Nanoliposomal Buparvaquone Immunomodulates Leishmania infantum-Infected Macrophages and Is Highly Effective in a Murine Model

Abstract

Visceral leishmaniasis is a fatal parasitic neglected disease affecting 1.5 million people worldwide. Based on a drug repositioning approach, the aim of this work was to investigate the in vitro immunomodulatory potential of buparvaquone (BPQ) and to establish a safe regimen to evaluate the in vivo efficacy of BPQ entrapped by negatively charged nanoliposomes (BPQ-LP) in Leishmania infantum-infected hamsters. Small-angle X-ray scattering, dynamic light scattering, and the -potential were applied in order to study the influence of BPQ on the liposome structure. Our data revealed that BPQ was located in the polar-apolar interface, snorkeling the polar region, and protected against aggregation inside the lipophilic region. The presence of BPQ also decreased the Z-average hydrodynamic diameter and increased the surface charge. Compared to intravenous and intramuscular administration, a subcutaneous route was a more effective route for BPQ-LP; at 0.4 mg/kg, BPQ-LP reduced infection in the spleen and liver by 98 and 96%, respectively. Treatment for 5 days resulted in limited efficacy, but 10 days of treatment resulted in an efficacy similar to that of a 15-day regimen. The nanoliposomal drug was highly effective, with a mean 50% effective dose of 0.25 mg/kg, reducing the parasite load in bone marrow by 80%, as detected using quantitative PCR analysis. In addition, flow cytometry studies showed that BPQ upregulated cytokines as tumor necrosis factor, monocyte chemoattractant protein 1, interleukin-10 (IL-10), and IL-6 in Leishmania-infected macrophages, eliminating the parasites via a nitric oxide-independent mechanism. This new formulation proved to be a safe and effective treatment for murine leishmaniasis that could be a useful candidate against visceral leishmaniasis.KEYWORDS Leishmania, drug delivery, liposomes, therapy T he worldwide prevalence and severity of leishmaniasis has led the World Health Organization to consider it a priority infectious disease (1). Due to the complexity of host-parasite interaction, as well as contradictory results from vaccination models, the control of infection is mainly dependent on chemotherapeutic intervention (2). There are now a number of therapies for various forms of leishmaniasis; the preferences for first-line and second-line treatment vary based on the type of disease and are often guided by regional practice. Pentavalent antimonials, such as Pentostam and Glucantime, have been used to treat leishmaniasis for the last 70 years (3). However, these drugs have multiple adverse effects and decreasing effectiveness due to the development of parasite resistance, limiting their application (4). In Brazil, pentavalent antimony is still effective for treating most infections, despite its high toxicity. Until now, Citation da Costa-Silva TA, Galisteo AJ, Jr, Lindoso JAL, Barbosa LRS, Tempone AG. 2017. Nanoliposomal buparvaquone immunomodulates Leishmania infantuminfected macrophages and is highly effective in a murine model. Antimicrob Agents

Targeting Channels and Transporters in Protozoan Parasite Infections

“…Anti-leishmanial activity was evaluated in vitro for L. donovani, Leishmania aethiopica, L. major, Leishmania amazonensis, Leishmania mexicana, Leishmania panamensis, L. infantum, Leishmania chagasi, L. braziliensis , and L. tropica promastigotes and amastigotes resulting in IC 50 -values of 0.001–5.495 μM (Mäntylä et al, 2004a , b ; Reimão et al, 2012 ; Jamal et al, 2015 ). Animal models showed that the in vivo efficiency was higher when prodrugs of buparvaquone were applied (Croft et al, 1992 ; Garnier et al, 2007 ) or when a nanoliposomal drug preparation was used (da Costa-Silva et al, 2017 ).…”

Sertraline Delivered in Phosphatidylserine Liposomes Is Effective in an Experimental Model of Visceral Leishmaniasis

“…where k B is the Boltzmann constant, T is the absolute temperature, η is the viscosity of the solvent, and D h and D app are the hydrodynamic diameter and the apparent diffusion coefficient, respectively (Costa-Silva et al, 2017).…”

“…The measurement for each sample was repeated for at least three times. In order to avoid multiple scattering, the samples were diluted 20-fold in the appropriate buffer before the measurements (Lamy et al, 1966; Costa-Silva et al, 2017). LP-SERT treatment was analyzed by culture microtitration as previously reported (Park and Lee, 2008).…”

“…Finding new uses for FDA-approved drugs is known as drug repositioning, and has been considered an excellent approach for neglected diseases to reduce the costs and time of the research (Andrews et al, 2014; Huang et al, 2015; Costa-Silva et al, 2017). Currently, all available drugs for the clinical treatment of leishmaniases were introduced by the repositioning approach.…”

The Multirole of Liposomes in Therapy and Prevention of Infectious Diseases

“…Another drug under test for liposome delivery is buparvaquone, an extensively studied drug for the treatment of visceral leishmaniosis. da Costa-Silva et al reported that buparvaquone, which has an immunomodulatory effect in host cells, when entrapped in phosphatidylserine (PS) exposing-liposomes, as a delivery approach to macrophage, is highly effective at low doses at eliminating Leishmania infantum parasites in a hamster model ( 52 ).…”