Search Results (787)

Sepsis is a clinical syndrome characterized by a dysregulated host response to infection, frequently resulting in septic shock and multi-organ failure. Emerging evidence highlights the critical role of neutrophil extracellular traps (NETs) in the pathophysiology of sepsis. NETs are extracellular structures composed of chromatin DNA, histones, and granular proteins released by neutrophils through a specialized form of cell death known as NETosis. While NETs contribute to the containment of pathogens, their excessive or dysregulated production in sepsis is associated with endothelial damage, immunothrombosis, and organ dysfunction. Several NET-associated biomarkers have been identified, including circulating cell-free DNA (cfDNA), histones, MPO-DNA complexes, and neutrophil elastase–DNA complexes, which correlate with the disease severity and prognosis. Therapeutic strategies targeting NETs are currently under investigation. Inhibition of NET formation using PAD4 inhibitors or ROS scavengers has shown protective effects in preclinical models. Conversely, DNase I therapy facilitates the degradation of extracellular DNA, reducing the NET-related cytotoxicity and thrombotic potential. Additionally, heparin and its derivatives have demonstrated the ability to neutralize NET-associated histones and mitigate coagulopathy. Novel approaches include targeting upstream signaling pathways, such as TLR9 and IL-8/CXCR2, offering further therapeutic promise. Full article

The development of ceria (CeO_2−x)-based nanoantioxidants requires fine-tuning of structural and surface properties for enhancing antioxidant behavior in biological environments. In this contest, here ultrasmall water-dispersible CeO_2−x nanoparticles (NPs), characterized by a high Ce³⁺/Ce⁴⁺ ratio, were synthesized in a non-polar solvent and phase-transfer to an aqueous environment through ligand-exchange reactions using citric acid (CeO_2−x@Cit) and post-treatment with dopamine hydrochloride (CeO_2−x@Dopa). The concept behind this work is to enhance via surface engineering the intrinsic antioxidant properties of CeO_2−x NPs. For this purpose, thanks to electron transfer reactions between dopamine and CeO_2−x, the CeO_2−x@Dopa was obtained, characterized by increased surface Ce³⁺ sites and surface functionalized with polydopamine bearing o-quinone structures as demonstrated by complementary spectroscopic (UV–vis, FT-IR, and XPS) characterizations. To test the antioxidant properties of CeO_2−x NPs, the scavenging activity before and after dopamine treatment against artificial radical 1,1-diphenyl-2-picrylhydrazyl (DPPH^·) and the ability to reduce the reactive oxygen species in Diencephalic Immortalized Type Neural Cell line 1 were evaluated. CeO_2−x@Dopa demonstrated less efficiency in DPPH^· scavenging (%radical scavenging activity 13% versus 42% for CeO_2−x@Cit before dopamine treatment at 33 μM DPPH^· and 0.13 mg/mL loading of NPs), while it markedly reduced intracellular ROS levels (ROS production 35% compared to 66% of CeO_2−x@Cit before dopamine treatment with respect to control—p < 0.001 and p < 0.01, respectively). While steric hindrance from the dopamine-derived polymer layer limited direct electron transfer from CeO_2−x NP surface to DPPH^·, within cells the presence of o-quinone groups contributed with CeO_2−x NPs to break the autoxidation chain of organic substrates, enhancing the antioxidant activity. The functionalization of NPs with o-quinone structures represents a valuable approach to increase the inherent antioxidant properties of CeO_2−x NPs, enhancing their effectiveness in biological systems by promoting additional redox pathways. Full article

Light quality and duration profoundly influence the growth and productivity of plant species. This study investigated the effects of a blue–red LED light combination, known to induce flowering, on the physiological state and content of biologically active substances in catmint (Nepeta nuda L.) grown under controlled in vitro conditions. White light (W) was used as a control and compared with two blue–red intensities: BR (high-intensity blue–red light) and BRS (low-intensity blue–red light or “BR with shadow”). BR-treated plants showed increased leaf area, mesophyll thickness, biomass and starch content but reduced levels of plastid pigments. BR also modified the oxidative state of plants by inducing lipid peroxidation while simultaneously activating ROS scavenging mechanisms and enhancing phenolic antioxidants. Interestingly, BR decreased the accumulation of the Nepeta sp.-specific iridoid, nepetalactone. These effects appear to be regulated by the phytohormones auxin, abscisic acid and jasmonates. BRS treatment produced effects similar to the W control but led to increased plant height and reduced leaf area and thickness. Both BR and BRS regimes induced the accumulation of proteins and amino acids. We conclude that blue–red light can enhance the survival capacity of micropropagated N. nuda during subsequent soil adaptation, suggesting that similar light pre-treatment could improve plant performance under stress conditions. 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

Male infertility is a pathological condition that affects many subjects and for which a progressive increase in cases has been observed in recent years. The mechanisms underlying male reproductive system dysfunction are not fully understood and the specific drugs use has not produced optimal results. Therefore, the focus on developing new therapeutic options to prevent or treat this dysfunction is continuously growing. Defective sperm function has been associated with oxidative stress (OS) due to reactive oxygen species (ROS) excessive production. OS is related to mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation, and ultimately sperm cell death. Many defense mechanisms to protect from ROS injuries have been developed; natural antioxidants, such as vitamin C and E are able to interact with oxidizing radicals, neutralizing them. Interestingly, resveratrol (RSV), a natural polyphenol with proven health-promoting actions, has been found to be an effective free radical scavenger in several in vitro and in vivo models, providing protection against OS. In this review, we discussed mechanisms related to the modulation of redox homeostasis in the testis and how the alteration of these processes can determine a damage in testicular function; particularly, we focused on the antioxidant properties of RSV that could give beneficial effects in preserving male fertility. Full article

Caleosin/peroxygenases (CLO/PXGs) play critical functional roles during plant development, oxylipin metabolism, and the response to abiotic/biotic stressors and environmental toxins. In Oryza sativa, peroxygenase-9 (OsPXG9) catabolizes intermediates in oxylipin biosynthesis produced by lipoxygenase-9 (9-LOX) and scavenges HOOH and CuOOH by transferring oxygen to hydroxy fatty acids (HFAs) but not to the free fatty acids. The resulting epoxide derivatives of HFAs are then enzymatically or non-enzymatically hydrolyzed into the corresponding trihydroxy derivatives. Results presented here demonstrate OsPXG9′s specificity for catabolizing products of the 9-LOX (and not for the 13-LOX) pathway of oxylipin biosynthesis. Overexpression of OsPXG9 reduces ROS (reactive oxygen species) abundance and reduces drought- and salt-stress-induced apoptotic cell death. The high expression level of OsPXG9 also stimulates drought- and salt-induced but not basal expression of antioxidant enzymes/pathways in plants, thereby increasing cellular resistance to drought. These results suggest that OsPXG9 decreases ROS abundance and is essential to increase resilience in rice plants exposed to exogenous or endogenous abiotic stress. Full article

Infertility is a significant global health concern, and incorporating antioxidants into sperm preparation media is one strategy to enhance sperm quality and decrease infertility rates. This study aimed to investigate the phytochemical compounds of red cotton stamen extracts and their effects as antioxidants in improving the quality of bull frozen semen. Among the extracts, RCU contained the highest levels of total phenolics, total tannins, and total monomeric anthocyanins along with the strongest ABTS free radical scavenging activity and protein denaturation inhibition. Exposing sperm to FeSO₄-induced oxidative stress resulted in significantly reduced motility, viability, and normal morphology. However, treatment with RCD, RCU, and RCM improved these parameters. Additionally, the FeSO₄-induced group showed elevated levels of reactive oxygen species (ROS) and advanced glycation end products (AGEs) compared to the normal control, whereas all red cotton stamen extracts effectively reduced these levels. In conclusion, red cotton stamen extracts, rich in phenolic bioactive compounds, demonstrated strong free radical scavenging capacity and improved sperm motility, viability, and morphology by neutralizing free radicals and enhancing antioxidant defenses. These findings suggest that the red cotton stamen extracts, particularly RCD and RCU, offer benefits for sperm preservation. Full article

Drought stress poses a major constraint on global crop productivity. Although aspartic proteases (APs) are primarily characterized in plant disease resistance, their roles in abiotic stress adaptation remain largely unexplored. Here, we demonstrate that rice (Oryza sativa) OsAP4 critically regulates drought stress tolerance at the seedling stage. Genetic manipulation through overexpression (OsAP4-OE) or CRISPR knockout (OsAP4-KO) resulted in significantly reduced or enhanced stress tolerance compared to wild-type plants, respectively. Through integrated approaches including yeast two-hybrid, bimolecular fluorescence complementation, pull-down, co-immunoprecipitation, and protein degradation assays, we established that OsAP4 physically interacts with and destabilizes OsCATA/OsCATC, two catalase enzymes responsible for reactive oxygen species (ROS) scavenging. Importantly, OsAP4 modulates ROS production under drought stress treatment conditions. Together, these findings reveal a novel OsAP4-OsCATA/OsCATC regulatory module governing rice drought stress responses. Full article

UVB skin pathology is initiated by reactive oxygen species (ROS), differentiating this condition from other inflammatory diseases involving first the immune cell activation by danger or pathogen molecular patterns followed by oxidative stress. Resolvin D2 (RvD2) has been found to reduce inflammation in preclinical models. However, whether or not RvD2 reduces skin pathology caused by UVB irradiation is not yet known. Therefore, the efficacy of RvD2 on skin pathology triggered by UVB irradiation in female hairless mice was assessed. RvD2 (0.3, 1 or 3 ng/mouse, i.p.) was found to protect the skin against UVB inflammation, as observed in the reduction in edema (46%), myeloperoxidase activity (77%), metalloproteinase-9 activity (39%), recruitment of neutrophils/macrophages (lysozyme⁺ cells, 76%) and mast cells (106%), epidermal thickening (93%), sunburn cell formation (68%), collagen fiber breakdown (55%), and production of cytokines such as TNF-α (100%). Considering the relevance of oxidative stress to UVB irradiation skin pathologies, an important observation was that the skin antioxidant capacity was recovered by RvD2 according to the results that show the ferric reducing antioxidant power (68%), cationic radical scavenges (93%), catalase activity (74%), and the levels of reduced glutathione (48%). Oxidative damage was also attenuated, as observed in the reduction in superoxide anion production (69%) and lipid hydroperoxides (71%). The RvD2 mechanism involved the inhibition of NF-κB activation, as observed in the diminished degradation of IκBα (48%) coupled with a reduction in its downstream targets that are involved in inflammation and oxidative stress, such as COX-2 (66%) and gp91^phox (77%) mRNA expression. In conclusion, RvD2 mitigates the inflammatory and oxidative pathologic skin aggression that is triggered by UVB. Full article

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

Background: Under oxidative stress conditions, the increased levels of reactive oxygen species (ROS) within cells disrupt the intracellular homeostasis. Tartary buckwheat peptides exert their effects by scavenging oxidative free radicals, such as superoxide anion and hydrogen peroxide, thereby reducing oxidative damage within cells. Meanwhile, these peptides safeguard mitochondria by maintaining the mitochondrial membrane potential, decreasing the production of mitochondrial oxygen free radicals, and regulating mitochondrial biogenesis and autophagy to preserve mitochondrial homeostasis. Through these mechanisms, Tartary buckwheat peptides restore the intracellular redox balance, sustain cellular energy metabolism and biosynthesis, and ensure normal cellular physiological functions, which is of great significance for cell survival and adaptation under oxidative stress conditions. Objectives: In this experiment, a classical cellular oxidative stress model was established. Indicators related to antioxidant capacity and mitochondrial membrane potential changes, as well as pathways associated with oxidative stress, were selected for detection. The aim was to elucidate the effects of Tartary buckwheat oligopeptides on the metabolism of cells in response to oxidative stress. Methods: In this study, we established an oxidative damage model of mouse skeletal muscle myoblast (SOL8) cells using hydrogen peroxide (H₂O₂), investigated the pre-protective effects of Tartary buckwheat oligopeptides on H₂O₂-induced oxidative stress damage in SOL8 cells at the cellular level, and explored the possible mechanisms. The CCK-8 method is a colorimetric assay based on WST-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodiumsalt], which is used to detect cell proliferation and cytotoxicity. Results: The value of CCK-8 showed that, when the cells were exposed to 0.01 mmol/L H₂O₂ for 1 h and 10 mg/mL Tartary buckwheat oligopeptides intervention for 48 h, these were the optimal conditions. Compared with the H₂O₂ group, the intervention group (KB/H₂O₂ group) showed that the production of ROS was significantly reduced (p < 0.001), the malondialdehyde (MDA) content was significantly decreased (p < 0.05), and the activity of catalase (CAT) was significantly increased (p < 0.01); the mitochondrial membrane potential in the KB/H₂O₂ group tended to return to the level of the control group, and they all showed dose-dependent effects. Compared with the H₂O₂ group, the mRNA expression of KEAP1 in the KB/H₂O₂ group decreased, while the mRNA expression of NRF2α, HO-1, nrf1, PGC-1, P62, and PINK increased. Conclusions: Therefore, Tartary buckwheat oligopeptides have a significant pre-protective effect on H₂O₂-induced SOL8 cells, possibly by enhancing the activity of superoxide dismutase, reducing ROS attack, balancing mitochondrial membrane potential, and maintaining intracellular homeostasis. Full article

The cryopreservation of boar sperm effectively extends its storage period but often leads to increased reactive oxygen species (ROS) production, compromising sperm quality. Plant extracts, rich in bioactive compounds such as polyphenols and flavonoids, have been shown to reduce ROS. Djulis (Chenopodium formosanum), also known as the “ruby of cereals”, is nutritionally rich and holds potential as a cryoprotective additive. This study aimed to determine the optimal concentration of extracts from different parts of djulis, including unhulled seeds and stems, for effective boar semen cryopreservation. Fresh semen from Taiwan indigenous boars was diluted with a modified GLT-cryoprotectant extender containing glycerol, low-density lipoprotein (LDL), and trehalose. The experimental groups included DSS25, DSS50, DS25, and DS50—representing djulis unshelled seed at 25 mg/mL and 50 mg/mL, and djulis stem at 25 mg/mL and 50 mg/mL in distilled water, respectively—alongside a control group without additives. Post-thaw assessments included sperm motility, kinetic parameters, viability, acrosome integrity, and the antioxidant properties of djulis extracts, such as DPPH radical scavenging activity and total phenolic acid content. Results showed that total motility (TM) was significantly higher in the DSS25 (48.8 ± 3.9), DSS50 (49.0 ± 6.7), and DS50 (49.0 ± 2.4) groups compared to the control group (31.3 ± 4.8). Similarly, progressive motility (PM) was significantly improved in DSS25 (27.5 ± 2.7) and DSS50 (26.8 ± 4.1) versus the control (12.8 ± 3.2). However, for straightness (STR), the control group (87.8 ± 1.3) exhibited significantly higher values than the DS50 group (83.5 ± 1.3) (p < 0.05). Viability and acrosome integrity showed no significant differences across groups. In conclusion, djulis extracts positively influence sperm motility and forward movement, with 1% djulis extract confirmed to enhance the quality of cryopreserved semen. Future research will focus on determining the optimal dosage of djulis extract for improved cryopreservation outcomes. Full article

Strawberry (Fragaria × ananassa Duch.) is an important fruit worldwide whose growth, development, and productivity are threatened by salinity. The WRKY transcription factors (TFs) were reported to play an important role in regulating abiotic stresses response. However, research on their roles to regulate salt stress tolerance in strawberry remains limited. In current study, the FvWRKY75 gene was isolated and characterized from the Ruegen strawberry, and induced by various stress treatment. The results showed that the FvWRKY75 transcription factor was a transcriptional activator and localized in the nucleus. Phenotypic and physiological analysis revealed that ectopic expression of FvWRKY75 in Arabidopsis improved salt tolerance by enhancing the antioxidant system activities, modulating ROS scavenging and upregulating stress-related genes. Y1H and dual luciferase assays revealed that FvWRKY75 can directly bind to the promoter of the FvCRK5 gene by recognizing the W-box element. Compared with the WT, ectopic expression of FvCRK5 gene in Arabidopsis enhanced salt tolerance characterized by the reduced ROS accumulation, higher chlorophyll content, lower MDA content, and enhanced SOD and POD activity. Herein, the FvWRKY75 gene acted as a positive regulator in salt stress resistance, at least in part, via the WRKY-CRK network to regulate the antioxidant enzyme defense system and stress-related genes to regulate salt stress tolerance in strawberry. Full article

Epigeal cotyledons with excised embryonic axes are often used as a model system to study the processes of cell division and expansion. These processes are regulated by diverse phytohormones and signaling molecules. Phytohormones modulate antioxidant defense systems and interact with reactive oxygen species (ROS) to synchronize normal plant cell growth. This study provides new information concerning alterations in enzymatic antioxidants linked to the production and scavenging of ROS in excised epigeal cotyledons of zucchini grown on solutions of methyl jasmonate (MeJA) and cytokinins (CKs)—N⁶-benzyl adenine and N₁-(2-chloropyridin-4-yl)-N₂-phenylurea—in the presence or absence of light under laboratory conditions. The cotyledon material was used to determine the dynamics of selected biochemical parameters starting from the 2nd to the 6th day of incubation. In general, our results revealed that exogenous MeJA caused a reduction in the content of hydrogen peroxide (H₂O₂) and free proline, as well as in the activity of superoxide dismutase (SOD), guaiacol peroxidase (POX) and catalase (CAT) in dark-grown cotyledons. Applied alone, both cytokinins increased most of the parameters studied, except proline and protein levels. However, when MeJA was combined with CKs, it acted in a diverse manner, ranging from antagonistic to synergistic depending on the cytokinin type, parameter measured and light regime. Similar alterations were also found in the levels of leaf pigments in the cotyledons grown under light conditions. In general, the changes in the antioxidant enzyme activities due to light were more intense than those observed in dark-grown cotyledons. The data obtained show, for the first time, the involvement of the hormonal interplay between MeJA and CKs on the biochemical changes in antioxidant defense during cotyledon growth under different light conditions. Full article

Background: Natural astaxanthin, a commercially valuable carotenoid, is primarily sourced from Haematococcus pluvialis, a microalga known for its remarkable resilience to environmental stress. Methods: In this study, the physiological and transcriptomic responses of H. pluvialis to ND were investigated at various time points under high light conditions. Results: Under high light conditions, nitrogen deprivation (ND) enhances astaxanthin content (33.23 mg g⁻¹) while inhibiting the formation of the secondary cell wall (SCW), increasing astaxanthin content by 29% compared to the nitrogen-replete group (25.64 mg g⁻¹); however, the underlying mechanisms remain unclear. ND reduced chlorophyll fluorescence parameters, elevated reactive oxygen species (ROS) levels, and increased starch and total sugar accumulation while decreasing protein and lipid content. Fatty acid content increased on the first day but had declined by the fifth day. A transcriptomic analysis revealed substantial alterations in gene expression in response to ND. Genes associated with the TCA cycle, glycolysis, astaxanthin biosynthesis, and cell motility were upregulated, while those involved in photosynthesis, lipid synthesis, ribosome biogenesis, amino acid synthesis, and SCW synthesis were downregulated. Additionally, ND modulated the expression of genes involved in ROS scavenging. Conclusions: These findings provide critical insights into the adaptive mechanisms of H. pluvialis in response to ND under high light, contributing to the development of strategies for enhanced production of astaxanthin-rich motile cells. Full article