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Authors
Abstract(s)
Na sociedade atual, a sustentabilidade tem sido uma preocupação crescente, refletindo-se
nas escolhas de produtos cosméticos, nomeadamente para o cuidado da pele. O uso de
extratos de algumas espécies de plantas aromáticas e medicinais têm tido destaque nas
indústrias cosmética e farmacêutica devido às propriedades benéficas que possuem, que são
valorizadas na saúde humana. Destes, o medronheiro (Arbutus unedo L.) ganhou destaque
pelas suas propriedades antioxidantes, anti-inflamatórias e regenerativas. Embora o fruto
seja bem conhecido, as folhas são frequentemente consideradas resíduos, apesar de serem
ricas em compostos bioativos. Assim, este projeto analisou três extratos aquosos de folhas
de A. unedo, provenientes de diferentes regiões de Portugal continental (Proença-a-Nova,
Odemira e Gouveia), com o objetivo de avaliar o seu potencial como ingredientes bioativos
para uma possível futura utilização em formulações cosméticas.
Para isso, testou-se a biocompatibilidade dos extratos in vitro em células da pele e as
propriedades antioxidantes, antimicrobianas, anti-inflamatórias e cicatrizantes dos
extratos. Além disso, foi realizada uma caracterização química através das técnicas de
UHPLC-PDA-MS/MS e GC-MS, para identificar os compostos bioativos que estão presentes
nas folhas e compará-los, de modo a avaliar a possível junção de produções, com o objetivo
de escalar a oferta considerando uma futura aplicação em formulações. A atividade
antioxidante foi avaliada através do método de captação de radicais livres para o DPPH. A
viabilidade celular foi testada em fibroblastos de ratinho, queratinócitos humanos e
macrófagos de ratinho, quando expostos aos diferentes extratos aquosos, utilizando o
ensaio MTT. A atividade anti-inflamatória foi medida em macrófagos, através da
quantificação da produção de óxido nítrico (NO) após a estimulação com lipopolissacarídeo
(LPS). A atividade antimicrobiana foi avaliada através do ensaio de microdiluição em caldo
contra um painel de bactérias Gram-positivas e negativas, leveduras e fungos, com foco na
aplicação cutânea. Foi avaliado também o potencial anti-acne recorrendo a um ensaio
enzimático que mediu a atividade da enzima lipase, e o potencial cicatrizante foi analisado
em fibroblastos segundo um ensaio de migração celular (scratch-wound).
Os resultados indicaram que os principais compostos fenólicos encontrados foram
derivados do ácido gálico e flavonoides na sua forma glicosilada (por exemplo, quercetina).
Todos os extratos exibiram uma capacidade antioxidante muito forte, com índices de
atividade antioxidante entre 4,41 e 6,61. Em termos de atividade antimicrobiana,
Cutibacterium acnes foi a estirpe mais suscetível a todos os extratos (CMI 0,5 mg/mL).
Todos os extratos demonstraram atividade anti-lipase, sendo o extrato de Odemira o mais
eficaz na inibição da enzima. Relativamente à viabilidade celular, todos os extratos mostraram ser biocompatíveis a uma concentração máxima de 0,5 mg/mL para todas as
linhas celulares testadas. No entanto, nenhum extrato demonstrou atividade antiinflamatória significativa e não se revelaram potenciais cicatrizantes.
Conclui-se que o estudo dos extratos deve ser aprofundando, especialmente em termos de
atividade anti-inflamatória, avaliando por exemplo outras vias para confirmar a ausência
deste potencial. Relativamente à diferença entre eles, seria interessante juntar alguns
extratos atendendo às características idênticas que apresentaram em determinadas
bioatividades. Entretanto, a elevada atividade antioxidante e baixa toxicidade, aliadas à
suscetibilidade de C. acnes aos extratos e ao potencial anti-lipase, indicam que estes são
promissores para uma futura aplicação cutânea, particularmente associada ao tratamento
de acne.
Today, sustainability is a growing concern, especially in the choices of cosmetic products, such as skincare. Extracts from some aromatic and medicinal plants have become popular in the cosmetic and pharmaceutical industries due to their beneficial properties for human health. The strawberry tree (Arbutus unedo L.) has garnered attention for its antioxidant, anti-inflammatory, and regenerative properties. Despite the well-known fruit, the leaves are often considered a waste product, even though they are rich in bioactive compounds. Thus, the project analyzed three aqueous extracts from A. unedo leaves, originating from different regions of mainland Portugal (Proença-a-Nova, Odemira, and Gouveia), to assess their potential to be used as bioactive ingredients in cosmetic formulations. The extract's biocompatibility with skin cells and its antioxidant, antimicrobial, antiinflammatory, and healing properties were tested in vitro to achieve this goal. We also performed chemical characterization using UHPLC-PDA-MS/MS and GC-MS techniques to identify the bioactive compounds present in the leaves and compare them to assess their potential for use in formulations, and to evaluate if a possible combination of plants from different origins would be a possibility, aiming for scaling-up the offer. Antioxidant activity was assessed using the DPPH radical scavenging method. Cell viability was tested in mouse fibroblasts, human keratinocytes, and mouse macrophages exposed to different aqueous extracts using the MTT assay. Anti-inflammatory activity was measured in macrophages by quantifying nitric oxide (NO) production after lipopolysaccharide (LPS) stimulation. Antimicrobial activity was evaluated through a broth microdilution assay against a panel of Gram-positive and negative bacteria, yeasts, and fungi, relevant for skin application. We also assessed the anti-acne potential using an enzymatic assay measuring lipase activity, and the healing potential was analyzed in fibroblasts through a scratch-wound assay. The analysis revealed that the primary phenolic compounds present in the extracts were derivatives of gallic acid and glycosylated flavonoids such as quercetin. All the extracts showed strong antioxidant properties, with antioxidant activity indexes ranging from 4.41 to 6.61. Regarding antimicrobial activity, Cutibacterium acnes was the most susceptible strain to all the extracts (MIC 0.5 mg/mL). Additionally, all extracts exhibited anti-lipase activity, with the Odemira extract being the most effective in inhibiting lipase. In terms of cell viability, all extracts were found to be biocompatible, with a maximum concentration of 0.5 mg/mL proving to be compatible with the tested cell lines. However, none of the extracts demonstrated significant anti-inflammatory activity or healing potential. In conclusion, further studies of the extracts are needed, especially regarding their antiinflammatory activity to confirm the absence of this property. However, the strong antioxidant activity, low toxicity, susceptibility of C. acnes to the extracts, and anti-lipase potential suggest that the extracts hold promise for future topical applications, especially for an anti-acne application.
Today, sustainability is a growing concern, especially in the choices of cosmetic products, such as skincare. Extracts from some aromatic and medicinal plants have become popular in the cosmetic and pharmaceutical industries due to their beneficial properties for human health. The strawberry tree (Arbutus unedo L.) has garnered attention for its antioxidant, anti-inflammatory, and regenerative properties. Despite the well-known fruit, the leaves are often considered a waste product, even though they are rich in bioactive compounds. Thus, the project analyzed three aqueous extracts from A. unedo leaves, originating from different regions of mainland Portugal (Proença-a-Nova, Odemira, and Gouveia), to assess their potential to be used as bioactive ingredients in cosmetic formulations. The extract's biocompatibility with skin cells and its antioxidant, antimicrobial, antiinflammatory, and healing properties were tested in vitro to achieve this goal. We also performed chemical characterization using UHPLC-PDA-MS/MS and GC-MS techniques to identify the bioactive compounds present in the leaves and compare them to assess their potential for use in formulations, and to evaluate if a possible combination of plants from different origins would be a possibility, aiming for scaling-up the offer. Antioxidant activity was assessed using the DPPH radical scavenging method. Cell viability was tested in mouse fibroblasts, human keratinocytes, and mouse macrophages exposed to different aqueous extracts using the MTT assay. Anti-inflammatory activity was measured in macrophages by quantifying nitric oxide (NO) production after lipopolysaccharide (LPS) stimulation. Antimicrobial activity was evaluated through a broth microdilution assay against a panel of Gram-positive and negative bacteria, yeasts, and fungi, relevant for skin application. We also assessed the anti-acne potential using an enzymatic assay measuring lipase activity, and the healing potential was analyzed in fibroblasts through a scratch-wound assay. The analysis revealed that the primary phenolic compounds present in the extracts were derivatives of gallic acid and glycosylated flavonoids such as quercetin. All the extracts showed strong antioxidant properties, with antioxidant activity indexes ranging from 4.41 to 6.61. Regarding antimicrobial activity, Cutibacterium acnes was the most susceptible strain to all the extracts (MIC 0.5 mg/mL). Additionally, all extracts exhibited anti-lipase activity, with the Odemira extract being the most effective in inhibiting lipase. In terms of cell viability, all extracts were found to be biocompatible, with a maximum concentration of 0.5 mg/mL proving to be compatible with the tested cell lines. However, none of the extracts demonstrated significant anti-inflammatory activity or healing potential. In conclusion, further studies of the extracts are needed, especially regarding their antiinflammatory activity to confirm the absence of this property. However, the strong antioxidant activity, low toxicity, susceptibility of C. acnes to the extracts, and anti-lipase potential suggest that the extracts hold promise for future topical applications, especially for an anti-acne application.
Description
Keywords
Acne Vulgaris Atividade
Antioxidante Atividade Anti-Inflamatória Atividade Antimicrobiana Atividade Cicatrizante Extratos de Plantas Medronheiro Viabilidade Celular