ABSTRACT
Essential oils (EOs) are bioactive compounds with therapeutic potential for use as alternatives or as support to conventional treatments. However, EOs present limitations, such as sensibility to environmental factors, which can be overcome through microencapsulation. The objective of this study was to produce, by spray drying, chitosan microparticles (CMs) loaded with EO of Lemongrass (Cymbopogon flexuosus), Geranium (Pelargonium x ssp) and Copaiba (Copaifera officinalis). Physicochemical and biological characterization of these microparticles showed that CMs presented spherical morphology, had an average size range of 2-3 µm with positive zeta potential (ZP) values, and enhanced thermal stability, compared to free EO. The encapsulation efficiency (EE) ranged from 4.8-58.6%, depending on the oil's properties. In vitro EO release from CMs was determined at different pHs, with 94% release observed in acid media. All microparticles were non-hemolytic at concentrations of up to 0.1 mg·mL-1. EOs and CMs presented acetylcholinesterase (AChE) inhibition activity (IC 50 ranged from 11.92 to 28.18 µg·mL-1). Geranium and Copaiba EOs presented higher toxicity against Artemia salina, and greater inhibition of acetylcholinesterase, indicating potential bioactivity for Alzheimer's disease (AD). Our findings demonstrate that CM systems may show promise for the controlled release of these EOs.
Subject(s)
Artemia/drug effects , Capsules/chemistry , Chitosan/chemistry , Cholinesterase Inhibitors/pharmacology , Cymbopogon/chemistry , Fabaceae/chemistry , Oils, Volatile/analysis , Pelargonium/chemistry , Animals , Blood/drug effects , Cholinesterase Inhibitors/toxicity , Cymbopogon/toxicity , Fabaceae/toxicity , Hemolysis , Hot Temperature , Humans , Hydrogen-Ion Concentration , Inhibitory Concentration 50 , Microscopy, Electron, Scanning , Oils, Volatile/chemistry , Particle Size , Pelargonium/toxicity , Spectroscopy, Fourier Transform InfraredABSTRACT
The aim of the study was to produce and characterize chitosan microparticles loaded with essential oils (CMEOs), evaluate the essential oil (EO) release profile and the CMEOs' anti-Candida activity. The chitosan microparticles (CMs) loaded with lemongrass essential oil (LEO) and geranium essential oil (GEO) were produced by the spray-drying method and characterized regarding CMEO morphological and physicochemical parameters and EO encapsulation efficiency (EE) and release profile. The planktonic activity was quantified by broth microdilution, and the activity against biofilm was quantified by biomass formation measurement. The LEO and GEO compositions were analyzed by gas chromatography combined with mass spectrometry (GC/MS), finding the main components citral (83.17%) and citronellol (24.53%). The CMs and CMEOs showed regular distribution and spherical shape (1 to 15 µm), without any morphological and physical modifications after EO incorporation. EE% ranged from 12 to 39%. In vitro release tests demonstrated the EO release rates, after 144 h, were 33% and 55% in PBS and HCl media, respectively. The minimum inhibitory concentration (MIC) values for CMEOs were lower than for CMs and pure EOs (P < 0.05). The higher CMEO biofilm inhibition percentage demonstrates the efficiency of microparticles against Candida biofilm. These results indicate that CMEOs are promising compounds that have antibiofilm activity against C. albicans.
