Search Results (653)

Introduction: Oxidative stress is a key factor in the pathogenesis of many chronic diseases, especially in postmenopausal women. Xylitol, a sugar alcohol with potential antioxidant properties, may affect oxidative balance when used as a sugar substitute. Aim: This pilot study aimed to assess the effect of replacing sucrose with xylitol on serum antioxidant capacity in postmenopausal women. Methods: This study included 34 women aged 50 to 65 years who successively consumed 5 g/d, 10 g/d, and 15 g/d of xylitol. The dietary intervention lasted a total of 6 weeks, with each phase covering a 2-week period. Diet was assessed twice based on a 7-day dietary interview (Diet 6.0, NIZP–PZH, Warsaw). The material for this study was venous blood. Antioxidant capacity was determined using the DPPH radical scavenging method and the ABTS cation radical scavenging method. Results: In both methods, a significant increase in serum antioxidant potential was observed after replacing sugar with xylitol (p < 0.0001). An increase in the ability to neutralize free radicals was observed in almost all women studied. Additional analysis of the effect of selected nutrients on the obtained effects of the nutritional intervention showed that the most significant effect could potentially be exerted by manganese, maltose, sucrose, and mercury, and the strongest positive correlation was exerted by vitamin A, retinol, and vitamin E. Although the values obtained in the constructed models were not statistically significant, the large effect indicates potentially significant relationships that could have a significant impact on serum antioxidant potential in the studied group of women. Conclusions: The results suggest a potential role of xylitol in enhancing antioxidant defense mechanisms in menopausal women. Although the sample size was relatively small, this study was powered at approximately 80% to detect large effects, supporting the reliability of the observed results. Nevertheless, given the pilot nature of this study, further research with larger cohorts is warranted to confirm these preliminary observations and to clarify the clinical significance of xylitol supplementation in populations exposed to oxidative stress. Full article

In the present research, metal–organic framework-5 (MOF-5) was synthesized and loaded with zerumbone (ZER@MOF-5), followed by the evaluation of its anticancer, antibacterial, antifungal, DNA-binding, and free radical scavenging potentials. The synthesized nanoparticles were characterized using X-ray diffraction, ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The in vitro anticancer activity of ZER@MOF-5 was studied in a human breast cancer cell line (MCF-7) using the CCK-8 assay. The interaction of ZER@MOF-5 with pBR322 plasmid DNA was assessed by gel electrophoresis. The antimicrobial effect of ZER@MOF-5 was examined in gram-positive and gram-negative bacterial strains and yeast strains using the microdilution method. The free radical scavenging activity was assessed using the DPPH assay. Cytotoxicity assay revealed a notable enhancement in the anticancer activity of zerumbone upon its encapsulation into MOF-5. The IC₅₀ value for ZER@MOF-5 was found to be 57.33 µg/mL, which was lower than that of free zerumbone (IC₅₀: 89.58 µg/mL). The results of the DNA-binding experiment indicate that ZER@MOF-5 can bind to target DNA and cause a conformational change in DNA. The results of the antibacterial activity experiment showed that the antibacterial ability of ZER@MOF-5 was limited compared to free zerumbone. The results of the DPPH assay demonstrated that the antioxidant activity of free zerumbone was higher than that of ZER@MOF-5. MOFs encapsulate compounds within their porous crystalline structure, which leads to prolonged circulation time compared to single ligands. Although the unique structure of MOFs may limit their antibacterial and antioxidant activity in the short term, it may increase therapeutic efficacy in the long term. However, to fully understand the long-term antibacterial and antioxidant effects of the ZER@MOF-5, further comprehensive in vitro and in vivo experiments are necessary. This finding indicates that the MOF-5 could potentially be an impressive carrier for the oral administration of zerumbone. Full article

Obesity and its associated complications, including oxidative stress, pose significant global health challenges. Natural products offer a promising avenue for developing novel therapeutic strategies. In this study, we investigated the potential of Panax japonicus (T. Nees) C.A. Meyer, a traditional medicinal plant known for its antioxidant and anti-obesity properties. A methanol extract of Panax japonicus and its fractions were evaluated for their in vitro antioxidant activities (tested using DPPH and reducing power assays), pancreatic lipase (PL) inhibitory capacities, and underlying mechanisms of action. The results indicated that the ethyl acetate fraction of P. japonicus (PJEA) exhibited the greatest potency, demonstrating strong antioxidant activity and significantly inhibiting digestive enzyme activity (pancreatic lipase). Mechanistic studies revealed that the PL inhibition was of a mixed type, combining both competitive and non-competitive mechanisms. Furthermore, PJEA demonstrated the ability to inhibit the differentiation of preadipocytes, primarily exerting its anti-adipogenic effects by downregulating the mRNA expression of PPARγ and the gene expression of C/EBPα. In addition, the extract suppressed the gene expression of FAS and ACC in adipose tissue. Isolation of the bioactive compounds from PJEA identified kaempferol 3-O-α-L-rhamnoside and catechin, which potentially contribute to the observed anti-obesity effects. Overall, this study highlights P. japonicus as a promising natural ingredient for scavenging free radicals and managing obesity, suggesting its potential for development into functional foods or therapeutic agents. Full article

Kiwifruit has attracted much attention in fruit and vegetable processing due to its high nutritional and economic value. However, there is a lack of systematic research on the effects of long-term frozen storage on the pulp quality of kiwifruit. Using kiwifruit pulp stored at −20 °C for 0, 3, 6, 9, and 12 months as the research materials, the dynamic changes in the phenotype, color, antioxidant activity, and flavor compounds were comprehensively evaluated. The results showed that frozen storage caused a significant decline in the quality of the fruit pulp. Specifically, the contents of chlorophyll and carotenoids decreased and the color deteriorated (color difference increased); the turbidity and centrifugal sedimentation rates increased, and pH and viscosity changed in different stages. Additionally, antioxidant compounds, such as vitamin C and total phenols, were significantly reduced with the extension of storage duration, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH)/2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging ability was decreased. The content of volatile aroma compounds diminished, leading to a notable shift in the flavor profile. Correlation analysis revealed that changes in volatile substances were significantly correlated with physical, chemical, and antioxidant indicators (p < 0.05). These correlations can serve as a key basis for assessing quality deterioration. This study systematically elucidated, for the first time, the mechanism of quality deterioration in kiwifruit pulp during frozen storage, thereby providing theoretical support for enterprises to optimize pulp grading strategies and the timing of by-product development. Hence, it is recommended that the duration of freezing should be limited to less than 9 months for kiwifruit pulp. Moreover, it is essential to consider varietal differences and new pretreatment technologies to further enhance the industrial utilization and economic value of frozen pulp. Full article

The phytochemical investigation and evaluation of the antioxidant activity of the leaves, bark, and roots of Cochlospermum angolense Welw ex Oliv—a valued plant that is widely used in traditional Angolan medicine—hold significant importance. Compounds were extracted from the aforementioned plant using acetone and ethanol and identified by HPLC-ESI-MSn. Both extracts demonstrated notable abilities to scavenge 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, and superoxide radicals, as well as to inhibit lipid peroxidation. A HPLC analysis revealed a diverse array of bioactive compounds, including flavonoids, phenols, alkaloids, quinones, and terpenes, which help neutralize free radicals and protect cells against oxidative stress, thereby contributing to the prevention of various diseases. Moreover, the acetone and ethanol extracts proved to be excellent sources of antioxidants. For the first time, the present study identified new compounds never reported in this species, such as (+)-abscisic acid, angustine B, pinobanksin, dihydrogenistein, (−)-8-prenylnaringenin, isoquercetin, samandarine, dihydromyricetin, and eupatoriocromene, in the leaves, bark, and roots, marking a significant advance in the chemical characterization of C. angolense. These findings enhance our understanding of the bioactive phytochemicals and antioxidant properties of C. angolense and open new avenues for future therapeutic and pharmacological research, further supporting its traditional use in Angolan medicine. Full article

Ilex vomitoria Ait. is a star substitute for “tea” in recent years. At present, research on I. vomitoria mainly focuses on its breeding and cultivation, and there are few reports on the seasonal changes of important components such as leaf nutrients. This study focuses on the leaves of the topmost annual branches of I. vomitoria. Leaves were harvested at different stages, and the nutrient elements, antioxidant substances, antioxidant capacity, and aroma components in the leaves were measured and analyzed. The results showed that the content of mineral elements, soluble sugars, vitamin C, amino acids, flavonoids, polyphenols, saponins, caffeine, and catechins, as well as the DPPH free radical scavenging ability, ABTS cation free radical scavenging ability, and FRAP iron ion reduction ability in the leaves of I. vomitoria showed significant differences with seasonal changes. The mineral element content in spring leaves is relatively high. Flavonoids and polyphenols are the main antioxidant substances in the leaves of I. vomitoria, indicating that the antioxidant capacity of spring leaves is the strongest. The content of aroma components in the leaves of I. vomitoria in spring is the highest, with alcohols ranging from 54.93% to 66.08%, followed by ketones from 17.63% to 48.07%, and aldehydes from 21.27% to 38.51%. Overall, spring leaves are more suitable for harvesting, development, and utilization. Full article

To improve the bioavailability of yak by-products, novel antioxidant peptides were prepared and identified from yak skin hydrolysate. The results showed that the ultrafiltration fraction of a molecular weight of less than 1 kDa had the strongest free radical scavenging activity. A total of 219 novel peptides were identified by mass spectrometry and five antioxidant peptides were screened based on molecular docking with Keap1 (LMGPR, GFDGD, FGFDGDF, GHNGLDGL, and GPAGPQGPR). These peptides may bind with Keap1 competitively and exert antioxidant effects by activating the Nrf2/ARE pathway. After synthesis, FGFDGDF showed a better free radical scavenging ability and protective effect on H₂O₂-induced oxidative damage of HepG2 cells among these peptides. The pretreatment of peptides could enhance the activity of intracellular antioxidant enzymes and reduce the level of malondialdehyde and IL-8. This study provides a scientific basis for the application of yak skin peptide as a novel antioxidant in functional food. Full article

A nitro-derivative of fenamic acid (4′–nitro–fenamic acid) was synthesized and used as ligand for the synthesis of four Co(II) complexes in the absence or presence of the N,N′-donors 2,2′–bipyridylamine, 1,10–phenanthroline and 2,9–dimethyl–1,10–phenanthroline. The characterization of the resultant complexes was performed with diverse techniques (elemental analysis, molar conductivity measurements, IR and UV-vis spectroscopy, single-crystal X-ray crystallography). The biological evaluation of the compounds encompassed (i) antioxidant activity via hydrogen peroxide (H₂O₂) reduction and free radical scavenging; (ii) antimicrobial screening against two Gram-positive and two Gram-negative bacterial strains; (iii) interactions with calf-thymus (CT) DNA; (iv) cleavage of supercoiled pBR322 plasmid DNA (pDNA), in the dark or under UVA/UVB/visible light irradiation; and (v) binding affinity towards bovine and human serum albumins. The antioxidant activity of the compounds against 2,2′–azinobis–(3–ethylbenzothiazoline–6–sulfonic acid) radicals and H₂O₂ is significant, especially in the case of H₂O₂. The complexes exhibit adequate antimicrobial activity against the strains tested. The complexes interact with CT DNA through intercalation with binding constants reaching a magnitude of 10⁶ M⁻¹. The compounds have a significantly enhanced pDNA-cleavage ability under irradiation, showing promising potential as photodynamic therapeutic agents. All compounds can bind tightly and reversibly to both albumins tested. Full article

Alginate lyases are critical enzymes in hydrolyzing alginate into alginate oligosaccharides (AOS), which are bioactive compounds known for their antioxidant properties and ability to lower serum glucose and lipid concentrations. However, elucidating catalytic mechanisms and discovering enzymes with enhanced catalytic efficiency remain long-term challenges. Here, we report AlgL2491, a novel bifunctional and cold-adapted alginate lyase from Pseudoalteromonas carrageenovora ASY5, belonging to the polysaccharide lyase family 18. This enzyme uniquely cleaves both polyguluronic (polyG) and polymannuronic (polyM), predominantly releasing disaccharides, trisaccharides, and tetrasaccharides after 12 h of hydrolysis. The enzyme achieves peak catalytic efficiency at 35 °C and pH 7.5, with activity increasing 5.5-fold in 0.5 M of NaCl. Molecular dynamics simulations demonstrate that salt ions enhance structural stability by minimizing conformational fluctuations and strengthening interdomain interactions, providing mechanistic insights into its salt-activated behavior. The alginate oligosaccharides (AOS) exhibit excellent free radical-scavenging activities of 86.79 ± 0.31%, 83.42 ± 0.18%, and 71.28 ± 2.27% toward hydroxyl, ABTS, and DPPH radicals, with IC50 values of 8.8, 6.74, and 9.71 mg/mL, respectively. These findings not only reveal the salt-activation mechanism of AlgL2491 and highlight the potential value of its hydrolysate in antioxidant activity but also provide a sustainable industrial solution in industrial-scale AOS production directly from marine biomass, eliminating the need for energy-intensive desalination of alginate, which may inform future biocatalyst design for marine polysaccharide valorization. Full article

Enzymatic browning is a major issue in potato processing, causing a decline in both nutritional value and quality. Although there are numerous studies on the mechanism of enzymatic browning of potato tubers, few relevant reports are available on the changes at the transcriptome level during enzymatic browning as well as on the differences in the browning process of potato tubers with differing degrees of enzymatic browning potential. To gain insights into the molecular mechanism of enzymatic browning after cutting, this study presents the transcriptional characterization of temporal molecular events during enzymatic browning of browning-resistant (BR) and browning-susceptible (BS) potato tubers. RNA-sequencing (RNA-seq) analysis detected 19,377 and 13,741 differentially expressed genes (DEGs) in BR and BS tubers, respectively, with similar function enrichment observed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Up-regulated DEGs were significantly enriched in the pathways related to phenol and lipid biosynthesis, while the down-regulated DEGs were significantly enriched in the pathways related to programmed cell death. Significant redox-related pathways occurred earlier in BS tubers compared to the BR tubers. Further analysis revealed that the BS tubers had a stronger phenolic synthesis ability compared to the BR tubers. However, the BR tubers showed a stronger free radical scavenging ability compared to the BS tubers. The results of our study provide insights into the temporal molecular events that occur during the enzymatic browning of potato tubers after cutting and the potential molecular mechanisms for different degrees of enzymatic browning. Full article

Lycopene, a natural pigment, is valuable for human health because of its strong antioxidant capacity. However, studies on the involvement of tomato miR394 in the regulation of lycopene have not been reported. The aim of this study was to reveal the molecular mechanism by which miR394 regulates lycopene synthesis by targeting ζ-carotene dehydrogenase (ZDS). The miR394-silenced transgenic tomato plants were constructed by short tandem target mimicry (STTM) technology, and the association between lycopene content and antioxidant capacity was analyzed by combining qRT-PCR, UV spectrophotometry, and a free radical scavenging assay. The targeting relationship between miR394 and ZDS was verified using a subcellular localization assay. The results showed that the silencing of miR394 significantly upregulated the expression of the ZDS gene and promoted lycopene accumulation. The antioxidant enzyme activities of STTM394 transgenic plants were significantly enhanced, and the free radical scavenging ability was obviously improved. Subcellular localization experiments confirmed that miR394 directly inhibited the chloroplast expression of ZDS. In conclusion, this study reveals for the first time that the miR394-ZDS module enhances the antioxidant capacity by regulating lycopene metabolism, which provides a new target for themolecular breeding of highly nutritious tomatoes. Full article

Hypnum cupressiforme Hedw. is a widely distributed moss species with significant bioactive potential, but the phytochemical composition and biological activity of this species are not well documented yet, particularly in Bulgaria. The current study aimed to investigate the amino acid composition, free sugars, sterol profile, total polyphenol content, antioxidant activity, DNA-protective effect, and the anti-inflammatory activity of ethanolic extracts of H. cupressiforme. Amino acid analysis revealed that proline (2.282 g/100 g), isoleucine (2.047 g/100 g), and glutamic acid (1.746 g/100 g) were the dominant constituents. The moss contained mannose (1.76 g/100 g) and fructose (1.43 g/100 g) as major free sugars and a diverse sterol profile containing stigmasterol (4.37 mg/g), β-sitosterol (4.29 mg/g), and campesterol (3.34 mg/g) as major phytosterols, which are known for their potential health benefits, such as cholesterol regulation and anti-inflammatory effects. The antioxidant activity of the extracts was determined by DPPH and ABTS assays and expressed moderate free radical scavenging ability (2.56 and 4.15 mM TE/g DW). Furthermore, the extracts also exhibited a potent DNA-protective effect against oxidative damage and anti-inflammatory activity. These findings contribute to the phytochemical knowledge of H. cupressiforme and suggest that Bulgarian specimens may be worth further investigation for pharmaceutical, nutraceutical, and cosmetic applications. Full article

Antioxidant peptides derived from woody oil resource by-products exhibit strong free radical scavenging abilities and offer potential applications in functional foods, nutraceuticals, and cosmetics. This review summarizes the latest advances in preparation technologies, including enzymatic hydrolysis, microbial fermentation, chemical synthesis, recombinant expression, and molecular imprinting, each with distinct advantages in yield, selectivity, and scalability. The structure–activity relationships of antioxidant peptides are explored with respect to amino acid composition, molecular weight, and 3D conformation, which collectively determine their bioactivity and stability. Additionally, emerging delivery systems—such as nanoliposomes, microencapsulation, and cell-penetrating peptides—are discussed for their role in enhancing peptide stability, absorption, and targeted release. Mechanistic studies reveal that antioxidant peptides from woody oil resources act through network pharmacology, engaging core signaling pathways, including Nrf2/ARE, PI3K/Akt, AMPK, and JAK/STAT, to regulate oxidative stress, mitochondrial health, and inflammation. Preliminary safety data from in vitro, animal, and early clinical studies suggest low toxicity and favorable tolerability. The integration of omics technologies, molecular docking, and bioinformatics is accelerating the mechanism-driven design and functional validation of peptides. In conclusion, antioxidant peptides derived from woody oil resources represent a sustainable, multifunctional, and scalable solution for improving human health and promoting a circular bioeconomy. Future research should focus on structural optimization, delivery enhancement, and clinical validation to facilitate their industrial translation. Full article

To tackle the degradation of sealing performance in nitrile butadiene rubber (NBR) seals due to material aging during long-term service, this study integrates experimental and molecular simulation methods to elucidate the aging mechanism. Experimental results reveal that the contents of C=C and C=O functional groups significantly decrease during aging, accompanied by enhanced hydrophobicity and increased crosslink density of NBR, indicating that crosslinking reactions dominate the aging process with the participation of C=C and C=O groups. Quantum mechanics (QM) and molecular dynamics (MD) simulations further demonstrate that α-H, C=C, and C≡N groups are preferentially oxidized due to their low bond energies. The oxidation of NBR generates unstable epoxy intermediates, which undergo chain scission to form ketones, aldehydes, and ultimately crosslinked structures. Using a multi-dimensional evaluation system based on bond dissociation energy (BDE), solubility parameter (Δδ), and migration coefficient (MSD), four antioxidants (4010NA, 4010, MC, and BHT) were screened. BHT emerges as the optimal choice, exhibiting superior free radical scavenging ability (BDE = 346.3 kJ/mol), good matrix compatibility (Δδ = 2.95), and anti-migration properties. The MD-based screening method established herein provides a theoretical basis for designing antioxidant systems in high-performance rubber materials, facilitating the development of advanced rubber products. Full article

Oxidative stress is a critical factor contributing to the pathogenesis of numerous diseases, including cardiovascular disorders, diabetes, and neurodegenerative conditions. In recent years, marine-derived antioxidants have emerged as promising therapeutic agents due to their unique biological activities and diverse sources. This comprehensive review explores the therapeutic potential of various marine antioxidants in mitigating oxidative stress-associated diseases. Marine organisms are rich in bioactive compounds, such as polysaccharides, polyphenols, carotenoids, peptides, and vitamins, which exhibit potent antioxidant and free radical scavenging abilities. These compounds have been shown to effectively inhibit oxidative reactions, repair oxidative damage, and enhance the body’s antioxidant defense mechanisms. For instance, marine polysaccharides and their derivatives can scavenge reactive oxygen species (ROS), protect neurons from oxidative damage, and alleviate inflammation in neurodegenerative diseases like Alzheimer’s and Parkinson’s diseases. Similarly, marine unsaturated fatty acids, such as omega-3 polyunsaturated fatty acids (PUFAs), have been found to reduce cardiovascular risks by lowering serum triglyceride levels and improving vascular endothelial function. Additionally, marine-derived superoxide dismutase (SOD) plays a crucial role in neutralizing ROS, thereby offering protection against oxidative stress in various diseases. Despite these promising findings, challenges remain in the field, including the need for improved extraction and purification technologies, more comprehensive activity evaluation systems, and further research into the safety and bioavailability of these compounds. This review provides a detailed overview of the current research status, highlighting the types, structural characteristics, antioxidant activities, and mechanisms of action of marine antioxidants. It also identifies key areas for future research and development, aiming to harness the full potential of marine-derived antioxidants in the prevention and treatment of oxidative stress-related diseases. Full article