Search Results (201)

In this study, water residue obtained from Salvia desoleana Atzei et Picci steam distillation was evaluated for its antioxidant activity in vitro using different experimental models. In particular, the study evaluated the antiradical and antioxidant activity of Salvia desoleana extracts using CUPRAC, FRAP, DPPH^•, and ABTS^•+ assays; and tested ROS scavenging activity in Caco-2 cell cultures. Phenolic compounds were identified by (HR) LC-ESI-QTOF MS/MS and quantified with HPLC-PDA. Furthermore, Keap1-Nrf2, iNOS, and NOX enzymes involved in oxidative stress and antioxidant defences were the targets of molecular docking on key polyphenols. Hydroxycinnamic acids and flavonoids are the most important classes of compounds detected in the extracts. Among these compounds, the most significant was rosmarinic acid, followed by caffeic acid, luteolin glucuronide, and methyl rosmarinate. Although all extracts have shown encouraging results, the ethanolic extract solubilised with water (SEtOHA) was the one with the highest hydroxycinnamic acid content and total phenol content (518.64 ± 5.82 mg/g dw and 106.02 ± 6.02 mg GAE/g dw), as well as the highest antioxidant and antiradical activity. The extracts have shown anti-inflammatory activity by inhibiting NO release in LPS-stimulated Caco-2 cells. Finally, the in silico evaluation against the three selected enzymes showed interesting results for both numerical affinity ranking and predicted ligand binding models. The outcome of this study suggests this by-product as a possible ally in counteracting oxidative stress, as established by its favourable antioxidant compound profile, thus suggesting an interesting future application as a nutraceutical. Full article

This study explores the antioxidant activity of green tea (Camellia sinensis, GT) and peppermint (Mentha × piperita, PM) infusions, individually and in combination, focusing on how preparation methods affect their efficacy. Antiradical and intracellular antioxidant activity was assessed using DPPH, ABTS, and DCF assays, alongside interaction analysis via combination index (CI) and dose reduction index (DRI). HPLC analysis determined the polyphenolic profiles of GT and PM. GT showed the strongest antioxidant activity, with the lowest IC₅₀ values (4.81 µg/mL in DPPH, 2.70 µg/mL in ABTS, 3.71 µg/mL in DCF), indicating potent radical-scavenging potential. PM exhibited moderate antiradical capacity but similar intracellular activity (IC₅₀ = 3.80 µg/mL). Co-maceration followed by lyophilization of GT:PM extracts led to nearly additive interactions (CI~1.0) and allowed significant dose reduction (DRI up to 4.44). In contrast, post-mixed extracts showed assay-dependent effects, including antagonism in intracellular ROS inhibition (CI = 1.83). Equimolar mixtures of model polyphenols: EGCG, quercetin, and rosmarinic acid demonstrated enhanced effects, with the strongest synergy in ternary mixtures (CI = 0.67–0.86), potentially achievable in GT:PM combinations. These findings highlight that extract preparation critically influences antioxidant efficacy, supporting co-maceration as a promising strategy for developing effective functional formulations based on plant extract combinations. Full article

Potato peel represents a major by-product of the potato-processing industry and a promising source of bioactive compounds with potential health benefits. This study investigates the biochemical and nutritional composition of peels from five purple and two red potato cultivars, with particular attention to their phytochemical profiles and antioxidant properties. Total phenolic content, carbohydrates, proteins, and lipids were quantified using UV–visible spectrophotometry. The phytochemical composition was further characterized via High-Performance Liquid Chromatography coupled with a Diode-Array Detector (HPLC-DAD). Antioxidant and radical-scavenging capacities of the extracts were assessed through Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Significant variability was observed across cultivars for all measured parameters. While all samples were rich in carbohydrates and proteins, they shared a common phenolic profile dominated by chlorogenic acid and its derivatives, as well as caffeic acid. Anthocyanin composition, however, was highly cultivar-specific. Notably, all extracts demonstrated strong antioxidant and antiradical activities, in agreement with their high total phenolic content. These findings highlight the potential of red and purple potato peels as valuable sources of functional ingredients for food and nutraceutical applications. Full article

Upcycling horticulture residues offers a sustainable solution to reduce environmental impact, maximize resource utilization, mitigate climate change, and contribute to the circular economy. We synthesized and characterized 14 natural deep eutectic solvents (NADESs) and applied them to upcycle horticulture residues, offering an innovative valorization approach. Using an initial many-factors-at-a-time (MFAT) screening followed by a rotatable central composite response surface methodology (RCCRSM) for optimization, quadratic models fitted the response data for all the synthesized NADESs given: TPC (R² = 0.984, p < 0.0001), TFC (R² = 0.9999, p < 0.0001), AA-CUPRAC (R² = 0.918, p < 0.0001), FRAP (R² = 1.000, p < 0001), and DPPH (R² = 0.9992, p < 0.0001). An ultrasound temperature of 45 °C, extraction time of 5 min, solvent volume of 25 mL, and solvent concentration of 90% (v/v) were considered the optimal conditions for achieving maximum desirability (0.9936) for TPC yield. For TFC and CUPRAC, the optimal conditions were 30 °C, 5 min, 25 mL, and 90% (v/v), with maximum desirability values of 0.9003 and 1.00, respectively. The maximum desirability for FRAP (0.9605) was achieved under conditions of 45 °C, 25 min, 25 mL, and 50%, while DPPH had a maximum desirability of 0.9313, with 50 °C, 15 min, 15 mL, and 70% (v/v) as the optimized conditions. Full article

Bromophenols (BPs), particularly those derived from marine sources, are known for their potent radical scavenging activity, effectively neutralizing reactive oxygen species (ROS). However, their exact mechanism of action remains largely unexplored, limiting our understanding of their potential as natural antioxidants. In this study, the antiradical mechanisms of two BP derivatives (1 and 2), previously isolated from the marine red alga Polysiphonia urceolata, were systematically investigated using thermodynamic and kinetic calculations. Both compounds demonstrated potent hydroperoxyl radical (HOO^•) scavenging activity in polar and lipid environments, with rate constants surpassing those of the well-known antioxidant standards Trolox and BHT. In lipid media, BP 2 exhibited approximately 600-fold greater activity than BP 1, with rate constants of 9.75 × 10⁵ and 1.64 × 10³ M⁻¹ s⁻¹, respectively. In contrast, both BPs showed comparable activity in aqueous media, with rate constants of 3.46 × 10⁸ and 9.67 × 10⁸ M⁻¹ s⁻¹ for 1 and 2, respectively. Mechanistic analysis revealed that formal hydrogen atom transfer (f-HAT) is the predominant pathway for radical scavenging in both lipid and polar environments. These findings provide critical insights into the antiradical mechanisms of natural BPs and underscore the potential of BP 1 and BP 2 as highly effective hydroperoxyl radical scavengers under physiological conditions. Full article

Blood orange peel flour (BO-pf)—a by-product of the citrus supply chain—still contains bioactive molecules with known health benefits, such as antiradical scavenging activity or an antiproliferative activity regarding tumors. In vitro studies have demonstrated that orange polyphenols showed potential involvement in necroptosis. In addition to previous research, we tested BO-pf on two colorectal cancer cell lines. Using HT29 and Caco2 cells, our experiments confirmed the regulation of inflammasome expression. They provided valuable insights into how BO-pf influences the cancer cell features (i.e., viability, proliferation, and pro- and anti-inflammatory activity). Notably, BO-pf extract is a rich source of polyphenolic compounds with antioxidant properties. Western blot and real-time PCR analyses showed that treatment with BO-pf extract demonstrated beneficial effects by influencing the expression of both pro-inflammatory cytokines (IL-1β, IL-6) through the modulation of the TLR4/NF-kB/NLRP3 inflammasome signaling. Moreover, the results of this study demonstrate that BO-pf extracts can enhance the expression of anti-inflammatory cytokines, such as IL-10 and TGFβ, suggesting that BO-pf extracts may represent a promising functional ingredient to counteract the intestinal inflammatory responses involved in IBD. Full article

The irradiation by gamma-rays is a widely used technique for disinfection in the pharmaceutical and cosmetic industries. In view of growing concerns by consumers about this technique, further investigation of the effects of radiation is required. In this work electron paramagnetic resonance (EPR) spectroscopy was applied to study the free radicals in irradiated horse chestnut (Aesculus hippocastanum L.) seeds and to evaluate the free radical scavenging activity (FRSA) using the stable DPPH radical. In order to evaluate the antiradical potential, a spectrophotometric study was also used. The identification and quantification of some individual polyphenol compounds before and after irradiation by 1, 5, and 10 kGy gamma rays of peeled and shell seeds were obtained by high performance liquid chromatography (HPLC). The EPR spectrum recorded on irradiated horse chestnut is a typical signal for irradiated cellulose-contained substances. The results show that the signal is stable, and it can be found in the samples irradiated with a dose of 1 kGy, 45 days after treatment, whereas for samples irradiated by 5 and 10 kGy, it is even found 250 days later. The study showed that free radical scavenging activity increases in shell seeds, while it decreases in peeled seed extracts after irradiation depending on the dosage, which corresponds to the total phenolic content. Shell seed extracts have significantly stronger antiradical activity than that of peeled seeds. Regarding the HPLC analysis, some polyphenolics were degraded and others were formed as a result of irradiation. The irradiation by 5 kGy dosage has a most significant positive effect on the antioxidant potential of shell chestnut seeds. Full article

Background/Objectives: Recently, there has been great interest in metallopharmaceuticals as potential anticancer agents. In this context, presented studies aim to synthesize and evaluate of two copper(II) complexes derived from phthalazine- and imidazoline-based ligands against on three human cancer cell lines: cervix epithelial cell line (HeLa), breast epithelial-like adenocarcinoma (MCF-7), and triple–negative breast epithelial cancer cell line (MDA-MB-231), as well as non-tumorigenic cell line (HDFa). Moreover their antimicrobial, and antioxidant properties were assessed. Methods: The synthetized compounds—both free ligands L1, L2, L3 and copper(II) complexes C1 and C2—were characterized by elemental analysis, infrared spectroscopy. Additionally, a single-crystal X-ray diffraction studies we performed for free ligand L3 and its copper(II) complex C2. The stability of Cu(II)-complexes C1 and C2 was evaluated by UV-Vis spectroscopy. The cytotoxic potency of free ligands and their copper(II) complexes was estimated on HeLa, MCF-7, MDA-MB-231, as well as non-cancerous HDFa by use of an MTT assay after 48 h of incubation. Moreover, the antimicrobial activity of ligands L1 and L3 and their copper(II) complexes C1 and C2 was evaluated using reference strains of the following bacteria and yeasts: Staphylococcus aureus, Escherichia coli, and Candida albicans. The free radical scavenging properties of free ligands L1, L3 and the corresponding copper(II) complexes C1, C2 was tested with two colorimetric methods—ABTS, DPPH, and reduction ability assay (FRAP). Additionally, the ADME webtool was used to assess the drug-likeness of the synthesized compounds, as well as their physicochemical and pharmacokinetic properties. Results: Copper(II) complex C2 exhibited antitumor properties towards MDA-MB-231 compared with Cisplatin (cancer cell viability rate of 23.6% vs. 22.5%). At a concentration of 200 μg/mL, complexes C1 and C2 were less cytotoxic than the reference Cisplatin against a normal, non-cancerous skin fibroblast cell line (HDFa). According to in vitro tests, C2 reduced the viability of HeLa, MCF-7, and MDA-MB-231 cells by about 57.5–81.2%. It was evident that all compounds were devoid of antibacterial or antifungal activity. In vitro assays revealed that a moderate antiradical effect was observed for free ligand L1 containing phthalazin-1(2H)-imine in the ABTS radical scavenging assay (IC₅₀ = 23.63 µg/mL). Conclusions: The anticancer studies revealed that the most potent compound was copper(II) complex C2 bearing a phthalazin-1(2H)-one scaffold. None of the tested compounds showed antimicrobial or antifungal activity. This feature seems to be beneficial in terms of their potential uses as anticancer agents in the future. In vitro antiradical assays revealed that a moderate antioxidant effect was observed only for free ligand L1 containing phthalazin-1(2H)-imine. Full article

Herein, nine square planar trans-arylbis(triphenylphosphine)palladium halides (PdX(PPh₃)₂Ar) were synthesized and fully characterized. The molecular structure of two complexes (1 and 2) have been determined by both X-ray diffraction and described thanks to Hirshfeld surface analysis. Investigation of the antioxidant activities showed that most of the complexes exhibit a strong dose-dependent radical scavenging activity towards DPPH radical as well as in the ABTS radical scavenging test. Complexes 1 [PdI(PPh₃)₂(4-MeOC₆H₄)] and 3 [PdCl(PPh₃)₂(4-MeOC₆H₄)] showed the highest activity in the DPPH assay with EC₅₀ values of 1.14 ± 0.90 and 1.9 ± 0.87 µM, respectively. In contrast, for the ABTS assay, quercetin (5.56 ± 0.97 µM) was slightly more efficient than the three complexes 1 (5.78 ± 0.98 µM), 2 (7.01 ± 0.98 µM), and 3 (11.12 ± 0.94 µM). The use of kinetic studies as a powerful parameter shows that complexes 1, 2, and 3 displayed the best antioxidant efficiency. The antioxidant effect of the nine palladium complexes has been also evaluated on the enzyme-catalyzed oxidation of the L012 probe (using HRP/H₂O₂) by using a chemiluminescence technique. As with the last model, complexes 1, 2, and 3 showed the best activity, with EC50 values of 3.56 ± 1.87, 148 0.71, and 5.8 ± 2.60 µM, respectively. Interestingly, those complexes (1, 2, and 3) even exhibited a higher dose-dependent activity than the quercetin (7.06 ± 2.56 µM) used as a standard. Taken together, the combined results reveal that the antiradical and enzyme (HRP) inhibitory activity of complexes decrease following the ligand order of p-OMePh > p-OAcPh >> Ph. Full article

Hazelnut processing generates a variety of by-products, including skins, shells, and defatted (DFT) flour, which contain valuable bioactive compounds. These by-products are rich in polyphenols, fibers, and other molecules that are suitable for incorporation into nutraceutical and cosmetic products. The efficiency of three natural deep eutectic solvents (NADES), such as betaine/sorbitol/water (BS), fructose/lactic acid/water (FL), and fructose/glycerol/water (FG) was compared with a control (C) extractant (ethanol/water). These NADES were combined with two extraction techniques: a conventional method involving heat and magnetic stirring, and ultra-sound-assisted extraction (US). The free radical scavenging capacity (FRC), total phenolic content (TPC), and the polyphenolic profile (HPLC) were evaluated. BS NADES exhibited superior efficiency for the extraction from the skin and shell, while FL was optimal for defatted flour. Although the skin is the least abundant hazelnut processing by-product, it exhibited the highest polyphenol content and antiradical activity, indicating potential for cosmetic applications. The suitability of DFT flour, skin, and the residual panel of extracts for thermochemical and biochemical conversion processes was investigated. Some of the materials were found to be conducive to thermochemical conversion, while others were suitable for anaerobic digestion. Full article

Skin aging is accelerated by inflammation processes generated by oxidative stress and external factors such as UV radiation. Plants belonging to the genus Kalanchoe that are rich sources of antioxidants could potentially strengthen the skin barrier if used as ingredients in cosmetic formulations. However, their use is limited due to the contents of bufadienolides, known cardiotoxins. This study aimed to establish a semi-quantitative profile of bufadienolides in the juices of K. blossfeldiana, K. daigremontiana, and K. pinnata using UHPLC combined with charged aerosol detection (CAD) and high-resolution mass spectrometry (HR-MS). Additionally, the study determined the ability of bufadienolides to penetrate the skin barrier using the Bronaugh Diffusion Cell Apparatus and Strat-M membrane. The study also assessed the ferric and molybdenum-reducing powers, as well as the radical scavenging capabilities of these plants juices using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) methods. The in vitro antihyaluronidase and antityrosinase activities and sun protection factor (SPF) were evaluated spectrophotometrically, indicating moderate capability to inhibit the skin enzymes, but low SPF protection for all analyzed juices. The semi-qualitative analysis demonstrated the presence of bufadienolides occurring in two juices from K. daigremontiana and K. pinnata, with the highest contents of 1,3,5-bersaldegenin-orthoacetate, bryophyllin-A/bryotoxin-C, bersaldegenin-acetate/bryophyllin-C, and diagremontianin. After passing through the skin model, no bufadienolide compounds were present in the subcutaneous filtrate. Antiradical and reduction assays revealed the antioxidant potential of K. blossfeldiana and K. pinnata. These results indicate that Kalanchoe juices have antiaging potential and appear safe for dermal applications. Full article

The growing interest in renewable and natural antioxidants has positioned lignin as one of the most significant bioresources for sustainable applications. Lignin, a polyphenolic biomolecule and a major by-product of chemical pulping and biorefinery processes, is abundant and widely accessible. Recent advancements in lignin modification, fractionation, and innovative biorefinery techniques have expanded its potential applications, particularly as a natural antioxidant. This review explores the underlying chemistry of lignin’s antioxidant activities, from model compounds to technical lignin resources, and examines its current applications. Additionally, we highlight the influence of lignin’s chemical structure and functional groups on its antioxidant efficacy, emphasizing its promising role in the development of practical and sustainable solutions. Full article

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections of the urinary tract, upper respiratory tract, gastrointestinal tract, central nervous system, etc. It is possible to develop bacteremia and sepsis in immunocompromised patients. A major problem in treatment is the development of antibiotic resistance. Therefore, new preparations of natural origin are sought, such as plant extracts, which are phytocomplexes and to which it is practically impossible to develop resistance. Geum urbanum L. (Rosacea) is a perennial herb known for many biological properties. This study aimed to investigate the redox-modulating capacity and effect of ethyl acetate (EtOAc) extracts from roots (EtOAcR) and aerial parts (EtOAcAP) of the Bulgarian plant on the phenotype inhibition of the P. aeruginosa Las/RhI quorum sensing (QS) system, which primarily determines drug resistance in pathogenic bacteria, including biofilm formation, motility, and pigment production. We performed QS assays to account for the effects of the two EtOAc extracts. At sub-minimal inhibitory concentrations (sub-MICs) ranging from 1.56 to 6.25 mg/mL, the biofilm formation was inhibited 85% and 84% by EtOAcR and 62% and 39% by EtOAcAP extracts, respectively. At the same sub-MICs, the pyocyanin synthesis was inhibited by 17–27% after treatment with EtOAcAP and 26–30% with EtOAcR extracts. The motility was fully inhibited at 3.12 mg/mL and 6.25 mg/mL (sub-MICs). We investigated the inhibitory potential of lasI, lasR, rhiI, and rhiR gene expression in biofilm and pyocyanin probes with the PCR method. Interestingly, the genes were inhibited by two extracts at 3.12 mg/mL and 6.25 mg/mL. Antiradical studies, assessed by DPPH, CUPRAC, and ABTS radical scavenging methods and superoxide anion inhibition showed that EtOAcAP extract has effective antioxidant capacity. These results could help in the development of new phytocomplexes that could be applied as biocontrol agents to inhibit the phenotype of the P. aeruginosa QS system and other antibiotic-resistant pathogens. Full article

Beneficial activities of phenolic compounds in the gastrointestinal tract, such as antiradical activity, are affected by the food matrix. The aim of this study was to investigate the influence of one constituent of the food matrix (dietary fiber β-glucan) on the release and antiradical activity of phenolic compounds from apples in gastrointestinal digestion. Simulated digestion in vitro was conducted on whole apples without or with added β-glucan. Antiradical activity was determined with the DPPH method. The total amount of released phenolic compounds in the stomach (563 mg kg⁻¹ fresh weight (fw), 85%) decreased in the intestine (314 mg kg⁻¹ fw, 47%) (p < 0.05). The presence of β-glucan decreased the release of phenolic compounds to 80 and 74% in the stomach and to 44 and 40% in the small intestine when there were lower and higher β-glucan amounts, respectively. A statistical analysis showed differences between release in digestion without or with β-glucan. B-glucan adsorbed up to 24 (stomach) and 32 mg g⁻¹ (small intestine) of the phenolics. Phenolic compounds scavenged more free radicals in the small intestine than in the stomach, and β-glucan decreased this activity, but not significantly. The interaction between β-glucan and phenolic compounds should be considered when explaining the beneficial effects in the stomach and small intestine. Full article

Fruits are essential components of the human diet, valued for their diverse bioactive compounds with potential health-promoting properties. This study focuses on three cold-hardy Actinidia species, namely A. arguta, A. kolomikta, and A. polygama, examining their polyphenolic content, antioxidant/antiradical activities, scavenging capacity and effects on intestinal cell viability (Caco-2 and HT29-MTX). A comprehensive profile of their phenolic compounds was identified, in descending order of total polyphenol content: A. kolomikta > A. arguta > A. polygama. Across species, 16 phenolic acids, 2 flavanols, 2 flavanones, 11 flavonols, and 3 flavones were quantified, with caffeine as a prominent compound. A. kolomikta achieved the highest antioxidant activity, with ‘Vitakola’ cultivar showing almost double the antioxidant activity compared to ‘Tallinn’ and ‘Pozdni’. By contrast, A. arguta ‘Geneva’ and A. polygama ‘Pomarancheva’ exhibited significantly lower activity in both FRAP and DPPH assays. Notably, A. kolomikta cultivars showed distinct radical-scavenging capacities, particularly for superoxide, wherein ‘Tallinn’ and ‘Pozdni’ achieved the highest values. Cell viability tests on Caco-2 and HT29-MTX cells revealed a dose-dependent reduction in viability, notably stronger in Caco-2 cells. Overall, this study underscores the therapeutic potential of Actinidia species. Full article