Nigella sativa oil entrapped polycaprolactone nanoparticles for leishmaniasis treatment

Abstract

This study is the first to investigate the antileishmanial activities of Nigella sativa oil (NSO) entrapped poly-ɛ-caprolactone (PCL) nanoparticles on Leishmania infantum promastigotes and amastigotes in vitro. NSO molecules with variable initial doses of 50, 100, 150, and 200 mg were successfully encapsulated into PCL nanoparticles identified as formulations NSO1, NSO2, NSO3, and NSO4, respectively. This process was characterised by scanning electron microscope, dynamic light scattering, Fourier transform infrared, encapsulation efficiency measurements, and release profile evaluations. The resulting synthetised nanoparticles had sizes ranging between 200 and 390 nm. PCL nanoparticles encapsulated 98% to 80% of initial doses of NSO and after incubation released approximately 85% of entrapped oil molecules after 288 h. All investigated formulations demonstrated strong antileishmanial effects on L. infantum promastigotes by inhibiting up to 90% of parasites after 192 h. The tested formulations decreased infection indexes of macrophages in a range between 2.4- and 4.1-fold in contrast to control, thus indicating the strong anti-amastigote activities of NSO encapsulated PCL nanoparticles. Furthermore, NSO-loaded PCL nanoparticles showed immunomodulatory effects by increasing produced nitric oxide amounts within macrophages by 2-3.5-fold in contrast to use of free oil. The obtained data showed significant antileishmanial effects of NSO encapsulated PCL nanoparticles on L. infantum promastigotes and amastigotes.

Fig. 1

SEM images of synthetised nanoparticles (a) empty, (b) NSO encapsulated PCL nanoparticles (NSO4 formulation)

Fig. 2

FTIR spectrum of the free NSO, Empty PCL NPs, and NSO‐PCL NPs

Fig. 3

In vitro release profiles of NSO encapsulated PCL nanoparticles and cumulative release amounts of oil from NSO1, NSO2, NSO3, and NSO4 formulations

Fig. 4

Cytotoxicity analysis of free oil and NSO encapsulated PCL nanoparticles on J774 macrophage cells following to 144 h incubation

Fig. 5

Growth inhibition percentages of L. infantum promastigotes that are exposed to NSO1, NSO2, NSO3, NSO4 formulations, and free oil for 72 h

Fig. 6

Growth inhibition percentages of L. infantum promastigotes that are exposed to NSO1, NSO2, NSO3, NSO4 formulations, and free oil for 144 h

Fig. 7

Growth inhibition percentages of L. infantum promastigotes that are exposed to NSO1, NSO2, NSO3, NSO4 formulations, and free oil for 192 h

Fig. 8

Infection indexes of the free NSO, empty PCL NPs, and different concentrations of synthetised NSO encapsulated PCL NPs