Novel and safe single-dose treatment of cutaneous leishmaniasis with implantable amphotericin B-Loaded microparticles

International audienceThe development of an effective amphotericin B (AmB) topical formulation to replace the systemically toxic injections currently used in cutaneous leishmaniasis (CL) treatment is challenging due to poor absorption through the skin. Aiming at an effective local chemotherapy, we designed PLGA (poly lactide-co-glycolide acid) microspheres loaded with deoxycholate amphotericin B (d-AmB) for both macrophage intracellular targeting and sustained extracellular release. For that, d-AmB/PLGA microspheres with sizes ranging from 0.5 μm to 20 μm were synthesized and tested both in vitro and in vivo. In vitro, d-AmB/PLGA was more selectively active against intracellular amastigotes of Leishmania amazonensis than free d-AmB (selectivity index = 50 and 25, respectively). In vivo, the efficacy of a single intralesional (i.l) injection with d-AmB/PLGA was determined in early and established BALB/c mouse ear lesions. In early lesions, a single injection given on day 10 of infection was more effective in controlling parasite growth than eight i.l. injections with free d-AmB, as measured on day 120. Such d-AmB/PLGA injection was also effective in established lesions (day 30), leading to 97% parasite burden reduction, as compared with d-AmB or liposomal AmB (Ambisome®) i.l. injection containing the same AmB dose. Pharmacokinetic studies showed that following d-AmB/PLGA injection, AmB leaked slower from non-infected than infected ears, yet remaining in the ear tissue for as long as 30 days. Of interest, AmB was not detectable in the circulating plasma for at least two weeks of d-AmB/PLGA injection, contrasting with the rapid and durable (2 days) detection after free d-AmB injection. Despite the transient ear swelling and local cell infiltration, no alterations in AST, ALT and creatinine serum levels was induced by d-AmB/PLGA. For its approved components, local efficacy, and single-dose applicability, this novel and safe AmB microsphere depot formulation has strong potential as a new therapy for human CL

Composições farmacêuticas microparticuladas contendo antiparasitários para terapia subcutânea prolongada, uso das ditas composições farmacêuticas para a produção de um medicamento e método de tratamento de parasitoses

DepositadaA inovação ora proposta se refere a uma composição farmacêutica contendo Anfotericina B, chalcona nitrada (CH8) ou Glucantime encapsulados em micropartículas de polímeros biodegradáveis de liberação lenta, ao processo de encapsulamento do fármaco no interior das partículas; ao uso destas composições farmacêuticas, a um medicamento e ao tratamento de parasitoses

Depot subcutaneous injection with chalcone CH8-loaded Poly (Lactic-Co-Glycilic Acid) microspheres as a single-dose treatment of cutaneous leishmaniasis

International audienceConventional chemotherapy of cutaneous leishmaniasis (CL) is based on multiple parenteral or intralesional injections with systemically toxic drugs. Aiming at a single-dose localized therapy, biodegradable PLGA (poly-(lactide-co-glycolide) microparticles loaded with 7.8% of an antileishmanial nitrochalcone named CH8 (CH8/PLGA) were constructed to promote sustained subcutaneous release. In vitro, murine macrophages avidly phagocytosed CH8/PLGA smaller than 6μm without triggering oxidative mechanisms. Upon 48-hour incubation, both CH8 and CH8/PLGA were 40 times more toxic to intracellular Leishmania amazonensis than to macrophages. In vivo, BALB/c were given one or three subcutaneous injections in the infected ear with 1.2mg/kg of CH8 in free or CH8/PLGA forms, while controls received three CH8-equivalent doses of naked PLGA microparticles or Glucantime. While a single injection with CH8/PLGA reduced the parasite loads by 91%, triple injections with free CH8 or CH8/PLGA caused 80% and 97% reduction, respectively, in relation to saline controls. Glucantime treatment was the least effective (only 36% reduction) and the most toxic as seen by elevated alanine aminotransferase serum levels. Together, those findings show that CH8/PLGA microparticles can be effectively and safely used for single-dose treatment of CL

Antitumoral, antileishmanial and antimalarial activity of pentacyclic 1,4-naphthoquinone derivatives

Pterocarpanquinones 8a-c, previously synthesized in our laboratory, and an homologous series of derivatives, compounds 9a-c prepared in this work, were evaluated on breast cancer cells (MCF-7) and on the parasites Leishmania amazonensis and Plasmodium falciparum, in culture. Compounds 8a-c were more potent than 9a-c on tumor cells and Leishmania amazonensis. On the other hand, 9a-c showed to be more active on Plasmodium falciparum. All the compounds studied were bioselective, presenting negligible cytotoxicity against fresh murine lymphocytes and human lymphocytes activated by the mitogen phytohemaglutinin (PHA)

Intranasal delivery of naked DNA encoding the LACK antigen leads to protective immunity against visceral leishmaniasis in mice

5 p.-3 fig.We previously showed that intranasal (i.n.) vaccination with pCIneo plasmid encoding the leishmanial LACK gene (pCIneo-LACK) induces long-lasting protective immunity against cutaneous leishmaniasis in mice. In this work, we proposed to investigate whether the efficacy of i.n. pCIneo-LACK is extensive to visceral leishmaniasis. BALB/c mice received two i.n. doses of 30 μg pCIneo-LACK prior to intravenous (i.v.) infection with Leishmania chagasi. Vaccinated mice developed significantly lower parasite burden in the liver and spleen than control mice receiving empty pCIneo or saline. The spleen cells of vaccinated mice produced significantly increased IFN-γ and IL-4 concomitant with decreased IL-10 production during infection. Serum levels of specific IgG were elevated whereas TNF-α were decreased as compared with controls. These results show that the practical needle-free i.n. pCIneo-LACK vaccine displays potential broad-spectrum activity against leishmaniasis.Peer reviewe

In Vivo Safety and Efficacy of Chalcone-Loaded Microparticles with Modified Polymeric Matrix against Cutaneous Leishmaniasis

Current chemotherapy of cutaneous leishmaniasis (CL) is based on repeated systemic or intralesional administration of drugs that often cause severe toxicity. Previously, we demonstrated the therapeutic potential of biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) loaded with 8% of the nitrochalcone CH8 (CH8/PLGA) prepared by a conventional bench method. Aiming at an industrially scalable process and increased drug loading, new MPs were prepared by spray drying: CH8/PDE with PLGA matrix and CH8/PVDE with PLGA + polyvinylpyrrolidone (PVP) matrix, both with narrower size distribution and higher drug loading (18%) than CH8/PLGA. Animal studies were conducted to evaluate their clinical feasibility. Both MP types induced transient local swelling and inflammation, peaking at 1–2 days, following a single intralesional injection. Different from CH8/PDE that released 90% of the drug in the ear tissue in 60 days, CH8/PVDE achieved that in 30 days. The therapeutic efficacy of a single intralesional injection was evaluated in BALB/c mice infected with Leishmania (Leishmania) amazonensis and golden hamsters infected with L. (Viannia) braziliensis. CH8/PVDE promoted greater reduction in parasite burden than CH8/PDE or CH8/PLGA, measured at one month and two months after the treatment. Thus, addition of PVP to PLGA MP matrix accelerates drug release in vivo and increases its therapeutic effect against CL

Synthesis and leishmanicidal activity of eugenol derivatives bearing 1,2,3-triazole functionalities

In this paper, it is described the synthesis and the evaluation of the leishmanicidal activity of twenty-six eugenol derivatives bearing 1,2,3-triazole functionalities. The evaluation of the compounds on promastigotes of Leishmania amazonensis (WHOM/BR/75/Josefa) showed that eugenol derivatives present leishmanicidal activities with varying degrees of effectiveness. The most active compound, namely 4-(3-(4-allyl-2-methoxyphenoxy)propyl)-1-(4-methylbenzyl)-1H-1,2,3-triazole (7k) (IC50 = 7.4 ± 0.8 μmol L−1), also targeted Leishmania parasites inside peritoneal macrophages (IC50 = 1.6 μmol L−1) without interfering with cell viability. The cytotoxicity of 7k against macrophage cells presented IC50 of 211.9 μmol L−1 and the selective index was equal to 132.5. Under similar conditions, compound 7k was more effective than glucantime and pentamidine, two drugs currently in the clinic. In addition, theoretical calculations showed that this compound also presents most physicochemical and pharmacokinetic properties within the ranges expected for orally available drugs. It is believed that eugenol bearing 1,2,3-triazole functionalities may represent a scaffold to be explored toward the development of new agents to treat leishmaniasis

Antileishmanial Sesquiterpenes from the Brazilian Red Alga Laurencia dendroidea

Investigation of the bioactive crude extracts from two populations of the red alga Laurencia dendroidea from the southeastern Brazilian coast led to the identification of five sesquiterpenes: (+)-obtusane (1), a triquinane derivative (2), (-)-elatol (3), obtusol (4), and cartilagineol (5). An antileishmanial bioassay against Leishmania amazonensis was conducted for crude lipophilic extracts and for sesquiterpenes 2, 3, and 4. Compounds 3 and 4 displayed in vitro and in vivo leishmanicidal activity and very low cytotoxicity.CAPESFINEP[3175/06]CNP