Search Results (297)

Nano- and microplastic pollution, together with the ongoing rise in global temperatures driven by climate change, represent increasingly critical environmental challenges. Although these stressors often co-occur in the environment, their combined effects on plant systems remain largely unexplored. To test the hypothesis that their interaction may exacerbate the effects observed under each stressor individually, we investigated the response of seedlings of Triticum turgidum to treatments with fluorescent polystyrene nanoplastics under optimal (25 °C) and elevated (35 °C) temperature conditions. We evaluated seedling growth, photosynthetic pigment content, and oxidative stress markers using both biochemical and histochemical techniques. In addition, we assessed enzymatic and non-enzymatic antioxidant responses. The use of fluorescently labeled nanoplastics enabled the visualization of their uptake and translocation within plant tissues. Elevated temperatures negatively affect plant growth, increasing the production of proline, a key protective molecule, and weakly activating secondary defense mechanisms. Nanoplastics disturbed wheat seedling physiology, with these effects being amplified under high temperature conditions. Combined stress enhances nanoplastic uptake in roots, increases oxidative damage, and alters antioxidant responses, reducing defense capacity in leaves while triggering compensatory mechanisms in roots. These findings underscore a concerning interaction between plastic pollution and climate warming in crop plants. Full article

Combined abiotic stresses often impose greater challenges to plant survival than individual stresses. In this study, we focused on elucidating the physiological and molecular mechanisms underlying the response of Dendrobium huoshanense to combined salt and heat stress by integrating physiological, transcriptomic, and metabolomic analyses. Our results demonstrated that high temperature plays a dominant role in the combined stress response. Physiological assays showed increased oxidative damage under combined stress, accompanied by significant activation of antioxidant enzyme systems (SOD, POD, CAT). Metabolomic analysis revealed significant enrichment of glutathione metabolism and flavonoid biosynthesis pathways, with key antioxidants such as glutathione and naringenin chalcone accumulating under combined stress. Transcriptomic data supported these findings, showing differential regulation of stress-related genes, including those involved in reactive oxygen species scavenging and secondary metabolism. These results highlight a coordinated defense strategy in D. huoshanense, involving both enzymatic and non-enzymatic antioxidant systems to maintain redox homeostasis under combined stress. This study provides novel insights into the molecular mechanisms underlying combined stress tolerance and lays the foundation for improving stress resilience in medicinal orchids. Full article

Air pollution acts as a pervasive oxidative stressor, disrupting global crop production and ecosystem health through the overproduction of reactive oxygen species (ROS). Hazardous pollutants impair critical physiological processes—photosynthesis, respiration, and nutrient uptake—triggering oxidative damage and yield losses. This review synthesizes current knowledge on plant defense mechanisms, emphasizing the integration of enzymatic (SOD, POD, CAT, APX, GPX, GR) and non-enzymatic (polyphenols, glutathione, ascorbate, phytochelatins) antioxidant systems to scavenge ROS and maintain redox homeostasis. We highlight the pivotal roles of transcription factors (MYB, WRKY, NAC) in orchestrating stress-responsive gene networks, alongside MAPK and phytohormone signaling (salicylic acid, jasmonic acid, ethylene), in mitigating oxidative stress. Secondary metabolites (flavonoids, lignin, terpenoids) are examined as biochemical shields against ROS and pollutant toxicity, with evidence from transcriptomic and metabolomic studies revealing their biosynthetic regulation. Furthermore, we explore biotechnological strategies to enhance antioxidant capacity, including overexpression of ROS-scavenging genes (e.g., TaCAT3) and engineering of phenolic pathways. By addressing gaps in understanding combined stress responses, this review provides a roadmap for developing resilient crops through antioxidant-focused interventions, ensuring sustainability in polluted environments. Full article

REG3A, a prominent member of the human regenerating islet-derived (REG) lectin family, plays a pivotal and multifaceted role in immune defense, inflammation, and cancer biology. Primarily expressed in gastrointestinal epithelial cells, REG3A reinforces barrier integrity, orchestrates mucosal immune responses, and regulates host–microbiota interactions. It also functions as a potent non-enzymatic antioxidant, protecting tissues from oxidative stress. REG3A expression is tightly regulated by inflammatory stimuli and is robustly induced during immune activation, where it limits microbial invasion, dampens tissue injury, and promotes epithelial repair. Beyond its antimicrobial and immunomodulatory properties, REG3A contributes to the resolution of inflammation and the maintenance of tissue homeostasis. However, its role in cancer is highly context-dependent. In some tumor types, REG3A fosters malignant progression by enhancing cell survival, proliferation, and invasiveness. In others, it acts as a tumor suppressor, inhibiting growth and metastatic potential. These opposing effects are likely dictated by a combination of factors, including the tissue of origin, the composition and dynamics of the tumor microenvironment, and the stage of disease progression. Additionally, the secreted nature of REG3A implies both local and systemic effects, further modulated by organ-specific physiology. Experimental variability may also reflect differences in methodologies, analytical tools, and model systems used. This review synthesizes current knowledge on the pleiotropic functions of REG3A, emphasizing its roles in epithelial defense, immune regulation, redox homeostasis, and oncogenesis. A deeper understanding of REG3A’s pleiotropic effects could open up new therapeutic avenues in both inflammatory disorders and cancer. Full article

The aging process is a complex and dynamic phenomenon influenced by genetic, environmental, and biochemical factors. One of the key contributors to aging and age-related diseases is oxidative stress, resulting from an imbalance between the generation of reactive oxygen species (ROS) and the efficiency of antioxidant defense systems. In this review, we introduce the concept of the oxidative stress complexity—a network encompassing ROS-generating systems, enzymatic and non-enzymatic antioxidants, and genetic determinants that collectively shape redox homeostasis. Emerging research highlights the significant influence of genetic variability on the activity and expression of selected and most examined antioxidant enzymes, including superoxide dismutase (SOD), paraoxonase 1 (PON1), catalase (CAT), and glutathione peroxidase (GPX), thereby modulating individual susceptibility to oxidative damage, disease onset, and the pace of aging. Particular attention is paid to the interplay among oxidative stress, chronic inflammation, and metabolic dysfunction in the pathogenesis of various age-related disorders. By integrating findings from molecular studies, clinical research, and population genetics, we discuss the diagnostic and prognostic potential of antioxidant enzymes as biomarkers of aging and explore strategies for redox-modulating interventions. Understanding these interrelations is essential for identifying biomarkers of biological aging and developing personalized strategies aimed at promoting healthy aging and reducing the risk of chronic disease. Full article

Elite soccer places significant neuromuscular and metabolic stress on athletes, leading to elevated production of reactive oxygen and nitrogen species (RONS), particularly in skeletal muscle, where intense contractile activity and increased oxygen flux drive oxidative processes. These reactive species play a dual role in skeletal muscle, supporting adaptive signaling at controlled levels while causing oxidative damage when poorly regulated. This paper presents an integrated synthesis of current knowledge on redox biology in elite soccer players, focusing on the origins and regulation of RONS, the functions of enzymatic and non-enzymatic antioxidant systems, and how both RONS and antioxidant responses influence muscle performance, fatigue, recovery, and long-term physiological adaptation. Drawing on studies conducted between 2000 and 2025, the discussion underscores the seasonal fluctuations in oxidative stress, individual variability in redox responses, and the potential adverse effects of unsystematic antioxidant supplementation. The analysis also emphasizes the value of using biomarker-guided, periodized antioxidant interventions tailored to training demands. Future directions include longitudinal tracking and the use of AI-assisted monitoring to enable personalized strategies for maintaining redox balance and optimizing performance in elite sport. Full article

The fine regulation of antioxidant systems and intracellular production of reactive oxygen species (ROS) is responsible for cellular redox balance. The main organelles responsible for ROS production are mitochondria, and they complete this process through the electron transport chain. These potentially harmful molecules are buffered by enzymatic and non-enzymatic antioxidant systems. Oxidative stress is determined by an imbalance between the production and clearance of ROS in favor of the accumulation of these detrimental species, which generate cellular damage by interacting with macromolecules. In neurodegenerative diseases, oxidative stress has been demonstrated to be a crucial component, both causal and consequential to the disease itself. On the other hand, neurodegeneration disrupts neuromuscular junctions, leading to reduced muscle use and subsequent atrophy. Additionally, systemic inflammation and metabolic dysfunction associated with neurodegenerative diseases exacerbate muscle degeneration. Thus, sarcopenia and atrophy are common consequences of neurodegeneration and play a significant role in these disorders. Regarding this, ROS have been defined as promoting sarcopenia, stimulating the expression of genes typical of this condition. Overall, this review aims to contribute to filling the gap in the literature regarding the consequences at the muscular level of the relationship between oxidative stress and neurodegenerative diseases. Full article

Neohesperidin (NH), a bioactive flavanone glycoside, exhibits multifaceted pharmacological properties including antioxidant and anti-inflammatory activities. However, its clinical application is severely constrained by inherent physicochemical limitations such as poor aqueous solubility and instability under physiological conditions. To address these challenges, this study developed a dual-carrier nano-liposomal system through the synergistic integration of phospholipid complexation and hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion technologies. Two formulations—NH-PC (phospholipid complex) and NH-PC-CD (phospholipid/HP-β-CD hybrid)—were fabricated via ultrasonication-assisted ethanol precipitation. Comprehensive characterization using FTIR and PXRD confirmed the amorphous dispersion of NH within lipid bilayers, with complete elimination of crystalline diffraction peaks, indicative of molecular-level interactions between NH’s hydroxyl groups and phospholipid polar moieties. The engineered nanosystems demonstrated remarkable solubility enhancement, achieving 321.77 μg/mL (NH-PC) and 318.75 μg/mL (NH-PC-CD), representing 2.01- and 1.99-fold increases over free NH. Encapsulation efficiencies exceeded 95% for both formulations, with sustained release profiles revealing 60.81% (NH-PC) and 80.78% (NH-PC-CD) cumulative release over 72 h, governed predominantly by non-Fickian diffusion kinetics. In vitro gastrointestinal simulations highlighted superior bioaccessibility for NH-PC-CD (66.35%) compared to NH-PC (58.52%) and free NH (20.85%), attributed to enhanced stability against enzymatic degradation. Storage stability assessments further validated the robustness of HP-β-CD-modified liposomes, with NH-PC-CD maintaining consistent particle size (<3% variation) and encapsulation efficiency (>92%) over 30 days. Antioxidant evaluations demonstrated concentration-dependent DPPH radical scavenging, wherein nanoencapsulation significantly amplified NH’s activity compared to its free form. This study establishes a paradigm for dual-functional nanocarriers, offering a scalable strategy to optimize the delivery of hydrophobic nutraceuticals while addressing critical challenges in bioavailability and physiological stability. Full article

Reactive oxygen species (ROS) serve as crucial signaling molecules that facilitate the interactions between plants and environmental stimuli, thereby influencing a wide range of physiological and biochemical processes, such as vegetative apex development and organ morphogenesis. In response to environmental stresses, plants enhance ROS production to initiate a robust protective response. To manage excessive ROS levels, plants have developed a sophisticated antioxidative defense system comprising both enzymatic and non-enzymatic components, which work synergistically to scavenge ROS and alleviate ROS-induced deleterious effects on biomolecules. This review provides a comprehensive overview of ROS metabolism, signaling transduction pathways, and their implications for the oxidative modification of nucleic acids, lipids, and proteins within plant cells. Full article

Oxidative stress, arising from environmental challenges such as drought, salinity, extreme temperatures, and pathogen attack, significantly impairs rice (Oryza sativa) growth, yield, and grain quality. This review provides a comprehensive synthesis of the mechanisms underlying oxidative stress in rice, with a focus on the generation of reactive oxygen species (ROS), their physiological and molecular impacts, and the antioxidant defense systems employed for mitigation. The roles of enzymatic and non-enzymatic antioxidants, along with key transcription factors, signaling pathways, and stress-responsive genes, are explored in detail. This study further highlights varietal differences in oxidative stress tolerance, emphasizing traditional, modern, and genetically engineered rice cultivars. Recent advances in breeding strategies, gene editing technologies, and multi-omics integration are discussed as promising approaches for enhancing stress resilience. The regulatory influence of epigenetic modifications and small RNAs in modulating oxidative stress responses is also examined. Finally, this paper identifies critical research gaps—including the need for multi-stress tolerance, long-term field validation, and deeper insights into non-coding RNA functions—and offers recommendations to inform the development of climate-resilient rice varieties through integrative, sustainable strategies. Full article

Pyropia haitanensis (T.J. Chang and B.F. Zheng) undergoes periodic dehydration and rehydration cycles, necessitating robust adaptive mechanisms. Despite extensive research on its physiological responses to desiccation stress, the comprehensive metabolic pathways and recovery mechanisms post-rehydration remain poorly understood. This study investigated the metabolic responses of P. haitanensis to varying degrees of desiccation stress using LC-MS and UPLC-MS/MS. Under mild dehydration, the thallus primarily accumulated sugars and proline, while moderate and severe dehydration triggered the accumulation of additional osmoprotectants like alanine betaine and trehalose to maintain turgor pressure and water retention. Concurrently, the alga activated a potent antioxidant system, including enzymes and non-enzymatic antioxidants, to counteract the increased reactive oxygen species levels and prevent oxidative damage. Hormonal regulation also plays a crucial role in stress adaptation, with salicylic acid and jasmonic acid upregulating under mild dehydration and cytokinins and gibberellin GA₁₅ accumulating under severe stress. Rehydration triggered the recovery process, with indole acetic acid, abscisic acid, and jasmonic acid promoting rapid cell recovery. Additionally, arachidonic acid, acting as a signaling molecule, induced general stress resistance, facilitating the adaptation of the thallus to the dynamic intertidal environment. These findings reveal P. haitanensis’ metabolic adaptation strategies in intertidal environments, with implications for enhancing cultivation and stress resistance in this economically important seaweed. Full article

The current study researched the biostimulant impacts of a natural-based solution (NBS) that contained eucalyptus and rosemary essential oils on cucumber crops. The effects of NBS (one time-NBS1; two times-NBS2) application on plant development and physiological attributes (chlorophylls, stomatal conductance), total phenolics, non-enzymatic and enzymatic antioxidant activities, leaf minerals content, cucumber quality attributes at harvest and after one-week storage were assessed through experiments. NBS1 spraying was less effective than NBS2 application because it resulted in a decrease in mineral accumulation (like reduced nitrogen) and other physiological characteristics (like chlorophylls). The plants’ enhanced oxidative stress and activation of several enzymatic antioxidant systems were reflected in the use of a commercial solution (CS) based on amino acids and biostimulants, which also boosted stomatal conductance, reduced nitrogen, calcium, and magnesium accumulation, and antioxidant capacity. No differences were found in plant height, number of leaves, plant biomass, chlorophyll fluorescence, total phenols, and various fruit quality attributes, including firmness, fresh weight, respiration rates, total soluble solids, ascorbic acid, decay, and marketability among the treatments. In fact, the effects of both CS and NBS treatment on cucumber plants and fruits were less pronounced, suggesting that more than two applications should be explored in the future. Full article

Plants face various abiotic stresses in their natural environments that trigger the production of reactive oxygen species (ROS), leading to oxidative stress and potential cellular damage. This comprehensive review examines the interplay between plant antioxidant defense systems and ROS under abiotic stress conditions. We discuss the major enzymatic antioxidants, including superoxide dismutase, catalase, reductases, and peroxidases, as well as non-enzymatic antioxidants, such as ascorbic acid, glutathione, polyphenols, and flavonoids, which play crucial roles in ROS detoxification. This review elaborates on different types of ROS, their production sites within plant cells, and their dual role as both damaging oxidants and key signaling molecules. We discuss how various abiotic stresses—including heat, cold, drought, flooding, salinity, and heavy metal toxicity—induce oxidative stress and trigger specific antioxidant responses in plants. Additionally, the mechanisms of ROS generation under these abiotic stress conditions and the corresponding activation of enzymatic and non-enzymatic scavenging systems are discussed in detail. This review also discusses recent advances in understanding ROS signaling networks and their integration with other stress-response pathways. This knowledge provides valuable insights into plant stress-tolerance mechanisms and suggests potential strategies for developing stress-resistant crops by enhancing antioxidant defense systems. Moreover, the strategic ROS modulation through priming, exogenous antioxidants, nanoparticles, or genetic tools can enhance plant resilience. Integrating these methods with agronomic practices (e.g., irrigation management) offers a sustainable path to climate-smart agriculture. Our review reveals that ROS accumulation can be detrimental; however, the coordinated action of various antioxidant systems helps plants maintain redox homeostasis and adapt to environmental stress. Full article

Heat stress (HS) is one of the most important stressors in chickens, and its adverse effects are primarily caused by disturbing the redox homeostasis. An increase in electron leakage from the mitochondrial electron transport chain is the major source of free radical production under HS, which triggers other enzymatic systems to generate more radicals. As a defense mechanism, cells have enzymatic and non-enzymatic antioxidant systems that work cooperatively against free radicals. The generation of free radicals, particularly the reactive oxygen species (ROS) and reactive nitrogen species (RNS), under HS condition outweighs the cellular antioxidant capacity, resulting in oxidative damage to macromolecules, including lipids, carbohydrates, proteins, and DNA. Understanding these detrimental oxidative processes and protective defense mechanisms is important in developing mitigation strategies against HS. This review summarizes the current understanding of major oxidative and antioxidant systems and their molecular mechanisms in generating or neutralizing the ROS/RNS. Importantly, this review explores the potential mechanisms that lead to the development of oxidative stress in heat-stressed chickens, highlighting their unique behavioral and physiological responses against thermal stress. Further, we summarize the major findings associated with these oxidative and antioxidant mechanisms in chickens. Full article

Termitomyces, a rare edible fungus with both nutritional and medicinal value, has garnered significant attention for its antioxidant properties. This study aims to elucidate the effects of various nutritional components on the antioxidant activity of Termitomyces. Through assays including FRAP, DPPH, ABTS, and •OH scavenging activity, strain XNQL025, which exhibits high antioxidant activity, was identified. Subsequent optimization of culture medium components using single-factor experiments and response surface methodology revealed that aspartic acid (Asp) significantly enhances the antioxidant capacity of this strain. Transcriptomic analysis showed that Asp activates key pathways, including glycolysis/gluconeogenesis, propanoate metabolism, amino sugar and nucleotide sugar metabolism, valine–leucine–isoleucine biosynthesis, and tryptophan metabolism, along with modulating the peroxisome and mitogen-activated protein kinase (MAPK) signaling pathways. These regulatory actions promote the synthesis of antioxidant compounds and establish a multi-layered antioxidant defense system comprising enzymatic (catalase) and non-enzymatic (leucine/chitooligosaccharides) components. The synergistic interaction between these systems significantly strengthens the antioxidant defense capacity of Termitomyces. This study is the first to elucidate the molecular network by which Asp enhances the antioxidant activity of Termitomyces, thereby providing a foundation for its development as a natural antioxidant. Full article