Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 558
Filter
1.
PLoS Negl Trop Dis ; 18(6): e0012242, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38900786

ABSTRACT

BACKGROUND: In Southeast Asia, treatment is recommended for all patients with post-kala-azar dermal leishmaniasis (PKDL). Adherence to the first-line regimen, twelve weeks of miltefosine (MF), is low and ocular toxicity has been observed with this exposure period. We assessed the safety and efficacy of two shorter-course treatments: liposomal amphotericin B (LAmB) alone and combined with MF. METHODOLOGY/PRINCIPAL FINDINGS: An open-label, phase II, randomized, parallel-arm, non-comparative trial was conducted in patients with parasitologically confirmed PKDL, 6 to ≤60 years. Patients were assigned to 20 mg/kg LAmB (total dose, in five injections over 15 days) alone or combined with allometric MF (3 weeks). The primary endpoint was definitive cure at 12 months, defined as complete resolution of papular and nodular lesions and >80% re-pigmentation of macular lesions. Definitive cure at 24 months was a secondary efficacy endpoint. 118/126 patients completed the trial. Definitive cure at 12 months was observed in 29% (18/63) patients receiving LAmB and 30% (19/63) receiving LAmB/MF (mITT), increasing to 58% and 66%, respectively, at 24 months. Most lesions had resolved/improved at 12 and 24 months for patients receiving LAmB (90%, 83%) and LAmB/MF (85%, 88%) by qualitative assessment. One death, unrelated to study drugs, was reported; no study drug-related serious adverse events were observed. The most frequent adverse drug reactions were MF-related vomiting and nausea, and LAmB-related hypokalaemia and infusion reactions. Most adverse events were mild; no ocular adverse events occurred. CONCLUSIONS/SIGNIFICANCE: Both regimens are suitably safe and efficacious alternatives to long-course MF for PKDL in South Asia. TRIAL REGISTRATION: CTRI/2017/04/008421.


Subject(s)
Amphotericin B , Antiprotozoal Agents , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Phosphorylcholine , Humans , Amphotericin B/therapeutic use , Amphotericin B/adverse effects , Amphotericin B/administration & dosage , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/therapeutic use , Phosphorylcholine/administration & dosage , Phosphorylcholine/adverse effects , Bangladesh , Male , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/adverse effects , Antiprotozoal Agents/administration & dosage , Adult , Adolescent , Female , Middle Aged , Young Adult , Child , India , Leishmaniasis, Visceral/drug therapy , Treatment Outcome , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Drug Therapy, Combination
2.
Microbiol Spectr ; 12(6): e0402623, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38712926

ABSTRACT

Post-kala-azar dermal leishmaniasis (PKDL) patients are a key source of Leishmania donovani parasites, hindering the goal of eliminating visceral leishmaniasis (VL). Monitoring treatment response and parasite susceptibility is essential due to increasing drug resistance. We assessed the drug susceptibility of PKDL isolates (n = 18) from pre-miltefosine (MIL) era (1997-2004) with isolates (n = 16) from the post-miltefosine era (2010-2019) and post-miltefosine treatment relapse isolates (n = 5) towards miltefosine and amphotericin B (AmB) at promastigote stage and towards sodium antimony gluconate (SAG) at amastigote stage. PKDL isolates were examined for mutation in gene-encoding AQP1 transporter, C26882T mutation on chromosome 24, and miltefosine-transporter (MT). PKDL isolates from the post-miltefosine era were significantly more susceptible to SAG than SAG-resistant isolates from the pre-miltefosine era (P = 0.0002). There was no significant difference in the susceptibility of parasites to miltefosine between pre- and post-miltefosine era isolates. The susceptibility of PKDL isolates towards AmB remained unchanged between the pre- and post-miltefosine era. However, the post-miltefosine era isolates had a higher IC50 value towards AmB compared with PKDL relapse isolates. We did not find any association between AQP1 gene sequence variation and susceptibility to SAG, or between miltefosine susceptibility and single nucleotide polymorphisms (SNPs in the MT gene. This study demonstrates that recent isolates of Leishmania have resumed susceptibility to antimonials in vitro. The study also offers significant insights into the intrinsic drug susceptibility of Leishmania parasites over the past two decades, covering the period before the introduction of miltefosine and after its extensive use. IMPORTANCE: Post-kala-azar dermal leishmaniasis (PKDL) patients, a key source of Leishmania donovani parasites, hinder eliminating visceral-leishmaniasis. Assessment of the susceptibility of PKDL isolates to antimony, miltefosine (MIL), and amphotericin-B indicated that recent isolates remain susceptible to antimony, enabling its use with other drugs for treating PKDL.


Subject(s)
Amphotericin B , Antimony , Antiprotozoal Agents , Drug Resistance , Leishmania donovani , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Phosphorylcholine , Humans , Leishmania donovani/drug effects , Leishmania donovani/genetics , Leishmania donovani/isolation & purification , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/drug therapy , Antiprotozoal Agents/pharmacology , Antimony/pharmacology , Antimony/therapeutic use , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/drug therapy , Drug Resistance/genetics , Amphotericin B/pharmacology , Parasitic Sensitivity Tests , Antimony Sodium Gluconate/pharmacology , Antimony Sodium Gluconate/therapeutic use , Mutation
3.
J Antimicrob Chemother ; 79(7): 1547-1554, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38727613

ABSTRACT

INTRODUCTION: Post-kala-azar dermal leishmaniasis (PKDL) arises as a dermal complication following a visceral leishmaniasis (VL) infection. Current treatment options for PKDL are unsatisfactory, and there is a knowledge gap regarding the distribution of antileishmanial compounds within human skin. The present study investigated the skin distribution of miltefosine in PKDL patients, with the aim to improve the understanding of the pharmacokinetics at the skin target site in PKDL. METHODS: Fifty-two PKDL patients underwent treatment with liposomal amphotericin B (20 mg/kg) plus miltefosine (allometric dosing) for 21 days. Plasma concentrations of miltefosine were measured on study days 8, 15, 22 and 30, while a punch skin biopsy was taken on day 22. A physiologically based pharmacokinetic (PBPK) model was developed to evaluate the distribution of miltefosine into the skin. RESULTS: Following the allometric weight-based dosing regimen, median miltefosine concentrations on day 22 were 43.73 µg/g (IQR: 21.94-60.65 µg/g) in skin and 33.29 µg/mL (IQR: 25.9-42.58 µg/mL) in plasma. The median individual concentration ratio of skin to plasma was 1.19 (IQR: 0.79-1.9). In 87% (45/52) of patients, skin exposure was above the suggested EC90 PK target of 10.6 mg/L associated with in vitro susceptibility. Simulations indicated that the residence time of miltefosine in the skin would be more than 2-fold longer than in plasma, estimated by a mean residence time of 604 versus 266 hours, respectively. CONCLUSION: This study provides the first accurate measurements of miltefosine penetration into the skin, demonstrating substantial exposure and prolonged retention of miltefosine within the skin. These findings support the use of miltefosine in cutaneous manifestations of leishmaniasis. In combination with parasitological and clinical data, these results are critical for the future optimization of combination therapies with miltefosine in the treatment of PKDL.


Subject(s)
Amphotericin B , Antiprotozoal Agents , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Phosphorylcholine , Skin , Humans , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/pharmacokinetics , Phosphorylcholine/administration & dosage , Phosphorylcholine/therapeutic use , Antiprotozoal Agents/pharmacokinetics , Antiprotozoal Agents/administration & dosage , Antiprotozoal Agents/therapeutic use , Male , Adult , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Female , Skin/parasitology , Leishmaniasis, Visceral/drug therapy , Middle Aged , Young Adult , Amphotericin B/pharmacokinetics , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Adolescent , Asia, Southern
5.
PLoS Negl Trop Dis ; 18(4): e0012134, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38669211

ABSTRACT

BACKGROUND: Currently available treatment options are mostly effective in achieving long-term cure in visceral leishmaniasis (VL) patients. However, there have been reports of recurrence of this illness in both immunosuppressed and immunocompetent patients. CASE PRESENTATION: We report the first case of recurrent VL relapse in a 19-year-old immunocompetent female with functional hypopituitarism (hypogonadotropic hypogonadism with central hypothyroidism) from Bangladesh, who has been treated three times previously with optimal dosage and duration- liposomal amphotericin B (LAmB) alone and in combination with miltefosine. We treated the patient successfully with a modified treatment regimen of 10 mg/kg body weight LAmB for two consecutive days along with oral miltefosine for seven days as loading dose. For secondary prophylaxis, the patient received 3 mg/kg body weight LAmB along with oral miltefosine for seven days monthly for five doses followed by hormonal replacement. The patient remained relapse free after 12 months of her treatment completion. CONCLUSION: In the absence of protective vaccines against Leishmania species and standard treatment regimen, this modified treatment regimen could help the management of recurrent relapse cases.


Subject(s)
Amphotericin B , Antiprotozoal Agents , Hypopituitarism , Leishmaniasis, Visceral , Phosphorylcholine , Recurrence , Female , Humans , Young Adult , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Bangladesh , Hypopituitarism/drug therapy , Leishmaniasis, Visceral/drug therapy , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/therapeutic use , Phosphorylcholine/administration & dosage , Treatment Outcome , Adult
6.
Biomolecules ; 14(4)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38672424

ABSTRACT

Originally developed as a chemotherapeutic agent, miltefosine (hexadecylphosphocholine) is an inhibitor of phosphatidylcholine synthesis with proven antiparasitic effects. It is the only oral drug approved for the treatment of Leishmaniasis and American Trypanosomiasis (Chagas disease). Although its precise mechanisms are not yet fully understood, miltefosine exhibits broad-spectrum anti-parasitic effects primarily by disrupting the intracellular Ca2+ homeostasis of the parasites while sparing the human hosts. In addition to its inhibitory effects on phosphatidylcholine synthesis and cytochrome c oxidase, miltefosine has been found to affect the unique giant mitochondria and the acidocalcisomes of parasites. Both of these crucial organelles are involved in Ca2+ regulation. Furthermore, miltefosine has the ability to activate a specific parasite Ca2+ channel that responds to sphingosine, which is different to its L-type VGCC human ortholog. Here, we aimed to provide an overview of recent advancements of the anti-parasitic mechanisms of miltefosine. We also explored its multiple molecular targets and investigated how its pleiotropic effects translate into a rational therapeutic approach for patients afflicted by Leishmaniasis and American Trypanosomiasis. Notably, miltefosine's therapeutic effect extends beyond its impact on the parasite to also positively affect the host's immune system. These findings enhance our understanding on its multi-targeted mechanism of action. Overall, this review sheds light on the intricate molecular actions of miltefosine, highlighting its potential as a promising therapeutic option against these debilitating parasitic diseases.


Subject(s)
Calcium , Chagas Disease , Homeostasis , Leishmaniasis , Phosphorylcholine , Phosphorylcholine/analogs & derivatives , Humans , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Chagas Disease/drug therapy , Chagas Disease/parasitology , Chagas Disease/metabolism , Calcium/metabolism , Leishmaniasis/drug therapy , Leishmaniasis/metabolism , Leishmaniasis/parasitology , Homeostasis/drug effects , Animals , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Mitochondria/metabolism , Mitochondria/drug effects , Leishmania/drug effects , Leishmania/metabolism , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/metabolism
7.
Rev Bras Parasitol Vet ; 33(1): e015023, 2024.
Article in English | MEDLINE | ID: mdl-38359300

ABSTRACT

In urban environments, domestic dogs (Canis familiaris) are a major reservoir for the parasite Leishmania infantum. Miltefosine has been used as the standard treatment for canine visceral leishmaniasis in Brazil. However, therapeutic failures have been reported. In the present study, two dogs (CG03 and CG06) with a diagnosis of infection by L. infantum underwent two cycles of treatment with miltefosine (Milteforan™ - Virbac®). Analyses showed increases in the parasite load of both CG03 and CG06, even after treatment. The clinical score of CG03 dropped from 1 to 0 (after one round of treatment), such that this dog became asymptomatic. CG06 showed clinical worsening, such that its score increased from 1 to 2. After the second therapeutic round, the parasite load in CG03 was found to have decreased, but it was still higher than before drug treatment even though this dog was physically asymptomatic. There was no decrease in the parasite load in CG06 and there was clinical worsening. The clinical response of these dogs to the treatment differed, but the parasite load remained high in both cases, which poses a risk to public health, making it essential take measures to prevent the sandfly vector from accessing the dog.


Subject(s)
Dog Diseases , Leishmania infantum , Leishmaniasis, Visceral , Phosphorylcholine/analogs & derivatives , Animals , Dogs , Dog Diseases/diagnosis , Dog Diseases/drug therapy , Dog Diseases/parasitology , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/veterinary , Phosphorylcholine/therapeutic use
8.
Lancet Infect Dis ; 24(1): e36-e46, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37640031

ABSTRACT

For the past 15 years, trials of combination therapy options for visceral leishmaniasis have been conducted with the aim of identifying effective, and safe treatment regimens that were shorter than existing monotherapy regimens and could also prevent or delay the emergence of drug resistance. Although first-line treatment currently relies on combination therapy in east Africa, this is not true in Latin America owing to disappointing trial results, with lower than expected efficacy seen for the combination treatment group. By contrast, several effective combination therapy regimens have been identified through trials on the Indian subcontinent; yet, first-line therapy is still AmBisome monotherapy as the drug is part of a free donation programme and is highly effective in this region. Achieving a short all-oral combination treatment will require new chemical entities, several of which are currently under evaluation. Future studies should systematically include pharmacological substudies to ensure optimal dosing for all patient groups. To achieve maximal impact of new combination treatments, mechanisms to ensure drug availability and access after trials should be established. Enhancing the longevity of current and novel treatments will require effective systems for early detection of emerging drug resistance.


Subject(s)
Antiprotozoal Agents , Leishmaniasis, Visceral , Humans , Leishmaniasis, Visceral/drug therapy , Antiprotozoal Agents/therapeutic use , Drug Therapy, Combination , Phosphorylcholine/therapeutic use , Combined Modality Therapy
9.
Parasitol Res ; 122(12): 3027-3035, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37796293

ABSTRACT

Leishmania (Mundinia) martiniquensis is a newly described species that causes human visceral, disseminated, and mucocutaneous leishmaniases. Amphotericin B deoxycholate (AmpB) is the first-line drug for the treatment of leishmaniasis in Thailand; however, several relapse cases of leishmaniasis caused by L. martiniquensis have been documented. In this study, in vitro susceptibility to AmpB and miltefosine (MIL) of wild-type (before treatment, LSCM1) and two AmpB-resistant L. martiniquensis strains (an in vitro-induced AmpB-resistant strain, AmpBRP2i, and a relapse strain, LSCM1-6) were determined. Results reveal that the IC50 value and resistance index against both drugs of promastigotes and intracellular amastigotes of the AmpBRP2i and LSCM1-6 strains were statistically significantly higher than those of the LSCM1 strain suggesting that cross-resistance with MIL occurred in both AmpB-resistant strains. The results of this study advocate further investigation into mechanisms that involve the complex nature of AmpB/MIL resistance in L. martiniquensis and development of effective methods for the identification of the AmpB-resistant parasites to help delivery of appropriate treatments for patients and for epidemiological surveys to survey the potential spread of drug-resistant strains.


Subject(s)
Antiprotozoal Agents , Leishmania , Leishmaniasis, Visceral , Leishmaniasis , Humans , Amphotericin B/pharmacology , Amphotericin B/therapeutic use , Leishmaniasis/drug therapy , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Chronic Disease , Recurrence , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Leishmaniasis, Visceral/parasitology
10.
J Antimicrob Chemother ; 78(11): 2702-2714, 2023 11 06.
Article in English | MEDLINE | ID: mdl-37726401

ABSTRACT

OBJECTIVES: To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response. METHODS: Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults. RESULTS: Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-treatment AUC0-24h 187 (162-203) and 242 (217-328) µg·h/mL, respectively], but were both within the IQR of end-of-treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-treatment exposure in paediatric patients and adults [AUCD0-28 517 (464-552) and 524 (456-567) µg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25-28) and 30 (28-32) days, respectively] were comparable to previously observed values in adults. CONCLUSIONS: Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure-response and exposure-toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients.


Subject(s)
Antiprotozoal Agents , Leishmaniasis, Visceral , Humans , Adult , Child , Paromomycin/therapeutic use , Leishmaniasis, Visceral/drug therapy , Antiprotozoal Agents/pharmacokinetics , Kenya , Phosphorylcholine/therapeutic use , Phosphorylcholine/pharmacokinetics , Uganda , Treatment Outcome
11.
J Mycol Med ; 33(4): 101436, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37774486

ABSTRACT

Fungal infections are a global health problem with high mortality and morbidity rates. Available antifungal agents have high toxicity and pharmacodynamic and pharmacokinetic limitations. Moreover, the increased incidence of antifungal-resistant isolates and the emergence of intrinsically resistant species raise concerns about seeking alternatives for efficient antifungal therapy. In this context, we review literature data addressing the potential action of miltefosine (MFS), an anti-Leishmania and anticancer agent, as a repositioning drug for antifungal treatment. Here, we highlight the in vitro and in vivo data, MFS possible mechanisms of action, case reports, and nanocarrier-mediated MFS delivery, focusing on fungal infection therapy. Finally, many studies have demonstrated the promising antifungal action of MFS in vitro, but there is little or no data on antifungal activity in vertebrate animal models and clinical trials, so have a need to develop more research for the repositioning of MFS as an antifungal therapy.


Subject(s)
Antifungal Agents , Mycoses , Animals , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Drug Repositioning , Mycoses/drug therapy , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use
12.
J Antimicrob Chemother ; 78(7): 1723-1731, 2023 07 05.
Article in English | MEDLINE | ID: mdl-37229566

ABSTRACT

OBJECTIVES: Cutaneous leishmaniasis (CL) is a neglected tropical disease causing a range of skin lesions for which safe and efficacious drugs are lacking. Oleylphosphocholine (OLPC) is structurally similar to miltefosine and has previously demonstrated potent activity against visceral leishmaniasis. We here present the in vitro and in vivo efficacy of OLPC against CL-causing Leishmania species. METHODS: The antileishmanial activities of OLPC were evaluated and compared with miltefosine in vitro against intracellular amastigotes of seven CL-causing species. Following the confirmation of significant in vitro activity, the performance of the maximum tolerated dose of OLPC was evaluated in an experimental murine model of CL followed by a dose-response titration and the efficacy evaluation of four OLPC formulations (two with a fast-release and two with a slow-release profile) using bioluminescent Leishmania major parasites. RESULTS: OLPC demonstrated potent in vitro activity of the same order as miltefosine in the intracellular macrophage model against a range of CL-causing species. A dose of 35 mg of OLPC/kg/day administered orally for 10 days was well-tolerated and able to reduce the parasite load in the skin of L. major-infected mice to a similar extent as the positive control paromomycin (50 mg/kg/day, intraperitoneally) in both in vivo studies. Reducing the dose of OLPC resulted in inactivity and modifying the release profile using mesoporous silica nanoparticles led to a decrease in activity when solvent-based loading was used in contrast to extrusion-based loading, which had no impact on its antileishmanial efficacy. CONCLUSIONS: Together, these data suggest that OLPC could be a promising alternative to miltefosine treatment for CL. Further investigations exploring experimental models with additional Leishmania species and skin pharmacokinetic and dynamic analyses are required.


Subject(s)
Antiprotozoal Agents , Leishmania major , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Mice , Animals , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Antiprotozoal Agents/therapeutic use , Phosphorylcholine/therapeutic use , Leishmaniasis, Visceral/drug therapy , Mice, Inbred BALB C
13.
Rev Bras Parasitol Vet ; 32(2): e001123, 2023.
Article in English | MEDLINE | ID: mdl-37194787

ABSTRACT

There are no records of autochthonous cases of canine visceral leishmaniasis in the city of Curitiba, Paraná state, Brazil. In 2020, a male French bulldog (CW01), approximately 2 years old was taken by its owners to a private veterinarian clinic. The suspicion of CVL was confirmed by means of a serology test (ELISA/IFAT reagent), rapid chromatographic immunoassay (DPP®) (ELISA - Biomanguinhos®), parasitological culture and quantitative polymerase chain reaction (qPCR). The animal routinely frequented parks in Curitiba and was taken on several trips to the municipalities of Bombinhas and Balneário Camboriú (Santa Catarina) and to Matinhos (Paraná) where CVL had not previously been reported. Treatment was initiated orally with Milteforan™ which resulted in a significant reduction in the parasitic load. The suspicion of autochthony was investigated through entomological research. A total of 10 traps were installed, one at the animal's home, seven in adjacent city blocks and two in a forest edge. No sandflies were trapped in the dog's home and adjacent houses. The traps in the forest edge caught one Migonemyia migonei female and five Brumptomyia spp. females. This case serves as a warning of the possible introduction of CVL in the city of Curitiba.


Subject(s)
Dog Diseases , Leishmaniasis, Visceral , Phosphorylcholine , Animals , Dogs , Female , Male , Brazil , Dog Diseases/diagnosis , Dog Diseases/drug therapy , Dog Diseases/parasitology , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/veterinary , Phosphorylcholine/therapeutic use
14.
Exp Parasitol ; 246: 108462, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36642298

ABSTRACT

Tegumentary leishmaniasis encompasses a spectrum of clinical manifestations caused by the parasitic protozoa of the genus Leishmania. In Brazil, there are at least seven Leishmania species that are endemic and responsible for this set of clinical manifestations of the disease. Current treatment is limited to a restricted number of drugs that in general have several drawbacks including parenteral use, toxicity, and severe side effects. Amphotericin B is considered a second-line drug for tegumentary leishmaniasis in Brazil, while miltefosine was recently approved for clinical use in the treatment of this disease. In this study, we investigated the in vitro susceptibility of Leishmania strains representative of the species endemic to Brazil, as well as a panel of thirteen clinical isolates of tegumentary leishmaniasis, to both amphotericin B and miltefosine. A moderate variation in the susceptibility to both drugs was found, where the EC50 values varied from 11.43 to 52.67 µM for miltefosine and from 12.89 to 62.36 nM for amphotericin B in promastigotes, while for the intracellular amastigotes, values ranged from 1.08 to 9.60 µM and from 1.69 to 22.71 nM for miltefosine and amphotericin B respectively. Furthermore, the clinical isolates and strains of the subgenus Viannia were evaluated for the presence of Leishmania RNA virus 1 (LRV1), as this is an important factor associated with disease severity and treatment outcome. These findings provide a preclinical dataset of the activity of these drugs against the causative species of tegumentary leishmaniasis in Brazil.


Subject(s)
Antiprotozoal Agents , Leishmania , Leishmaniasis, Cutaneous , Leishmaniasis , Humans , Amphotericin B/pharmacology , Amphotericin B/therapeutic use , Brazil/epidemiology , Leishmaniasis/drug therapy , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology
15.
Int J Mol Sci ; 24(2)2023 Jan 13.
Article in English | MEDLINE | ID: mdl-36675150

ABSTRACT

Visceral leishmaniasis is a neglected vector-borne tropical disease caused by Leishmania donovani and Leishmania infantum that is endemic not only in East African countries, but also in Asia, regions of South America and the Mediterranean Basin. For the pharmacological control of this disease, there is a limited number of old and, in general, poorly adherent drugs, with a multitude of adverse effects and low oral bioavailability, which favor the emergence of resistant pathogens. Pentavalent antimonials are the first-line drugs, but due to their misuse, resistant Leishmania strains have emerged worldwide. Although these drugs have saved many lives, it is recommended to reduce their use as much as possible and replace them with novel and more friendly drugs. From a commercial collection of anti-infective drugs, we have recently identified nifuratel-a nitrofurantoin used against vaginal infections-as a promising repurposing drug against a mouse model of visceral leishmaniasis. In the present work, we have tested combinations of miltefosine-the only oral drug currently used against leishmaniasis-with nifuratel in different proportions, both in axenic amastigotes from bone marrow and in intracellular amastigotes from infected Balb/c mouse spleen macrophages, finding a potent synergy in both cases. In vivo evaluation of oral miltefosine/nifuratel combinations using a bioimaging platform has revealed the potential of these combinations for the treatment of this disease.


Subject(s)
Antiprotozoal Agents , Leishmania donovani , Leishmaniasis, Visceral , Nifuratel , Animals , Female , Mice , Leishmaniasis, Visceral/drug therapy , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use
16.
EBioMedicine ; 86: 104378, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36462405

ABSTRACT

BACKGROUND: Miltefosine treatment failure in visceral leishmaniasis in Brazil has been associated with deletion of the miltefosine susceptibility locus (MSL) in Leishmania infantum. The MSL comprises four genes, 3'-nucleotidase/nucleases (NUC1 and NUC2); helicase-like protein (HLP); and 3,2-trans-enoyl-CoA isomerase (TEI). METHODS: In this study CRISPR-Cas9 was used to either epitope tag or delete NUC1, NUC2, HLP and TEI, to investigate their role in miltefosine resistance mechanisms. Additionally, miltefosine transporter genes and miltefosine-mediated reactive oxygen species homeostasis were assessed in 26 L. infantum clinical isolates. A comparative lipidomic analysis was also performed to investigate the molecular basis of miltefosine resistance. FINDINGS: Deletion of both NUC1, NUC2 from the MSL was associated with a significant decrease in miltefosine susceptibility, which was restored after re-expression. Metabolomic analysis of parasites lacking the MSL or NUC1 and NUC2 identified an increase in the parasite lipid content, including ergosterol; these lipids may contribute to miltefosine resistance by binding the drug in the membrane. Parasites lacking the MSL are more resistant to lipid metabolism perturbation caused by miltefosine and NUC1 and NUC2 are involved in this pathway. Additionally, L. infantum parasites lacking the MSL isolated from patients who relapsed after miltefosine treatment were found to modulate nitric oxide accumulation in host macrophages. INTERPRETATION: Altogether, these data indicate that multifactorial mechanisms are involved in natural resistance to miltefosine in L. infantum and that the absence of the 3'nucleotidase/nuclease genes NUC1 and NUC2 contributes to the phenotype. FUNDING: MRC GCRF and FAPES.


Subject(s)
Antiprotozoal Agents , Leishmania infantum , Leishmania infantum/genetics , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Nucleotidases/metabolism
17.
Front Immunol ; 13: 1005366, 2022.
Article in English | MEDLINE | ID: mdl-36248839

ABSTRACT

Background: Keloids are a fibroproliferative disease characterized by unsatisfactory therapeutic effects and a high recurrence rate. Objective: This study aimed to investigate keloid-related circulating metabolic signatures. Methods: Untargeted metabolomic analysis was performed to compare the metabolic features of 15 keloid patients with those of paired healthy volunteers in the discovery cohort. The circulating metabolic signatures were selected using the least absolute shrinkage. Furthermore, the selection operators were quantified using multiple reaction monitoring-based target metabolite detection methods in the training and test cohorts. Results: More than ten thousand metabolic features were consistently observed in all the plasma samples from the discovery cohort, and 30 significantly different metabolites were identified. Four differentially expressed metabolites including palmitoylcarnitine, sphingosine, phosphocholine, and phenylalanylisoleucine, were discovered to be related to keloid risk in the training and test cohorts. In addition, using linear and logistic regression models, the respective risk scores for keloids based on a 4-metabolite fingerprint classifier were established to distinguish keloids from healthy volunteers. Conclusions: In summary, our findings show that the characteristics of circulating metabolic fingerprinting manifest phenotypic variation in keloid onset.


Subject(s)
Keloid , Humans , Keloid/pathology , Logistic Models , Palmitoylcarnitine/therapeutic use , Phosphorylcholine/therapeutic use , Sphingosine
18.
Parasitol Res ; 121(10): 2849-2860, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35997843

ABSTRACT

The purpose of the present study was to evaluate the efficacy of the treatment with a recombinant cysteine proteinase from Leishmania, rldccys1, associated with allopurinol or miltefosine on Leishmania (Leishmania) infantum chagasi-infected hamsters. Golden Syrian hamsters infected with L. (L.) infantum chagasi were treated with either miltefosine (46 mg/kg) or allopurinol (460 mg/kg) alone by oral route or associated with rldccys1 (150 µg/hamster) by subcutaneous route for 30 days. Infected hamsters were also treated with miltefosine (46 mg/kg) plus rldccys1 (150 µg/hamster) for 30 days (phase 1) followed by two additional doses of rldccys1 (250 µg/hamster) (phase 2). After the end of treatment, the animals were analyzed for parasite load, body weight, serum levels of immunoglobulins, cytokine expression, and drug toxicity. The data showed a significant decrease of parasite load in infected hamsters treated with allopurinol or miltefosine alone or associated with rldccys1, as well as in those treated with rldccys1 alone. Significantly lower levels of serum IgG were detected in hamsters treated with allopurinol plus rldccys1. The treatment with miltefosine associated with rldccys1 prevented relapse observed in animals treated with miltefosine alone. A significant loss of body weight was detected only in some hamsters treated with miltefosine for 1 month and deprived of this treatment for 15 days. There were no significant differences in transcript expression of IFN-γ and IL-10 in any of treated groups. Neither hepatotoxicity nor nephrotoxicity was observed among controls and treated groups. These findings open perspectives to further explore this immunochemotherapeutic schedule as an alternative for treatment of visceral leishmaniasis.


Subject(s)
Antiprotozoal Agents , Leishmania infantum , Leishmaniasis, Visceral , Allopurinol/therapeutic use , Animals , Antiprotozoal Agents/therapeutic use , Body Weight , Cricetinae , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Mesocricetus , Phosphorylcholine/therapeutic use
19.
Acta Parasitol ; 67(3): 1421-1424, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35861895

ABSTRACT

The genus Naegleria consists of free-living amoebae widely distributed worldwide in soil and freshwater habitats. Primary amoebic meningoencephalitis (PAM) is an uncommon and most likely fatal disease. The incubation period is approximately 7 days. The first symptoms are headache, nasal congestion, fever, vomiting, stiff neck within 3-4 days after the first symptoms, confusion, abnormal behavior, seizures, loss of balance and body control, coma, and death. We describe the case of a child who presented with PAM due to Naegleria sp., fully recovered from the infection without apparent sequels after treatment with a regimen that included miltefosine and voriconazole.


Subject(s)
Amebiasis , Central Nervous System Protozoal Infections , Naegleria fowleri , Naegleria , Amebiasis/diagnosis , Amebiasis/drug therapy , Central Nervous System Protozoal Infections/diagnosis , Central Nervous System Protozoal Infections/drug therapy , Child , Humans , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/therapeutic use , Voriconazole/therapeutic use
20.
Toxicol Pathol ; 50(6): 787-792, 2022 08.
Article in English | MEDLINE | ID: mdl-35726637

ABSTRACT

Osteoarthritis (OA) can lead to a significant functional disability. Poly[2-(methacryloyloxy)ethyl phosphorylcholine] (pMPC) liposomes are a novel treatment modality for OA, intended to restore the natural lubrication properties of articular cartilage. Here, we report on two studies aimed to assess the local and systemic safety and toxicity of pMPCylated liposomes in comparison with physiological saline, in Sprague-Dawley (SD) rats and in sheep after a single intra-articular (IA) injection. The animals were sacrificed after 1 and 6 weeks (rats) and 3 and 6 weeks (sheep). No signs of toxicity or abnormal clinical findings were observed. Histopathological evaluation revealed no signs of reactivity or abnormal findings in the injected joints or in any other organs. In conclusion, a single IA injection of the pMPCylated liposomes demonstrated an excellent safety profile and did not result in local reactivity or systemic toxicity, thus supporting its further development for use in humans.


Subject(s)
Cartilage, Articular , Osteoarthritis , Animals , Disease Models, Animal , Humans , Injections, Intra-Articular , Liposomes/therapeutic use , Osteoarthritis/drug therapy , Osteoarthritis/pathology , Phosphorylcholine/therapeutic use , Rats , Rats, Sprague-Dawley , Sheep
SELECTION OF CITATIONS
SEARCH DETAIL
...