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Browsing by Author "Duarte, Marco Filipe Pinto"

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  • Sustainable postbiotics for cosmetic and skincare applications
    Publication . Duarte, Marco Filipe Pinto; Madureira, Ana Raquel Mendes Ferreira Monteiro; Amaro, Ana; Pintado, Maria Manuela Estevez
    Skin is the largest human organ and performs vital functions such as protection, water and electrolytes preservation, thermoregulation and fat storage. Skin maintenance and preservation such as cleaning, protection and alteration is carried out with cosmetic products. In the development of new cosmetic products, the use of postbiotics has been suggested, a new class of molecules derived from probiotics, defined as a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”. They can be produced by fermentation, using culture media with glucose as the carbon source, and lactic acid bacteria of the genus Lactobacillus, and/or yeasts, mainly Saccharomyces cerevisiae as fermentative microorganisms. Postbiotics comprise different metabolites, and have important biological properties (antioxidant, anti-inflammatory, etc), which is why their use in cosmetics should be considered. During this work, the production of postbiotics was carried out by fermentation with sugarcane straw and bagasse, as a source of carbon and other active compounds, and as a more sustainable and promising process to obtain more bioactive extracts at the end. For this, the saccharification process of these biomasses was carried out, testing the use of enzymes (Celluclast and Shearzyme Plus), the type of substrate (straw or bagasse) and the duration of the process (24h and 48h). Fermentation was carried out sequentially (SQSF) after saccharification, or simultaneously with saccharification (SSF). The fermentative microorganisms tested were L. plantarum, L. fermentum and S. cerevisiae. The extracts produced (cells-free) were characterized regarding their composition, and main biological properties such as antioxidant and antimicrobial. The most promising extract was also characterized for its cytotoxicity, anti-inflammatory activity, cytokeratin 14/collagen I α1 production, and impact on skin microbiota ex vivo. The best extracts were obtained by performing fermentations in sequential mode (SQSF), with bagasse for 48h and straw for 72h, using L. plantarum and S. cerevisiae, respectively. Among these, the extract that showed the best results was the SQSF S. cerevisiae with straw fermented for 72h (SQSF ScStr 72h). Its use has been shown to be safe at concentrations below or equal to ~2% for keratinocytes and ~0.7% for fibroblasts. It showed antioxidant activity, with Ec50 of 1.88 mg.mL-1, and inhibited elastase and tyrosinase activities by 83.4% and 42.4%, respectively, at the maximum concentration tested (2%). In addition, it promoted the production of cytokeratin 14, and demonstrated anti-inflammatory activity at a concentration of 1%. Finally, in the skin microbiota of human volunteers, the extract inhibited the Cutibacterium acnes bacterium and the Malassezia fungal genus. In short, postbiotics were successfully produced using straw as substrate, and as source of carbon and phenolic compounds. These postbiotics showed bioactive properties that potentiate their use in the development of cosmetic and skincare products, such as the treatment of acne or other skin diseases, due to their anti-inflammatory and inhibitory effect on the bacteria responsible for acne, as well as on potentially colonizing fungi.
    2022-10-03Master thesis Open access Show more