Search Results (777)

Antioxidants regulate oxidative reactions by impeding, delaying, or inhibiting the oxidation of biomolecules. Concerns regarding the toxicity of synthetic antioxidants have driven the search for safer alternatives. In this study, the antioxidant activities of three nontoxic carbon-based nanomaterials—carbon dots from citric acid precursor (CB-Ca), iron-doped carbon dots (CB-Fe) and carbon dots derived from Momordica charantia leaves (CB-Mc)—were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydrogen peroxide (H₂O₂) scavenging, ferric-reducing antioxidant power, and total antioxidant capacity (TAC) assays. Scavenging activity was carried out at varying concentrations, and half-maximal inhibitory concentration (IC₅₀) was calculated using non-linear regression. Reductive ability and TAC were expressed as mg ascorbic acid equivalents/g nanomaterial. CB-Fe exhibited the most potent DPPH scavenging activity (IC₅₀ = 254.2 ± 37.37 µg/mL), surpassing CB-Mc and CB-Ca by 2- to 3-fold. In contrast, CB-Ca had the highest H₂O₂ scavenging (IC₅₀ = 84.2 ± 11.87 µg/mL), while CB-Mc had the highest TAC of 77.95 mg ascorbic acid Eq/g. CB-Fe also displayed superior ferric ion reducing capacity. The study concluded that each carbon dot type exhibits unique antioxidant profiles and may offer some special advantages in nanomedicine and other applications. Full article

Consumers increasingly seek clean-label meat products with improved nutrition and stability. We evaluated a collagen hydrolysate–cranberry mixture (CH-CR) as a functional additive in cooked sausages. Two formulations—control and CH-CR—were assessed for fatty acid profile; lipid and protein oxidation during storage; antioxidant capacity ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and half-maximal inhibitory concentration (IC50); amino acid composition; and instrumental color. Relative to the control, CH-CR produced a more favorable lipid profile: lower saturated fatty acids (SFAs) 23.9% vs. 28.0%, higher monounsaturated fatty acids (MUFAs) 53.2% vs. 49.3%, slightly higher polyunsaturated fatty acids (PUFAs) 23.3% vs. 22.7%, a higher PUFA/SFA ratio of 0.97 vs. 0.81, and a lower omega-6/omega-3 (n-6/n-3) ratio of 13.5 vs. 27.1, driven by higher alpha-linolenic acid (ALA) 1.6% vs. 0.8%, with trans fats <0.1%. Storage studies showed attenuated oxidation in CH-CR: lower peroxide value (PV) at day 10 8.1 ± 0.4 vs. 9.8 ± 0.5 meq/kg and lower thiobarbituric acid-reactive substances (TBARS) at day 6 0.042 ± 0.004 vs. 0.055 ± 0.006 mg MDA/kg and day 10 0.156 ± 0.016 vs. 0.590 ± 0.041 mg MDA/kg); the acid value at day 10 was similar. Antioxidant capacity increased with CH-CR FRAP 30.5 mg gallic acid equivalents (GAE)/g vs. not detected; DPPH inhibition was 29.88% vs. 10.23%; IC50 56.22 vs. 149.51 µg/mL. The amino acid profile reflected collagen incorporation—higher glycine+proline+hydroxyproline 2.37 vs. 1.38 g/100 g and a modest rise in indispensable amino acids (IAAs) 5.72 vs. 5.42 g/100 g, increasing the IAA/total amino acid (TAA) ratio to 0.411 vs. 0.380. CH-CR samples were lighter and retained redness better under light, with comparable overall color stability. Overall, CH-CR is a natural strategy to improve fatty acid quality and oxidative/color stability in sausages. Full article

Consumer demand for organic and nitrite-free meat products has stimulated the search for sustainable alternatives to synthetic curing agents. Conventional nitrites are effective in stabilizing color, inhibiting lipid oxidation, and suppressing pathogens, but their use raises health concerns due to potential nitrosamine formation. This study investigated the application of Portulaca oleracea powder as a multifunctional ingredient to fully replace sodium nitrite in organic cooked frankfurters. Two formulations were produced: control frankfurters with sodium nitrite and experimental frankfurters with purslane powder 1.2%. Physicochemical, oxidative, proteomic, and antioxidant parameters were monitored during refrigerated storage. Purslane incorporation improved the lipid profile by increasing α-linolenic acid and lowering the ω-6/ω-3 ratio, while peroxide, thiobarbituric acid reactive substances (TBARS), and acid values remained significantly lower than in nitrite-containing controls after 10 days. Protein oxidation was also reduced, and SDS-PAGE profiles confirmed that the major structural muscle proteins remained stable, indicating that purslane addition did not disrupt the core proteome. Antioxidant assays showed strong ferric-reducing antioxidant power (FRAP) activity 13.7 mg GAE/g and enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity 22.3%, highlighting purslane’s contribution to oxidative stability. Although redness (a*) was lower than in nitrite controls, overall color stability (L*, b*) remained high. Taken together, purslane enhanced oxidative stability and quality attributes of nitrite-free organic frankfurters; microbiological validation is ongoing and will be reported separately. Full article

In this study, the cosmeceutical potential of a 70% ethanol extract of Rosa lucieae was investigated as a multifunctional bioactive ingredient. The extract was systematically evaluated for its antioxidant, anti-melanogenic, and anti-aging properties, and was comprehensively phytochemically profiled using ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry. The analysis tentatively identified 21 metabolites, including phenolic acids (gallic acid, ellagic acid, and corilagin), flavonoids (catechin, rutin, quercetin, hyperoside, and quercitrin), and glycosidic derivatives (e.g., phlorizin), several of which are well-documented for their skin-protective effects. Quantitative measurements confirmed high polyphenol and flavonoid contents, correlating with strong radical-scavenging and reducing capacities in α-diphenyl-β-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, as well as ferric ion reducing antioxidant power assays. Moreover, the extract inhibited tyrosinase activity and 3,4-dihydroxyphenylalanine oxidation, thereby suppressing melanin biosynthesis. In addition, marked inhibitory effects against collagenase, elastase, and hyaluronidase were observed; these enzymes are critically involved in extracellular matrix degradation and skin aging. Taken together, these results indicate that the biological activities of R. lucieae are supported by a diverse polyphenol- and flavonoid-rich chemical profile, highlighting the potential of this plant as a natural multifunctional ingredient for cosmeceutical, nutraceutical, functional food, and preventive healthcare applications. Full article

Grape pomace (GP), a significant by-product of winemaking, is gaining increasing recognition for its potential as a source of bioactive compounds with antioxidant and cardioprotective properties. This study aimed to characterize the polyphenolic profile, fatty acid composition, and antioxidant activity of 17 GP samples from Transylvanian cultivars. Polyphenolic content was determined using the Folin–Ciocalteu method and high-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC–DAD–ESI MS) analysis. Fatty acid composition was analyzed using gas chromatography with flame ionization detection (GC–FID). Antioxidant capacity was assessed using five methods, which included the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis (3-ethylbenzothialzoline-6-sulfonic acid) (ABTS) radical scavenging, ferric-reducing antioxidant power (FRAP), cupric ion reducing antioxidant capacity (CUPRAC), and reducing power (RP) assays. Additionally, all extracts were analyzed by Fourier transform infrared (FTIR) spectroscopy to identify the presence of functional groups and chemical bonds associated with bioactive compounds. The results showed that Neuburger (NE), Radames (RA), and Regent (RE) cultivars had the highest phenolic concentrations, particularly of catechin, epicatechin, and procyanidin dimers. NE and Feteascǎ Regalǎ (FR) exhibited the greatest radical scavenging and electron transfer activities across multiple antioxidant assays. Rose Blaj (RB) and Astra (AS) displayed the most favorable fatty acid profiles, with high unsaturated-to-saturated fatty acid (UFA/SFA) and hypocholesterolemic-to-hypercholesterolemic fatty acid (H/H) ratios, as well as low atherogenicity (AI) and thrombogenicity (TI) indices, suggesting cardioprotective potential. Additionally, RB and NE cultivars also demonstrated a strong chelation of Cu²⁺ and Fe²⁺ ions, enhancing their antioxidant efficacy by mitigating metal-catalyzed oxidative stress. These findings underscore the potential of GP, particularly from NE, RB, RA, and AS cultivars, the last three of which were homologated in Transylvania at SCDVV Blaj, as valuable sources of health-promoting compounds for use in food, nutraceuticals, and other health-related applications. Full article

Background: Generating oxidative stress in a predictable and controllable way without the risk of causing harm is important for enabling the safe validation of interventions such as dietary polyphenols and ensuring ethical standards in human studies, while also advancing mechanisms involved in the induced oxidative stress. Although, many experimental animal and in vitro models have been developed to conduct oxidative stress-based research, to date, very few reliable human models are available. Objective: This study’s main objective was to establish a standardised exercise model to induce oxidative stress in a repeatable and controllable manner and was tested with dietary polyphenols. Method: We applied a single blinded, randomised, cross-over, placebo-controlled trial with adult (25.95 ± 6.25 years) males (N = 40) where the induction of oxidative stress was achieved by an incremental aerobic exercise activity followed by a maximal anaerobic activity until exhaustion. To assess the model, rooibos polyphenolics was used as one of the interventions, while markers of safety and oxidative stress were measured on various occasions during the trial period. Results: The exercise regime reliably and repeatably induced oxidative stress, evidenced by increased levels of oxidative damage markers, i.e., oxidised glutathione (p = 0.003), malondialdehyde (p = 0.004), and a Comet assay tail moment (p < 0.05), while unconjugated bilirubin (p = 0.002) and the ferric reducing antioxidant potential (p < 0.001) increased over the study period, in the male study participants, irrespective of the oral intervention. Conclusions: This model showed an exercise regime that could be adapted to induce oxidative stress in a reliable and repeatable fashion without risk of causing harm. This study also demonstrated that a dietary polyphenolic intervention with rooibos did not complicate the onset of oxidative stress. Full article

Objectives: Our study aimed to examine the antioxidative and anti-inflammatory potential of the lyophilized aqueous leaf extract of Vitis vinifera. Methods: The antioxidant capacity of the extract was evaluated using the DPPH and FRAP assays. The in vivo phase of the study included 40 male Wistar albino rats. One half of the animals were used to induce the carrageenan model of acute inflammation, while the other half were used for examination of the extract effect on the redox state. Rats from the experimental group drank tap water containing 150 mg/kg Vitis vinifera extract for 14 days, while control animals received saline at the same volume. The molecular docking studies of polyphenols present in the leaf extract were conducted in AutoDock Vina. Results: In vitro assessment of the antioxidative capacity of the applied extract revealed significant free radical scavenging activity (IC₅₀ value 11.63 µg/mL), along with a pronounced ferric reducing ability (0.143 at 700 nm). Moreover, animal treatment with the extract led to significant paw edema inhibition (30.34%, 35.06%, and 41.54% in the second, third, and fourth hours, respectively) and to pro-oxidative marker reduction. Additionally, Vitis vinifera extract significantly increased catalase activity and glutathione levels. The in silico results showed that rutin binds to cyclooxygenase 1 (−8.2 kcal/mol) and 2 (−8.3 kcal/mol), as well as to antioxidant enzymes (catalase: −8.6 kcal/mol, SOD: −7.4 kcal/mol), indicating its key role in mediating the biological activity of the tested extract. Conclusions: This study highlights the significant antioxidant and anti-inflammatory potential of V. vinifera lyophilized aqueous leaf extract from the Serbian market, supported by both in vivo and in silico analyses. Full article

Heme enzymes that bind and reduce O₂ are susceptible to poisoning by NO. The high reactivity and affinity of NO for ferrous heme produces stable ferrous-NO complexes, which in theory should preclude O₂ binding and turnover. However, NO inhibition is often competitive with respect to O₂ and rapidly reversible, thus providing cellular and organismal survival advantages. This kinetic paradox has prompted a search for mechanisms for reversal and hence resistance. Here, I critically review proposed resistance mechanisms for NO dioxygenase (NOD) and cytochrome c oxidase (CcO), which substantiate reduction or oxidation of the tightly bound NO but nevertheless fail to provide kinetically viable solutions. A ferrous heme intermediate is clearly not available during rapid steady-state turnover. Reversible inhibition can be attributed to NO competing with O₂ in transient low-affinity interactions with either the ferric heme in NOD or the ferric heme-cupric center in CcO. Toward resolution, I review the underlying principles and evidence for kinetic control of ferric heme reduction via an O₂-triggered ferric heme spin crossover and an electronically-forced motion of the heme and structurally-linked protein side chains that elicit electron transfer and activate O₂ in the flavohemoglobin-type NOD. For CcO, kinetics, structures, and density functional theory point to the existence of an analogous O₂ and reduced oxygen intermediate-controlled electron-transfer gate with a linked proton pump function. A catalytic cycle and mechanism for CcO is finally at hand that links each of the four O₂-reducing electrons to each of the four pumped protons in time and space. A novel proton-conducting tunnel and channel, electron path, and pump mechanism, most notably first hypothesized by Mårten Wikström in 1977 and pursued since, are laid out for further scrutiny. In both models, low-energy spin-orbit couplings or ‘spintronic’ interactions with O₂ and NO or copper trigger the electronic motions within heme that activate electron transfer to O₂, and the exergonic reactions of transient reactive oxygen intermediates ultimately drive all enzyme, electron, and proton motions. Full article

Foliar application with iron is a promising strategy for improving nitrogen nutrition and productivity in horticultural crops. In this study, the effect of the foliar application of iron oxide nanoparticles (IONPs) compared to conventional iron sources on physiological, biochemical, and productive parameters of Spinacia oleracea L. was evaluated. Plants were treated with different concentrations (0, 25, 50, and 100 ppm) of IONPs, ferric sulfate (FS), and iron chelate (IC). Biomass, yield, nitrate reductase enzyme activity, soluble protein and amino acid contents, SPAD values, and photosynthetic pigments were analyzed. The results showed that IONPs, particularly at 50–100 ppm, promoted significant increases in biomass (50% more than the control), yield (47%), and nitrate reductase enzyme activity (NR_max) (246%) compared to the control (0 ppm) without negatively affecting pigment levels or leaf physiological condition. Likewise, increases in soluble protein and photosynthetic pigment levels were observed, reflecting improved nitrogen assimilation and photosynthetic efficiency. These findings suggest that IONPs represent an efficient and safe alternative to traditional Fe sources, contributing to the development of sustainable agricultural systems aimed at improving the nutritional value and productivity of leafy crops. Full article

Objective: The study investigates the dietary effects of Moringa oleifera leaf powder on obesity, blood biochemical parameters, and organ health in hyperlipidemic zebrafish (Danio rerio). Methodology: Adult hyperlipidemic zebrafish (n = 56/group) were fed for 12 weeks either with a high-cholesterol diet (HCD, 4% w/w) or HCD supplemented with 0.5% (w/w) M. oleifera leaf powder (0.5% MO) or HCD with 1.0% (w/w) M. oleifera leaf powder (1.0% MO). At different time points (0 to 12 weeks), the survivability and body weight (BW) of zebrafish were measured, while various biochemical and histological evaluations were performed after 12 weeks of feeding the respective diets. Additionally, an in silico approach was used to assess the binding interactions of MO phytoconstituents with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Results: Following 12-week supplementation, higher zebrafish survivability was observed in the MO-supplemented groups compared to the survivability of the HCD group. Relative to the initial BW, only 4% BW enhancement was observed post 12 weeks of dietary intake of 1.0% MO, in contrast to 27% BW gain in the HCD group. MO supplementation at both (0.5% and 1.0%) effectively mitigates the HCD-induced dyslipidemia and significantly minimizes the atherogenic coefficient and atherogenic index. Similarly, MO reduces elevated blood glucose levels, the ALT/AST ratio, and augments ferric ion reduction (FRA) and paraoxonase (PON) activity in a dose-dependent manner. Likewise, MO (particularly at 1.0%) effectively restrained HCD-induced steatosis, hepatic interleukin (IL)-6 production, and protected the kidneys, testes, and ovaries from oxidative stress and cellular senescence. The in silico findings underscore that the six phytoconstituents (chlorogenic acid, isoquercetin, kaempferol 3-O-rutinoside, astragalin, apigetrin, and myricetin) of MO exhibited a strong interaction with HMG-CoA reductase active and binding site residues via hydrogen and hydrophobic interactions. Conclusions: The findings demonstrated an antioxidant, anti-inflammatory, and hypoglycemic effect of MO, guiding the events to prevent HCD-induced metabolic stress and safeguard vital organs. Full article

The efficient purification of Pb(II)-containing wastewater is essential for safeguarding public health and maintaining the aquatic environment. In this study, novel hydrous ferric oxide (HFO) nanoparticle-embedded poly(vinylidene fluoride) (PVDF) composite adsorption membranes were developed through a simple blending method for efficient Pb(II) removal. This composite membrane (denoted as HFO-PVDF) combines the excellent selectivity of HFO nanoparticles for Pb(II) with the membrane’s advantage of easy scalability. The optimized HFO-PVDF_(1.5) membrane achieved adsorption equilibrium within 20 h and exhibited excellent adsorption capacity. Moreover, adsorption capacity markedly enhanced with increasing temperature, confirming the endothermic nature of the process. The developed HFO-PVDF membranes demonstrate significant potential for real-world wastewater treatment applications, exhibiting exceptional selectivity for Pb(II) in complex ionic matrices and could be effectively regenerated via a relatively straightforward process. Furthermore, filtration and dynamic regeneration tests demonstrated that at an initial Pb(II) concentration of 5 mg/L, the membrane operated continuously for 10–13 h before regeneration, treating up to 200 L/m² of wastewater before breakthrough, highlighting potential for cost-effective industrial wastewater treatment. This study not only demonstrates the high efficiency of the HFO-PVDF membrane for heavy metal ion removal but also provides a theoretical foundation and technical support for its practical application in water treatment. Full article

Synergizing iron nutrition and rice quality is essential for the development of integrated high-quality rice. In this study, a two-year field experiment was conducted to investigate the influence of ferric oxide nanoparticles (Fe₂O₃ NPs) foliar spraying on rice yield, quality, and iron bioavailability, with spraying water as the control (CK). Our results demonstrate that Fe₂O₃ NPs foliar application increase grain yield by 1.22–3.97% for the improved filled grain rate and 1000-grain weight, essentially attributed to improved net photosynthetic rate and SPAD value after heading. In addition, Fe₂O₃ NPs application achieved a higher rate of brown rice, polished rice, and head rice, and decreased chalkiness grain rate and chalkiness degree. Rice taste value treated with Fe₂O₃ NPs application was notably increased by 2.75–9.43% compared to CK, respectively, which is also reflected in the superior breakdown value (5.85–15.18%) and inferior setback value (12.38–28.19%). Meanwhile, foliar spraying Fe₂O₃ NPs significantly increased the iron content (16.97–58.74% and 26.48–94.01%) and proportion (2.90–5.35% and 13.10–26.44%), while they decreased the molar ratio of phytate to Fe (19.70–33.67% and 31.55–45.77%) in brown rice and polished rice, increasing iron bioavailability. Our findings indicate that Fe₂O₃ NPs can be effectively applied as a foliar fertilizer to enhance rice yield, quality, and iron nutrition. Full article

In this work, eco-friendly ceric ammonium nitrate (CAN) and ferric chloride hexahydrate catalysts in ethanol/acetonitrile systems were used to efficiently synthesize novel dihydropyrimidinone (-thione) derivatives via the Biginelli reaction. The obtained compounds with phenolic fragments at the C4 position demonstrated enhanced antioxidant properties. Significant structure–activity relationships were indicated by three complementary assays (PFRAP, ABTS, and AAPH-induced DNA oxidation): oxo-derivatives demonstrated superior ferric ion reduction (PFRAP), while thio-substituted analogs consistently outperformed their carbonyl counterparts in radical scavenging. Remarkably, all compounds surpassed the reference antioxidant BHT, demonstrating the potential of synthesized dihydropyrimidine structures as multifunctional antioxidants for therapeutic applications. The study also shows the relationship between the catalyst–solvent system and its effect on product yields, using ceric ammonium nitrate and ferric chloride hexahydrate. Full article

The efficacy of Lagerstroemia speciosa (banaba) leaf extract (BLE), policosanol (POL), and their combination (BLE+POL) was evaluated in zebrafish (Danio rerio) against high cholesterol (HC)- and galactose (HG)-induced metabolic stress and organ toxicity. After 12 weeks of dietary intervention, BLE+POL significantly reduced HC+HG-augmented weight gain and improved hepatic and nephromegaly. Compared with BLE or POL alone, the combined intake of BLE+POL more effectively alleviated dyslipidemia and blood glucose levels. Likewise, BLE+POL effectively reduced blood malondialdehyde (MDA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels and boosted plasma sulfhydryl content, ferric ion reduction ability (FRA), and paraoxonase (PON) activity. Histological outcomes suggest that BLE+POL has higher efficacy than either BLE or POL in mitigating HC+HG-induced fatty liver changes, hepatic inflammation, kidney senescence, and reactive oxygen species (ROS) production. Consistently, BLE+POL augmented the spermatozoa counts in the testes, enhanced mature vitellogenic oocytes in ovaries, and protected them from the HC+HG-induced oxidative stress. Compared with either BLE or POL, a combined intake of BLE+POL displayed a superior effect in inhibiting the apoptosis and accumulation of lipid peroxidation species 4-hyrdoxynonenal (4-HNE) in the brain. A combined intake of BLE+POL exhibited a pronounced impact than the BLE and POL alone and can be utilized as an effective formulation to counteract the HC+HG-induced events. Full article

Abiotic processes have ramifications in wastewater treatment, in situ degradation of organic matter, and cycling of nutrients in wetland ecosystems. Experiments were conducted to investigate abiotic oxidation of organic compounds (lactate) as a function of electron acceptors (ferric citrate and hydrous ferric oxide (HFO), media composition, and pH under anaerobic conditions, using sodium bicarbonate as the buffering agent. Dissolved inorganic carbon (DIC) was used as a proxy for the oxidation of substrates. HFO media generated more DIC compared to ferric citrate containing media. Light and pH had major roles in the oxidation of lactate in the presence of ferric iron. Under dark conditions in the presence or absence of Fe(III), the DIC produced was low in all pH conditions. Inhibition of DIC production was also observed upon photo exposure when Fe (III) was absent. Isotopically, the system showed initial mixing between the bicarbonate and the carbon dioxide produced from oxidation later being dominated by carbon isotope value of lactate used. These redox conditions align with previous studies suggesting cleavage of organic compounds by hydroxyl radicals. The slower redox processes observed here, compared to previous studies, could be due to the scavenging effect of chloride ion on the hydroxyl radical. Full article