Produção e caracterização de compósitos obtidos a partir de extrato de própolis utilizando electrospinning e avaliação da atividade antioxidante
Data
2023-03-15
Autores
Bernardo, Leonardo Ribeiro 
Orientadores
Braga, Anna Rafaela Cavalcante
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A busca de princípios ativos (P.A.) em fontes de origem animal e vegetal para sua aplicação em fármacos, cosméticos, alimentos e afins é de extrema valia e importância. Dentro das fontes de origem animal, a própolis de abelhas, é uma das fontes mais conhecidas, descritas e utilizada para fins terapêuticos e funcionais. Utilizado, majoritariamente, devido as atividades antifúngicas, antioxidantes e anti-inflamatórias. Sua composição constituída por ceras, balsamos, resinas, ácidos graxos, pólen, óleos essenciais, compostos fenólicos e outros compostos orgânicos e minerais, tem como seus principais constituintes moleculares, integrantes da classe dos flavonoides, provenientes do pólen coletado para a confecção da própolis. Esta classe de metabólitos secundários vegetais, de característica comum a presença de anéis aromáticos, são uns dos principais compostos estudados e conhecidos, principalmente no âmbito de suas atividades biológicas, sendo eles, normalmente relacionados com os efeitos biológicos desempenhados pela própolis. Porém os flavonoides, possuem obstáculos como exemplos a baixa estabilidade, baixa solubilidade em água e rápida biotransformação, que limitam a utilização e implementação de biomoléculas desta classe em formulações viáveis. Similarmente, a própolis, também possui obstáculos, como sua baixa biodisponibilidade e rápida degradação no trato gastrointestinal. Principalmente quando administrados pela via oral, que atualmente é a principal via de administração. Com isso, o advento de técnicas de produção de nanoestruturas (NEs), como as técnicas de produção de compósitos como nanofibras (NFs) por electrospinning, são importantes ferramentas a fim de mitigar tais limitações, devido sua capacidade de operação coaxial e axial, sendo possível produzir compósitos contendo esses produtos com biopolímeros, proteínas ou metais, transformando em compostos mais termoestáveis, biodisponíveis, resistentes a biotransformação e hidrossolúveis e consequentemente melhorando aspectos de liberação e biotransformação destes candidatos a P.A. Portanto, o presente trabalho tem como objetivo produzir compósitos utilizando soluções poliméricas adicionados a própolis, assim como caracterizar estas estruturas e avaliar a atividade antioxidante da matéria prima selecionada e dos compósitos formados. Como resultados obtidos, foram produzidos compósitos de extrato de própolis, obtendo-se sólidos de aparência fibrosa, não unidirecionais, e levemente heterogêneos, quando observado pelas imagens obtidas a partir da análise de microscopia de varredura eletrônica (MEV) e espectroscopia de raios X por dispersão em energia (EDS), a partir da espectroscopia no infravermelho por transformada de Fourier (FTIR), foi constatada a presença do ativo, extrato de própolis, e dos demais componentes zeína e poli(óxido de etileno) (PEO). Nas análises termogravimétricas, os compostos bioativos da própolis foram constatados estáveis em temperatura ambiente, porém, ainda termosensíveis a altas temperaturas, degradando-se em estágio único e irreversível por meio de processos exo e endotérmicos. Por meio da colorimetria observou-se que as amostras são pouco sensíveis a radiação UV. Adicionalmente, os resultados referentes aos ensaios de liberação e avaliação da atividade antioxidante, apresentaram manutenção da atividade antioxidantes após 18 h de ensaio. Por fim, como conclusão, é possível fabricar nanofibras por electrospinnig utilizando zeína, PEO e extrato de própolis, que são liberáveis e sua atividade antioxidante se mantem de maneira satisfatória. Em trabalhos futuros do grupo de pesquisa, sugere-se uma melhor caracterização de seus compostos fenólicos liberados e de demais atividades biológicas.
The search for active principles (AP) in animal and plant sources for their application in pharmaceuticals, cosmetics, food, and the like is extremely valuable and vital. Among the animal sources, bee propolis is one of the best known, described, and used for therapeutic and functional purposes. It is mainly used due to its antifungal, antioxidant, and anti-inflammatory activities. Its composition comprises waxes, balsams, resins, fatty acids, pollen, essential oils, phenolic compounds, and other organic and mineral compounds. Its main molecular constituents are members of the flavonoid class, which come from the pollen collected for making propolis. This class of secondary plant metabolites, with the common characteristic of the presence of aromatic rings, is one of the main compounds studied and known, especially in the context of their biological activities, and they are usually related to the biological effects performed by propolis. However, flavonoids have obstacles, such as low stability, low water solubility, and rapid biotransformation, which limit the use and implementation of biomolecules of this class in viable formulations. Similarly, propolis usage has some obstacles, such as its low bioavailability and rapid degradation in the gastrointestinal tract. Especially when administered orally, which is currently the main route of administration; with this, the advent of nanostructure production techniques (NEs), such as the production of composites as nanofibers (NFs) by electrospinning, are essential tools to mitigate such limitations, due to their ability to operate coaxially and axially, being possible to produce composites containing these products with biopolymers, proteins or metals, transforming them into more thermostable, bioavailable, biotransformation resistant and water-soluble compounds and consequently improving release and biotransformation aspects of these A.P. Therefore, this work aims to produce composites using polymeric solutions added to propolis, as well as to characterize these structures and evaluate the antioxidant activity of the selected raw material and the composites formed. As obtained results, composites of propolis extract were produced, obtaining solids of fibrous appearance, not unidirectional, and slightly heterogeneous, when observed by the images obtained from the analysis of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), the presence of the active ingredient, propolis extract, and the other components zein and polyethylene oxide (PEO) was verified. In thermogravimetric analyses, the bioactive compounds of propolis were found to be stable at room temperature but still thermosensitive at high temperatures, degrading in a single and irreversible stage through exo- and endothermic processes. Utilizing colorimetry, it was observed that the samples were not very sensitive to UV radiation. Additionally, the results concerning the release assays and antioxidant activity evaluation showed maintenance of the antioxidant activity after 18 h of the assay. Finally, in conclusion, it is possible to manufacture nanofibers by electrospinning using zein, PEO, and propolis extract, which are releasable, and their antioxidant activity is maintained adequately. In future works of the research group, a better characterization of their released phenolic compounds and other biological activities is suggested.
The search for active principles (AP) in animal and plant sources for their application in pharmaceuticals, cosmetics, food, and the like is extremely valuable and vital. Among the animal sources, bee propolis is one of the best known, described, and used for therapeutic and functional purposes. It is mainly used due to its antifungal, antioxidant, and anti-inflammatory activities. Its composition comprises waxes, balsams, resins, fatty acids, pollen, essential oils, phenolic compounds, and other organic and mineral compounds. Its main molecular constituents are members of the flavonoid class, which come from the pollen collected for making propolis. This class of secondary plant metabolites, with the common characteristic of the presence of aromatic rings, is one of the main compounds studied and known, especially in the context of their biological activities, and they are usually related to the biological effects performed by propolis. However, flavonoids have obstacles, such as low stability, low water solubility, and rapid biotransformation, which limit the use and implementation of biomolecules of this class in viable formulations. Similarly, propolis usage has some obstacles, such as its low bioavailability and rapid degradation in the gastrointestinal tract. Especially when administered orally, which is currently the main route of administration; with this, the advent of nanostructure production techniques (NEs), such as the production of composites as nanofibers (NFs) by electrospinning, are essential tools to mitigate such limitations, due to their ability to operate coaxially and axially, being possible to produce composites containing these products with biopolymers, proteins or metals, transforming them into more thermostable, bioavailable, biotransformation resistant and water-soluble compounds and consequently improving release and biotransformation aspects of these A.P. Therefore, this work aims to produce composites using polymeric solutions added to propolis, as well as to characterize these structures and evaluate the antioxidant activity of the selected raw material and the composites formed. As obtained results, composites of propolis extract were produced, obtaining solids of fibrous appearance, not unidirectional, and slightly heterogeneous, when observed by the images obtained from the analysis of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), the presence of the active ingredient, propolis extract, and the other components zein and polyethylene oxide (PEO) was verified. In thermogravimetric analyses, the bioactive compounds of propolis were found to be stable at room temperature but still thermosensitive at high temperatures, degrading in a single and irreversible stage through exo- and endothermic processes. Utilizing colorimetry, it was observed that the samples were not very sensitive to UV radiation. Additionally, the results concerning the release assays and antioxidant activity evaluation showed maintenance of the antioxidant activity after 18 h of the assay. Finally, in conclusion, it is possible to manufacture nanofibers by electrospinning using zein, PEO, and propolis extract, which are releasable, and their antioxidant activity is maintained adequately. In future works of the research group, a better characterization of their released phenolic compounds and other biological activities is suggested.
Descrição
Citação
BERNARDO, Leonardo Ribeiro. Produção e caracterização de compósitos obtidos a partir de extrato de própolis utilizando electrospinning e avaliação da atividade antioxidante. 2023. 44 f. Dissertação (Mestrado em Bioprodutos e Bioprocessos) - Instituto de Saúde e Sociedade, Universidade Federal de São Paulo, Santos, 2023.