Owners' experiences of administering meglumine antimoniate injections to dogs with leishmaniosis: An online questionnaire study.

BACKGROUND: This study examined the experiences of owners of dogs with leishmaniosis who treated their dogs with daily subcutaneous meglumine antimoniate injections. The owners' perceived ease of administering the injections, the occurrence of problems and the effects on the owners and on the dog‒owner bond were evaluated. METHODS: Dogs prescribed meglumine antimoniate as a treatment for leishmaniosis were identified using the database of the veterinary pharmacy of the Faculty of Veterinary Medicine, Utrecht University. An online questionnaire was sent to the owners of these dogs to evaluate the perceived ease of administering the injections, the occurrence of problems and the effects on the owner and the dog-owner bond. RESULTS: Responses were received from 64 dog owners. Most respondents (78%) reported that administering the injections was not difficult. Pain or the development of nodules at the injection site was reported in 50% and 40% of the dogs, respectively. Polyuria was reported in 44% of the dogs. Some owners reported that administering the injections had a negative impact on their psychological wellbeing (20%), and some would have liked more veterinary support (11%). LIMITATIONS: Some questions were answered by a limited number of people, and their responses may not be representative. CONCLUSION: Dog owners remain highly motivated to persevere with meglumine antimoniate treatment and are willing to administer the injections themselves. The availability of active support when needed during the therapy cycle may further improve their acceptance of and confidence in giving the injections.

Natural resistance to meglumine antimoniate is associated with treatment failure in cutaneous leishmaniasis caused by Leishmania (Viannia) panamensis.

The multifactorial basis of therapeutic response can obscure the relation between antimicrobial drug susceptibility and clinical outcome. To discern the relationship between parasite susceptibility to meglumine antimoniate (SbV) and therapeutic outcome of cutaneous leishmaniasis, risk factors for treatment failure were considered in evaluating this relationship in ninety-one cutaneous leishmaniasis patients and corresponding clinical strains of Leishmania (Viannia) panamensis. Parasite susceptibility to 32 µg SbV/mL (plasma Cmax) was evaluated in primary human macrophages, PBMCs, and U937 macrophages. Early parasitological response to treatment was determined in lesions of a subgroup of patients, and pathogenicity of Sb-resistant and sensitive clinical strains was compared in BALB/c mice. Parasite survival in cell models and patient lesions was determined by qRT-PCR of Leishmania 7SLRNA transcript. Parasite loads in BALB/c mice were quantified by limiting dilution analysis. The disparate Sb-susceptibility of parasite subpopulations distinguished by isoenzyme profiles (zymodemes) was manifest in all cell models. Notably, Sb-resistance defined by parasite survival, was most effectively discerned in U937 macrophages compared with primary human host cells, significantly higher among strains from patients who failed treatment than cured and, significantly associated with treatment failure. Each unit increase in transformed survival rate corresponded to a 10.6-fold rise in the odds of treatment failure. Furthermore, treatment failure was significantly associated with naturally Sb-resistant zymodeme 2.3 strains, which also produced larger lesions and parasite burdens in BALB/c mice than Sb-sensitive zymodeme 2.2 strains. The confounding effect of host risk factors for treatment failure in discerning this association was evidenced in comparing strains from patients with and without the defined risk factors for treatment failure. These results establish the association of natural resistance to meglumine antimoniate with treatment failure, the importance of host risk factors in evaluating drug susceptibility and treatment outcome, and the clinical and epidemiological relevance of natural Sb-resistance in L. (V.) panamensis subpopulations.

Phylogenetic analysis and antimony resistance of Leishmania major isolated from humans and rodents.

Cutaneous Leishmaniasis (CL) is one of the world's neglected diseases which is caused by Leishmania spp. The aim of this study was to assess molecular profile and antimony resistance of Leishmania isolated from human and rodent hosts. Samples were collected from suspected CL patients referred to health centres and wild rodent's traps in Gonbad-e-Qabus region, north-eastern Iran. Smears were subjected to PCR-RFLP to identify Leishmania species. In addition, ITS1-PCR products were sequenced for phylogenetic analysis. Clinical isolates and rodent samples were subjected to MTT assay to determine IC50 values and in vitro susceptibilities. Expression levels of antimony resistance-related genes were determined in CL isolates. Out of 1,949 suspected patients with CL and 148 rodents, 1,704 (87.4%) and 6 (4.05%) were positive with direct smear, respectively. Digestion patterns of BusRI (HaeIII) endonuclease enzyme were similar to what expected for Leishmania major. Phylogenetic analysis revealed that the highest interspecies similarity was found between current L. major sequences with L. major obtained from Russia and Uzbekistan. Out of 20 L. major samples tested, 13 (65%) were resistant to meglumine antimoniate (MA) treatment, with an activity index (AI) exceeding 4. The remaining 7 samples (35%) responded to MA treatment and were classified as sensitive isolates, with a confirmed sensitive phenotype based on their AI values. The comparison expression analysis of three major antimony resistance-associated genes in unresponsive clinical isolates demonstrated significant fold changes for TDR1 (4.78-fold), AQP1 (1.3-fold), and γ-GCS (1.17-fold) genes (P < 0.05). Herein, we demonstrate genetic diversity and antimony resistance of L. major isolated from human and reservoir hosts in north-eastern Iran, which could be the basis for planning future control strategies.

Topical application of ozonated sunflower oil accelerates the healing of lesions of cutaneous leishmaniasis in mice under meglumine antimoniate treatment.

Besides being scarce, the drugs available for treating cutaneous leishmaniasis have many adverse effects. Ozone is an option to enhance the standard treatment due to the wound-healing activity reported in the literature. In this study, we evaluated the efficiency of ozonated sunflower oil as an adjuvant in treating cutaneous lesions caused by Leishmania amazonensis. BALB/c mice were infected with L. amazonensis, and after the lesions appeared, they were treated in four different schedules using the drug treatment with meglumine antimoniate (Glucantime®), with or without ozonated oil. After thirty days of treatment, the lesions' thickness and their parasitic burden, blood leukocytes, production of NO and cytokines from peritoneal macrophages and lymph node cells were analyzed. The group treated with ozonated oil plus meglumine antimoniate showed the best performance, improving the lesion significantly. The parasitic burden showed that ozonated oil enhanced the leishmanicidal activity of the treatment, eliminating the parasites in the lesion. Besides, a decrease in the TNF levels from peritoneal macrophages and blood leukocytes demonstrated an immunomodulatory action of ozone in the ozonated oil-treated animals compared to the untreated group. Thus, ozonated sunflower oil therapy has been shown as an adjuvant in treating Leishmania lesions since this treatment enhanced the leishmanicidal and wound healing effects of meglumine antimoniate.

Efficacy of the treatment using a microemulsion loaded with epoxy-α-lapachone in combination with meglumine antimoniate against murine infection by Leishmania (Leishmania) amazonensis.

Leishmaniasis is a disease caused by Leishmania spp., affecting millions of people around the world. For decades, its treatment has been based on pentavalent antimonials, which notoriously cause toxic side effects in patients. In this study, epoxy-α-lapachone incorporated into an oil-in-water-type microemulsion (ELAP-ME) and meglumine antimoniate (MA) were assayed in monotherapy and in combination (ELAP-ME/MA) in BALB/c mice infected with Leishmania (Leishmania) amazonensis. In general, there was a reduction in paw lesion size (up to 37% reduction) and decreases of parasite loads in the footpad (∼40%) and lymph nodes (∼31%) of animals treated with ELAP-ME/MA, when compared to the non-treated control groups. Analyses of serum biochemical parameters revealed that the ELAP-ME/MA showed lower renal and hepatic toxicity when compared to MA 2-doses/week monotherapy. These findings indicate that the ELAP-ME/MA combination may be a promising approach for the treatment of cutaneous leishmaniasis.

Disseminated Leishmaniasis, a Severe Form of Leishmania braziliensis Infection.

Disseminated leishmaniasis (DL) is an emergent severe disease manifesting with multiple lesions. To determine the relationship between immune response and clinical and therapeutic outcomes, we studied 101 DL and 101 cutaneous leishmaniasis (CL) cases and determined cytokines and chemokines in supernatants of mononuclear cells stimulated with leishmania antigen. Patients were treated with meglumine antimoniate (20 mg/kg) for 20 days (CL) or 30 days (DL); 19 DL patients were instead treated with amphotericin B, miltefosine, or miltefosine and meglumine antimoniate. High levels of chemokine ligand 9 were associated with more severe DL. The cure rate for meglumine antimoniate was low for both DL (44%) and CL (60%), but healing time was longer in DL (p = 0.003). The lowest cure rate (22%) was found in DL patients with >100 lesions. However, meglumine antimoniate/miltefosine treatment cured all DL patients who received it; therefore, that combination should be considered as first choice therapy.

Comparison of Meglumine Antimoniate and Miltefosine in Cutaneous Leishmaniasis.

OBJECTIVE: To compare the efficacy and safety of meglumine antimoniate and miltefosine in the treatment of cutaneous leishmaniasis in Pakistan. STUDY DESIGN: Randomised-controlled trial. Place and Duration of the Study: Department of Dermatology, Combined Military Hospital, Lahore and Peshawar, from January to December 2021. METHODOLOGY: Smear positive and/or skin biopsy-confirmed cases of cutaneous leishmaniasis in adult males aged between 18-60 years were enrolled after receiving informed consent. Patients were randomly divided into Group A and Group B by lottery method. Group A received intramuscular meglumine antimoniate 15-20mg/kg/day, and Group B received oral miltefosine 50 mg thrice a day for a duration of 28 days. Data were analysed by SPSS 22. Effectiveness and safety of therapeutic agents were calculated by Independent t-test and p-value of 0.05 or less was taken as significant. RESULTS: Sixty-six patients, 33 in each group, participated in the study. Total number of cutaneous leishmaniasis lesions were 77 in Group A and 76 in Group B. The duration of lesions was 3.5 months in Group A and 3.2 months in Group B. Treatment response, in terms of complete or near complete resolution of lesions, was significantly higher in Group A as compared to Group B (p = 0.011). Both therapeutic agents had considerable side-effects with more patients withdrawn from Group A as compared to Group B (p = 0.010). CONCLUSION: Intra-muscular meglumine antimoniate was more effective in comparison to oral miltefosine in the treatment of cutaneous leishmaniasis. However, efficacy of meglumine antimoniate is mired by its side-effect profile. KEY WORDS: Cutaneous leishmaniasis, Meglumine antimoniate, Miltefosine, Efficacy, Side-effects, Adverse effects, Safety, Treatment, Old world cutaneous leishmaniasis.

Immunosuppressants alter the immune response associated with Glucantime® treatment for Leishmania infantum infection in a mouse model.

Background: Immunosuppression is a major risk factor for the development of visceral leishmaniasis (VL). The number of patients receiving immunosuppressant drugs such as TNF antagonist (anti-TNF) and methotrexate (MTX) is increasing. In these patients, VL is more severe, their response to treatment poorer, and they are at higher risk of relapse, a consequence (largely) of the poor and inappropriate immune response they develop. Objectives: To examine the effect of immunosuppressive treatment on the host immune response and thus gain insight into the reduced efficacy of pentavalent antimonials in these patients. Experiments were performed using BALB/c mice immunosuppressed with anti-TNF or MTX, infected with Leishmania infantum promastigotes, and then treated with Glucantime® at clinical doses. Results: Immunosuppression with both agents impeded parasite elimination from the spleen and bone marrow. Low pro-inflammatory cytokine production by CD4+ and CD8+ T cells was detected, along with an increase in PD-1 and IL-10 expression by B and T cells in the immunosuppressed groups after treatment. Conclusion: The immunosuppressed mice were unable to develop specific cellular immunity to the parasite, perhaps explaining the greater risk of VL relapse seen in pharmacologically immunosuppressed human patients.

Comparative analysis of the severity and progression of cutaneous leishmaniasis caused by Leishmania tropica in untreated and glucantime-treated patients.

Millions of people worldwide are affected by cutaneous leishmaniasis (CL), a disease that has a significant impact on morbidity and mortality. Understanding the immune responses responsible for tissue damage or the process of lesion healing plays a pivotal role in shaping optimal treatment strategies. In this study, we investigated immunological phenotypes for three groups: glucantime treated (n = 30) and untreated (n = 30) CL patients infected with Leishmania tropica (L. tropica), and healthy controls (n = 20). T-lymphocytes (CD4+ and CD8+), and B lymphocytes (CD14+ and CD19+) were isolated using antibody-conjugated microbeads and magnetic field isolation to achieve high purity. A higher significant difference was observed between T-lymphocytes (CD4+ and CD8+), and B-lymphocytes (CD14+ and CD19+) cells in CL-infected groups before and after treatment (p < 0.0001). When compared, there was also a significant difference among T-lymphocytes (CD4+ and CD8+), B lymphocytes (CD14+ and CD19+) p < 0.0001, p < 0.0005, and p < 0.0007, respectively between CL-infected individuals (before and after treatment) to controls. Our findings suggest that an increased proportion of these cells seen in treated patients may mediate healing, while it is also possible that they may contribute to tissue injury. Understanding the immune system and lesion size of CL can help develop immunotherapies and comprehend the evolution of this parasitic disease.

Treatment of leishmaniasis with chemotherapy and vaccine: a mathematical model.

Leishmaniasis, an infectious disease, manifests itself mostly in two forms, cutaneous leishmaniasis (CL) and, a more severe and potentially deadly form, visceral leishmaniasis (VL). The current control strategy for leishmaniasis relies on chemotherapy drugs such as sodium antimony gluconate (SAG) and meglumine antimoniate (MA). However, all these chemotherapy compounds have poor efficacy, and they are associated with toxicity and other adverse effects, as well as drug resistance. While research in vaccine development for leishmaniasis is continuously progressing, no vaccine is currently available. However, some experimental vaccines such as LEISH-F1+MPL-SE (V) have demonstrated some efficacy when used as drugs for CL patients. In this paper we use a mathematical model to address the following question: To what extent vaccine shots can enhance the efficacy of standard chemotherapy treatment of leishmaniasis? Starting with standard MA treatment of leishmaniasis and combining it with three injections of V , we find, by Day 84, that efficacy increased from 29% to 65-91% depending on the amount of the vaccine. With two or just one injection of V , efficacy is still very high, but there is a definite resurgence of the disease by end-time.

Naloxone Effects Against Cutaneous Leishmaniasis Caused by Leishmania major Strain MRHO/IR/75/ER in the BALB/c Mice.

INTRODUCTION: Cutaneous leishmaniasis (CL) is a serious health problem in some parts of the world, such as Iran. Since the use of pentavalent antimonial compounds such as meglumine antimoniate (Glucantime, MA) for the treatment of CL has side effects, naloxone as a new treatment in the footpad of Leishmania major (L. major)-infected BALB/c mice was investigated by evaluating the lesion size and the parasite burden. METHOD: The animals were infected with L. major (MRHO/IR/75/ER). 40 BALB/c mice were divided into 4 groups (10/group), and were treated as follows 39 days after L. major infection: Group 1 treated with intraperitoneal injections of MA (100 mg/kg, positive control group) daily for six weeks; Group 2 received a 100 µl injection of PBS (negative control group); Group 3 received subcutaneous (SC) injections of naloxone (10 mg/kg) daily for six weeks (Naloxone1), and Group 4 was SC injected with naloxone (10 mg/kg) weekly for six weeks (Naloxone2). The lesion size was measured using a digital caliper. RESULT: After the end of treatment, the lesion parasite burden was evaluated. As compared to the negative control group, the groups that received MA and naloxone (groups 1, 3, and 4) showed fewer parasites. Also, the naloxone-treated mice showed significantly smaller lesion sizes than the negative control group (p˂0.05), but they did not differ significantly from the MA-treated mice. CONCLUSION: Taken together, the results suggest that naloxone might be a promising and alternative treatment for CL.

A Novel Topical Formulation of the Leishmaniasis Drug Glucantime as a Nanostructured Lipid Carrier-Based Hydrogel.

Leishmaniasis is a parasitic disease caused by Leishmania parasites. Meglumine antimoniate, or Glucantime, is the primary drug used to treat this disease. Glucantime with a standard painful injection administration route has high aqueous solubility, burst release, a significant tendency to cross into aqueous medium, rapid clearance from the body, and insufficient residence time at the injury site. Topical delivery of Glucantime can be a favorable option in the treatment of localized cutaneous leishmaniasis. In this study, a suitable transdermal formulation in the form of nanostructured lipid carrier (NLC)-based hydrogel containing Glucantime was prepared. In vitro drug release studies confirmed controllable drug release behavior for hydrogel formulation. An in vivo permeation study on healthy BALB/C female mice confirmed appropriate penetration of hydrogel into the skin and sufficient residence time in the skin. In vivo performance of the new topical formulation on the BALB/C female mice showed a significant improvement in reduction of leishmaniasis wound size, lowering parasites number in lesions, liver, and spleen compared with commercial ampule. Hematological analysis showed a significant reduction of the drug's side effects, including variance of enzymes and blood factors. NLC-based hydrogel formulation is proposed as a new topical administration to replace the commercial ampule.

Survival time and prognostic factors in canine leishmaniosis in a non-endemic country treated with a two-phase protocol including initial allopurinol monotherapy.

BACKGROUND: Leishmania infantum is an intracellular protozoan parasite which is endemic in countries of the Mediterranean Basin. Leishmaniosis is increasingly diagnosed in non-endemic areas due to the relocation of dogs from endemic areas and the travel of dogs to and from these areas. The prognosis of leishmaniosis in these dogs may differ from that of those in endemic areas. The aims of this study were (1) to determine the Kaplan-Meier estimated survival time for dogs with leishmaniosis in the Netherlands (a non-endemic country), (2) to determine if clinicopathological variables at the time of diagnosis predicted the survival of these dogs, and (3) to evaluate the effect of a two-phase therapy protocol of allopurinol monotherapy followed by meglumine antimoniate and/or miltefosine in the case of incomplete remission or relapse. METHODS: The database of the Department of Clinical Sciences of Companion Animals of the Faculty of Veterinary Medicine, Utrecht University was investigated for leishmaniosis patients. Patient records were reviewed for signalment and clinicopathological data at the time of diagnosis. Only treatment-naive patients were included. Follow-up was performed during the study by phone contact and included treatment received and date and cause of death. Univariate analysis was performed using the Cox proportional hazards regression model. RESULTS: The estimated median Kaplan-Meier survival time was 6.4 years. In the univariate analysis, increases in monocyte, plasma urea and creatinine concentrations, and urine protein to creatinine ratio were all significantly associated with decreased survival time. The majority of patients only received allopurinol monotherapy. CONCLUSIONS: Canine leishmaniosis patients in our study population in the Netherlands, which is non-endemic for the disease, had an estimated Kaplan-Meier median survival time of 6.4 years, which is comparable to the outcome of other reported therapy protocols. Increased plasma urea and creatinine concentrations and monocyte concentration were statistically associated with an increased risk of death. We conclude that initial allopurinol monotherapy for 3 months should be effective in more than half of canine leishmaniosis cases, provided there is adequate follow-up, and that meglumine antimoniate or miltefosine therapy should be started as the second phase of the protocol in cases where remission is incomplete or there is a relapse.

Clinicopathological characteristics of cutaneous and mucocutaneous leishmaniasis in patients treated with TNF-α inhibitors.

BACKGROUND AND OBJECTIVES: The increasing use of biologics in the treatment of inflammatory diseases has led to more cases of leishmaniasis in patients subjected to iatrogenic immunosuppression. The main objective was to describe the characteristics of the patients with cutaneous (CL) or mucocutaneous (MCL) leishmaniasis who were receiving a biological therapy at the time of diagnosis. PATIENTS AND METHODS: A multicenter retrospective study was design based on a cohort of patients diagnosed with CL or MCL. All patients who were being treated with biologicals were included. For each case, two matched non-exposed patients were included for comparison. RESULTS: 38 patients were diagnosed with CL or MCL while being treated with tumor necrosis factor alpha (TNF-α) inhibitors. Leishmaniasis presented more frequently as a plaque (58.3%) with a larger median lesion size (2.5 cm), ulceration (92.1%), and required a greater median number of intralesional meglumine antimoniate infiltrations (3 doses) (P < 0.05) than in non-exposed patients. We found no systemic involvement in patients being treated with anti-TNF-α. We did not find differences regarding the treatment characteristics whether biologic therapy was modified or not. CONCLUSIONS: Although management should be individualized, maintenance of biologic therapy does not seem to interfere with treatment of CL or MCL.

Drugs and nanoformulations for the management of Leishmania infection: a patent and literature review (2015-2022).

INTRODUCTION: Leishmaniasis is an important disease caused by parasites of the Leishmania. Due to the urgent need for financial incentives and research and development of new anti-Leishmania, a point that stands out is the creation of patents that comprise drugs and nanoformulations in treating the disease. AREAS COVERED: Information on individual patents and patent families containing potential drugs and nanoformulations were obtained by searching the Orbit software (QUESTEL SAS, France) using the following terms: Leishmania; treatment; nanoparticle*; drug×. The data obtained ranged from 2015 to 2022. EXPERT OPINION: Meglumine antimoniate is a pentavalent antimonial widely used in the classic treatment of leishmaniasis. It is part of the classic treatment recommended by WHO, being the first-choice drug globally about 75 years ago. Thus, the need to introduce new anti-Leishmania therapies into clinical medicine is evident since cases of resistance to monotherapy and multitherapy have increased greatly. Associated with this, the search for patents that are good candidates in treating this disease assues interest in investments of financial resources and raises a ray of hope for safe, effective, and low-cost therapies to become licensed for the treatment of leishmaniasis.

Treatment of Cutaneous Leishmaniasis with Allopurinol Plus Itraconazole in Iran.

Cutaneous leishmaniasis (CL) is a serious tropical disease and a neglected health challenge in Iran. Although limited data are available regarding anthroponotic CL, cases resistant to meglumine antimoniate (Glucantime) are increasingly being reported. Via an open-label noncontrolled case series, allopurinol (10 mg/kg/day) plus itraconazole (3-4 mg/kg/day) were orally administered for 1 month to 27 patients (56 lesions) with anthroponotic CL, most of whom were resistant to Glucantime. A mean lesion size of 3.5 ± 1.9 cm at baseline was reduced to 0.6 ± 1.0 after 1 month of treatment. Excellent treatment response was observed in 85.7% of lesions after 1 month. Recurrence only occurred in one patient in the 3-month follow-up session. This study presents preliminary evidence that oral allopurinol plus itraconazole could be an effective treatment in patients with anthroponotic CL.

A Randomized, Controlled, Noninferiority, Multicenter Trial of Systemic vs Intralesional Treatment With Meglumine Antimoniate for Cutaneous Leishmaniasis in Brazil.

BACKGROUND: Meglumine antimoniate (MA) remains the main treatment for cutaneous leishmaniasis (CL). Uncontrolled studies suggest that intralesional MA (IL-MA) may be noninferior and safer than systemic MA (S-MA). METHODS: Multicenter, randomized, controlled, open-label, phase 3 clinical trial to evaluate the efficacy and toxicity of IL-MA in 3 infiltrations at 14-day intervals compared with S-MA (10-20 mg Sb5+/kg/day, 20 days) for CL, with noninferiority margin of 20%. Primary and secondary outcomes were definitive cure at day 180 and epithelialization rate at day 90 of treatment, respectively. A 2-year follow-up was performed to assess relapses and emergence of mucosal lesions. Adverse events (AEs) were monitored according to the Division of AIDS AE grading system. RESULTS: We evaluated 135 patients. The cure rates (95% confidence interval) for IL-MA and S-MA treatment were, respectively, 82.8% (70.5-91.4) and 67.8% (53.3-78.3) per protocol (PP) and 70.6% (58.3-81.0) and 59.7% (47.0-71.5) per intention to treat (ITT). The epithelialization rates of the IL-MA and S-MA treatment were, respectively, 79.3% (66.6-88 + 8) and 71.2% (57.9-82.2) PP and 69.1% (55.2-78.5) and 64.2% (50.0-74.2) ITT. AEs in the IL-MA and S-MA groups were, respectively, clinical, 45.6% and 80.6%; laboratory, 26.5% and 73.1%; and electrocardiogram, 8.8% and 25.4%. Ten participants in the S-MA group and 1 in the IL-MA group were discontinued due to severe or persistent AEs. CONCLUSIONS: IL-MA provides a similar cure rate and results in less toxicity compared with S-MA and may be used as first-line therapy for CL patients. CLINICAL TRIALS REGISTRATION: REBEC: RBR-6mk5n4.

Low doses of 3-phenyl-lawsone or meglumine antimoniate delivery by tattooing route are successful in reducing parasite load in cutaneous lesions of Leishmania (Viannia) braziliensis-infected hamsters.

Current therapeutic ways adopted for the treatment of leishmaniasis are toxic and expensive including parasite resistance is a growing problem. Given this scenario, it is urgent to explore treatment alternatives for leishmaniasis. The aim of this study was to evaluate the effect of 3-phenyl-lawsone (3-PL) naphthoquinone on Leishmania (Viannia) braziliensis infection, both in vitro and in vivo, using two local routes of administration: subcutaneous (higher dose) and tattoo (lower dose). In vitro 3-PL showed low toxicity for macrophages (CC50 >3200 µM/48h) and activity against intracellular amastigotes (IC50 = 193 ± 19 µM/48h) and promastigotes (IC50 = 116 ± 26 µM/72h), in which induced increased ROS generation. Additionally, 3-PL up-regulated the production of cytokines such as tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6) and IL-10 in infected macrophages. However, the anti-amastigote action was independent of nitric oxide production. Treatment of hamsters infected with L. (V.) braziliensis from one week after infection with 3-PL by subcutaneous (25 µg/Kg) or tattooing (2.5 µg/Kg) route, during 3 weeks (3 times/week) or 2 weeks (2 times/week) significantly decreased the parasite load (p<0.001) in the lesion. The reduction of parasite load by 3-PL treatment was comparable to reference drug meglumine antimoniate administered by the same routes (subcutaneous 1mg/Kg and tattoo 0.1mg/Kg). In addition, treatment started from five weeks after infection with 3-PL per tattoo also decreased the parasite load. These results show the anti-leishmanial effect of 3-PL against L. (V.) braziliensis and its efficacy by subcutaneous (higher dose) and tattoo (lower dose) routes. In addition, this study shows that drug delivery by tattooing the lesion allows the use of lower doses than the conventional subcutaneous route, which may support the development of a new therapeutic strategy that can be adopted for leishmaniasis.

The therapeutic effect of larval saliva and hemolymph of Lucilia sericata on the treatment of Leishmania major lesion in BALB/c mice946.

BACKGROUND: Treatment of cutaneous leishmaniasis (CL) remains a major challenge for the public health and medical community. It has been claimed that natural compounds derived from fly larvae have anti-leishmania properties against some species of Leishmania. The present study aimed at assessing the in vitro effects of larval products of Lucilia sericata against the promastigote and intracellular amastigote forms of Leishmania major. Also, the therapeutic effect of larval products on lesions induced by L. major infection was evaluated in BALB/c mice models. METHODS: Parasite specimens and macrophage cells were exposed to varying concentrations of larval products for 24-120 h. Lesion progression and parasite load were investigated in the models to assess the therapeutic effects of the products. RESULTS: The larval products displayed more potent cytotoxicity against L. major promastigotes. The IC50 values for larval saliva and hemolymph were 100.6 and 37.96 ug/ml, respectively. The IC50 of glucantime was 9.480 ug/ml. Also, the saliva and hemolymph of L. sericata exhibited higher cytotoxicity against the promastigotes of L. major but were less toxic to the macrophage cells. Treatment with leishmanicidal agents derived from larvae of L. sericata decreased the infection rate and the number of amastigotes per infected host cell at all concentrations. Lesion size was significantly (F (7, 38) = 8.54, P < 0.0001) smaller in the treated mice compared with the untreated control group. The average parasite burden in the treated mice groups (1.81 ± 0.74, 1.03 ± 0.45 and 3.37 ± 0.41) was similar to the group treated with a daily injection of glucantime (1.77 ± 0.99) and significantly lower (F (7, 16) = 66.39, P < 0.0001) than in the untreated control group (6.72 ± 2.37). CONCLUSIONS: The results suggest that the larval products of L. sericata were effective against L. major parasites both in vivo and in vitro. However, more clinical trial studies are recommended to evaluate the effects of these larval products on human subjects.