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33 result(s) for "Gouvinhas, Irene"
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Phytochemical and antioxidant analysis of medicinal and food plants towards bioactive food and pharmaceutical resources
Plants with medicinal properties play an increasingly important role in food and pharmaceutical industries for their functions on disease prevention and treatment. This study characterizes the phenolic composition and antioxidant activity of seven medicinal and food plants, including the leaves of Salvia officinalis L., Rosmarinus officinalis L., Olea europaea L., and Punica granatum L., as well as the leaves and young stems of Ruta graveolens L., Mentha piperita L., and Petroselinum crispum , Mill., by using colorimetric, chromatographic, and spectrophotometric assays. Results revealed that the hydro-methanolic leaf extracts of P. granatum (pomegranate) displayed the highest content of total phenols (199.26 mg gallic acid per gram of plant dry weight), ortho -diphenols (391.76 mg gallic acid per gram of plant dry weight), and tannins (99.20 mg epicatechin per gram of plant dry weight), besides a higher content of flavonoids (24 mg catechin per gram of plant dry weight). The highest antioxidant capacity measured by ABTS, DPPH, and FRAP (2.14, 2.27, and 2.33 mM Trolox per gram of plant dry weight, respectively) methods was also obtained in pomegranate leaf extracts, being 4–200 times higher than the other species. Such potent antioxidant activity of pomegranate leaves can be ascribed to the presence of different types of phenolic compounds and the high content in tannins, whilst phenolic acids and flavonoids were found to be the dominant phenolic classes of the other six plants. Consequently, despite the well-known antioxidant properties of these plant species, our study suggests pomegranate leaf can stand out as a relatively more valuable plant source of natural bioactive molecules for developing novel functional food-pharma ingredients, with potential for not only promoting human health but also improving bio-valorization and environment.
Seed Phytochemical Profiling of Three Olive Cultivars, Antioxidant Capacity, Enzymatic Inhibition, and Effects on Human Neuroblastoma Cells (SH-SY5Y)
This work evaluated the phytochemical composition of olive seed extracts from different cultivars (‘Cobrançosa’, ‘Galega’, and ’Picual’) and their antioxidant capacity. In addition, it also appraised their potential antineurodegenerative properties on the basis of their ability to inhibit enzymes associated with neurodegenerative diseases: acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYR). To achieve this goal, the phenolic composition of the extracts was determined through high-performance liquid chromatography coupled with photodiode-array detection and electrospray ionization/ion trap mass spectrometry (HPLC-DAD-ESI/MSn). The antioxidant capacity was assessed by two different methods (ABTS•+ and DPPH•), and the antineurodegenerative potential by the capacity of these extracts to inhibit the aforementioned related enzymes. The results showed that seed extracts presented a high content of phenolic compounds and a remarkable ability to scavenge ABTS•+ and DPPH•. Tyrosol, rutin, luteolin-7-glucoside, nüzhenide, oleuropein, and ligstroside were the main phenolic compounds identified in the extracts. ‘Galega’ was the most promising cultivar due to its high concentration of phenolic compounds, high antioxidant capacity, and remarkable inhibition of AChE, BChE, and TYR. It can be concluded that olive seed extracts may provide a sustainable source of bioactive compounds for medical and industrial applications.
Effects of Eriobotrya japonica (Thunb.) Lindl. Leaf Extract on Zebrafish Embryogenesis, Behavior, and Biochemical Pathways
Eriobotrya japonica (Thunb.) Lindl. leaves are rich in polyphenolic compounds, yet their toxicological effects in aquatic models remain poorly understood. This study evaluated the impact of a hydroethanolic E. japonica leaf extract on zebrafish embryos through the use of morphological, behavioral, and biochemical parameters. The 96 h LC50 was determined as 189.8 ± 4.5 mg/L, classifying the extract as practically non-toxic, according to OECD guidelines. Thereby, embryos were exposed for 90 h to 75 and 150 mg/L concentrations of the E. japonica leaf extract. While no significant effects were noted at the lowest concentration of 150 mg/L, significant developmental effects were observed, including reduced survival, delayed hatching, underdevelopment of the swim bladder, and retention of the yolk sac. These malformations were accompanied by marked behavioral impairments. Biochemical analysis revealed a concentration-dependent increase in superoxide dismutase (SOD) and catalase (CAT) activity, suggesting the activation of antioxidant defenses, despite no significant change in reactive oxygen species (ROS) levels. This indicates a potential compensatory redox response to a pro-oxidant signal. Additionally, the acetylcholinesterase (AChE) activity was significantly reduced at the highest concentration, which may have contributed to the observed neurobehavioral changes. While AChE inhibition is commonly associated with neurotoxicity, it is also a known therapeutic target in neurodegenerative diseases, suggesting concentration-dependent dual effects. In summary, the E. japonica leaf extract induced concentration-dependent developmental and behavioral effects in zebrafish embryos, while activating antioxidant responses without triggering oxidative damage. These findings highlight the extract’s potential bioactivity and underscore the need for further studies to explore its safety and therapeutic relevance.
Optimization of the Extraction Methodology of Grape Pomace Polyphenols for Food Applications
This study aims to take advantage of the wine industry by-products and extract bioactive compounds from grape pomace by applying methodologies susceptible to be integrated easily into industrial workflows because of the association with standard instrumentation and facilities, while the main factors affecting the efficiency of the process have been optimized. The sampling consisted of two grape varieties: ‘Touriga Nacional’ and ‘Sousão’. A response surface methodology (RSM) method was used to optimize the extraction conditions based on three independent variables according to the chemical characteristics and stability/lability traits associated with polyphenols; the main bioactive phytochemical in grape pomace: solvent (50%, 70%, and 90% ethanol); temperature (20 °C, 40 °C, and 60 °C); and pH (0.5% HCl, 2% HCl, and 3.5% HCl). The phytochemical profile, as well as the radical scavenging and reducing powers were determined on 27 different samples. The highest yield and antioxidant activity corresponded to extracts obtained at 60 °C using 3.5% HCl and 70% ethanol. The values for total phenols and flavonoids were 44.93 mg of gallic acid equivalents (GAE) and 22.95 mg of catechins equivalents (CE) per gram, respectively. Concerning the evaluation of antioxidant capacity using various assays such as ABTS, DPPH, and FRAP, the results obtained were 0.30, 0.43, and 0.36 mmol of Trolox equivalent antioxidant capacity (TEAC) per gram, correspondingly. The analysis of the extract obtained with the best extraction performance using these parameters via High-Performance Liquid Chromatography–Mass Spectrometry has been also performed, allowing us to identify fourteen (14) compounds, including phenolic acids (n = 3), flavonols (n = 7), and anthocyanins (n = 4). As a result of this process, the best conditions for the production of a natural and environmentally friendly dye, not only avoiding waste but also reusing these by-products, were achieved.
Exploring the Impact of Ultrasound-Assisted Extraction on the Phytochemical Composition and Bioactivity of Tamus communis L. Fruits
Background/Objectives: The health benefits of Tamus communis fruits have been associated with their high phenolic content, which comprises several flavonoids. However, the extraction methods might significantly impact these valuable compounds’ bioactivity. Therefore, the current study assesses how different extraction techniques affect T. communis extracts’ antioxidant, anti-aging, antimicrobial, cytotoxic, anti-inflammatory, and phenolic contents. Methods: Conventional method (TCE-CM) and ultrasound-assisted extraction (TCE-UM) were the methods employed. Results: The increased phenolic content of TCE-UM, particularly flavonoids and phenolic acids, was demonstrated to be a contributing factor to its higher biological activity. Key enzymes linked to dermatological conditions, such as elastase, collagenase, hyaluronidase, and tyrosinase, were significantly inhibited by both extracts at 1 mg/mL; TCE-UM showed the highest tyrosinase inhibition (65.61  ±  5.21%) compared to TCE-CM (21.78  ±  2.19%). TCE-UM also demonstrated exceptional antibacterial performance, showing notable antibiofilm and metabolic inactivation effects and potent activity against pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans. Both extracts showed concentration-dependent anti-inflammatory properties; TCE-UM had a lower IC50 value (26.46 ± 2.30%) in nitric oxide inhibition tests, suggesting stronger anti-inflammatory capabilities. Conclusions: These findings underscore the superior bioactivity of TCE-UM and suggest that ultrasonic extraction is a more efficient method for isolating bioactive phenolic compounds from T. communis fruits, presenting promising applications in anti-aging and antimicrobial formulations.
Exploring the Antioxidant Potential of Phenolic Compounds from Winery By-Products by Hydroethanolic Extraction
The residues generated in the wine industry (pomace, stems, seeds, wine lees, and grapevine shoots) are a potential source of bioactive compounds that can be used in other industries despite being sometimes underestimated. Different extraction methods using various solvents and extraction conditions are currently being investigated. Due to its natural occurrence in wines, safe behavior, and low toxicity when compared to other organic solvents, ethanol is used as an extracting agent. The aim of this study was to identify the winery by-product from the Região Demarcada do Douro and its corresponding extraction solvents that yields the most favorable results in (poly)phenols content and antioxidant capacity. To achieve this, five different ratios of ethanol: water, namely 0:100, 25:75, 50:50, 75:25, and 100:0 (v/v), for extracting the phenolic compounds were employed. Afterwards, the determination of total phenolic content (TPC), ortho-diphenols content (ODC), and flavonoid content (FC) as well as the antioxidant capacity of the obtained extracts using three different methods was performed. Since the best results of the spectrophotometric assays were obtained mostly with hydroethanolic extracts of stems (50:50, v/v), identification by HPLC-DAD has carried out. It was possible to conclude that the Tinta Roriz variety displayed the highest number of identified (poly)phenols.
Acorn Flour as a Source of Bioactive Compounds in Gluten-Free Bread
Polyphenols are important bioactive compounds whose regular ingestion has shown different positive impacts in health. Celiac patients have nutritional deficiencies, bringing many problems to their health. Thus, it is important to develop gluten-free (GF) products, such as bread, with nutritional benefits. The acorn is the fruit of holm oak and cork oak, being an underexploited resource nowadays. Its nutritional and functional characteristics are remarkable: rich in unsaturated fatty acids and fiber, vitamin E, chlorophylls, carotenoids, phenolic compounds, and antioxidant properties. The purpose of this study was to assess the use of acorn flour as a bioactive compounds source and natural GF ingredient for baking GF bread. Bread loaves were prepared with buckwheat, rice, acorn flour, and potato starch. Two levels of acorn flour (23% and 35% of the flour mixture) were tested. The physical, nutritional, and sensory characteristics of the bread were analysed, as well as the composition of phenolic compounds: total phenols, ortho-diphenols, and flavonoids. The phenolic profile was assessed by Reverse Phase–High-Performance Liquid Chromatography–Diode Array Detector (RP-HPLC-DAD). The antioxidant activity of the bread extracts was determined by 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), diphenyl-1-picrylhidrazyl radical (DPPH), and ferric reducing antioxidant power (FRAP) methodologies. Acorn flour can be considered a good source of bioactive compounds and antioxidants in GF bread. Acorn flour showed good technological properties in GF baking, improving bread nutritional and sensory characteristics.
Impact of Winemaking Techniques on the Phenolic Composition and Antioxidant Properties of Touriga Nacional Wines
The Touriga Nacional grape variety is renowned in Portuguese red wines for its intense color and aromatic complexity, largely attributed to its rich phenolic composition. Several factors influence the phenolic profile of wines, including edapho-climatic conditions, grape variety, and winemaking techniques such as fermentation, maceration, barrel aging, and maturation. In this study, the technique for winemaking was the only controlled variable, allowing for a specific evaluation of its impact on phenolic composition and antioxidant capacity. Ten single-varietal Touriga Nacional wine samples from the 2019 vintage, produced in the Cima Corgo sub-region of the Douro by different wineries, were analyzed. The phenolic composition was determined using colorimetric methods to quantify total phenols, ortho-diphenols, flavonoids, anthocyanins, and tannins. Antioxidant capacity was assessed through the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and Ferric Reducing Antioxidant Power (FRAP) assays. Since all wines shared the same grape variety, region, and harvest year, the fermentation technique was the main differentiating factor, enabling a direct comparison of its influence on phenolic extraction and antioxidant properties. Additionally, Reversed-Phase High-Performance Liquid Chromatography with Photodiode Array Detection coupled with Mass Spectrometry (RP-HPLC-DAD-ESI-MS/MS) was employed to identify and quantify individual phenolic compounds. This study highlights the key role of winemaking techniques in modulating the phenolic composition and antioxidant potential of Touriga Nacional wines.
Valorisation of Winery By-Products: Revealing the Polyphenolic Profile of Grape Stems and Their Inhibitory Effects on Skin Aging-Enzymes for Cosmetic and Pharmaceutical Applications
Grape (Vitis vinifera L.) stems, a by-product of winemaking, possess significant potential value due to their rich polyphenolic composition, which allows their exploitation for cosmetic and pharmaceutical applications. This presents a promising opportunity for valorisation aimed at developing innovative products with potential health-promoting effects. In this study, the polyphenolic profile of extracts from grape stems of seven white grape varieties was determined using spectrophotometric and chromatographic methods, specifically high-performance liquid chromatography coupled with a photodiode array detector and electrospray ionization multi-stage mass spectrometry (HPLC-PDA-ESI-MSn), as well as on their ferric-reducing antioxidant power (FRAP) and radical scavenging capacity, using 2,2-diphenyl-1-picrylhydrazyl (DPPH●) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS●+) radicals. This study also evaluated the anti-aging activity and skin depigmenting activity of these extracts. These findings revealed a diverse polyphenolic profile, encompassing proanthocyanidins and catechin derivatives (PCDs), phenolic acids, and flavonols. Among the varieties studied, ‘Códega do Larinho’ exhibited the highest concentrations of six distinct polyphenols and the highest total phenolic content. It also demonstrated the highest results for antioxidant capacity and elastase and tyrosinase inhibition. Pearson’s correlation analysis showed a significant positive correlation between certain PCDs with both FRAP and DPPH assays, as well as between the identified flavonols and anti-elastase activity. These results underscore the potential health benefits of grape stem extracts and emphasize the importance of their polyphenolic composition in enhancing antioxidant and anti-aging properties, thus supporting their application in different industries.
Assessment of Phenolic Content, Antioxidant and Anti-Aging Activities of Honey from Pittosporum undulatum Vent. Naturalized in the Azores Archipelago (Portugal)
Pittosporum undulatum Vent. is an invasive species scattered across all of the Azores’s Islands. Identifying processes to obtain economic returns from the plant is of great interest. This work aims to evaluate honey from P. undulatum from the Azores by determining its phenolic content and biological activities, to enhance its value and equate its potential applications in the food, cosmetic, and/or pharmaceutical industries. Herein, the phenolic content and antioxidant capacity were evaluated by spectrophotometric methods. Furthermore, and for the first time, anti-aging capacity was determined in honey samples. The total phenols content revealed values from 20.82 to 112.13 mg GA/100 g, from 10.25 to 103.26 mg GA/100 g for ortho-diphenols, and from 2.94 to 40.96 mg CAT/100 g for flavonoids content. Regarding the antioxidant capacity, the values ranged from 0.05 to 2.27 mmol Trolox/100g. Concerning the anti-aging capacity, promising results were obtained, namely for tyrosinase inhibitory capacity, with values ranging between 4.36% and 9.37%, while the values of elastase inhibitory capacity ranged from 37.52% to 45.88%. This study allowed us to understand the phytochemicals and biological activities of honey from P. undulatum, enhancing the possible health benefits, namely for potential anti-aging treatment, valorizing, at the same time, a national food product.