Caracterização e avaliação da atividade biológica de micropartículas de quitosana contendo óleos essenciais

Abstract

Essential oils(EOs) are bioactive compounds with therapeutic potential, presenting innumerable biological activities such as: analgesic, anti-inflammatory, antioxidantandantimicrobial, so they have been described as an alternativeor as supportingtherapy to conventional treatments.However, EOs are susceptible to degradation by physical and chemical agents, requiring external protection, which can be provided by encapsulationwithchitosan-based particles, abiocompatible and biodegradable polymer.Thus, the objective of this study was to produce chitosan microparticlesloaded with copaiba resin oil and essential oils (MP-EO) of Lemongrass (Cymbopogon flexuosus), Geranium (Pelargonium x ssp)and Copaiba(Copaifera officinalis), and evaluate the biological activityof the microparticles for acetylcholinesterase inhibition, toxicity to Artemia salinaand hemolysis assay.Microparticleswere produced by spray drying and characterized by efficiency (EE) and encapsulation content(EC), SEM, particle size distribution, zeta potential, thermal analysisand FTIR. The Lemongrass, Geranium and Copaiba were analyzed by GC-MS, and the main components are citral (83.17%), citronellol (24.53%) and β-caryophyllene (51.49%and 58.96%), respectively. The EE was in the range of 4.8 –58.6%, in whichthe MP-EOs with copaiba resinoiland geranium presented the better results. The microparticles presented spherical morphology and the average size range was 2μmto 3μm. Zeta potential values of the MP-EOs were found to be positive (+29 to +47 mV). The thermograms indicated thermal stability of MP-EOs with higher degradation over 250°C. Based on acetylcholinesteraseinhibition activity results, the essential oils and microparticleshad good activity(IC50 in the range 11.92μg/mL–28.18 μg/mL within 25 min of enzyme incubation),and the activity against Artemia salinashowed that the EOs of geranium andcopaiba presented higher toxicity.All microparticles were non-hemolytic at concentrations upto 0.1mg/mL.In vitroassays of EOrelease fromthe microparticleswere also performed and the results evidenced the potential use of chitosan microparticles as a systemfor the controlled release of essential oils.