.3%).

CONCLUSION

According to the literature, different types of drugs based on chitosan and their derivatives demonstrated considerable in vitro and in vivo anti-leishmanial activity against various Leishmania spp. Based on the findings of this review study, chitosan and its derivatives could be considered as an alternative and complementary source of valuable components against leishmaniasis with a high safety index. Nevertheless, more investigations are required to elaborate on this result, mainly in clinical settings.

Structural characterization of naphthalene sulfonamides and a sulfonate ester and their in vitro efficacy against Leishmania tarentolae promastigotes

Structural and biological activity analyses of two naphthalene sulfonamides and a naphthalene sulfonate ester.

In Vitro Antileishmanial Activity and GC-MS Analysis of Whole Plant Hexane Fraction of Achillea wilhelmsii (WHFAW)

In this study, GC-MS analysis has shown that whole plant hexane fraction of Achillea wilhelmsii (WHFAW) consists of 66 compounds which exhibited antileishmanial activity. Antileishmanial bioassay was the method used for determining antileishmanial activity. The inhibitory concentration (IC50) which was observed for whole plant hexane fraction of Achillea wilhelmsii (WHFAW) against parasitic and vector-borne disease, leishmaniasis, is 58.27 ± 0.52 μg/mL. For leishmanicidal assay, Leishmania major is the species used for analysis. Whole plant methanol extract of Achillea wilhelmsii (WMEAW) and whole plant aqueous fraction of Achillea wilhelmsii (WAFAW) exhibited no antileishmanial activity.

Health economic evaluation of moist wound care in chronic cutaneous leishmaniasis ulcers in Afghanistan

Background

The present health economic evaluation in Afghanistan aims to support public health decision makers and health care managers to allocate resources efficiently to appropriate treatments for cutaneous leishmaniasis (CL) elicited by Leishmania tropica or Leishmania major.

Methods

A decision tree was used to analyse the cost and the effectiveness of two wound care regimens versus intra-lesional antimony in CL patients in Afghanistan. Costs were collected from a societal perspective. Effectiveness was measured in wound free days. The incremental cost-effectiveness ratio (ICER) and incremental net monetary benefit (NMB) were calculated. The model was parameterized with baseline parameters, sensitivity ranges, and parameter distributions. Finally, the model was simulated and results were evaluated with deterministic and probability sensitivity analyses. Final outcomes were the efficiency of the regimens and a budget impact analysis in the context of Afghanistan.

Results

Average costs per patients were US$ 11 (SE = 0.016) (Group I: Intra-dermal Sodium Stibogluconate [IL SSG]), US$ 16 (SE = 7.58) (Group II: Electro-thermo-debridement [ETD] + Moist wound treatment [MWT]) and US$ 25 (SE = 0.48) (Group III: MWT) in patients with a single chronic CL ulcer. From a societal perspective the budget impact analysis shows that the regimens’ drug costs are lower than indirect disease cost. Average effectiveness in wound free days are 177 (SE = 0.36) in Group II, 147 (SE = 0.33) in Group III, and 129 (SE = 0.27) in Group I. The ICER of Group II versus Group I was US$ 0.09 and Group III versus Group I US$ 0.77, which is very cost-effective with a willingness-to-pay threshold of US$ 2 per wound free day. Within a Monte-Carlo probabilistic sensitivity analysis Group II was cost-effective in 80% of the cases starting at a willingness-to-pay of 80 cent per wound free day.

Conclusions

Group II provided the most cost-effective treatment. The non-treatment alternative is not an option in the management of chronic CL ulcers. MWT of Group III should at least be practiced. The cost-effectiveness of Group III depends on the number of dressings necessary until complete wound closure.

Electronic supplementary material

The online version of this article (doi: 10.1186/s40249-018-0389-4) contains supplementary material, which is available to authorized users.

Biopharmaceutical Assessment and Irritation Potential of Microemulsions and Conventional Systems Containing Oil from Syagrus cearensis for Topical Delivery of Amphotericin B Using Alternative Methods

The aim of this study was to compare the biopharmaceutical characteristics and irritation potentials of microemulsions (MEs) and conventional systems (CSs) containing oil from Syagrus cearensis for topical delivery of Amphotericin B (AmB). Pseudo-ternary phase diagrams were constructed using a water titration method to develop the MEs, and the CSs were prepared according to the classical technique of phase inversion. In the skin permeation and retention study, dermatomed pig skin without stratum corneum was used as an alternative disturbed skin model. The irritation potential was evaluated using three different methods, chorioallantoic membrane assays (HET-CAM and CAM-TBS), and bovine corneal opacity and permeability (BCOP) test. The optimized formulation (ME1) consisting of 0.1% (w/w) Amphotericin B, 9.1% (w/w) catolé oil, 81% (w/w) Smix (1:1, Tween 20 and Kolliphor EL) possessed droplet size of 31.02 ± 0.9 nm, zeta potential of -23.4 mV, and viscosity 0.63 ± 0.1 Pa.s. ME1 exhibited greater retention of AmB in to skin layers (84.79 ± 2.08 μg cm^-2) than all the others formulations. In general, MEs showed higher drug release and retention than CSs and all of the formulations showed greater retentivity than permeability. Only MEs developed using Labrasol/Plurol Oleique (L/PO) as the surfactant and co-surfactant exhibited a moderate irritation potential; all other MEs and CSs were classified as non-irritants or slight irritants. The results indicate that formulations containing oil from S. cearensis are promising alternatives for the delivery of AmB targeting the treatment of cutaneous leishmaniasis.

Anti-Leishmanial Activity (In Vitro and In Vivo) of Allicin and Allicin Cream Using Leishmania major (Sub-strain Zymowme LON4) and Balb/c Mice

BACKGROUND

Leishmania is a unicellular protozoan parasite that produces several human diseases, ranging from localized self-healing cutaneous lesions to deadly visceral infections.

OBJECTIVE

The effect of allicin on the growth of Leishmania major (L. major) promastigotes was evaluated under in vitro conditions. Moreover, the efficacy of a topical allicin cream was examined in BALB/c (Bagg albino, laboratory-bred strain of the House Mouse) mice with cutaneous leishmanial lesions compared to the currently used drug, sodiumstibogluconate (pentostam).

METHODS

Cytotoxiciy and promastigote proliferation were measured. Different concentrations (50, 100, 150, and 200 μM) of liquid allicin were tested on L. major promastigotes twice: after 24 and 48 hours using an MTT colorimetric assay. In the in vivo condition, the efficacies of allicin cream and liquid allicin at two concentrations (0.15 μM/mouse and 0.30 μM/mouse) were evaluated. Serum factors of the control and treated groups were tested to evaluate the toxic effects of allicin on the liver and kidney.

RESULTS

Allicin at a concentration of 50 μM inhibited the growth of Leishmania promastigotes. Topical application of allicin cream reduced lesion sizes in mice. No significant differences in biochemical analysis were observed between the control and treated groups.

CONCLUSIONS

Allicin has antileishmanial effects under in vitro and in vivo conditions and may be used in clinical applications.

Apoptotic protein profile in Leishmania donovani after treatment with hexaazatrinaphthylenes derivatives

Two hexaazatrinaphthylene derivatives, DGV-B and DGV-C previously known to induce an apoptotic-like process in Leishmania donovani parasites were used in this study. For this purpose, two different human protein commercial arrays were used to determine the proteomic profile of the treated parasites compared to non-treated ones. One of the commercial arrays is able to detect the relative expression of 35 human apoptosis-related proteins and the other one is able to identify 9 different human kinases. The obtained results showed that the two tested molecules were able to activate a programmed cell death process by different pathways in the promastigote stage of the parasite. The present study reports the potential application of two commercialised human apoptotic arrays to evaluate the action mechanism of active compounds at least against Leishmania donovani. The obtained data would be useful to establish the putative activated apoptosis pathways in the treated parasites and to further support the use of hexaazatrinaphthylene derivatives for the treatment of leishmaniasis in the near future. Nevertheless, further molecular studies should be developed in order to design and evaluate specific apoptotic arrays for Leishmania genus.

Lesson of the month 2: Chronic erythematous painless plaque on the eyelid co-presenting with multiple ulcerated nodules on the extremities

Cutaneous leishmaniasis is a parasitic disease caused by the Leishmania species, transmitted by the bite of an infected sandfly. The typical cutaneous lesion is a painless ulcer with a raised, indurated margin and often covered with an adherent crust. The lesions are mostly located on exposed sites such as the face and the extremities. Eyelid involvement is rare, making up only 2-5% of cases with facial cutaneous leishmaniasis. Herein, we report a 50-year-old male who presented with an erythematous plaque on the upper eyelid and multiple ulcerated nodules located on the extremities. Following microscopic examination of the lesional smear, a diagnosis of cutaneous leishmaniasis was made, and the patient was successfully treated with intramuscular meglumine antimonate therapy.

In vitro activities of hexaazatrinaphthylenes against Leishmania spp

The in vitro activity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species of Leishmania is described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC(50)s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives against Leishmania species, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

Antileishmanial activity of Ferula assa-foetida oleo gum resin against Leishmania major: An in vitro study

Background:

In Ayurveda, asafetida is introduced as a valuable remedy for flatulence, hysteria, nervous disorders, whooping cough, pneumonia and bronchitis in children and also considered as an aphrodisiac agent. Presently, Leishmaniasis is common in most countries of the world and is a serious health problem in the world. Some plant medicines and natural products have a new candidate for treatment of leishmaniasis.

Objective:

This study was designed to evaluate Ferula assa-foetida oleo gum resin (asafetida) on mortality and morbidity Leishmania major in vitro.

Materials and Methods:

Mostigotes were isolated from mice spleens and then transformed to promastigotes in Novy-Nicolle-Mac Neal (NNN medium supplemented with penicillin (100 U/ml), streptomycin (100 μg/ml) and 20% heat-inactivated fetal calf serum (FCS) at 25°C. A fixed initial density of the parasites was transferred to screw-capped vials containing 5 ml of RPMI₁₆₄₀ media to which different concentrations of 2.5, 5, 10 and 20 μg asafetida were added and each concentration was done in triplicates. Each run also included control. The mortality of parasitoids was measured by the slide and the enzyme-linked immunosorbent assay (ELISA) methods.

Results:

After 72 h, asafetida inhibited growth of parasites in all doses in stationary and logarithmic phases. The ELISA measurement suggested that the viability of parasites significantly decreased after 48h (P < 0.05).

Conclusion:

The results show that asafetida could prevent from growth and viability of parasites and this oleo gum resin can be useful for treatment of leishmaniasis.

Ecological Determinants of Forest to the Abundance ofLutzomyia longiflocosain Tello, Colombia

Lutzomyia longiflocosais considered the most likely vector of cutaneous leishmaniasis in the sub-Andean region of the upper valley of the Magdalena River between 1,000 and 2,000 meters in the Department of Huila, Colombia.L. longiflocosais anthropophilic, has endophagic behavior, and is especially important since its dominance in epidemics recorded in the last decade in the departments of Huila, Tolima, and the outbreak in Norte de Santander. The aim of our work is to identify ecological determinants in forest microhabitat level defining the abundance ofL. longiflocosa. We use sampling; this was performed in 56 microhabitats of 28 forests with CDC traps for two consecutive nights from 18:00 to 06:00 hours. Each microhabitat (favorable and unfavorable) was located 10 m from the ecotone, with an approximate area of 10 m2. Thirty-five variables were examined as potential explanatory variables which were recorded in each microhabitat. Regression models were used to identify ecological determinants. Our results confirm that there are favorable microhabitats in the forest with specific ecological determinants that define the aggregated distribution of the species and provide the conditions necessary for survival and abundance ofL. longiflocosa.

Leishmanicidal activity of polysaccharides and their oxovanadium(IV/V) complexes

The parasites of the genus Leishmania cause a range of leishmaniasis diseases, whose treatment is impaired due to intramacrophage parasites living in the mammalian host. Immunostimulation has been considered an important strategy to leishmaniasis treatment. The immunomodulatory effects of the polysaccharides arabinogalactan (ARAGAL), galactomannan (GMPOLY), and xyloglucan (XGJ), as well as their oxovanadium (IV/V) complexes (ARAGAL:VO, GMPOLY:VO, and XGJ:VO) were evaluated on peritoneal macrophages. At 25 μg/mL of GMPOLY:VO and of XGJ:VO, and 10 μg/mL of ARAGAL:VO, nitric oxide (NO) production by the macrophages was not altered compared with the control group. All polymers increased the production of interleukins 1 beta and 6 (IL-1β and IL-6), but the oxovanadium complexes were more potent activators of these mediators. ARAGAL:VO 10 μg/mL, GMPOLY:VO and XGJ:VO 25 μg/mL led to an increase of 562%, 1054%, and 523% for IL-1β, respectively. For IL-6 at the same concentration, the levels increased by 539% and 794% for ARAGAL:VO and GMPOLY:VO, respectively. Polysaccharides and their oxovanadium complexes exhibited important leishmanicidal effects on amastigotes of Leishmania (L.) amazonensis. The native and complexed polymers reduced the growth of promastigote-form Leishmania by ∼60%. This effect was reached at concentrations 12 times lower than that observed for Glucantime (300 μg/mL promoted an inhibition of ∼60%). The 50% inhibitory concentration (IC50) values for the complexes were determined. XGJ:VO showed the lowest IC50 value (6.2 μg/mL; 0.07 μg/mL of vanadium), which for ARAGAL:VO was 6.5 μg/mL (0.21 μg/mL of vanadium) and 7.3 μg/mL (0.06 μg/mL of vanadium) for GMPOLY:VO. The upregulation of IL-1β and IL-6 release and downregulation of NO production by macrophages and the important leishmanicidal effect are essential to stablish their potential use against this pathology.

Interferon-gamma and interlukin-4 patterns in BALB/c mice suffering from cutaneous leishmaniasis treated with cantharidin

Background:

Cutaneous leishmaniasis is a health problem in the world. Lesions should be treated on cosmetically or functionally important sites, such as the face and hands. Cantharidin is a terpenoid compound produced naturally by beetles of Meloidae and Oedemeridae families.

Objectives:

The current study aimed to investigate the effect of cantharidin on Cutaneous Leishmaniasis (CL) lesions and IFN-γ and IL-4 patterns in infected BALB/c mice.

Materials and Methods:

Infected BALB/c mice were divided into five groups as: untreated (control group), eucerin-treated and 0.05%, 0.1% and 0.5% cantharidin-treated. Lesions diameter was measured by Vernier caliper every three days for four weeks. Cytokines levels were measured by enzyme-linked immunosorbent assay (ELISA) using U-CyTech kit.

Results:

The results indicated that treatment with cantharidin exacerbates lesions compared with the controls, except for 0.05% cantharidin dose that restrained lesion growth significantly. Interferon gamma level in cantharidin-treated groups was significantly less than that of the control group. But interlukin-4 level was similar among the groups.

Conclusions:

The current study results indicated that high doses of cantharidin exacerbates leishmaniasis lesion, but low dose of cantharidin inhibits lesion growth.

Antiparasitic effects of gold nanoparticles with microwave radiation on promastigots and amastigotes of Leishmania major

PURPOSE

This study aimed to determine the efficacy of thermotherapy in the presence of gold nanoparticles (GNPs) and microwave (MW) radiation at a frequency of 2450 MHz on the survival of Leishmania major promastigotes and amastigotes.

MATERIALS AND METHODS

L. major promastigotes (strain MRHO/IR/75/ER) were cultured in RPMI-1640 medium supplemented with foetal bovine serum and antibiotic. The promastigotes were incubated with GNPs for 2 h. After washing, thermotherapy was performed by MW irradiation. After 48 h the promastigote survival rate was assessed using Alamar Blue assay. In the second part of the study, after culture and proliferation of J744 cells, the infected macrophages were incubated with the GNPs and were inserted under MW irradiation. After 24 h, the number of amastigotes in the macrophages was determined after Giemsa staining by a light microscope.

RESULT

Increased exposure time of the microwave to the parasites in the presence of GNPs induced a significant decline in promastigotes survival rate in comparison to similar samples without GNPs. The least survival of amastigotes was also recorded in the groups containing GNPs. The presence of GNPs during MW irradiation was more lethal for promastigotes and amastigotes in comparison to MW alone.

CONCLUSION

Thermotherapy using MW radiation in the presence of GNPs may be proposed as a new approach to treat leishmaniasis in future studies.

New world cutaneous leishmaniasis treated with intralesional injection of pentavalent antimony

Cutaneous leishmaniasis is a skin infection caused by the Leishmania species, an intracellular protozoan parasite that is transmitted by various species of female sandflies. According to the geographic distribution and vectors, leishmaniasis is classified as Old World or New World cutaneous leishmaniasis. In Korea, 24 cases of Old World cutaneous leishmaniasis have been reported, but New World cutaneous leishmaniasis has not been reported as yet. A 37-year-old man presented with a 3-month history of a painful and erythematous nodule with two satellite papules on the left postauricular area and a papule on the left arm after traveling to the Amazon region in Brazil. After we performed skin biopsies of the lesions, diagnosis of cutaneous leishmaniasis was made by the histopathological findings. After intralesional injection of sodium stibogluconate (Pentostam®, GlaxoSmithKline) twice a week for 4 weeks, the lesions improved with scarring. Herein, we discuss this case of New World cutaneous leishmaniasis that was successfully treated with intralesional injection of sodium stibogluconate (Pentostam®) in Korea.

Leishmania major infection in humanized mice induces systemic infection and provokes a nonprotective human immune response

Background

Leishmania (L.) species are the causative agent of leishmaniasis. Due to the lack of efficient vaccine candidates, drug therapies are the only option to deal with cutaneous leishmaniasis. Unfortunately, chemotherapeutic interventions show high toxicity in addition to an increased risk of dissemination of drug-resistant parasites. An appropriate laboratory animal based model is still missing which allows testing of new drug strategies in the context of human immune cells in vivo.

Methodology/Principal Findings

Humanized mice were infected subcutaneously with stationary phase promastigote L. major into the footpad. The human immune response against the pathogen and the parasite host interactions were analyzed. In addition we proved the versatility of this new model to conduct drug research studies by the inclusion of orally given Miltefosine. We show that inflammatory human macrophages get infected with Leishmania parasites at the site of infection. Furthermore, a Leishmania-specific human-derived T cell response is initiated. However, the human immune system is not able to prevent systemic infection. Thus, we treated the mice with Miltefosine to reduce the parasitic load. Notably, this chemotherapy resulted in a reduction of the parasite load in distinct organs. Comparable to some Miltefosine treated patients, humanized mice developed severe side effects, which are not detectable in the classical murine model of experimental leishmaniasis.

Conclusions/Significance

This study describes for the first time L. major infection in humanized mice, characterizes the disease development, the induction of human adaptive and innate immune response including cytokine production and the efficiency of Miltefosine treatment in these animals. In summary, humanized mice might be beneficial for future preclinical chemotherapeutic studies in systemic (visceral) leishmaniasis allowing the investigation of human immune response, side effects of the drug due to cytokine production of activated humane immune cells and the efficiency of the treatment to eliminate also not replicating (“hiding”) parasites.

As many as 12 million people suffer from Leishmania (L.) infection worldwide with about one to two million newly infected people every year. Due to the lack of vaccine strategies, the only option is chemotherapeutic intervention which can cause serious side effects. Therefore, new prevention or treatment strategies are urgently needed in addition to an appropriate animal model for testing. We infected humanized mice in the footpad with stationary phase promastigote L. major and analyzed the human innate and adaptive immune response by flow cytometry, histology, and quantitative PCR. Infected macrophages were detectable at the site of infection and in lymphoid organs. Additionally, we were able to measure Leishmania-specific T cell priming in humanized mice. However, these human immune defense mechanisms were not sufficient to prevent systemic spreading and lethality. By the inclusion of Miltefosine, we tested this novel model for its versatility in conducting drug studies. The oral treatment was able to reduce parasitic load but also revealed side effects which are described in humans but not in mice. Therefore, we propose humanized mice as a novel model, which offers the opportunity to study new therapy strategies in chronic leishmaniasis in the context of a human immune system.

Interest in paromomycin for the treatment of visceral leishmaniasis (kala-azar)

Leishmaniasis is an important vector-borne disease, and it is classified as one of the most important tropical fly-borne infections. This disease can cause two types of clinical manifestations: cutaneous forms and visceral forms. Visceral leishmaniasis, which is also called kala-azar, is a very serious infection that can be fatal. The management of visceral leishmaniasis requires informed diagnostic and therapeutic approaches. Continuous research and development regarding the treatment of visceral leishmaniasis had led to many improvements. Paromomycin is a relatively new antibiotic drug that has been used for the treatment of visceral leishmaniasis for several years. This article reviews and discusses the use of paromomycin for visceral leishmaniasis therapy.

Efficacy of Topical Liposomal Amphotericin B versus Intralesional Meglumine Antimoniate (Glucantime) in the Treatment of Cutaneous Leishmaniasis

Background. Topical treatment of cutaneous leishmaniasis is an attractive alternative avoiding toxicities of parenteral therapy while being administered through a simple painless route. Recently liposomal formulations of amphotericin B have been increasingly used in the treatment of several types of leishmaniasis. Aims. The efficacy of a topical liposomal amphotericin B formulation was compared with intralesional glucantime in the treatment of cutaneous leishmaniasis. Methods. From 110 patients, the randomly selected 50 received a topical liposomal formulation of amphotericin B into each lesion, 3–7 drops twice daily, according to the lesion's size and for 8 weeks. The other group of 60 patients received intralesional glucantime injection of 1-2 mL once a week for the same period. The clinical responses and side effects of both groups were evaluated weekly during the treatment course. Results. Per-protocol analysis showed no statistically significant difference between the two groups (P = 0.317, 95% confidence interval (CI) = 1.610 (0.632–4.101)). Moreover, after intention-to-treat analysis, the same results were seen (P = 0.650, 95% CI = 0.1.91 (0.560–2.530)). Serious post treatment side effects were not observed in either group. Conclusions. Topical liposomal amphotericin B has the same efficacy as intralesional glucantime in the treatment of cutaneous leishmaniasis.

Leishmania amazonensis: effects of oral treatment with copaiba oil in mice

Leishmaniasis is a severe public-health problem, with high rates of morbidity and mortality. Efforts to find new, effective and safe oral agents for the treatment of leishmaniasis have been ongoing for several decades, in order to avoid the problems with the currently used antimonials. In the present study, we found that a copaiba oil oral treatment (Group IV) caused a significant reduction in the average lesion size (1.1±0.4mm) against Leishmania amazonensis lesions compared with untreated mice (Group I) (4.4±1.3mm). To prove the safety of the oil, the toxicity and genotoxicity were also determined. Histopathological evaluation did not reveal changes in the copaiba oil-treated animals compared to the control animals. In the mutagenicity evaluation, (micronucleus test) the dose tested (2000mg/kg) showed no genotoxic effects. Morphological and ultrastructural analyses demonstrated notable changes in parasite cells treated with this oleoresin. The main ultrastructural effect was mitochondrial swelling. We also demonstrated that in vitro copaiba oil treatment of L. amazonensis led to an increase in plasma membrane permeability, and depolarization in the mitochondrial membrane potential in parasite cells. Although the mechanism of action of the oleoresin is still unclear, these findings indicate that copaiba oil is a possible new drug, which would provide a safer, shorter, less-expensive, and more easily administered treatment for leishmaniasis.

Recent advances in leishmaniasis treatment

About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.

Leishmaniasis of the auricle mimicking carcinoma

Leishmaniasis of the auricle has been rarely reported in our region of the world, where it is labeled as "Old World Leishmaniasis." It may mimic other pathologies, such as malignancies or other infectious processes. We present a case of an auricular Leishmania lesion which was first suspected to be a carcinoma. Four previous auricular Old World Leishmania cases have been reported. The epidemiology, clinical presentation, diagnosis, and treatment of this entity are briefly reviewed.

The Leishmania surface protease GP63 cleaves multiple intracellular proteins and actively participates in p38 mitogen-activated protein kinase inactivation

The Leishmania parasite is a widespread disease threat in tropical areas, causing symptoms ranging from skin lesions to death. Leishmania parasites typically invade macrophages but are also capable of infecting fibroblasts, which may serve as a reservoir for recurrent infection. Invasion by intracellular pathogens often involves exploitation of the host cell cytoskeletal and signaling machinery. Here we have observed a dramatic rearrangement of the actin cytoskeleton and marked modifications in the profile of protein tyrosine phosphorylation in fibroblasts infected with Leishmania major. Correspondingly, exposure to L. major resulted in degradation of the phosphorylated adaptor protein p130Cas and the protein-tyrosine phosphatase-PEST. Cellular and in vitro assays using pharmacological protease inhibitors, recombinant enzyme, and genetically modified strains of L. major identified the parasite protease GP63 as the principal catalyst of proteolysis during infection. A number of additional signaling proteins were screened for degradation during L. major infection as follows: a small subset was cleaved, including cortactin, T-cell protein-tyrosine phosphatase, and caspase-3, but the majority remained unaffected. Protein degradation occurred in cells incubated with Leishmania extracts in the absence of intact parasites, suggesting a mechanism permitting transfer of functional GP63 into the intracellular space. Finally, we evaluated the impact of Leishmania on MAPK signaling; unlike p44/42 and JNK, p38 was inactivated upon infection in a GP63- and protein degradation-dependent manner, which likely involves cleavage of the upstream adaptor TAB1. Our results establish that GP63 plays a central role in a number of hostcell molecular events that likely contribute to the infectivity of Leishmania.

A review of photodynamic therapy in cutaneous leishmaniasis

We present a review of six clinical studies investigating the use of photodynamic therapy (PDT) using porphyrin precursors for the treatment of Old World cutaneous leishmaniasis (CL). Thirty-nine patients with a total of 77 lesions received PDT using a range of treatment schedules following topical application of aminolevulinic acid (ALA) or methyl-aminolevulinate (MAL). The tissue response to PDT is accompanied by a mild burning sensation, erythema and reversible hypo- and hyperpigmentation. Few mechanistic studies have addressed the principles underlying the use of PDT for CL. All six reviewed papers suggest that PDT with porphyrin precursors is relatively effective in treating CL. Data are still limited, and PDT cannot at this point be recommended in routine clinical practice. The mechanism of action of this promising therapeutic modality needs to investigated further and additional controlled trials need to be performed.

[Topical treatment of persistent cutaneous leishmaniasis with paromomycin]

Cutaneous leishmaniasis is an infectious disease with increasing prevalence in Germany. Diagnosis and therapy may be difficult due to the variability of the clinical and histomorphological picture and resistance to therapy. In this case study we report on a female patient with a persistent cutaneous leishmaniasis successfully treated with topical administration of paromomycin.

Effect of topical honey application along with intralesional injection of glucantime in the treatment of cutaneous leishmaniasis

Background

Leishmaniasis is an endemic disease in Iran. Although many treatments have been suggested for this disease, there hasn't been an effective and safe treatment yet. Regarding the healing effect of honey in the chronic ulcers and its reported therapeutic effect in cutaneous leishmaniasis, we performed a study to better evaluate the efficacy of honey in cutaneous leishmaniasis and its final scar.

Methods

In a prospective clinical trial, 100 patients with confirmed cutaneous leishmaniasis were selected and randomized into 2 groups. Group A were treated with topical honey twice daily along with intralesional injection of glucantime once weekly until complete healing of the ulcer or for maximum of 6 weeks. Group B were treated with intralesional injection of glucantime alone until complete healing of the ulcer or for a maximum of 6 weeks, too. The patients were followed for 4 months. The collected data were analyzed statistically using statistical tests including Chi-square, Mann Whitney and Kaplan – Mayer tests.

Results

In this study, 45 patients that had cutaneous leishmaniasis were treated with intralesional glucantime alone and 45 patients were treated with topical honey and glucantime . Ten patients left out the study. In the glucantime alone treated group, 32 patients (71.1%) had complete cure whereas in the group treated with both glucantime & topical honey, 23 patients (51.1%) achieved complete cure. This difference was significant statistically (p = 0.04).

Conclusion

Further studies to better clarify the efficacy of honey in cutaneous leishmaniasis is needed. We suggest that in another study, the efficacy of honey with standardized level of antibacterial activity is evaluated against cutaneous leishmaniasis.

Activity of Brazilian and Bulgarian propolis against different species of Leishmania

Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species--Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L. major from the Old World--associated to different clinical forms of leishmaniasis. The composition of the extracts has been previously characterized by high temperature high resolution gas chromatography coupled to mass spectrometry. Considering the chemical differences among the extracts and the behavior of the parasites, it was observed significant differences in the leishmanicidal activities with IC50/1 day values in the range of 2.8 to 229.3 microg/ml . An overall analysis showed that for all the species evaluated, Bulgarian extracts were more active than the ethanol Brazilian extract. As the assayed propolis extracts have their chemical composition determined it merits further investigation the effect of individual components or their combinations on each Leishmania species.