Browsing by Author "Lanza, Juliane Sousa"

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    Nanostructured systems improve the antimicrobial potential of the essential oil from cymbopogon densiflorus leaves.
    (2019) Seibert, Janaína Brandão; Rosa, Juliana dos Santos; Almeida, Tamires Cunha; Amparo, Tatiane Roquete; Rodrigues, Ivanildes Vasconcelos; Lanza, Juliane Sousa; Frezard, Frederic Jean Georges; Soares, Rodrigo Dian de Oliveira Aguiar; Teixeira, Luiz Fernando de Medeiros; Souza, Gustavo Henrique Bianco de; Vieira, Paula Melo de Abreu; Barichello, José Mario; Santos, Orlando David Henrique dos
    The physicochemical characteristics of nanostructured suspensions are important prerequisites for the success of new drug development. This work aimed to develop nanometric systems containing Cymbopogon densiflorus leaf essential oil and to evaluate their antimicrobial activity. The essential oil was isolated by hydrodistillation from leaves and analyzed by GC-MS. The main constituents were found to be trans-p-mentha-2,8-dien-1-ol, cis-p-mentha2,8-dien-1-ol, trans-p-mentha-1(7),8-dien-2-ol, cis-piperitol, and cis-p-mentha-1(7),8-dien-2-ol. In silico prediction analysis suggested that this oil possesses antimicrobial potential and the main mechanism of action might be the peptidoglycan glycosyltransferase inhibition. Nanoemulsions were prepared by the phase inversion method, and liposomes were made by the film hydration method. Qualitative evaluation of the antimicrobial activity was performed by the diffusion disk assay with 24 microorganisms; all of them were found to be sensitive to the essential oil. Subsequently, this property was quantified by the serial microdilution technique, where the nanoformulations demonstrated improved activity in comparison with the free oil. Bactericidal action was tested by the propidium iodide method, which revealed that free essential oil and nanoemulsion increased cytoplasmic membrane permeability, while no difference was observed between negative control and liposome. These results were confirmed by images obtained using transmission electron microscopy. This study has shown an optimization in the antimicrobial activity of C. densiflorus essential oil by a nanoemulsion and a liposomal formulation of the active substances.
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    Seasonality study of essential oil from leaves of Cymbopogon densiflorus and nanoemulsion development with antioxidant activity.
    (2019) Seibert, Janaína Brandão; Rodrigues, Ivanildes Vasconcelos; Carneiro, Simone Pinto; Amparo, Tatiane Roquete; Lanza, Juliane Sousa; Frezard, Frederic Jean Georges; Souza, Gustavo Henrique Bianco de; Santos, Orlando David Henrique dos
    The development of formulations that maintain the biological and physical chemistry properties of essential oils is an important choice when they are used as an active ingredient. This study aimed to characterize the essential oil from leaves of Cymbopogon densiflorus and evaluate the antioxidant activity of the oil, and to produce a nanoemulsion formulation containing it. The essential oil was obtained by hydrodistillation, and seasonality was analysed every 2 months by gas chromatography–mass spectrometry, showing that more than 90% of the composition was maintained for the whole period and that the major compounds were trans‐p‐menta‐2,8‐dien‐1‐ol, cis‐p‐menta‐2,8‐dien‐1‐ol, trans‐p‐menta‐1(7),8‐dien‐2‐ol, cis‐piperitol, and cis‐p‐menta‐1(7),8‐dien‐2‐ol. Stable nanoemulsions were prepared by phase inversion method encapsulating the essential oil. The antioxidant activity was evaluated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid (ABTS) methods. In the first test, free and nanoemulsified essential oil showed half‐maximal inhibitory concentration (IC50) values equivalent to 14.689 and 3.692 mg mL−1, respectively. In the second test, these values were 0.567 and 0.43 mg mL−1. The development of nanoemulsion‐based essential oil from leaves of C. densiflorus was viable, and the formulated oil was able to reproduce the antioxidant activity at a concentration four times lower than that of the pure essential oil.