RESUMEN
The oral efficacy and safety of a leishmanicidal nitrochalcone (CH8) were studied in BALB/c mouse infections with Leishmania amazonensis and Leishmania infantum Although 10-fold-higher doses of CH8 were needed to produce the same antiparasitic effect as that seen with the reference drug miltefosine, the latter was nephrotoxic, whereas CH8 restored disease toxicity markers to normal. This study shows the therapeutic potential of an orally active and hepato-/nephroprotective chalcone against cutaneous and visceral leishmaniases.
Asunto(s)
Antiprotozoarios/química , Antiprotozoarios/uso terapéutico , Chalconas/uso terapéutico , Leishmaniasis/tratamiento farmacológico , Administración Oral , Animales , Chalconas/química , Femenino , Leishmania/efectos de los fármacos , Leishmania/patogenicidad , Leishmania infantum/efectos de los fármacos , Leishmania infantum/patogenicidad , Leishmaniasis/microbiología , Ratones , Ratones Endogámicos BALB C , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Fosforilcolina/uso terapéuticoRESUMEN
Conventional 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 poly(lactic-co-glycolic acid) (PLGA) 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 6 µm without triggering oxidative mechanisms. Upon 48 h of 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 1.2 mg/kg of CH8 in free or CH8/PLGA forms, whereas controls received three CH8-equivalent doses of naked PLGA microparticles or meglumine antimoniate (Glucantime; Sanofi-Aventis). Although a single injection with CH8/PLGA reduced the parasite loads by 91%, triple injections with free CH8 or CH8/PLGA caused 80 and 97% reductions, respectively, in relation to saline controls. Meglumine antimoniate treatment was the least effective (only 36% reduction) and the most toxic, as indicated by elevated alanine aminotransferase serum levels. Together, these findings show that CH8/PLGA microparticles can be effectively and safely used for single-dose treatment of CL.
Asunto(s)
Antiprotozoarios/uso terapéutico , Chalconas/química , Leishmaniasis Cutánea/tratamiento farmacológico , Microesferas , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Animales , Antiprotozoarios/química , Femenino , Leishmaniasis Cutánea/metabolismo , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/parasitología , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
In the present study a family of macrocyclic and acyclic analogues as well as seco-analogues of avermectins were prepared from commercial Ivermectin (IVM) and their antileishmanial activity assayed against axenic promastigote and intracellular amastigote forms of Leishmania amazonensis. Contrarily to the filaricidal activity, the leishmanicidal potentiality of avermectin analogues does not appear to depend on the integrity of the non-conjugated Delta(3,4)-hexahydrobenzofuran moiety. Conjugated Delta(2,3)-IVM or its corresponding conjugated secoester show higher anti-leishmania activity than the parent compound. Surprisingly, the diglycosylated northern sub-unit exhibits the same anti-amastigote potentiality as the southern hexahydrobenzofuran. As expected for compounds derived from the widely used Ivermectin antibiotic, little toxicity has been noticed for most of the novel analogues prepared.