Cellular Internalization and Toxicity of Chitosan Nanoparticles Loaded with Nobiletin in Eukaryotic Cell Models (<i>Saccharomyces cerevisiae</i> and <i>Candida albicans</i>)

This study involved the synthesis and characterization of chitosan nanoparticles loaded with nobiletin (CNpN) and assessed their toxicity and cellular internalization in eukaryotic cell models (Saccharomyces cerevisiae and Candida albicans). Nanoparticles were prepared via the nanoprecipitation method and physicochemically characterized to determine their hydrodynamic diameter using dynamic light scattering (DLS), their surface charge through ζ-potential measurements, and their chemical structure via Fourier-transform infrared spectroscopy (FTIR). The hydrodynamic diameter and ζ-potential of chitosan nanoparticles (CNp) and CNpN were found to be 288.74 ± 2.37 nm and 596.60 ± 35.49 nm, and 34.51 ± 0.66 mV and 37.73 ± 0.19 mV, respectively. The scanning electron microscopy (SEM) images displayed a particle size of approximately 346 ± 69 nm, with notable sphericity for CNpN. FTIR analysis provided evidence of potential imine bonding between chitosan and nobiletin. Membrane integrity damage could be observed in both S. cerevisiae and C. albicans yeast stained with propidium iodide, demonstrating membrane integrity damage caused by CNp and CNpN, where higher concentration treatments inhibited the development of yeast cells. These findings suggest a selective therapeutic potential of CNpN, which could be promising for the development of antifungal and anticancer therapies. This study contributes to understanding the interaction between nanoparticles and eukaryotic cells, offering insights for future biomedical applications

Antifungal and antimycotoxigenic activity of essential oils from Eucalyptus globulus, Thymus capitatus and Schinus molle

Abstract Essential oils (EO) of eucalyptus (Eucalyptus globulus L.), thymus (Thymus capitatus L.) pirul (Schinus molle L.) were evaluated for their efficacy to control Aspergillus parasiticus and Fusarium moniliforme growth and their ability to produce mycotoxins. Data from kinetics radial growth was used to obtain the half maximal inhibitory concentration (IC50). The IC50 was used to evaluate spore germination kinetic and mycotoxin production. Also, spore viability was evaluated by the MTT assay. All EO had an effect on the radial growth of both species. After 96 h of incubation, thymus EO at concentrations of 1000 and 2500 µL L–1 totally inhibited the growth of F. moniliforme and A. parasiticus, respectively. Eucalyptus and thymus EO significantly reduced spore germination of A. parasiticus. Inhibition of spore germination of F. moniliforme was 84.6, 34.0, and 30.6% when exposed to eucalyptus, pirul, and thymus EO, respectively. Thymus and eucalyptus EO reduced aflatoxin (4%) and fumonisin (31%) production, respectively. Spore viability was affected when oils concentration increased, being the thymus EO the one that reduced proliferation of both fungi. Our findings suggest that EO affect F. moniliforme and A. parasiticus development and mycotoxin production

Control of mycotoxigenic fungi with microcapsules of essential oils encapsulated in chitosan

Abstract Aspergillus and Fusarium are the fungi genera most frequently isolated from cereal grains and other commodities. They are capable of producing mycotoxins, which can affect the human and animal health. Synthetic fungicides have been used to control these fungi, nevertheless, they have acquired resistance and other alternatives are necessary since they now need higher amounts. Therefore, the aim of this study was to evaluate the efficacy of cinnamon, clove and thyme essential oils (EOs) alone and encapsulated in chitosan on the radial growth, spore germination and mycotoxin production by Fusarium verticillioides and Aspergillus parasiticus. The composition of the EOs was determined by gas chromatography mass spectrometry (GC-MS). EOs inhibited radial growth and spore germination of both fungal species better than when they were encapsulated, plus, they reduced mycotoxin production. The major components were eugenol in cinnamon and clove EO (70 and 63%, respectively) and 2-methyl-5-(1-methyethyl)-phenol (46.2%) in thyme EO. The microparticles with clove and thyme EO showed good surface charges, higher than +30 mV and their average size for the three types of microparticles was about 750 nm. Our findings suggest that EOs both alone and encapsulated in chitosan have a fungistatic effect on Fusarium verticillioides and Aspergillus parasiticus

Control of mycotoxigenic fungi with microcapsules of essential oils encapsulated in chitosan

<div><p>Abstract Aspergillus and Fusarium are the fungi genera most frequently isolated from cereal grains and other commodities. They are capable of producing mycotoxins, which can affect the human and animal health. Synthetic fungicides have been used to control these fungi, nevertheless, they have acquired resistance and other alternatives are necessary since they now need higher amounts. Therefore, the aim of this study was to evaluate the efficacy of cinnamon, clove and thyme essential oils (EOs) alone and encapsulated in chitosan on the radial growth, spore germination and mycotoxin production by Fusarium verticillioides and Aspergillus parasiticus. The composition of the EOs was determined by gas chromatography mass spectrometry (GC-MS). EOs inhibited radial growth and spore germination of both fungal species better than when they were encapsulated, plus, they reduced mycotoxin production. The major components were eugenol in cinnamon and clove EO (70 and 63%, respectively) and 2-methyl-5-(1-methyethyl)-phenol (46.2%) in thyme EO. The microparticles with clove and thyme EO showed good surface charges, higher than +30 mV and their average size for the three types of microparticles was about 750 nm. Our findings suggest that EOs both alone and encapsulated in chitosan have a fungistatic effect on Fusarium verticillioides and Aspergillus parasiticus.</p></div