Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (437)

Search Parameters:
Keywords = ORAC assay

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
17 pages, 762 KB  
Article
Porcine Blood: An Eco-Efficient Source of Multifunctional Protein Hydrolysates
by Sandra Borges, Joana Odila, Glenise Voss, Rui Martins, André Almeida and Manuela Pintado
Foods 2026, 15(2), 254; https://doi.org/10.3390/foods15020254 - 10 Jan 2026
Viewed by 101
Abstract
Porcine blood is a major slaughterhouse by-product and a sustainable source of high-quality proteins with potential food and nutraceutical applications. This study valorized porcine whole blood (WB, 6.7 ± 0.1% protein) and red cell fraction (CF, 50.4 ± 0.2% protein) through alcalase hydrolysis, [...] Read more.
Porcine blood is a major slaughterhouse by-product and a sustainable source of high-quality proteins with potential food and nutraceutical applications. This study valorized porcine whole blood (WB, 6.7 ± 0.1% protein) and red cell fraction (CF, 50.4 ± 0.2% protein) through alcalase hydrolysis, generating hydrolysates (WBH and CFH) with bioactive and techno-functional properties. Optimal hydrolysis conditions, defined as enzyme-to-substrate (E/S) and incubation time yielding the highest degree of hydrolysis (DH) with cost-effective enzyme usage, were 1% E/S for 4 h (WBH) and 2.5% E/S for 4 h (CFH). WBH showed a higher DH (59.5 ± 2.6%) than CFH (30.8 ± 3.3%). Antioxidant assays revealed higher ABTS activity in CFH (14.1 vs. 11.1 mg ascorbic acid equivalents/g, p < 0.05), while both exhibited similar ORAC values (166.8–180.2 mg Trolox equivalents/g, p > 0.05). After simulated gastrointestinal digestion, ABTS activity was preserved, whereas ORAC decreased (~40%). ACE inhibitory activity was also pronounced, particularly in CFH (IC50 = 59.5 µg protein/mL), but digestion converged values between hydrolysates (118–135 µg protein/mL). Techno-functional tests showed moderate emulsifying activity (~40%), with CFH displaying markedly higher oil absorption (4.79 vs. 1.31 g oil/g). Considering the limited information on porcine blood hydrolysates under gastrointestinal conditions, these findings provide new insights into their stability and support their potential as multifunctional ingredients for health-promoting foods and functional formulations. Full article
Show Figures

Figure 1

17 pages, 5547 KB  
Article
Impact of Structural Features on the Antioxidant Activity of Organofluorine Diaryl Hydrazones
by Zsuzsanna K. Zsengellér, Maxim Mastyugin, Adrianna R. Fusco, Bernadett R. Vlocskó, Coryn Ferguson, Diana Pintye, Hamad Nasim, Saira Salahuddin, Brett C. Young, Béla Török and Marianna Török
Molecules 2026, 31(1), 78; https://doi.org/10.3390/molecules31010078 - 24 Dec 2025
Viewed by 452
Abstract
Preeclampsia (PE) affects 2–8% of pregnancies, yet it lacks curative treatment options. Oxidative stress caused by the release of reactive oxygen and nitrogen species (ROS/RNS) in the placenta is common in abnormal placental development. It can cause downstream signaling and the formation of [...] Read more.
Preeclampsia (PE) affects 2–8% of pregnancies, yet it lacks curative treatment options. Oxidative stress caused by the release of reactive oxygen and nitrogen species (ROS/RNS) in the placenta is common in abnormal placental development. It can cause downstream signaling and the formation of anti-angiogenic factors, e.g., soluble fms-like tyrosine kinase 1 (sFLT-1), leading to symptoms of PE, such as hypertension, proteinuria, and, in severe cases, eclampsia. Mitochondria-targeted antioxidants were developed to reduce oxidative stress and alleviate PE symptoms. Ten organofluorine diaryl hydrazones were designed as potential antioxidants, synthesized, and tested for their activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays. Compounds 2, 3, 5, and 6 showed excellent antioxidant capacity in all three assays and were tested in an in vitro human trophoblast cell culture system mimicking PE in which the cells were exposed to oxidative stress inducing the release of sFLT-1. The anti-angiogenic factor sFLT-1 was greatly reduced in cells treated with antioxidants. Compounds 5 and 6 were more effective in preventing sFLT-1 release than 2 and 3. Density functional theory calculations of the electronic structures of compounds 2, 5, and 6 were conducted at the M06-2X/6-311G+(d,p) level to further understand the reactivity profile of these molecules. The electron density of delocalized bonds (EDDB(r)) was calculated to analyze the effect of delocalization on radical stabilization. Full article
Show Figures

Figure 1

23 pages, 1732 KB  
Article
Freeze-Drying and Convective Drying of the Underutilized Red Seaweed Sarcodiotheca gaudichaudii: A Comparative Study on Key Chemical Parameters and Biological Activities
by Alexis Pasten, Antonio Vega-Galvez, Michael Araya, Elsa Uribe, Nicol Mejias, Joan Manriquez and Fabiola Jamett
Processes 2026, 14(1), 66; https://doi.org/10.3390/pr14010066 - 24 Dec 2025
Viewed by 357
Abstract
Seaweeds are emerging renewable biomass resources rich in valuable phytochemicals; however, effective stabilization strategies are required to enable their incorporation into sustainable food and bioprocessing applications. This study investigated the effects of convective drying (40–80 °C) and freeze-drying on the chemical composition and [...] Read more.
Seaweeds are emerging renewable biomass resources rich in valuable phytochemicals; however, effective stabilization strategies are required to enable their incorporation into sustainable food and bioprocessing applications. This study investigated the effects of convective drying (40–80 °C) and freeze-drying on the chemical composition and functional properties of the underexplored red seaweed Sarcodiotheca gaudichaudii. The drying method significantly modulated nutrient retention, pigment stability, and bioactivity. Freeze-drying and high-temperature convective drying (≥70 °C) resulted in higher protein and saturated fatty acid contents but led to substantial losses of pigments and antioxidant capacity. In contrast, moderate convective drying (40–60 °C) favored the retention of minerals, polyunsaturated fatty acids, essential amino acids, and pigments, while enhancing total phenolic and flavonoid contents and improving antioxidant performance (DPPH and ORAC). All extracts exhibited dose-dependent α-glucosidase inhibition (25–58%) within a concentration range of 0.10–40.0 mg/mL, with freeze-dried samples showing the strongest inhibitory effect. Similarly, cytotoxicity assays conducted on A549 and AGS cancer cell lines at concentrations of 1.25–40.0 mg/mL revealed that freeze-dried extracts consistently displayed the lowest IC50 values. Overall, convective drying better preserved nutritional quality, whereas freeze-drying maintained higher biological functionality, revealing a process-dependent trade-off relevant to industrial biomass stabilization and functional ingredient development. Full article
(This article belongs to the Special Issue Processes in Agri-Food Technology)
Show Figures

Figure 1

20 pages, 574 KB  
Article
Bioactive and Phenolic Profiles in Pinus pinaster Bark: A Comparative Study of Microwave and Ultrasound Extraction Methods
by Diana Barros, José Ignacio Alonso-Esteban, Tiane C. Finimundy, Carla Pereira, Josiana A. Vaz, Ricardo Pereira-Pinto, Élia Fernandes, Preciosa Pires, Joana Santos, Lillian Barros and Manuela Vaz-Velho
ChemEngineering 2026, 10(1), 2; https://doi.org/10.3390/chemengineering10010002 - 22 Dec 2025
Viewed by 505
Abstract
This study conducted a comprehensive comparison of two green extraction methods, microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), for recovering bioactive phenolic compounds from Pinus pinaster bark. The goal was to valorize timber industry waste and enhance the value of by-products through the [...] Read more.
This study conducted a comprehensive comparison of two green extraction methods, microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), for recovering bioactive phenolic compounds from Pinus pinaster bark. The goal was to valorize timber industry waste and enhance the value of by-products through the development of eco-friendly processes to extract phenolic compounds from Pinus pinaster Aiton subsp. atlantica in northwest Portugal. MAE achieved significantly higher extraction yields than UAE (11.13 vs. 3.47 g extract/100 g bark) and superior total phenolic content (833 vs. 514 mg GAE/g). MAE extracts also exhibited enhanced antioxidant activity in most assays tested (DPPH, ABTS, ORAC, and OxHLIA), while both extracts effectively inhibited lipid peroxidation (TBARS) and showed activity against Gram-positive bacteria. Phenolic profile analysis revealed that MAE recovered a substantially higher amount of total phenolic compounds (230.0 mg/g) compared to UAE (86.95 mg/g), with procyanidins identified as the predominant compounds. The greater recovery of this complex procyanidin mixture by MAE is strongly associated with the enhanced bioactivities observed. Overall, this study confirms MAE as a highly efficient and sustainable technology for transforming pine bark waste into valuable antioxidant and antimicrobial extracts with potential applications in the food and pharmaceutical industries. Full article
Show Figures

Figure 1

17 pages, 1556 KB  
Article
From Waste to Resource: Extraction and Characterization of Polyphenols from Dalmatian Olive Mill Wastewater
by Nina Knezovic, Ajka Pribisalic, Katarina Jurcic, Ivica Ljubenkov, Barbara Soldo, Danijela Skroza, Mladenka Sarolic, Sanja Luetic, Davorka Sutlovic and Zlatka Knezovic
Antioxidants 2026, 15(1), 12; https://doi.org/10.3390/antiox15010012 - 21 Dec 2025
Viewed by 400
Abstract
Background: Olive cultivation and olive oil production are key agricultural sectors in the Dalmatia region, where numerous oil mills operate. Analyses have shown that extra virgin olive oils (EVOO) produced in this area contain respectable amounts of polyphenols, which contribute to superior oil [...] Read more.
Background: Olive cultivation and olive oil production are key agricultural sectors in the Dalmatia region, where numerous oil mills operate. Analyses have shown that extra virgin olive oils (EVOO) produced in this area contain respectable amounts of polyphenols, which contribute to superior oil quality due to their antioxidant properties. During processing, hydrophilic phenolic compounds predominantly transfer into olive mill wastewater (OMW), making it a concentrated source of valuable bioactive molecules. The antioxidant, anti-inflammatory, and photoprotective effects of these polyphenols are highly relevant for cosmetic and pharmaceutical use. Methods: A total of 186 OMW samples were collected from oil mills in the Split-Dalmatia County across three production seasons (2023–2025). Total polyphenol content (TPC) was measured spectrophotometrically, while polyphenol composition was determined by High Performance Liquid Chromatography (HPLC). Antioxidant activity was evaluated using hydrogen atom transfer (HAT; 2,2-diphenyl-1-picrylhydrazyl) (DPPH), electron transfer (ET; ferric reducing antioxidant power) (FRAP), and oxygen radical absorbance capacity assay (ORAC). Results: The obtained results indicated high total polyphenols concentrations, with values ranging from 111.8 to 6717.2 mg of gallic acid equivalents per L of OMW (mg GAe L−1). In the vast majority of analyzed samples, hydroxytyrosol was the predominant phenol compound. The antioxidant activity of the samples was high. Full article
(This article belongs to the Special Issue Bioactive Antioxidants from Agri-Food Wastes, 2nd Edition)
Show Figures

Graphical abstract

19 pages, 1243 KB  
Article
Characterization of Steam Volatiles and Evaluation of the Antioxidant Properties of Different Extracts from Leaves and Roots of Aegopodium podagraria L.
by Renata Baranauskienė, Ieva Račkauskienė and Petras Rimantas Venskutonis
Molecules 2025, 30(24), 4786; https://doi.org/10.3390/molecules30244786 - 15 Dec 2025
Viewed by 334
Abstract
This study presents the results on the composition of hydro-distilled essential oils and the antioxidant properties of extracts isolated with different polarity solvents from the leaves (GLEO) and roots (GREO) of wild-grown Lithuanian goutweed (Aegopodium podagraria L.). The yields of GLEO and [...] Read more.
This study presents the results on the composition of hydro-distilled essential oils and the antioxidant properties of extracts isolated with different polarity solvents from the leaves (GLEO) and roots (GREO) of wild-grown Lithuanian goutweed (Aegopodium podagraria L.). The yields of GLEO and GREO were 0.22% and 0.04%. The identified compounds numbered 117 and 88, which constituted 99.4 and 99.2% of the total integrated peak area, respectively. The major GLEO constituents were sesquiterpenes germacrene D (17.53%), (E)-β-bergamotene (11.75%), (E,E)-α-farnesene (7.23%), and (E)-caryophyllene (5.29%), while monoterpene α-pinene (19.24%) was quantitatively dominant in GREO, followed by sesquiterpenes germacrene B (4.59%), (E)-caryophyllene (4.51%), β-barbatene (4.26%), and β-bazzanene (4.10%). Polyacetylene (Z)-falcarinol, which is an important bioactive compound, constituted 4.60% in GREO. The antioxidant characteristics of water, methanol, and acetone extracts were evaluated by the TPC, DPPH/ABTS•+ scavenging, and ORAC assays. The water and methanol extracts of the leaves were the strongest antioxidants; their TPC and ORAC values were 62.12 and 56.84 mg GAE/g, and 1426 and 1293 µM TE/g, respectively; the EC50 values of DPPH and ABTS•+ scavenging were 1.18 and 2.48, and 2.45 and 3.57 mg/mL, respectively. The results obtained may assist in developing antioxidants, cosmeceuticals, nutraceuticals, and other health-beneficial preparations from A. podagraria extracts. Full article
Show Figures

Graphical abstract

33 pages, 1135 KB  
Review
Antioxidant, Antimicrobial, and Anticancer Activity of Basil (Ocimum basilicum)
by Efthymios Poulios, Sousana K. Papadopoulou, Evmorfia Psara and Constantinos Giaginis
Antioxidants 2025, 14(12), 1469; https://doi.org/10.3390/antiox14121469 - 7 Dec 2025
Cited by 1 | Viewed by 1539
Abstract
Background/Objectives: For many years, herbs and spices have been used, due to their aroma and flavor, in the food industry and cuisine. It is also well known that phytochemicals from these plant parts have many health benefits and are used for the prevention [...] Read more.
Background/Objectives: For many years, herbs and spices have been used, due to their aroma and flavor, in the food industry and cuisine. It is also well known that phytochemicals from these plant parts have many health benefits and are used for the prevention and treatment of many human diseases. Basil (with the most representative species Ocimum basilicum) is a perennial herb with a characteristic aroma, containing many bioactive components such as phenolic acids, flavonoids, tannins, saponins, alkaloids, polysaccharides, vitamins, proteins, amino acids, and essential oils, with beneficial effects on human health. The aim of this study is to review the antioxidant, antimicrobial, and anticancer activity of basil, according to recent literature. Methods: A thorough search in the international databases (Scopus, PubMed, Google Scholar, and Web of Sciences) was conducted from January 2015 to October 2025, using characteristic keywords in combinations. Results: Bioactive components of basil show a significant antioxidant activity, as detected by radical scavenging activity (measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays), activation of antioxidant enzymes (glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT)), enhancement of reduced glutathione (GSH) and reduction in malondialdehyde (MDA) and thiobarbituric acid-reactive substance (TBARS) levels, and protection of cells from hydrogen peroxide (H2O2)-toxicity. Additionally, inhibition of growth and cell death of many Gram-positive and Gram-negative bacteria strains, maintained by cell membrane damage, inhibition of efflux pumps, as well as inhibition of biofilm formation, anti-protozoan, antifungal, and antiviral activities, have been noticed for basil bioactive components. A synergism with antibiotics has also been reported. Finally, anticancer activity has been reported, according to apoptosis induction, cell cycle arrest, anxiety reduction, and health improvement of cancer patients. Conclusions: Basil bioactive components have been reported for their high antioxidant, antimicrobial, and anticancer properties. However, future studies, especially at the clinical level, are strongly proposed in order to unravel the significant role of basil in human health and the safety of its bioactive components in healthcare usage. Full article
(This article belongs to the Section Natural and Synthetic Antioxidants)
Show Figures

Figure 1

19 pages, 475 KB  
Article
Exploring the Nutritional Value and Bioactive Potential of Craterellus cornucopioides (L.) Pers. as a Functional Food Source
by Mariana-Gabriela Bumbu, Mihaela Niculae, Irina Ielciu, Adela Pintea, Zsolt Matyas, Ștefan Alexandru Anton, Daniela Benedec, Melinda Fogarasi, Ioan Marcus, Oana Roșca-Casian, Nicodim Fiț and Daniela Hanganu
Foods 2025, 14(23), 4124; https://doi.org/10.3390/foods14234124 - 1 Dec 2025
Viewed by 483
Abstract
This study aimed to explore the phytochemical variability, nutrient composition, and bioactive profile of the edible mushroom species Craterellus cornucopioides with specimens originating from Romanian flora. Its nutritional profile, including its proximate composition and energy value, was determined using standardized analytical methods. The [...] Read more.
This study aimed to explore the phytochemical variability, nutrient composition, and bioactive profile of the edible mushroom species Craterellus cornucopioides with specimens originating from Romanian flora. Its nutritional profile, including its proximate composition and energy value, was determined using standardized analytical methods. The mean contents of total polyphenols and caffeic acid derivatives, quantified by spectrophotometric assay, were established. HPLC–DAD–ESI+ analysis enabled the identification and quantification of individual phenolic constituents. Its antioxidant potential was systematically assessed using the following in vitro complementary assays: FRAP, ABTS, CUPRAC, DPPH, and ORAC. Antimicrobial activity was evaluated in vitro against MSSA, MRSA, Bacillus cereus, Enterococcus faecalis, Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans using well diffusion, broth microdilution, and anti-biofilm assays. The high amounts of polyphenols, including gentisic acid and protocatechuic acid, underlined a biologically relevant phytochemical composition. In fact, all tested extracts and, in particular, CE3 extract consistently displayed strong antioxidant properties, as indicated by five complementary in vitro tests (FRAP, ABTS, CUPRAC, DPPH, and ORAC). In addition, CE1-4 extracts expressed in vitro antimicrobial potential towards all tested organisms except for Pseudomonas aeruginosa. Our results underscore C. cornucopioides’ nutritional, antioxidant, and antimicrobial potential, thus supporting its classification as an edible but under-explored mushroom species with promising applications in both the food and pharmaceutical industries. Full article
(This article belongs to the Special Issue Mushrooms and Edible Fungi as Future Foods)
Show Figures

Figure 1

21 pages, 1871 KB  
Article
Determination of Bioactive Compounds, Antioxidant Capacity, Safety Assessment, and Antimicrobial Effect of Tristerix corymbosus Extracts
by Katia Fernández Moreno, Gabriela Maturana, Sofía Blanco-Haros, Ulises Norambuena-Jopia, Gabriela Valenzuela-Barra, María Carolina Zúñiga-López and Jessica Bravo Garrido
Molecules 2025, 30(23), 4610; https://doi.org/10.3390/molecules30234610 - 30 Nov 2025
Viewed by 361
Abstract
Quitral (Tristerix corymbosus), a Chilean and Argentine parasitic mistletoe, is traditionally used by Mapuche natives to treat stomach ulcers, nervous disorders, and cholesterol reduction, although scientific support is scarce. Methanolic and chloroform extracts from its leaves and stems were prepared. Chemical [...] Read more.
Quitral (Tristerix corymbosus), a Chilean and Argentine parasitic mistletoe, is traditionally used by Mapuche natives to treat stomach ulcers, nervous disorders, and cholesterol reduction, although scientific support is scarce. Methanolic and chloroform extracts from its leaves and stems were prepared. Chemical analysis included antioxidant capacity assays (ORAC-FL and DPPH) and chromatographic determinations. The antimicrobial activity was tested against nine bacteria and two yeast strains. Additionally, cytotoxicity (hemolysis) and toxicity (against Caenorhabditis elegans) assays were performed. The results revealed that the methanolic leaf extracts had the highest ORAC-FL value, with DPPH assays showing solvent-dependent differences. Thirty-one compounds were tentatively identified, of which 61% were phenolic compounds, primarily flavonoids like quercetin and its derivatives. Antimicrobial results showed activity against Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, and Enterococcus faecalis), but not against yeast Candida guillermondii and Candida tropicalis. Methanolic extracts induced dose-dependent erythrocyte hemolysis, while chloroform extracts showed no relevant cytotoxicity. Toxicity against Caenorhabditis elegans was also dose-dependent for methanolic extracts; leaf extract reduced survival at 50 mg mL−1 after 24 h. These findings partially validate some traditional uses, highlight the importance of solvent polarity in extraction and biological effects, and establish quitral as a flavonoid source. Full article
Show Figures

Figure 1

22 pages, 2414 KB  
Article
Unseparated Olive Pruning Waste as a Sustainable Feedstock: DoE-Optimized Extracts with Antioxidant Activity Equivalent to Isolated Leaves
by Elisabetta Tumminelli, Valeria Cavalloro, Daniela Ratto, Giorgio Marrubini, Emanuela Martino, Paola Rossi, Daniela Rossi and Simona Collina
Antioxidants 2025, 14(12), 1441; https://doi.org/10.3390/antiox14121441 - 29 Nov 2025
Viewed by 2166
Abstract
Olive cultivation generates substantial pruning waste, yet current valorization strategies focus solely on leaves despite the logistical challenges of separating them. This study optimized the extraction of bioactive compounds from unseparated pruning waste (branches and leaves) using a D-optimal design of experiments to [...] Read more.
Olive cultivation generates substantial pruning waste, yet current valorization strategies focus solely on leaves despite the logistical challenges of separating them. This study optimized the extraction of bioactive compounds from unseparated pruning waste (branches and leaves) using a D-optimal design of experiments to evaluate solvent composition, temperature, and time effects in thirteen experiments. Optimized conditions were scaled up, and extracts were tested via DPPH, ORAC assays, and ROS inhibition in HaCaT cells. Extracts from unseparated pruning waste demonstrated antioxidant capacity equivalent to isolated leaf extracts, and effectiveness in reducing the oxidative stress by approximately 60% compared to the H2O2 condition. This approach eliminates costly leaf separation while maintaining bioactivity, offering a scalable circular economy solution for olive waste management. The practical implications are substantial: whole pruning waste valorization reduces processing costs and time, decreases agricultural waste by utilizing currently discarded branches, and simplifies supply chains for industries requiring olive-derived antioxidants. Our findings challenge the current paradigm in olive waste biorefining, providing a more economically viable and environmentally sustainable pathway for producing antioxidant-rich extracts suitable for cosmetics, nutraceutical, and pharmaceutical applications. Full article
(This article belongs to the Special Issue Antioxidants from Sustainable Food Sources—2nd Edition)
Show Figures

Graphical abstract

14 pages, 625 KB  
Article
Ultrasound-Assisted Extraction to Recover Antioxidant Compounds: A Comparative Analysis of Green Solvents for the Sustainable Valorization of Olive Leaves
by Nils Leander Huamán-Castilla, Salome Mamani-Pari, Dayana Ramos Allcca, María Fernanda Quispe Angulo, Gregorio Arroyo and Nilton Cesar León-Calvo
Processes 2025, 13(12), 3856; https://doi.org/10.3390/pr13123856 - 28 Nov 2025
Viewed by 492
Abstract
The olive industry produces large quantities of olive leaves, an agro-industrial byproduct without commercial value and with significant environmental disposal challenges. However, olive leaves are a rich source of antioxidant compounds known for their diverse biological properties. This highlights the need for green [...] Read more.
The olive industry produces large quantities of olive leaves, an agro-industrial byproduct without commercial value and with significant environmental disposal challenges. However, olive leaves are a rich source of antioxidant compounds known for their diverse biological properties. This highlights the need for green processes that utilize environmentally friendly solvents. Thus, this research aimed to evaluate the effectiveness of two different solvents: ethanol (at concentrations of 0%, 15%, and 30%) and glycerol (also at 0%, 15%, and 30%), combined with moderate temperatures (50 °C and 70 °C) using ultrasound-assisted extraction (20 kHz and 60% amplitude for 30 min) to recover antioxidant compounds from olive leaves. Our results showed that 30% glycerol at 70 °C was more effective at recovering polyphenols (14.85 ± 0.09 mg GAE g−1 dw) compared to ethanol (12.26 ± 0.13 mg GAE g−1 dw) under the same conditions. Additionally, the antioxidant capacity, measured using DPPH and ORAC assays, yielded higher results with 30% glycerol, showing values of 2.65 ± 0.16 mg mL−1 and 684.65 ± 20.79 µmol TE g−1 dw, respectively. The polyphenol profile quantified different families of polyphenols like phenolic acids, flavanols, flavonols, stilbenes, and secoiridoids. However, oleuropein, a secoiridoid, was the most predominant polyphenol found in the extracts (1122.52 ± 33.72 μg g−1 dw). Interestingly, the use of 30% ethanol at 70 °C reduced the glucose and fructose content by 48% and 84%, respectively. Therefore, glycerol emerges as an efficient green solvent for the extraction of antioxidant compounds. These findings support the valorization of this agricultural residue by recovering its valuable components, contributing to food sustainability and a circular economy. Full article
(This article belongs to the Special Issue Advances in Green Extraction and Separation Processes)
Show Figures

Figure 1

23 pages, 1191 KB  
Article
Comparative Study on Extracts from Traditional Medicinal Plants Echinacea purpurea (L.) Moench and Onopordum acanthium (L.): Antioxidant Activity In Vitro and Anxiolytic Effect In Vivo
by Maria Vlasheva, Mariana Katsarova, Ilin Kandilarov, Hristina Zlatanova-Tenisheva, Petya Gardjeva, Petko Denev, Kiril Atliev, Nora Sadakova, Maria Dimitrova, Ilia Kostadinov and Stela Dimitrova
Pharmaceuticals 2025, 18(12), 1801; https://doi.org/10.3390/ph18121801 - 26 Nov 2025
Viewed by 540
Abstract
Background: Echinacea purpurea (L.) Moench (EP) and Onopordum acanthium (L.) (OA) are promising medicinal plants with diverse biological activities but there is no information on the effects of their combinations. To harness the therapeutic potential of both while minimizing the risk of [...] Read more.
Background: Echinacea purpurea (L.) Moench (EP) and Onopordum acanthium (L.) (OA) are promising medicinal plants with diverse biological activities but there is no information on the effects of their combinations. To harness the therapeutic potential of both while minimizing the risk of adverse effects, we prepared two combinations (CE1 and CE2) of EP and OA in ratios 1:1 and 3:1, respectively. Methods: Oxygen radical absorbance capacity (ORAC), hydroxyl radical absorbance capacity (HORAC), and an electrochemical assay were used to determine the antioxidant activity of the extracts in vitro. The anxiolytic and immunomodulatory properties were studied in rats. Animals were subjected to acute cold stress and anxiety-like behavior was evaluated by the elevated plus maze (EPM) and social interaction test (SIT). Serum IFN-γ, TNF-α and IL-10 levels were measured by ELISA. Results: CE2 demonstrated the highest antioxidant activity (1841.7 μmolTE/g by ORAC, 277.2 GAE/g by HORAC, and 39.6 by electrochemical method). Moreover CE2 produced anxiolytic-like effects—significantly increasing the open arms entries ratio (OAER; p < 0.001), open arms time ratio (OATR; p < 0.01) in the EPM, and prolonging the social interaction time (p < 0.05) versus the stressed control. OA increased OAER (p < 0.01) and OATR (p < 0.001), while EP increased only OAER (p < 0.01). CE1 showed no significant behavioral consequences. CE2 significantly reduced IFN-γ (p < 0.05), and IL-10 levels were elevated in OA and CE2 groups (p < 0.01). No significant changes in TNF-α levels were observed across groups. Conclusions: These findings indicate that CE2 and OA attenuate anxiety-like behavior and modulate the immune response primarily by stimulating IL-10 production. Full article
Show Figures

Graphical abstract

27 pages, 3518 KB  
Article
Correlation of Antioxidant and Antibacterial Activities of the Aqueous Pinus pinaster Aiton Bark Extract Within a Cytocompatible Concentration Range
by Diana Barros, Liliana Grenho, Maria Helena Fernandes, Pedro Sousa Gomes and Élia Fernandes
Antioxidants 2025, 14(11), 1377; https://doi.org/10.3390/antiox14111377 - 19 Nov 2025
Viewed by 742
Abstract
This study explores the antioxidant, antibacterial, and cytocompatibility properties of aqueous Pinus pinaster bark extract (PBE). PBE was prepared using two solvent systems—100% distilled water and 1% DMSO in aqueous solution—at a solid-to-liquid ratio of 1:20 (w/v), following ISO [...] Read more.
This study explores the antioxidant, antibacterial, and cytocompatibility properties of aqueous Pinus pinaster bark extract (PBE). PBE was prepared using two solvent systems—100% distilled water and 1% DMSO in aqueous solution—at a solid-to-liquid ratio of 1:20 (w/v), following ISO guidelines. Extract characterization included yield determination, FTIR analysis, quantification of total phenolic (TPC) and flavonoid (TFC) contents, and assessment of antioxidant activity using four complementary methods: free radical scavenging (DPPH and ABTS), metal ion reduction (FRAP), and a competitive reaction assay (ORAC). The phenolic compound profile was further examined by HPLC-DAD. The results indicated that the two extracts exhibited comparable values across all evaluated parameters when expressed per gram of PBE. The TPC and TFC were approximately 400 mg GAE (gallic acid equivalents)/g PBE and 92 mg CE (catechin equivalents)/g PBE, respectively. Antioxidant capacity values were about 880, 1030, 3210, and 585 mg TE (Trolox equivalents)/g PBE for the DPPH, ABTS, ORAC, and FRAP assays, respectively. Furthermore, in both extracts, the phenolic and flavonoid contents exhibited strong positive correlations with antioxidant activity across all four chemical assays. The 100% aqueous extract was additionally evaluated for antibacterial activity and cytocompatibility with eukaryotic cells. Compared to the control, the extract demonstrated IC50 values of 0.304, 0.678, and 0.845 mg/mL PBE for the inhibition of Staphylococcus aureus, Escherichia coli, and fibroblast cells, respectively. Antioxidant and antibacterial activities showed a positive association within concentration ranges that remained non-cytotoxic to fibroblasts. Overall, these findings indicate that the aqueous PBE retains cytocompatibility across a wide concentration range while maintaining both antioxidant and antibacterial activities, underscoring its potential for biological applications involving direct contact with eukaryotic cells. Full article
(This article belongs to the Special Issue Antioxidant Phytochemicals for Promoting Human Health and Well-Being)
Show Figures

Figure 1

17 pages, 1552 KB  
Article
Ultrasound Impact on Extraction Yield and Properties of Starch and Polyphenols from Canna indica L. Rhizomes
by Vigna Nivetha Chandrasekaran, Charlotte Silvestre, Julien Antih, Prakash Maran Jeganathan, Karine Portet, Gaelle Vesta, Hippolyte Kodja, Thomas Petit, Kaies Souidi, Florence Bichon and Patrick Poucheret
Separations 2025, 12(11), 307; https://doi.org/10.3390/separations12110307 - 6 Nov 2025
Viewed by 506
Abstract
In this present study, the efficiency of ultrasound-assisted extraction (UAE) in increasing the yields of extraction of starch and polyphenols from Canna indica L. (Canna) rhizomes were analyzed, along with its influence on the physiochemical properties of the extracted compounds. Extraction parameters (temperature, [...] Read more.
In this present study, the efficiency of ultrasound-assisted extraction (UAE) in increasing the yields of extraction of starch and polyphenols from Canna indica L. (Canna) rhizomes were analyzed, along with its influence on the physiochemical properties of the extracted compounds. Extraction parameters (temperature, time, and solid-to-liquid ratio) were optimized through Box–Behnken response surface design (BBD). The physiochemical and functional properties of starch and polyphenols were investigated through scanning electron microscopy (SEM), the swelling and solubility index, oil and water absorption index, total polyphenol yield, and antioxidant activity assays (DPPH and ORAC). The starch yield obtained from Canna at the optimum extraction conditions (temperature 40 °C, time 10 min, and solid-to-liquid ratio 1:30 g/mL) was 19.81%. The obtained starch yield was found to be significantly higher than the yield attained through the conventional extraction method without adverse changes in the physicochemical and functional properties. The total polyphenol extraction yield from the Canna rhizome, through UAE, was significantly higher (1061.72 mg GAE/100 g) than that of the conventional method. The antioxidant activity of bioactive compounds was proportional to the attained polyphenol yield. Our results suggest that UAE optimized conditions efficiently and improved Canna starch and polyphenol extraction yields while preserving their functional properties. Full article
(This article belongs to the Special Issue Isolation and Identification of Biologically Active Natural Compounds)
Show Figures

Figure 1

21 pages, 4404 KB  
Article
Exploring the Antidiabetic Properties of Polyalthia longifolia Leaf and Stem Extracts: In Vitro α-Glucosidase and Glycation Inhibition
by Guglielmina Froldi, Marguerite Kamdem Simo, Laura Tomasi, Giulia Tadiotto, Francine Medjiofack Djeujo, Xavier Gabriel Fopokam, Emmanuel Souana, Modeste Lambert Sameza, Pierre Michel Jazet and Fabrice Fekam Boyom
Molecules 2025, 30(21), 4264; https://doi.org/10.3390/molecules30214264 - 31 Oct 2025
Viewed by 700
Abstract
Polyalthia longifolia, a member of the Annonaceae family, is traditionally used for its medicinal properties, including as an antidiabetic remedy, primarily in Asia and sub-Saharan Africa. This study investigated the potential of six P. longifolia extracts in counteracting hyperglycemia and diabetes-related complications. [...] Read more.
Polyalthia longifolia, a member of the Annonaceae family, is traditionally used for its medicinal properties, including as an antidiabetic remedy, primarily in Asia and sub-Saharan Africa. This study investigated the potential of six P. longifolia extracts in counteracting hyperglycemia and diabetes-related complications. Aqueous, ethanol, and methanol extracts from leaves and stems were evaluated for their antihyperglycemic, antiglycation, and antiradical properties using α-glucosidase, BSA, and ORAC assays, respectively. Phytochemical characterization was conducted using TPC and TFC assays, and HPLC analysis identified specific bioactive compounds, including various phenolic compounds (gallic acid, (+)-catechin, epicatechin, caffeic acid, ellagic acid and rosmarinic acid) and flavonoids (luteolin, kaempferol and baicalein). The MTT assay on the human cell line HT-29 assessed the activity of extracts on cell viability, showing slight cytotoxicity. Results demonstrated significant antidiabetic activity of the ethanol and methanol extracts from P. longifolia leaves. This study provides new insights into the potential use of P. longifolia in diabetes mellitus and supports the valorization of traditional medicinal plants. Full article
(This article belongs to the Special Issue Bioactivity of Natural Compounds: From Plants to Humans, 2nd Edition)
Show Figures

Graphical abstract

Back to TopTop