ABSTRACT
Leishmaniasis is a group of diseases caused by a protozoa parasite from one of over 20 Leishmania species. Depending on the tissues infected, these diseases are classified as cutaneous, mucocutaneous and visceral leishmaniasis. For the treatment of leishmaniasis refractory to antimony-based drugs, pentamidine (PTM) is a molecule of great interest. However, PTM displays poor bioavailability through oral routes due to its two strongly basic amidine moieties, which restricts its administration by a parenteral route and limits its clinical use. Among various approaches, nanotechnology-based drug delivery systems (nano-DDS) have potential to overcome the challenges associated with PTM oral administration. Here, we present the development of PTM-loaded PLGA nanoparticles (NPs) with a focus on the characterization of their physicochemical properties and potential application as an oral treatment of leishmaniasis. NPs were prepared by a double emulsion methodology. The physicochemical properties were characterized through the mean particle size, polydispersity index (PdI), zeta potential, entrapment efficiency, yield process, drug loading, morphology, in vitro drug release and in vivo pharmacological activity. The PTM-loaded PLGA NPs presented with a size of 263 ± 5 nm (PdI = 0.17 ± 0.02), an almost neutral charge (-3.2 ± 0.8 mV) and an efficiency for PTM entrapment of 91.5%. The release profile, based on PTM dissolution, could be best described by a zero-order model, followed by a drug diffusion profile that fit to the Higuchi model. In addition, in vivo assay showed the efficacy of orally given PTM-loaded PLGA NPs (0.4 mg kg-1) in infected BALB/c mice, with significant reduction of organ weight and parasite load in spleen (p-value < 0.05). This work successfully reported the oral use of PTM-loaded NPs, with a high potential for the treatment of visceral leishmaniasis, opening a new perspective to utilization of this drug in clinical practice.
Subject(s)
Antiprotozoal Agents/administration & dosage , Leishmaniasis/drug therapy , Pentamidine/administration & dosage , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Administration, Oral , Animals , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/pharmacokinetics , Biological Availability , Disease Models, Animal , Leishmaniasis/parasitology , Mice , Mice, Inbred BALB C , Nanoparticles/chemistry , Organ Size/drug effects , Parasite Load , Particle Size , Pentamidine/chemistry , Pentamidine/pharmacokineticsABSTRACT
OBJECTIVES: This paper describes the antileishmanial properties of LQB-118, a new compound designed by molecular hybridization, orally active in Leishmania amazonensis-infected BALB/c mice. METHODS: In vitro antileishmanial activity was determined in L. amazonensis-infected macrophages. For in vivo studies, LQB-118 was administered intralesionally (15 µg/kg/day, five times a week), intraperitoneally (4.5 mg/kg/day, five times a week) or orally (4.5 mg/kg/day, five times a week) to L. amazonensis-infected BALB/c mice throughout experiments lasting 85 or 105 days. At the end of the experiments, serum levels of alanine aminotransferase, aspartate aminotransferase and creatinine were measured as toxicological parameters. RESULTS: LQB-118 was active against intracellular amastigotes of L. amazonensis [50% inhibitory concentration (IC(50)) 1.4 µM] and significantly less so against macrophages (IC(50) 18.5 µM). LQB-118 administered intralesionally, intraperitoneally or orally was found to control both lesion and parasite growth in L. amazonensis-infected BALB/c mice, without altering serological markers of toxicity. CONCLUSIONS: These results demonstrate that the molecular hybridization of a naphthoquinone core to pterocarpan yielded a novel antileishmanial compound that was locally and orally active in an experimental cutaneous leishmaniasis model.
