Percorrer por autor "Sousa, Ana Sofia"
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- An overview on mushroom polysaccharides: health-promoting properties, prebiotic and gut microbiota modulation effects and structure-function correlationPublication . Araújo-Rodrigues, Helena; Sousa, Ana Sofia; Relvas, João Bettencourt; Tavaria, Freni K.; Pintado, ManuelaMushroom polysaccharides are recognized as “biological response modifiers”. Besides several bioactivities, a growing interest in their prebiotic potential has been raised due to the gut microbiota modulation potential. This review comprehensively summarizes mushroom polysaccharides' biological properties, structure-function relationship, and underlying mechanisms. It provides a recent overview of the key findings in the field (2018–2024). Key findings and limitations on structure-function correlation are discussed. Although most studies focus on β-glucans or extracts, α-glucans and chitin have gained interest. Prebiotic capacity has been associated with α-glucans and chitin, while antimicrobial and wound healing potential is attributed to chitin. However, further research is of utmost importance. Human fecal fermentation is the most reported approach to assess prebiotic potential, indicating impacts on intestinal biological, mechanical, chemical and immunological barriers. Gut microbiota dysbiosis has been directly connected with intestinal, cardiovascular, metabolic, and neurological diseases. Concerning gut microbiota modulation, animal experiments have suggested proinflammatory cytokines reduction and redox balance re-establishment. Most literature focused on the anticancer and immunomodulatory potential. However, anti-inflammatory, antimicrobial, antiviral, antidiabetic, hypocholesterolemic, antilipidemic, antioxidant, and neuroprotective properties are discussed. A significant overview of the gaps and research directions in synergistic effects, underlying mechanisms, structure-function correlation, clinical trials and scientific data is also given.
- Antibacterial and antioxidant potential of aqueous extracts of bio-residues from agrocybe cylindracea and pleurotus ostreatus myceliumPublication . Sousa, Ana Sofia; Nunes, Catarina; Barros, Joana; Ferreira, Inês; Freitas, Ana C.; Morais, Alcina M. M. B.; Nunes, João; Pintado, ManuelaThe production of fresh mushrooms results in a large quantity of bio-residues, which may account for more than 20% of a crop volume and contributes to production costs and environmental impact, if not used. These products consist mainly of stalks, mushrooms of irregular dimensions and shape and basal material. Thus, the main objective of MicoBioExtract project is the valorisation of these bio-residues and the development of add-value by-products with bioactive compounds such as polysaccharides and phenolic compounds produced by mushrooms. In the present work, the aqueous extracts from Agrocybe cylindracea byproducts (ACB) and Pleurotus ostreatus mycelium (POM) were evaluated for potential antioxidant and antimicrobial activities. Water soluble substances were extracted from mushrooms according to two different methods. In method 1 it was performed a hot extraction (extract 1A; 90 °C; 1 h; 500 rpms). In method 2, the biomass was submitted to an extraction at room temperature (extract 2B) and the resulting residue was extracted with hot water (extract 2C; 90 °C; 1 h; 500 rpms). The aqueous extracts from POM were obtained only by method 1. Extracts were lyophilized and their bioactivity evaluated measuring the antioxidant (ABTS, DPPH and ORAC) and antimicrobial (determination of the minimum inhibitory concentration – MIC) activities. The mutagenicity was also tested (Ames assay with and without S9). Moreover, it was determined the total phenolics content of the extracts and α and β – glucans (Folin Ciocalteu and Beta-Glucan Assay methods, respectively). The results obtained from antioxidant methods showed that all extracts from both mushrooms are a potential source of natural antioxidant and phenolic compounds. According to ABTS, extract 2B from ACB showed the best value with 8.48±0.33 mg ascorbic acid equivalent (AAE)/g dry extract and 4.14±0.52 mg AAE/g dry extract for POM. Regarding the antimicrobial activity, MIC results showed that ACB and POM extracts inhibited the growth of Gram- (Salmonella enteritidis) and Gram+ (Bacillus cereus and Listeria monocytogenes). Concerning the mutagenicity, the results showed no toxic effect except for extract 1A from ACB. Regarding the β-glucan content, the extracts from ACB presented higher content of β-glucan than the C extracts from POM. Thus, aqueous extracts from mushroom bio-residues showed potential antioxidant and antimicrobial properties and to develop a circular bioeconomy approach.
- Application of a PGP bacterial bioinoculant in a vineyard: impact on soil biochemical properties and must compositionPublication . Prieto-Fernández, Ángeles; Pereira, Sofia; Sousa, Ana Sofia; Rodríguez-Garrido, Beatriz; González-Prieto, Serafin; Castro, Paula; Trasar-Cepeda, CarmenThe ReCROP project, funded by the PRIMA-Med programme, focuses on the development of sustainable agricultural production systems through the combined use of biotechnological tools and environmentally friendly agronomic practices to enhance soil functions and health. As part of this project, a PGP bacterial strain was used as a bioinoculant in a vineyard of the Mencía variety, located within the DO Ribeiro region (Galicia, NW Spain). This study presents the results of bioinoculation performed over two consecutive cropping seasons, 2023 and 2024. At the harvest, soil and grape samples were collected from both non-inoculated and inoculated vines. Soil analysis included general characterization, determination of labile C compounds, C and N mineralization, and the measurement of several enzymatic activities. Must was analyzed for pH, sugar content, and organic acids. The bioinoculation led to an increase in labile C compounds, enhanced N mineralization, and stimulated several enzymatic activities. Additionally, preliminary results indicate that the must composition was altered by the bioinoculant, which modified the profile of organic acids.
- Application of a PGP bacterial bioinoculant in a vineyard: impact on soil biochemical properties and must compositionPublication . Prieto-Fernández, Ángeles; Pereira, Sofia; Sousa, Ana Sofia; Rodríguez-Garrido, Beatriz; González-Prieto, Serafin; Castro, Paula; Trasar-Cepeda, CarmenIntroduction: Sustainable agriculture increasingly relies on the use of environmentally friendly practices and biotechnological tools to maintain soil health and productivity. The ReCROP project, funded by the PRIMA-Med programme, aims to enhance soil functions and resilience through integrated cropping systems. As part of this initiative, we evaluated the effects of a plant growth-promoting (PGP) bacterial bioinoculant applied in a vineyard of the Mencía grape variety located in the Ribeiro Denomination of Origin (Galicia, NW Spain). This study explores the bioinoculant's influence on soil biochemical properties and must composition over two growing seasons. Experimental field site: The field trial was conducted in a vineyard located in the Denomination of Origin (D.O.) Ribeiro area, specifically in A Gandarela – Esposende, within the municipality of Ribadavia (Galicia, NW Spain). The vineyard is situated at GPS coordinates 42.2959, -8.1327 and is registered in the SIGPAC system under code 32 70 00 44 148. The site is representative of typical Ribeiro vineyards, characterized by a temperate Atlantic climate. The experimental area covered approximately 0.03 ha and consisted of three plots, each with an approximate area of 100 m². Material and methods: The study was conducted over two consecutive cropping seasons (2023 and 2024) in the described experimental vineyard. A plant growth-promoting (PGP) bacterial strain, Arthrobacter nicotinovorans EAPAA, was used as a bioinoculant. The selected PGP strain presents beneficial traits such as phosphorus solubilization and nitrogen fixation. The strain was cultured in Tryptic Soy Broth (TSB) and the inoculum consisted of 500 mL of a bacterial suspension with an optical density of 1.0, applied at the base of each grapevine stock in early spring. In each plot, four grapevines were inoculated and four were treated with 1/3 diluted TSB as controls. At harvest, soil and grape samples were collected from both non-inoculated and inoculated vines. Soil samples were taken at the base of each vine and pooled to obtain one composite sample for the inoculated and one for the non-inoculated treatments per plot. Conclusions: The bioinoculation with the PGP strain Arthrobacter nicotinovorans EAPAA in a Mencía vineyard led to several soil beneficial effects: Improved availability of labile C and labile P; Enhanced soil biological and biochemical activity, particularly of the N and P cycles. The bioinoculation also appears to induce modifications of must composition, which should be further studied to analyse their impact in the vinification process. These findings suggest that the bioinoculant can contribute to improving soil functionality and may influence grape quality, offering a promising strategy for sustainable vineyard management.
- Biocatalytic nanobots: enhancing reactive oxygen species neutralisation for targeted therapy in inflammatory bowel diseasePublication . Sousa, Ana Sofia; Mayer, André; Reis, Celso A.; Pintado, Maria Manuela; Coscueta, Ezequiel R.Background & idea: Inflammatory bowel disease (IBD) is marked by chronic intestinal inflammation and an overproduction of reactive oxygen species (ROS) within the gastrointestinal mucosa. Elevated ROS levels contribute to tissue damage and impair mucosal healing, thereby intensifying the inflammatory process. Conventional treatments, such as corticosteroids and immunosuppressants, primarily target systemic inflammation but are limited in addressing the localized oxidative stress characteristic of IBD. To overcome these limitations, our study introduces a polymeric biocatalytic nanobot (NB) system designed to combine efficient propulsion with ROS neutralisation. The NB is built around a chitosan core with mucoadhesive properties, which promotes prolonged retention at inflamed mucosal surfaces and may also enhance the delivery of bioactive compounds.
- Biocatalytic nanobots: modulating oxidative stress in cellular models of inflammatory bowel diseasePublication . Coscueta, Ezequiel R.; Sousa, Ana Sofia; Mayer, André; Reis, Celso A.; Pintado, Maria ManuelaIntroduction: Inflammatory bowel disease (IBD) is a chronic disorder marked by elevated levels of reactive oxygen species (ROS), which exacerbate local inflammation and lead to intestinal mucosal damage (1). Intelligent nanotechnologies, such as biocatalytic nanobots (NBs), offer targeted strategies to reduce oxidative stress (2). This study investigates a self- propelled NB designed to neutralize extracellular ROS and maintain biocompatibility with colonic cells, paving the way for future integrations of bioactive compounds to address intracellular stress further. Methods: The NB core was fabricated using chitosan via ionic gelation with sodium tripolyphosphate (TPP) as the crosslinking agent. A biotin-avidin coupling system was used to anchor catalase onto the NB surface, promoting the decomposition of hydrogen peroxide (H?O?) into oxygen (O?) and enabling propulsion. Mobility was assessed via fluorescence microscopy in ultrapure water (control) and H?O? solutions (30 ?M and 300 ?M), with the analysis of the mean square displacement (MSD), mean squared speed (MSS), diffusion coefficient, average distance, trajectory bending, and displacement efficiency. Biocompatibility was evaluated on co-culture of colon cell lines (Caco-2 and HT29-MTX), while extracellular and intracellular ROS levels were quantified via the Pierce Quantitative Peroxide and DCFDA/H2DCFDA assays, respectively. Results: The NB exhibited increased propulsion in H?O? solutions, with the MSD as a function of time, highlighting a significant difference in mobility favoring H?O?. The comparison of the MSD’s intersection and slope reinforced the improved mobility under H?O? conditions. The MSS did not indicate differences between H?O and H?O?. There was a noteworthy increase in the diffusion coefficient in H?O?. The particles traveled a markedly greater distance in H?O?, confirming better directional movement in this medium. The trajectory curvature was not different, suggesting similar randomness in movement patterns across both media. The displacement efficiency was significantly greater in H?O?, indicating more direct movement from the origin. These findings confirmed robust movement in ROS-rich environments. The NB displayed no detectable cytotoxicity in co- culture of Caco-2 and HT29-MTX cells, and the reduction of extracellular H?O? correlated with a significant decrease in intracellular ROS. This underscores the indirect impact of the neutralization of extracellular ROS on intracellular oxidative stress. Conclusions and Impact: This self-propelled, biocatalytic NB platform offers a powerful approach to addressing oxidative stress in IBD, operating at the extracellular level while maintaining cell viability. Enhanced propulsion in ROS-rich conditions positions these NBs for site-specific applications in inflamed tissues. Future developments will include bioactive payloads to target intracellular ROS, thereby expanding this technology's therapeutic potential for advanced IBD management. Ongoing work will incorporate additional modules to enhance stability, guide navigation, and broaden therapeutic functionalities.
- Chitosan-olive oil microparticles for phenylethyl isothiocyanate delivery: optimal formulationPublication . Coscueta, Ezequiel R.; Sousa, Ana Sofia; Reis, Celso A.; Pintado, ManuelaPhenylethyl isothiocyanate (PEITC), a chemopreventive compound, is highly reactive due to its considerably electrophilic nature. Furthermore, it is hydrophobic and has low stability, bioavailability and bioaccessibility. This restricts its use in biomedical and nutraceutical or food applications. Thus, the encapsulation of this agent has the function of overcoming these limitations, promoting its solubility in water, and stabilizing it, preserving its bioactivity. So, polymeric microparticles were developed using chitosan-olive oil-PEITC systems. For this, an optimisation process (factors: olive oil: chitosan ratio and PEITC: chitosan ratio) was implemented through a 3-level factorial experimental design. The responses were: the particle size, zeta-potential, polydisperse index, and entrapment efficiency. The optimal formulation was further characterised by FTIR and biocompatibility in Caco-2 cells. Optimal conditions were olive oil: chitosan and PEITC: chitosan ratios of 1.46 and 0.25, respectively. These microparticles had a size of 629 nm, a zeta-potential of 32.3 mV, a polydispersity index of 0.329, and entrapment efficiency of 98.49%. We found that the inclusion process affected the optical behaviour of the PEITC, as well as the microparticles themselves and their interaction with the medium. Furthermore, the microparticles did not show cytotoxicity within the therapeutic values of PEITC. Thus, PEITC was microencapsulated with characteristics suitable for potential biomedical, nutraceutical and food applications.
- Development of a biocatalytic polymeric nanobot core for applications in inflammatory bowel diseasePublication . Sousa, Ana Sofia; Mayer, André; Reis, Celso A.; Pintado, Maria Manuela; Coscueta, Ezequiel R.
- Exploring the bioactive potential of mushroom aqueous extracts: antimicrobial, antioxidant, and prebiotic propertiesPublication . Afonso, Tiago Barros; Marçal, Sara; Vale, Pedro; Sousa, Ana Sofia; Nunes, João; Pintado, ManuelaMushrooms provide essential nutrients and bioactive compounds, namely glucans, protein, and phenolic compounds. In this study, two aqueous extractions were performed (M1 and M2) using Pleurotus ostreatus, Pleurotus eryngii, and Agrocybe cylindracea. In M1, a hot extraction (extract M1) (90 °C, 700 rpm, 1 h) was performed. In M2, a room-temperature extraction (extract M2A) followed by a hot extraction (extract M2B) (90 °C, 700 rpm, 1 h) of the extract M2A residue was performed. The M2B extracts showed the lowest extraction yields (12.58–21.78%), while the other yields ranged between 30.91% and 46.03%. All extracts had high protein (12.09–32.97 g/100 g of dry extract), glucan (12.69–48.57 g/100 g of dry extract), and phenolic contents (7.90–16.65 mg GAEs/g of dry extract) and high antioxidant (ABTS and ORAC assays), antimicrobial, antibiofilm, and prebiotic activities. So, they have potential to be used as functional ingredients or natural preservatives. Extracts from A. cylindracea stood out since they had higher protein content, antioxidant activity, and prebiotic activity (extract M1) and inhibited a higher number of foodborne bacteria (only extract M2A). However, unlike extracts from P. ostreatus and P. eryngii, at 40 mg/mL, they had cytotoxic effects.
- Impact of extracellular polymeric substances (EPS), biochar, and microbial inoculants on maize growth and irrigation needsPublication . Overall, Alexandra; Moreira, Helena; Sousa, Ana Sofia; Wilfert, Philipp; van Loosdrecht, Mark; Castro, Paula M. L.; Pereira, S. I. A.