Browsing by Author "Costa, Ana"
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- Environmental changes in the Atlantic World: how did the trade of enslaved people shape the landscapesPublication . Costa, Ana; Pombo de Freitas, Maria da Conceição; Gomes Coelho, Rui; Cachao, MarioABSTRACT: This paper focuses on the environmental changes that occurred along the margins of Cacheu River (Guinea-Bissau) and Sado River (Portugal), in the context of the transatlantic trade of enslaved people and its aftermath (15th century to the present). We collected four sediment cores in the estuarine areas of those two rivers – Cacheu1, Cacheu2, Cacheu3 and Laxique. The sediments were analysed for environmental proxies and radiocarbon dated. The preliminary analyses of Cacheu1 and Cacheu2 reveal a long sedimentary sequence covering changes over the last 8000 years. The preliminary analyses of sediments collected from the Sado River indicate anthropic influence and the introduction of N-fertilisers in the river alluvial plain before the 18th century, probably related to the production of rice. New dating will improve the resolution of the age-depth models produced for the sedimentary sequences in recent years and will allow a more accurate environmental evolution model.
- Exploring the Multifaceted Potential of a Peptide Fraction Derived from Saccharomyces cerevisiae Metabolism: Antimicrobial, Antioxidant, Antidiabetic, and Anti-Inflammatory PropertiesPublication . Branco, Patricia; Mauricio, Elisabete; Costa, Ana; Ventura, Diogo; Roma-Rodrigues, Catarina; Duarte, Maria Paula; Fernandes, AlexandraABSTRACT: The rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction's cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through alpha-amylase and ff-glucosidase inhibitory assays. The results demonstrate that the 2-10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 +/- 32.5 mu M TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNF ff gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes alpha-amylase (IC50 of 199.3 +/- 0.9 mu g/mL) and alpha-glucosidase (IC20 of 270.6 +/- 6.0 mu g/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides.