Microemulsion of Brazil nut oil as a natural product to improve superoxide release in human phagocytes

Abstract

The aim of this study was to develop and characterize a Brazil nut oil microemulsion system and determine the effect of this microemulsion on the superoxide release in human phagocytes. The microemulsion was formulated using distilled water, Brazil nut as the oily phase, Sorbitan monooleate, Polysorbate 80, and butan-1-ol. Hydrophile-lipophile balance of Brazil nut oil was determined, pseudoternary diagrams were prepared, and microemulsion diagram regions were preselected. Preliminary and accelerated stability tests, rheological characterization and dynamic light scattering were performed. The immunomodulatory effect of the microemulsion on the interactions with leukocytes was determined by superoxide release. The developed formulations were classified as oil-in-water, showed a Newtonian profile, with linear viscosity and droplet sizes of 46.9; 66.5 and 34.3 nm. When we assessed the interaction of the microemulsion of Brazil nut oil with phagocytes, we observed an increase in superoxide release. Our findings indicate that the developed formulation improved the immunomodulatory activity of the Brazil nut oil, proving to be a natural product option for future applications, in particular for infectious diseases.

Development, characterization and stability of microemulsionated formulations of bacaba, Oenocarpus bacaba oil

“…The high surfactant concentration in the selected formulations coincides with that employed in other studies of microemulsion prospection (Ribeiro et al 2015;Boonme et al 2006;Prajapati et al 2012;Fiori et al 2017). The high proportion of surfactant results from the need to reduce the surface tension between the oily and aqueous phase, to enable smaller droplet sizes and provide stability to the formulation, the basic characteristics of viable microemulsions (Fanun 2012;Pessoa et al 2015).…”

“…The emulsions were analyzed under a microscope (BEL ® Photonics, Italy) at 40x magnification, and the globules were photographed (one picture for each replicate, adding up to three pictures for each HLB value) for determination of their area using the Image J® software. Mean droplet size, standard deviation and coefficient of variation in function of globule area were calculated (Zanin et al 2002;Fiori et al 2017).…”

“…Microemulsion stability was analyzed according to Fiori et al (2017) and Gustmann et al (2017). For preliminary stability, the formulations selected from the pseudoternary diagram were submitted to alternate heating/cooling cycles of 24 hours, at 40 ± 1 °C and 5 ± 1 °C, respectively, during 14 ACTA AMAZONICA days.…”

“…Rheological parameters were measured for each formulation, before and after the accelerated stability test, according to Fiori et al (2017) and Gustmann et al (2017) using a Modular Compact Rheometer (MCR 102, Anton Paar ® Germany GmbH, Ostfildern, Germany). The tests were conducted under controlled conditions at 25 °C and statistically significant differences within samples before and after the test were evaluated using analysis of variance (ANOVA), followed by multiple comparisons by Tukey test.…”

“…Dynamic light scattering analysis were performed using a Zetasizer Nano (Z90, Malvern ® Instruments, United Kingdom) with excitation at 632.8 nm, according to Fiori et al (2017) and Gustmann et al (2017). Colloidal structures of the formulations were prepared for analysis by the dynamic light scattering technique, to evaluate the hydrodynamic diameter of the dispersed system.…”