Pharmaceutics (Nov 2021)

Annatto Oil Loaded Nanostructured Lipid Carriers: A Potential New Treatment for Cutaneous Leishmaniasis

  • Marianna Araújo Ferreira,
  • Renato Ferreira de Almeida Júnior,
  • Thiago Souza Onofre,
  • Bruna Renata Casadei,
  • Kleber Juvenal Silva Farias,
  • Patricia Severino,
  • Camilo Flamarion de Oliveira Franco,
  • Fernanda Nervo Raffin,
  • Túlio Flávio Accioly de Lima e Moura,
  • Raquel de Melo Barbosa

DOI
https://doi.org/10.3390/pharmaceutics13111912
Journal volume & issue
Vol. 13, no. 11
p. 1912

Abstract

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Annatto (Bixa orellana L.) is extensively used as food pigment worldwide. Recently, several studies have found it to have healing and antioxidant properties, as well as effective action against leishmaniasis. Therefore, the purpose of this study was to incorporate the oil obtained from annatto seeds into a nanostructured lipid carrier (NLC) and evaluate its physicochemical properties and biological activity against Leishmania major. Nanoparticles were prepared by the fusion-emulsification and ultrasonication method, with the components Synperonic™ PE (PL) as the surfactant, cetyl palmitate (CP) or myristyl myristate (MM) as solid lipids, annatto oil (AO) (2% and 4%, w/w) as liquid lipid and active ingredient, and ultra-pure water. Physicochemical and biological characterizations were carried out to describe the NLCs, including particle size, polydispersity index (PDI), and zeta potential (ZP) by dynamic light scattering (DLS), encapsulation efficiency (EE%), thermal behavior, X-ray diffraction (XRD), transmission electron microscopy (TEM), Electron Paramagnetic Resonance (EPR), cytotoxicity on BALB/c 3T3 fibroblasts and immortalized human keratinocyte cells, and anti-leishmaniasis activity in vitro. Nanoparticles presented an average diameter of ~200 nm (confirmed by TEM results), a PDI of less than 0.30, ZP between −12.6 and −31.2 mV, and more than 50% of AO encapsulated in NLCs. Thermal analyses demonstrated that the systems were stable at high temperatures with a decrease in crystalline structure due to the presence of AOs (confirmed by XRD). In vitro, the anti-leishmania test displayed good activity in encapsulating AO against L. major. The results indicate that the oily fraction of Bixa orellana L. in NLC systems should be evaluated as a potential therapeutic agent against leishmaniasis.

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