Search Results (361)

This study systematically investigated the oxidation of chitosan using the TEMPO/NaClO/NaBr catalytic system under varying experimental conditions, namely temperature, reaction time, and pH, in order to optimize the oxidation process. Response surface methodology (RSM) was employed to determine the optimal parameters for maximizing the efficiency of the reaction. The structural modifications to the chitosan following oxidation were confirmed using Fourier-transform infrared spectroscopy (FTIR), alongside additional analytical techniques, which validated the successful introduction of carbonyl and carboxyl functional groups. Solvent-cast films were prepared from both native and oxidized chitosan in order to evaluate their functional performance. The antibacterial activity of these films was assessed against Gram-negative (Salmonella) and Gram-positive (Streptococcus faecalis) bacterial strains. The oxidized chitosan films exhibited significantly enhanced antibacterial effects, particularly at shorter incubation periods. In addition, antioxidant activity was evaluated using DPPH radical scavenging and ferrous ion chelation assays, which both revealed a marked improvement in radical scavenging ability and metal ion binding capacity in oxidized chitosan. These findings confirm that TEMPO-mediated oxidation effectively enhances the physicochemical and bioactive properties of chitosan, highlighting its potential for biomedical and environmental applications. Full article

Lignin, the most abundant renewable aromatic biopolymer on Earth, is rapidly emerging as a powerful enabler of next-generation sustainable technologies. This review shifts the focus to the latest industrial breakthroughs that exploit lignin’s multifunctional properties across energy, agriculture, healthcare, and environmental sectors. Lignin-derived carbon materials are offering scalable, low-cost alternatives to critical raw materials in batteries and supercapacitors. In agriculture, lignin-based biostimulants and controlled-release fertilizers support resilient, low-impact food systems. Cosmetic and pharmaceutical industries are leveraging lignin’s antioxidant, UV-protective, and antimicrobial properties to create bio-based, clean-label products. In water purification, lignin-based adsorbents are enabling efficient and biodegradable solutions for persistent pollutants. These technological leaps are not merely incremental, they represent a paradigm shift toward a materials economy powered by renewable carbon. Backed by global sustainability roadmaps like the European Green Deal and China’s 14th Five-Year Plan, lignin is moving from industrial residue to strategic asset, driven by unprecedented investment and cross-sector collaboration. Breakthroughs in lignin upgrading, smart formulation, and application-driven design are dismantling long-standing barriers to scale, performance, and standardization. As showcased in this review, lignin is no longer just a promising biopolymer, it is a catalytic force accelerating the global transition toward circularity, climate resilience, and green industrial transformation. The future of sustainable innovation is lignin-enabled. Full article

Apigenin and sodium butyrate have been reported to help alleviate oxidative stress. This study evaluated the jejunal transcriptomic responses in ducks receiving apigenin and sodium butyrate supplementation under oxidative stress. In total, 200 healthy 300-day-old female Jinyun Ma ducks (1.53 kg ± 0.15) were randomly divided into four groups, with five replicates per group. The groups were as follows: a control group (CON): ducks were fed a basal diet with sterile saline injection; a diquat-injection (DIQ) group: ducks were fed a basal diet with diquat injection; an apigenin plus diquat group (API): ducks were fed a basal diet containing apigenin (500 mg/kg) with diquat injection; and a sodium butyrate plus diquat group (SB): ducks were fed a basal diet containing sodium butyrate (500 mg/kg) with diquat injection. The injection dose of diquat is 8 mg/kg body weight. Analysis revealed that the dietary supplementation of apigenin and sodium butyrate reduced malondialdehyde (MDA) levels and increased total antioxidant capacity (T-AOC) (p < 0.05). Compared to the DIQ group, sodium butyrate supplementation during oxidative stress elevated jejunal villus height and villus height/crypt depth ratio in ducks (p < 0.05). The study identified that some candidate genes, including solute carrier family 4 member 3 (SLC4A3), ADAM metallopeptidase domain 12 (ADAM12), and B-cell lymphoma 2-associated-athanogene 3 (BAG3), were significantly upregulated, whereas claudin 23 (CLDN23) and glucose-6-phosphatase catalytic subunit 1 (G6PC1) were markedly downregulated in the API group in comparison with that in the DIQ group (p < 0.05). Collectively, our findings provide molecular evidence for the beneficial effects of apigenin and sodium butyrate against oxidative stress in the jejunum of ducks. Full article

With the increasing severity of global climate change and soil salinization, the development of microorganisms that enhance crop salt tolerance has become a critical focus of agricultural research. In this study, we explored the potential of a novel Streptomyces species Qhu-G9 as a plant growth-promoting rhizobacterium (PGPR) under salt stress conditions, employing whole-genome sequencing and functional annotation. The genomic analysis revealed that Qhu-G9 harbors various genes related to plant growth promotion, including those involved in phosphate solubilization, indole-3-acetic acid (IAA) biosynthesis, antioxidant activity, and nitrogen fixation. A total of 8528 coding genes were annotated in Qhu-G9, with a significant proportion related to cell metabolism, catalytic activity, and membrane transport, suggesting its broad growth-promoting potential. In vitro experiments demonstrated that Qhu-G9 exhibited strong iron siderophore production, IAA synthesis, phosphate solubilization, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, all of which correlate with its plant growth-promoting capacity. Further plant growth trials revealed that Qhu-G9 significantly enhances the growth of Avena sativa and Onobrychis viciifolia seedlings under salt stress conditions, improving key physiological parameters, such as chlorophyll content, relative water content, and photosynthetic efficiency. Under salt stress conditions, inoculation with Qhu-G9 resulted in notable increases in total biomass, root length, and plant height. Biochemical analyses further confirmed that Qhu-G9 alleviates the oxidative damage induced by salt stress by boosting antioxidant enzyme activities, reducing peroxide levels, and promoting the accumulation of osmotic regulators. These findings suggest that Qhu-G9 holds great promise as a PGPR that not only promotes plant growth, but also enhances plant tolerance to salt stress; thus, it has significant agricultural potential. Full article

Lactiplantibacillus plantarum B22 exhibits a high esterase/lipase activity, but the genomic and probiotic potential remains unclear. We employed an integrated approach combining whole-genome sequencing, molecular docking studies, and phenotypic assays to dissect the genomic and functional basis underlying the high lipolytic activity and probiotic traits of L.plantarum B22. This strain exhibited a robust lipase activity (3.45 ± 0.13 U/mL), with whole-genome analysis revealing that the complete genome of this strain spans 2,027,325 bp, encoding 2005 genes with a guanine-cytosine (GC) content of 35.06%. Notably, 13 esterase/lipase genes were identified, 4 of which (gene3060, gene3059, gene2553, gene0798) harbor conserved catalytic triads (Ser-His-Gly/Ala), essential for lipase function. Molecular docking studies confirmed strong binding affinity to tributyrin (ΔG ≤ –5.52 kcal/mol) and elucidated the interaction mechanisms, involving hydrogen bonding and hydrophobic interactions between the esterase/lipase enzymes and tributyrin. Phenotypic and genomic analyses further demonstrated that L. plantarum B22 possesses excellent tolerance to simulated human gastrointestinal tract conditions, along with potent antioxidant and antimicrobial activities, highlighting its strong probiotic potential. Genomic annotation also identified 68 genes associated with lipid metabolism and an intact fatty acid synthesis pathway. Importantly, the analysis of phenotypes and genes involved in virulence factors, and the production of harmful metabolites suggests that L. plantarum B22 is safe. Collectively, this study offers novel insights into the genome-guided functional characterization of L. plantarum B22, providing a robust foundation for its development as a functional probiotic strain. Full article

Superoxide dismutases (SODs) maintain redox homeostasis through the catalytic dismutation of superoxide anions, thereby affording protection to organisms against oxidative damage. The SOD family, encompassing Cu/Zn-SOD, Mn-SOD, Fe-SOD, and Ni-SOD, exhibits structural diversity and constitutes a multilevel antioxidant defense system with discrete subcellular localizations. Beyond their antioxidant functions, SODs also function as immunomodulatory proteins, regulating the maturation, proliferation, and differentiation of immune cells. They further fulfill a crucial role in host responses to parasitic infections. The current review synthesizes and critically evaluates extant research to comprehensively delineate the molecular architecture of SODs, their intricate post-translational modification (PTM) networks, and their dual regulatory mechanisms at the interface of immunomodulation and pathological processes. This review establishes a critical framework for elucidating the biological significance of redox homeostasis maintenance. Full article

Peach fruit faces severe postharvest losses due to thin epidermis and susceptibility to Rhizopus stolonifer-induced soft rot. Chemical control risks residue and resistance issues, demanding eco-friendly alternatives. This study elucidated the mechanism by which trans-2-hexenal (E2H) mitigated postharvest soft rot caused by Rhizopus stolonifer in peach (Prunus persica cv. Hujing Milu) fruit. The results demonstrated that E2H treatment significantly delayed lesion expansion by 44.7% and disease incidence by 23.9% while effectively maintaining fruit quality by delaying firmness loss, reducing juice leakage, and suppressing malondialdehyde (MDA) accumulation. E2H treatment upregulated phenylpropanoid pathway gene expression, enhancing key phenylpropanoid metabolism enzymes activities (phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), polyphenol oxidase (PPO), peroxidase (POD)), leading to the increase of total phenolics by 7.9%. E2H treatment analysis revealed significant enhancements in both chitinolytic activity (CHI) and β-1,3-glucanase (GLU) activity by 85.7% and 12.9%, indicating potentiation of the enzymatic defense system. Concurrently, E2H treatment could improve the redox modulation capacity of peach fruits through promoting catalytic efficiency of redox-regulating enzymes, increasing the accumulation of ascorbic acid (AsA) by 8.1%, inhibiting the synthesis of dehydroascorbic acid (DHA) by 18.6%, as well as suppressing the biosynthesis of reactive oxygen species (ROS). These coordinated enhancements in pathogenesis-related proteins (CHI, GLU), phenylpropanoid metabolism activation, and antioxidant systems are strongly associated with E2H-induced resistance against Rhizopus stolonifer, though contributions from other factors may also be involved. Full article

A direct non-catalytic synthesis of a new water-soluble polynitro-hydroxylated fullerene derivative, C₆₀(NO₂)₁₈(OH)₂, was carried out using a mixture of concentrated nitric and sulfuric acids. The resulting poly-nitro adduct was comprehensively characterized by elemental C-H-N analysis, energy-dispersive X-ray spectroscopy, infrared (IR) and electron spectroscopy, nuclear magnetic resonance (NMR), high-performance liquid chromatography (HPLC), and thermogravimetric analysis (TGA). A detailed investigation of the physicochemical properties of aqueous solutions of C₆₀(NO₂)₁₈(OH)₂ demonstrated that the synthesized compound is a previously undescribed mixed polynitro-hydroxyl adduct of light fullerene C₆₀, featuring a high degree of nitration (18 nitro groups per fullerene core). The composition and structure of the adduct were confirmed by spectroscopic and refractometric analyses. In terms of redox behavior, the compound exhibits significant reducing and antioxidant properties. These physicochemical characteristics suggest the potential of C₆₀(NO₂)₁₈(OH)₂ for further development as a biocompatible nanomaterial suitable for medical applications. Full article

Metabolic syndrome (MetS), characterized by obesity, insulin resistance, and dyslipidemia, is a major risk factor for renal injury. Oxidative stress (OxS) plays a pivotal role in its progression; however, the underlying molecular mechanisms are not fully understood. In this study, we established a rat model of MetS using a high-fat diet combined with a single-dose streptozotocin injection in male Wistar rats. MetS rats exhibited systemic OxS, evidenced by elevated circulating levels of free oxygen radicals and decreased antioxidant defense capacity, as well as hypertension, renal lipid peroxidation, glomerular hyperfiltration, and renal tubular injury. Transcriptomic profiling of renal tissue revealed significant downregulation of six OxS-related genes: C-C motif chemokine ligand 5 (CCL5), glutamate-cysteine ligase catalytic subunit, glutathione peroxidase 6, recombination activating gene 2, NAD(P)H: quinone oxidoreductase 1, and selenoprotein P-1. Among these downregulated genes, CCL5 was further confirmed to be repressed at both mRNA and protein levels across intrarenal and systemic compartments. Given its documented functions in immune signaling and redox homeostasis, CCL5 downregulation may contribute to enhanced oxidative damage in MetS-associated renal injury. These findings highlight the role of redox gene dysregulation in the pathogenesis of MetS-related kidney disease and support the potential of CCL5 as a biomarker for oxidative renal injury. 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

In this study, we investigated the functional role of Peroxiredoxin 5 (SmPrx5) in the cuttlefish Sepiella maindroni. The full-length SmPrx5 cDNA is 934 base pairs (bp) in length, comprising a 31 bp 5′ untranslated region (UTR), a 330 bp 3′ UTR, and an open reading frame (ORF) of 573 bp that encodes a polypeptide consisting of 190 amino acids. Sequence analysis revealed the presence of a conserved peroxidase catalytic motif VPGAFTPGCSQTHLPG and the signature domain DGTGLTCSL, indicating that SmPrx5 belongs to the 2-Cys Prx subfamily. Quantitative real-time PCR (RT-qPCR) analysis demonstrated that SmPrx5 is broadly expressed across various tissues in S. maindroni, with particularly high expression levels observed in the testes, hemocytes, liver, and ovaries. Upon challenge with Vibrio alginolyticus, SmPrx5 expression was significantly upregulated in both the liver and hemocytes, peaking at 24 h post-infection and gradually returning to baseline levels within 48 h. Furthermore, the recombinant SmPrx5 protein exhibited notable antioxidant activity in vitro, suggesting its involvement in the oxidative stress response. These findings enhance our understanding of the molecular mechanisms underlying immune defense in marine cephalopods and highlight the potential role of Prx5 in host immunity. Full article

Crop productivity is severely constrained by abiotic and biotic stresses, necessitating innovative strategies to enhance stress resilience. Glycerol-3-phosphate (G3P) is a central metabolite in carbohydrate and lipid metabolism, playing crucial roles in stress responses. In this study, we engineered a novel glycerol-3-phosphate dehydrogenase (GPDH) gene, designated OEGD, by fusing the N-terminal NAD-binding domain of rice OsGPDH1 with the feedback-resistant C-terminal catalytic domain of Escherichia coli gpsA. Overexpression of OEGD in rice enhanced tolerance to drought, phosphorus deficiency, high temperature, and cadmium (Cd²⁺) stresses, while also improving plant growth and yield under drought stress at the adult stage. Notably, the accumulation of glycerol-3-phosphate (G3P) and activities of antioxidant enzymes (SOD, POD, CAT) were significantly elevated in the transgenic plants following osmotic stimuli, and fatty acid profiles were altered, favoring stress adaptation. Transcriptomic analyses revealed that OEGD modulates cell wall biogenesis, reactive oxygen species (ROS) scavenging, and lipid metabolism pathways, with minimal disruption to core G3P metabolic genes. These findings highlight the potential of OEGD as a valuable genetic resource for improving stress resistance in rice. Full article

Arsenic, a potent metalloid contaminant of drinking water, is known for its ability to act as an initiator and modulator of disease in a variety of human tissues. Upon ingestion, arsenic is bio-transformed in the liver into a variety of metabolites, including arsenite. Arsenite permeates the blood–brain barrier (BBB), inducing oxidative stress that can be detrimental to brain neurons. As the primary glial cell at the BBB interface, astrocytes play a pivotal role in detoxifying xenobiotics such as arsenite via the production of the tripeptide antioxidant γ-glutamylcysteine, or glutathione (GSH). In this study, we assessed the mRNA levels of key components of the GSH synthetic pathway in astrocytes exposed to arsenite compared to vehicle controls. These components included xCT [substrate-specific light chain of the substrate importing transporter, system x_c⁻ (Sx_c⁻)], glutamate-cysteine ligase [both catalytic (GCL_C) and modifying (GCL_M) subunits], and glutathione synthetase (GS). Additionally, we analyzed protein levels of some components by Western blotting and evaluated functional activity of Sx_c⁻ using a fluorescence-based cystine uptake assay. Finally, we utilized a luminescence-based glutathione assay to determine the intracellular and extracellular GSH content in arsenite-treated cells. Arsenite significantly increased xCT, GCL_C, GCL_M, and GS mRNA levels, an effect blocked by the transcriptional inhibitor actinomycin D (ActD). A corresponding increase in Sx_c⁻ activity was also observed in the arsenite treatment groups, along with significant increases in GCL_C and GCL_M protein expression. However, no increase in GS protein expression was detected. Finally, arsenite treatment significantly increased extracellular GSH levels, an effect which was also prevented by the inclusion of ActD. Overall, our study provides evidence that arsenite transcriptionally regulates several cellular processes necessary for GSH synthesis in primary cortical astrocyte cultures, thereby contributing to a better understanding of how this environmental toxicant influences antioxidant defenses in the brain. However, these results should be interpreted with caution regarding their applicability to vivo systems. Full article

Aloe vera is effectively utilized to synthesize zinc oxide nanoparticles (Av-ZnO NPs), providing an alternative to traditional chemical and physical methods. This sustainable approach minimizes the environmental impacts and enhances their compatibility with herbal ecosystems. We comprehensively analyzed the optical, structural, morphological, and catalytic properties of Av-ZnO NPs using various analytical methods. The results indicated that the nanoparticles primarily exhibited a spherical shape. X-ray diffraction (XRD) revealed the successful formation of a highly crystalline hexagonal wurtzite structure, with an average size estimated at 12.2 nm. The antimicrobial properties of the Av-ZnO NPs indicated moderate antibacterial effectiveness. Using the DPPH free radical scavenging method, we evaluated the antioxidant properties, where the Av-ZnO NPs exhibited improved the radical scavenging efficiency, reflected by a lower IC₅₀ value compared to the plant extract. Additionally, we assessed the photocatalytic functionality through the degradation of methylene blue (MB) dye, finding that the Av-ZnO NPs achieved approximately 82.43% degradation in 210 min, demonstrating their potential for environmental remediation. These findings suggest that green-synthesized ZnO NPs could play a noteworthy role in various nanotechnology applications and biomedical fields, while also promoting environmental sustainability. Full article

Mitochondria play a central role in energy metabolism and continuously adapt through dynamic processes such as fusion and fission. When the balance between these processes is disrupted, it can lead to mitochondrial dysfunction and increased oxidative stress, contributing to the development and progression of various cardiometabolic diseases (CMDs). Their role is crucial in diabetes mellitus (DM), since their dysfunction drives β-cell apoptosis, immune activation, and chronic inflammation through excessive ROS production, worsening endogenous insulin secretion. Moreover, sympathetic nervous system activation and altered dynamics, contribute to hypertension through oxidative stress, impaired mitophagy, endothelial dysfunction, and cardiomyocyte hypertrophy. Furthermore, the role of mitochondria is catalytic in endothelial dysfunction through excessive reactive oxygen species (ROS) production, disrupting the vascular tone, permeability, and apoptosis, while impairing antioxidant defense and promoting inflammatory processes. Mitochondrial oxidative stress, resulting from an imbalance between ROS/Reactive nitrogen species (RNS) imbalance, promotes atherosclerotic alterations and oxidative modification of oxidizing low-density lipoprotein (LDL). Mitochondrial DNA (mtDNA), situated in close proximity to the inner mitochondrial membrane where ROS are generated, is particularly susceptible to oxidative damage. ROS activate redox-sensitive inflammatory signaling pathways, notably the nuclear factor kappa B (NF-κB) pathway, leading to the transcriptional upregulation of proinflammatory cytokines, chemokines, and adhesion molecules. This proinflammatory milieu promotes endothelial activation and monocyte recruitment, thereby perpetuating local inflammation and enhancing atherogenesis. Additionally, mitochondrial disruptions in heart failure promote further ischemic injury and excessive oxidative stress release and impair ATP production and Ca²⁺ dysregulation, contributing to cell death, fibrosis, and decreased cardiac performance. This narrative review aims to investigate the intricate relationship between mitochondrial dysfunction and CMDs. Full article