Browsing by Author "Machado, Manuela"
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- Age-related gastrointestinal alterations affect adipolysis induced by dairy and hybrid high-protein yogurts in differentiated 3T3-L1 adipocytesPublication . Gigante, Mirna Lúcia; Baptista, Débora Parra; Silva, Kívea Kássia de Paiva e; Machado, Manuela; Costa, Eduardo M.; Pintado, Manuela
- Anti-obesity potential of a yogurt functionalized with a CLNA-rich pomegranate oilPublication . Machado, Manuela; Sousa, Sérgio; Rodriguez-Alcalá, Luís M.; Gomes, Ana Maria; Pintado, ManuelaPomegranate oil is rich in conjugated linolenic acids, compounds which have attracted attention due to their potential applicability in obesity management as they are capable of modulating leptin and adiponectin secretion and regulate fatty acids storage and glucose metabolism. Among the possible bioactive foodstuffs capable of delivering these bioactive compounds yogurts have shown potential. Thus, the purpose of this work was to develop functional yogurts through the addition of pomegranate oil either in its free or encapsulated (used as a protective strategy against oxidation and gastrointestinal tract passage) forms. To that end, the pomegranate oil (free and encapsulated) was incorporated in yogurt and the functional yogurt capacity to modulate hepatic lipid accumulation, adipocyte metabolism (in terms of lipolysis, and adipokines secretion) and immune response was evaluated. The results obtained showed that the pomegranate oil's incorporation led to an improvement in the yogurts' nutritional values, with a reduction in its atherogenic and thrombogenic indexes (more than 78% for atherogenic and 76% for thrombogenic index) and an enhancement of its hypocholesterolemic/hypercholesterolemic ratio (more than 62%) when compared to the control yogurt. Furthermore, data also showed for the first time how these functional yogurts promoted modulation of metabolic processes post GIT as they were capable of reducing by 40% triglycerides accumulation in steatosis-induced Hep G2 cells and by 30 % in differentiated adipocytes. Moreover, samples also showed a capacity to modulate the leptin and adiponectin secretion (56 % of increase in adiponectin) and reduce the IL-6 secretion (ca 44%) and TNF-α (ca 12%) in LPS-stimulated cells. Thus, the CLNA-rich yogurt here developed showed potential as a viable nutraceutical alternative for obesity management.
- Antiadhesive and antibiofilm effect of malvidin-3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures upon staphylococcusPublication . Silva, Sara; Costa, Eduardo M.; Machado, Manuela; Morais, Rui; Calhau, Conceição; Pintado, ManuelaSeveral reports on the biological activity of anthocyanin-rich extracts have been made. However, despite the association of said activity with their anthocyanin content, to the best of our knowledge, there are no previous works regarding the antimicrobial, antibiofilm and/or antiadhesive properties of anthocyanins alone. Therefore, the present work aimed to determine the effects of malvidin-3-glucoside, a major component of a previously reported extract, and the impact of its association with neochlorogenic acid (the only non-anthocyanin phenolic present in said extract), upon several Staphylococcus strains with varying resistance profiles. Results show that, while malvidin- 3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures were unable to considerably inhibit bacterial growth after 24 h, they still possessed an interesting antibiofilm activity (with reductions of biofilm entrapped cells up to 2.5 log cycles, metabolic inhibition rates up to 81% and up to 51% of biomass inhibition). When considering the bacteria’s capacity to adhere to plain polystyrene surfaces, the inhibition ranges were considerably lower (21% maximum value). However, when considering polystyrene surfaces coated with plasmatic proteins this value was considerably higher (45% for adhesion in the presence of extract and 39% for adhesion after the surface was exposed to extract). Overall, the studied anthocyanins showed potential as future alternatives to traditional antimicrobials in adhesion and biofilm formation prevention.
- Antioxidant activity, phenolic profile, cytotoxicity and genotoxicity of plant extractsPublication . Melo, Adma N. F. de; Afonso, Tiago B.; Ribeiro, Tânia; Machado, Manuela; Carvalho, Marta; Carocho, Márcio; Tavaria, Freni; Teixeira, Paula; Barros, Lillian; Pintado, ManuelaThe outbreak of COVID-19 disease caused by SARS-CoV-2 forced the scientific world to search for new alternatives to help control the virus. Plant extracts have natural compounds that might provide a starting point for the research on the use of plants as an excellent source of new antiviral agents against viruses, including COVID-19 to be included in disinfectants, fabrics or other materials. In this study, the polyphenols content (Folin-Ciocalteu), antioxidant capacity (DPPH, ABTS and ORAC) and the phenolic profile (HPLC) of different hydroethanolic (ethanol:H2O 50:50 v/v) extracts of medicinal plants cultivated under controlled conditions in Portugal (echinacea, rosemary, laurel, thyme and rock rose) were determined, as well as the cytotoxicity effect against a keratinocyte cell line using cell viability assay by PrestoBlue and genotoxicity effect using the AMES test. According to the results, total phenolic content ranged from 204.54 ± 1.78 / 274.20 ± 3.14 (mg EAG/g extract) with the rock rose extract presenting the highest content (p < 0.05). The extracts showed a good antioxidant capacity demonstrated by the high values found for ORAC, which ranged 2855.03 ± 9.75 / 5285.35 ± 60.04 µMol Trolox/mg extract. HPLC analysis revealed the presence of different compounds in the extracts such as the kaempferol-O-glucuronide, catechin, protocatechuic acid and galloyl glucoside, representing a potential source of bioactive components with antioxidant capacity. No toxicity was observed towards the keratinocyte cells and none of them showed mutagenic effects. Based on the results of safety and high polyphenols content of the extracts they demonstrate a great potential as antimicrobial agents. This will allow the design of new experiments aimed at evaluating the antiviral activity of these extracts, especially against SARS-CoV-2.
- Antioxidant activity, phenolic profile, cytotoxicity and genotoxicity of plant extractsPublication . Melo, Adma N. F. de; Afonso, Tiago B.; Ribeiro, Tânia; Machado, Manuela; Carvalho, Marta; Carocho, Márcio; Tavaria, Freni; Carvalho, Marta; Teixeira, Paula; Barros, Lillian; Pintado, Manuela
- Application of encapsulated tomato by-product extract as a colorant in mascarponePublication . Molina, Adriana K.; Leichtweis, Maria G.; Machado, Manuela; Silva, Sara; Pintado, Manuela; Barreira, João C. M.; Dias, Maria Inês; Prieto, Miguel Á.; Barros, Lillian; Pereira, CarlaAgricultural by-products, often underutilized, represent a significant opportunity to obtain sustainable value-added products to develop new functional foods. In this context, the (typically discarded) aerial parts of tomato plants (Solanum lycopersicum L. var. cerasiforme), were studied as new sources of natural bioactive compounds, focusing the extraction and encapsulation (using spray drying with maltodextrin as the encapsulant) of chlorophylls. The encapsulated natural colorant was subsequently incorporated into mascarpone cheese to assess its stability and effect on nutritional and antioxidant properties. The obtained extracts were mainly characterized by high concentrations of bioactive compounds, particularly quercetin-3-O-deoxyhexoside (14.4 ± 0.3 mg/g). The colorant imparted a greener hue to the mascarpone (a* –6.0 ± 0.05 vs. –1.7 ± 0.05 in control, p < 0.001) and maintained antioxidant activity (OxHLIA EC₅₀ = 1440 ± 72 to 1166 ± 66 μg/mL, p = 0.030) without altering the nutritional profile (p > 0.05). Moreover, no cytotoxicity was observed, and the fatty acid composition remained unchanged. Accordingly, the studied encapsulated colorant might be used as a functional ingredient in other dairy products, imparting an attractive color while preserving nutritional integrity. In conclusion, the incorporation of TAPC is an effective strategy to enrich dairy products with natural pigments and bioactive compounds without compromising quality. Future research is needed to explore its application in other food matrices and assess long-term storage effects.
- Are antimicrobial peptides a 21st-century solution for atopic dermatitis?Publication . Machado, Manuela; Silva, Sara; Costa, Eduardo M.Atopic dermatitis (AD) is a chronic inflammatory skin disorder that is the result of various environmental, bacterial and genetic stimuli, which culminate in the disruption of the skin’s barrier function. Characterized by highly pruritic skin lesions, xerosis and an array of comorbidities among which skin infections are the most common, this condition results in both a significant loss of quality of life and in the need for life-long treatments (e.g., corticosteroids, monoclonal antibodies and regular antibiotic intake), all of which may have harmful secondary effects. This, in conjunction with AD’s rising prevalence, made the development of alternative treatment strategies the focus of both the scientific community and the pharmaceutical industry. Given their potential to both manage the skin microbiome, fight infections and even modulate the local immune response, the use of antimicrobial peptides (AMPs) from more diverse origins has become one of the most promising alternative solutions for AD management, with some being already used with some success towards this end. However, their production and use also exhibit some limitations. The current work seeks to compile the available information and provide a better understanding of the state of the art in the understanding of AMPs’ true potential in addressing AD.
- Assessment of the bioaccessibility and bioavailability prediction of omega 3 and conjugated fatty acids by in vitro standardized digestion model (INFOGEST) and cell modelPublication . Salsinha, Ana Sofia; Cunha, Sara A.; Machado, Manuela; Rodriguez-Alcalá, Luís Miguel; Relvas, João B.; Pintado, ManuelaOmega 3 EPA and DHA are polyunsaturated fatty acids with relevant health benefits. Conjugated linoleic and linolenic acids are known for their anti-carcinogenic effect, anti-inflammatory properties and body weight reduction. To achieve therapeutical doses, high amounts of these fatty acids’ food sources must be consumed. Thus, the intake of enriched oils with a high concentration of these fatty acids is often used. But several factors influence their bioavailability. Here, by using the INFOGEST static in vitro protocol of gastrointestinal tract digestion it was studied the bioaccessibility of these fatty acids in different matrixes: Pomegranate and Fish oil and omega 3, CLA and CLNA soft-gel enriched capsules. After digestion, the Recovery Index for the major bioactive PUFAs are very low: Pomegranate oil is 2%, Fish oil 11–13%, CLNA 17%, CLA 6% and Omega 3 capsules 3%. Higher initial concentrations of these PUFAs seem to be related to higher degrees of oxidation. In Pomegranate oil, CLNA and Omega 3 capsules, the digestion process negatively influenced the antioxidant potential. The opposite was verified for the Fish oil and CLA capsules. Importantly, bioaccessibility studies of similar matrixes are very scarce and intestinal permeability is absent in most of the studies. Intestinal permeability studies were performed using a Caco-2/HT29-MTX co-culture: there is significative incorporation of the bioactive fatty acids into the intestinal cells, which may affect their permeability performance. Interestingly, most fatty acids remain in the non-bioaccessible fraction which may be relevant when designing oral routes of administration and in gut microbiota modulation.
- ATR-FTIR analysis of thermoplastic rubber plates containing food byproduct particles: effect of particle size and production orderPublication . Silva, Sara; Silva, Isa; Machado, Manuela; Costa, Eduardo M.; Ribeiro, Tania B.; Pintado, Mª Manuela
- ATR-FTIR as a high throughput tool for quick screening of lipolysis in 3T3- L1 adipocytesPublication . Machado, Manuela; Costa, Eduardo M.; Silva, Sara; Pintado, ManuelaLipolysis is an important biological process responsible for delivering fatty acids appropriately to meet energy needs. An unbalanced amount of free fatty acids is associated with insulin resistance and an increase in triglyceride levels. This process is related to the degradation of triglycerides in differentiated adipocytes. Typically, the rate of lipolysis in adipocytes is measured using commercial kits (for triglyceride quantification or glycerol release), or by assessing the mRNA levels of lipases and regulatory proteins, and in some cases, by chromatographic techniques to quantify free fatty acids. Both techniques are time-consuming and expensive, which can be a disadvantage in the search for new compounds to reduce fat accumulation in adipose tissue. Therefore, Fourier transform infrared spectroscopy (FTIR) can be a valuable tool for measuring lipolysis due to its ease of operation, rapid analysis time, and low cost.