Browsing by Author "Pereira, Ana Margarida"
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- Effect of mannan oligosaccharides extracts in uropathogenic escherichia coli adhesion in human bladder cellsPublication . Faustino, Margarida; Silva, Sara; Costa, Eduardo; Pereira, Joana Odila; Pereira, Ana Margarida; Pereira, Carla F.; Durão, Joana; Pintado, Manuela E.; Carvalho, Ana P.
- Effect of mannan oligosaccharides extracts in uropathogenic escherichia coli adhesion in human bladder cellsPublication . Faustino, Margarida; Silva, Sara; Costa, Eduardo M.; Pereira, Ana Margarida; Pereira, Joana Odila; Oliveira, Ana Sofia; Ferreira, Carlos M. H.; Pereira, Carla F.; Durão, Joana; Pintado, Manuela E.; Carvalho, Ana P.Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.
- Iron-peptide complexes from spent yeast: evaluation of iron absorption using a Caco-2 monolayerPublication . Oliveira, Ana Sofia; Ferreira, Carlos M. H.; Pereira, Joana Odila; Silva, Sara; Costa, Eduardo M.; Pereira, Ana Margarida; Faustino, Margarida; Durão, Joana; Pintado, Manuela E.; Carvalho, Ana P.Anaemia is one of the most prevalent nutritional diseases worldwide with Fe deficiency being its major cause. In fact, the limited bioavailability of dietary iron and its interaction with food compounds contribute to its poor absorption in the human body and dietary Fe supplementation has been widely used to address this issue. By incorporating a circular economy framework, this study takes a novel approach of production of iron-peptide complexes from spent yeast peptide-rich extracts as a more effective substitute to conventional salt-based iron supplements, which are related with adverse consequences. Considering the regulation of iron absorption on duodenal enterocytes, iron-peptides complexes absorption was assessed using a Caco-2 monolayer, evaluating both iron uptake and the capacity to stimulate ferritin synthesis, after their in vitro simulated gastrointestinal digestion following INFOGEST protocol. An iron salt and a commercially available benchmark (iron bisglycinate) were also included in this study to compare the absorption performance. Results showed that iron-peptide complexes exhibited a similar behaviour (no statistically significant alterations (p > 0.05)) concerning the other tested samples, thus being a promising alternative for iron dietary supplementation. The remaining digested peptides from the complexes also showed potential antioxidant activity, suggesting protection of iron from oxidation within human body.
- Production of iron-peptide complexes from spent yeast for nutraceutical industryPublication . Oliveira, Ana Sofia; Ferreira, Carlos M. H.; Pereira, Joana Odila; Sousa, Sérgio; Faustino, Margarida; Durão, Joana; Pereira, Ana Margarida; Pintado, Manuela E.; Carvalho, Ana P.Iron (Fe) deficiencies are a major health condition concern and over the years many solutions in the form of Fe supplementation have been investigated. Organic Fe-complexes are the most promising for Fe deficiencies remediation. The aim of present study was to value peptide rich waste streams from β-glucan and mannan production from spent yeast (Gpep and Mpep, respectively) as Fe-peptide complexes for Fe supplementation. These waste streams were first subjected to ultrafiltration treatment before assessing the capacity of these fractions to complex Fe was evaluated, without, and with nitrogen. Results have shown that Gpep> 1 kDa was the best fraction with a optimal pH of 6.0 and a time of 30 min. The resulting Fe-peptide complex was characterized using powder XDR, fluorescence, FTIR, SEM and Mastersizer Laser Diffraction. Results have shown that Gpep and Mpep waste streams have potential application as Fe supplementation in the form of Fe peptide complexes.
- Purification of bioactive peptides from spent yeast autolysatesPublication . Oliveira, Ana Sofia; Pereira, Ana Margarida; Ferreira, Carlos M.H.; Pereira, Joana Odila; Amorim, Manuela; Faustino, Margarida; Durão, Joana; Pintado, Manuela E.; Carvalho, Ana P.Spent brewer’s yeast have been described as an important source for bioactive peptides, with their properties well proven over the years. Besides the brewing sector, growing of large-scale processes on synthetic biology industry has generated a substantial amount of spent engineered yeast with further potential to be valued in a circular economy approach. In line with this perception, in this work, peptide-rich fractions were obtained from spent yeast peptide-rich extract autolysate (“ESY1”), using two different techniques, namely protein ultrafiltration and size-exclusion chromatography (SEC). Both methods allowed the production of different peptide fractions with diverse protein content, molecular weight distribution and peptides sequences. Overall, fractions with higher protein content and more purified reveal higher bioactivities, namely antihypertensive and anticholesterolemic, emphasizing that the purification process is an important step to include in production process of a dietary supplement with these specific features. In addition, significant antioxidant capacity values for peptide fractions purified by SEC were obtained, highlighting their potential use in economic sectors where antioxidant capacity has a massive impact, such as cosmetics.
- Spent yeast valorization for food applications: effect of different extraction methodologiesPublication . Oliveira, Ana Sofia; Pereira, Joana Odila; Ferreira, Carlos; Faustino, Margarida; Durão, Joana; Pereira, Ana Margarida; Oliveira, Carla Maria; Pintado, Manuela E.; Carvalho, Ana P.Over the years, synthetic biology has been growing with the use of engineered yeast strains for the production of sustainable ingredients to meet global healthcare, agriculture, manufacturing and environmental challenges. However, as seen from the brewing industry perspective, these processes generate a substantial amount of spent yeast that contains high nutritional value related to its high protein content, showing its potential to be used as an alternative protein source. Taking into account the rising demand for protein because of the growth in the global population, the present study aims to produce peptide-rich extracts by different potentially scalable and sustainable methodologies in a circular economy approach for the food and nutraceutical industries. The results demonstrated that extraction from genetically modified strains allowed the production of extracts with an excellent nutritional profile and low molecular weight peptides. Furthermore, autolysis was shown to be a potential sustainable approach for this production, though other green metrics need to be explored in order to establish this process at an industrial level.
- Up-scalable approaches for yeast mannan oligosaccharides (MOS) production: characterization and immunomodulatory propertiesPublication . Faustino, Margarida; Durão, Joana; Pereira, Carla F.; Pereira, Ana Margarida; Oliveira, Ana Sofia; Sousa, Sérgio; Ribeiro, Alessandra Braga; Pereira, Joana Odila; Ferreira, Carlos M. H.; Pintado, Manuela E.; Carvalho, Ana P.Mannan oligosaccharides (MOS) are widely used as feed additives due to their effects on gut microbiome modulation. Its application in the nutraceutical and functional food industries is also increasing. Numerous studies portraying MOS production from β-mannans can be found, but its production from yeast mannans is barely explored. Herein, two up-scalable approaches to produce yeast-derived MOS are presented: hydrothermal and acidic processing. Process efficiency was evaluated, and the resulting extracts were characterized (ATR-FT-IR, PXRD, SEM, MWD, DSC, sugar, and protein content). Extracts were also evaluated for their cytotoxicity and immunomodulatory effect; furthermore, a simulated gastrointestinal tract digestion was performed to confirm their biological potential. The hydrothermal process resulted in the highest yield, whereas the acidic process resulted in lower molecular weight populations. Immunomodulatory results indicate that MOS digested extracts do not hold anti-inflammatory activity but grant an immunostimulant effect, whereas the non-digested MOS acidic extract showed an anti-inflammatory potential. This work provides valuable contributions towards the industrial production of yeast-derived MOS extracts, highlighting their potential for applications in various fields while contributing to a circular economy approach.
- Use of various sugarcane byproducts to produce lipid extracts with bioactive properties: physicochemical and biological characterizationPublication . Pereira, Joana Odila; Oliveira, Diana; Faustino, Margarida; Vidigal, Susana S. M. P.; Pereira, Ana Margarida; Ferreira, Carlos M. H.; Oliveira, Ana Sofia; Durão, Joana; Rodríguez-Alcalá, Luís M.; Pintado, Manuela E.; Madureira, Ana Raquel; Carvalho, Ana P.Sugarcane, a globally cultivated crop constituting nearly 80% of total sugar production, yields residues from harvesting and sugar production known for their renewable bioactive compounds with health-promoting properties. Despite previous studies, the intricate interplay of extracts from diverse sugarcane byproducts and their biological attributes remains underexplored. This study focused on extracting the lipid fraction from a blend of selected sugarcane byproducts (straw, bagasse, and filter cake) using ethanol. The resulting extract underwent comprehensive characterization, including physicochemical analysis (FT-IR, DSC, particle size distribution, and color) and chemical composition assessment (GC-MS). The biological properties were evaluated through antihypertensive (ACE), anticholesterolemic (HMG-CoA reductase), and antidiabetic (alpha-glucosidase and Dipeptidyl Peptidase-IV) assays, alongside in vitro biocompatibility assessments in Caco-2 and Hep G2 cells. The phytochemicals identified, such as β-sitosterol and 1-octacosanol, likely contribute to the extract’s antidiabetic, anticholesterolemic, and antihypertensive potential, given their association with various beneficial bioactivities. The extract exhibited substantial antidiabetic effects, inhibiting α-glucosidase (5–60%) and DPP-IV activity (25–100%), anticholesterolemic potential with HMG-CoA reductase inhibition (11.4–63.2%), and antihypertensive properties through ACE inhibition (24.0–27.3%). These findings lay the groundwork for incorporating these ingredients into the development of food supplements or nutraceuticals, offering potential for preventing and managing metabolic syndrome-associated conditions.
- Vaginal prevention of Candida albicans: synergistic effect of lactobacilli and mannan oligosaccharides (MOS)Publication . Faustino, Margarida; Pereira, Joana Odila; Pereira, Ana Margarida; Oliveira, Ana Sofia; Ferreira, Carlos M. H.; Pereira, Carla F.; Durão, Joana; Pintado, Manuela E.; Carvalho, Ana P.Vulvovaginal candidiasis (VVC) affects approximately 30-50% of women at least once during their lifetime, causing uncomfortable symptoms and limitations in their daily quality of life. Antifungal therapy is not very effective, does not prevent recurrencies and usually causes side effects. Therefore, alternative therapies are urgently needed. The goal of this work was to investigate the potential benefits of using mannan oligosaccharides (MOS) extracts together with a Lactobacillus sp. pool, composed by the most significant species present in the vaginal environment, to prevent infections by Candida albicans. Microbial growth of isolated strains of the main vaginal lactobacilli and Candida strains was assessed in the presence of MOS, to screen their impact upon growth. A pool of the lactobacilli was then tested against C. albicans in competition and prophylaxis studies; bacterial and yeast cell numbers were quantified in specific time points, and the above-mentioned studies were assessed in simulated vaginal fluid (SVF). Finally, adhesion to vaginal epithelial cells (HeLa) was also evaluated, once again resorting to simultaneous exposure (competition) or prophylaxis assays, aiming to measure the effect of MOS presence in pathogen adherence. Results demonstrated that MOS extracts have potential to prevent vaginal candidiasis in synergy with vaginal lactobacilli, with improved results than those obtained when using lactobacilli alone. KEY POINTS: Potential benefits of MOS extracts with vaginal lactobacilli to prevent C. albicans infections. MOS impacts on growth of vaginal lactobacilli pool and C. albicans in SVF. MOS extracts in synergy with L. crispatus inhibit C. albicans adhesion in HeLa cells.