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Low energy nanoemulsions as a carrier of thyme and lemon balm essential oils

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Resumo:The aim of this work was to produce monomodal and stable thyme and lemon balm-loaded nanoemulsions (NE), through a low energy approach. NEs were prepared by the emulsion phase inversion method using sunflower oil as carrier and Tween 80 as surfactant. Different surfactant-to-oil ratios (SOR) and essential oil (EO) loadings were evaluated. Nanoemulsions presented a monomodal diameter distribution below 200 nm and high negative zeta potential (>-40 mV). Nanoemulsions loaded with EOs were physically stable for 3 months at 4 degrees C and 20 degrees C. Nanoemulsions with thyme EO presented the highest radical scavenging activity by DPPH and ABTS tests. Loaded nanoemulsions were not effective against Escherichia coli but could inhibit Staphylococcus aureus. Cytotoxicity studies using cell counting kit-8 and resazurin assays revealed a dose-responsive effect of nanoemulsions on Caco-2 cells after incubation for 24 h. A concentration of 100 mu g oil/mL of NE for unloaded and thyme loaded and 50 mu g oil/mL of NE for lemon balm loaded showed to be safe to use.
Autores principais:Sampaio, Cátia I.
Outros Autores:Bourbon, Ana Isabel Juncá Sottomayor Lisboa; Gonçalves, Catarina; Pastrana, Lorenzo M.; Dias, Alice; Cerqueira, Miguel Ângelo Parente Ribeiro
Assunto:Lemon balm oil Low energy emulsification Thyme oil Nanoencapsulation
Ano:2022
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso aberto
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:The aim of this work was to produce monomodal and stable thyme and lemon balm-loaded nanoemulsions (NE), through a low energy approach. NEs were prepared by the emulsion phase inversion method using sunflower oil as carrier and Tween 80 as surfactant. Different surfactant-to-oil ratios (SOR) and essential oil (EO) loadings were evaluated. Nanoemulsions presented a monomodal diameter distribution below 200 nm and high negative zeta potential (>-40 mV). Nanoemulsions loaded with EOs were physically stable for 3 months at 4 degrees C and 20 degrees C. Nanoemulsions with thyme EO presented the highest radical scavenging activity by DPPH and ABTS tests. Loaded nanoemulsions were not effective against Escherichia coli but could inhibit Staphylococcus aureus. Cytotoxicity studies using cell counting kit-8 and resazurin assays revealed a dose-responsive effect of nanoemulsions on Caco-2 cells after incubation for 24 h. A concentration of 100 mu g oil/mL of NE for unloaded and thyme loaded and 50 mu g oil/mL of NE for lemon balm loaded showed to be safe to use.