Detalhes bibliográficos
| Ano de defesa: |
2024 |
| Autor(a) principal: |
Rossato, Aline |
| Orientador(a): |
Sagrillo, Michele Rorato |
| Banca de defesa: |
Anjos, Josiane Fontoura dos,
Siqueira , Fallon dos Santos,
Silva , William Leonardo da,
Rech, Virginia Cielo |
| Tipo de documento: |
Tese
|
| Tipo de acesso: |
Acesso embargado |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Franciscana
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Nanociências
|
| Departamento: |
Biociências e Nanomateriais
|
| País: |
Brasil
|
| Palavras-chave em Português: |
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| Palavras-chave em Inglês: |
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| Área do conhecimento CNPq: |
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| Link de acesso: |
http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/1318
|
Resumo: |
Olea europaea L., known as olive, is a widely used plant whose fruits and oil have important pharmacological properties. The leaves, usually discarded as waste, have the potential to be reused, promoting the circular economy. Although plant extracts are used in therapies for chronic diseases, their low stability makes their use difficult. Nanoencapsulation of these extracts in delivery systems can overcome limitations such as photosensitivity and oxidation, representing a promising alternative. Therefore, the aim of the study was to investigate, initially through in silico tests, the possible pharmacological and cytotoxic properties of the major fatty acids present in the olive leaf extract, already described in the literature, and subsequently to produce a hydroalcoholic extract of olive leaves (EFO) and a nanoemulsion containing this extract (NE), in order to evaluate their pharmacological and cytotoxic effects in vitro. Electrospun wound dressing films were then produced using the polymer poly-ε-caprolactone (PCL) in order to evaluate their efficacy in vitro and in vivo on skin wounds. In silico studies demonstrated that the major fatty acids present in the olive leaf extract are biologically safe and have good antimicrobial and anti-inflammatory properties. The hydroalcoholic extract produced was evaluated for its chemical composition, total amount of phenolic compounds and antioxidant activity. LC-DAD analysis of the EFO identified the presence of flavonoids such as rutin (110.14 mg/g of extract) and phenolic compounds such as hydroxytyrosol (8 mg/g of extract) and oleuropein (5.36 mg/g of extract). The extract also demonstrated a high amount of phenolic compounds and excellent antioxidant activity. The NE produced was characterized by mean droplet size, IPD, pH and Zeta potential. The droplets presented a nanometric size of 157 ± 0.4 nm, IPD of 0.200 ± 0.02, pH of 4.9 ± 0.08 and negative Zeta potential of -11.8 ± 0.5. The evaluation of the in vitro safety profile (peripheral blood mononuclear cells) demonstrated safe concentrations (30-7.5 mg/mL) of exposure to EFO and NE, in which none of the concentrations were cytotoxic, being capable of reducing the levels of nitric oxide (NO) and Reactive Oxygen Species (ROS). Regarding the antimicrobial and antibiofilm activity of the free and nanostructured compound, the results demonstrated that both presented antimicrobial and antibiofilm activity against strains of Pseudomonas aeruginosa (PAO1), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25213), Enterococcus faecalis (ATCC 51299) and Candida albicans (ATCC 14053), at concentrations lower than 30 mg/mL. Finally, nanofibrous healing films of PCL and olive leaf extract or nanoemulsion containing the extract were produced. The films immersed in EFO and NE presented better cell viability, showing no cytotoxicity or genotoxicity against fibroblast cells. The results of antimicrobial activity through disk diffusion tests demonstrated that the films immersed in EFO and NE present antimicrobial activity against the Staphylococcus aureus strain (ATCC 25213), presenting an inhibition zone of 8.25 ± 0.5 mm to 9.5 ± 0.5 mm. In addition, the results of the in vivo tests demonstrated that the dressings were able to accelerate the wound healing process. This study stands out as a pioneer in the development of nanosystems containing hydroalcoholic extract of Olea europaea L. leaves, as well as the free extract as possible alternatives in the treatment of skin infections. |
