A New Approach To The Treatment of Leishmaniasis: Quercetin-Loaded Polycaprolactone Nanoparticles

Abstract

Antileishmanial drugs used in the treatment of leishmaniasis are toxic and expensive. Moreover,parasites have recently developed resistance against them. Hence there is an increasing need fordeveloping new antileishmanial medicines. Quercetin, found in the roots, leaves and fruits of many plants,is a natural polyphenolic flavonoid. Quercetin has antibacterial, antiviral, anti-carcinogenic, and antioxidantproperties. On the other hand, because of its weak solubility in water, quercetin has had limited use onhumans. To increase its bio-availability and maximize its therapeutic effects, quercetin has recently beenencapsulated with nanoparticulate carrier systems. The aim of this study is to encapsulate quercetin in biodegradable,bio-compatible poly-ε-caprolactone (PCL) nanoparticles, to characterize the synthesizednanoparticles and to analyze their in vitro antileishmanial efficacy on L.infantum parasites. QuercetinloadedPCL nanoparticles (QPNPs) were synthesized using oil-in-water single emulsion solvent evaporationmethod. Their characterization was done using scanning electron microscopy (SEM) and dynamic lightscattering (DLS) equipments. Encapsulation effectiveness and release profiles of QPNPs are calculated withUV-Vis spectrophotometry. The antileishmanial effectiveness of the synthesized nanoparticles was analyzedin L.infantum promastigote culture and amastigote-macrophage culture. The results indicated that QPNPshad an average size of 380 nm, a zeta potential of -6.56 mV, and a PDI value of 0.21. The measurementsshowed the quercetin-loaded nanoparticles to have an encapsulation effectiveness of 64% and a reactionefficiency of 55%. After an incubation of 192 hours, nanoparticles were seen to release 58% of theirquercetin content. The synthesized QPNPs had IC50 values on L.infantum promastigotes and amastigotesof 86 and 144 μg/mL respectively. This means that QPNPs have reduced the vitality of promastigotes about20 times and of amastigotes about 5 times as compared to the control group. These results demonstratethe strong antileishmanial potentials of QPNPs. It is believed that if these positive findings are supportedby further in vivo studies, QPNPs may be used in the treatment of leishmaniasis.