Search Results (208)

Reactive oxygen species (ROS) are often seen solely as harmful byproducts of oxidative metabolism, yet evidence reveals their paradoxical roles in both promoting and inhibiting cancer progression. Despite advances, precise context-dependent mechanisms by which ROS modulate oncogenic signaling, therapeutic response, and tumor microenvironment dynamics remain unclear. Specifically, the spatial and temporal aspects of ROS regulation (i.e., the distinct effects of mitochondrial versus cytosolic ROS on the PI3K/Akt and NF-κB pathways, and the differential cellular outcomes driven by acute versus chronic ROS exposure) have been underexplored. Additionally, the specific contributions of ROS-generating enzymes, like NOX isoforms and xanthine oxidase, to tumor microenvironment remodeling and immune modulation remain poorly understood. This review synthesizes current findings with a focus on these critical gaps, offering novel mechanistic insights into the dualistic nature of ROS in cancer biology. By systematically integrating data on ROS source-specific functions and redox-sensitive signaling pathways, the complex interplay between ROS concentration, localization, and persistence is elucidated, revealing how these factors dictate the paradoxical support of tumor progression or induction of cancer cell death. Particular attention is given to antioxidant mechanisms, including NRF2-mediated responses, that may undermine the efficacy of ROS-targeted therapies. Recent breakthroughs in redox biosensors (i.e., redox-sensitive fluorescent proteins, HyPer variants, and peroxiredoxin–FRET constructs) enable precise, real-time ROS imaging across subcellular compartments. Translational advances, including redox-modulating drugs and synthetic lethality strategies targeting glutathione or NADPH dependencies, further highlight actionable vulnerabilities. This refined understanding advances the field by highlighting context-specific vulnerabilities in tumor redox biology and guiding more precise therapeutic strategies. Continued research on redox-regulated signaling and its interplay with inflammation and therapy resistance is essential to unravel ROS dynamics in tumors and develop targeted, context-specific interventions harnessing their dual roles. Full article

Nanoceria is a multifaceted enzyme-like catalyst of ROS-mediated (reactive oxygen species) reactions, which results in its multiple biomedical applications. Biodegradable polysaccharide coatings improve biocompatibility, while the effects of these coatings on the ROS-related activity of nanoceria in cells need thorough studies. Here, we used human embryonic lung fibroblasts to study the effects of maltodextrin and chitosan coatings on cellular oxidative metabolism of nanoceria by examining cell viability, mitochondrial potential, accumulation of nanoparticles in cells, intracellular ROS, expression of NOX4 (NADPH oxidase 4), NRF2 (nuclear factor erythroid 2-related factor 2), NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), and STAT3 (signal transducer and activator of transcription 3) proteins as well as the expression of biomarkers of DNA damage/repair, cell proliferation, and autophagy. Both types of polysaccharide-coated nanoceria were non-toxic up to millimolar concentrations. For maltodextrin-coated nano-CeO₂, in contrast to bare nanoparticles, there was no oxidative DNA damage/repair with moderate activation of NOX4 expression. Like bare nanoceria, maltodextrin-coated nanoparticles demonstrate the proliferative impact and do not activate autophagy. However, maltodextrin-coated nanoparticles have an activating impact on mitochondrial potential and the NF-κB pathway. Chitosan-coated nanoceria causes short-term intracellular oxidative stress, activation of the expression of NOX4, STAT3, and NRF2, oxidative DNA damage, and double-strand breaks accompanied by activation of DNA repair systems. In contrast to maltodextrin-coated nanoparticles, chitosan-coated nanoceria inhibits the NF-κB pathway and activates autophagy. These findings would be useful in the development of advanced nanoceria-based pharmaceuticals and contribute to the understanding of the biochemical properties of nanoceria as a modulator of ROS-dependent signaling pathways. Full article

The NADPH oxidase 2 (NOX2) complex is a critical regulator of immune homeostasis. It is utilized by phagocytic leukocytes including neutrophils, monocytes, and macrophages to generate reactive oxygen species (ROS) that drive microbe clearance and modulate inflammatory responses. Within NOX2, the essential scaffold protein p47phox plays a pivotal role in orchestrating enzyme activation and facilitating the assembly and membrane translocation of cytosolic components of the complex. Tight regulation of p47phox activity is crucial, and its disruption is linked to a number of pathological conditions. Conversely, its hyperactivity contributes to oxidative stress, tissue damage, the progression of cardiovascular diseases, neurodegenerative disorders, inflammatory conditions, metabolic syndromes, and cancer. In this review, we detail the structural and functional roles of p47phox, mechanisms of its regulation, and its multifaceted contributions to disease pathogenesis. We explore the latest advances in p47phox-targeted therapeutic strategies, discuss current challenges in the field, highlight p47phox’s potential as a transformative target in redox biology and propose future directions to unlock its clinical utility. 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

CD38, a nicotinamide adenine dinucleotide (NAD⁺) glycohydrolase, increases in old murine macrophages after infection compared to young controls. We aimed to determine whether the increase in CD38 in old murine macrophages after infection is directly associated with enhanced inflammation induced by the oral pathogens Aggregatibacter actinomycetemcomitans (Aa) or Porphyromonas gingivalis (Pg) when compared to young controls. Additionally, we determined the effects of a specific CD38 inhibitor (78c) on CD38, NAD⁺, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α expressions, and anti-oxidative responses in old murine macrophages induced by oral pathogens. Old and young murine macrophages were either uninfected or infected with the oral pathogens Aa or Pg for 1 to 24 h. Protein levels of CD38 and protein kinases, including nuclear factor kappa-B (NF-κB), phosphoinositide 3-kinase (PI3K), and mitogen-activated protein kinases (MAPKs), NAD⁺, and inflammatory cytokine (IL-1β, IL-6, TNF-α) levels were evaluated. Additionally, old murine macrophages were treated with a vehicle or a CD38 inhibitor (78c) and cells were either uninfected or infected with Aa or Pg. CD38, NAD⁺, cytokine (IL-1β, IL-6, TNF-α) levels, reactive oxygen species (ROS), NAPDH oxidase 1 (Nox1), and anti-oxidative enzymes, including superoxide dismutase1 (Sod1), glutathione peroxidase 4 (Gpx4), Peroxiredoxin 1 (Prdx1), thioredoxin reductase 1 (Txnrd1), and catalase (Cat), were evaluated. The results showed that old murine macrophages significantly enhanced CD38 and reduced NAD⁺ levels 24 h after Aa or Pg infection compared to young controls. This enhanced CD38 in old murine macrophages was not directly correlated with the activation of protein kinases (NF-κB, PI3K, and MAPKs), nor the (IL-1β, IL-6, TNF-α) levels in macrophages. The inhibition of CD38 by 78c reduced CD38, enhanced NAD⁺ levels, attenuated IL-1β, IL-6 and TNF-α pro-inflammatory cytokine levels, reduced ROS and Nox1 expressions, and enhanced expressions of Sod1, Gpx4, Prdx1, Txnrd1, and Cat in old murine macrophages infected with Aa or Pg. These results suggest that the inhibition of CD38 by 78c is a promising therapeutic strategy to treat aging-associated periodontitis. Full article

Diabetic muscular atrophy is a complication of diabetes mellitus that can decrease quality of life. Its complex mechanisms include alterations in proteolytic pathways, oxidative stress, and intracellular lipid accumulation. NADPH oxidase enzymes (NOX) play a key role in the production of ROS, contributing to oxidative damage and insulin resistance. Apocynin, a NOX inhibitor, has antioxidant and anti-inflammatory effects, suggesting its therapeutic potential in various diabetic complications. This study evaluated the impact of apocynin on the mechanisms of muscle atrophy in slow- and fast-twitch muscles of diabetic rats. Diabetes was induced in male Wistar rats by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Apocynin treatment (3 mg/kg/day) was administered for 8 weeks. Fasting blood glucose levels, lipid profile, and weight gain were measured. Both slow-twitch (soleus) and fast-twitch (extensor digitorum longus, EDL) skeletal muscles were weighed and used to assess triglycerides (TG) content, histological analysis, lipid peroxidation levels, and gene expression evaluated by qRT-PCR. Apocynin reduced blood glucose levels, improved body weight, and exhibited hypolipidemic effects. It significantly increased muscle weight in EDL and soleus, especially in EDL muscle, lowering triglycerides, lipid peroxidation, and increasing fiber size. Additionally, it decreased mRNA expression levels of MuRF-1, atrogin-1, myostatin and p47phox mRNA and upregulated PGC-1α and follistatin mRNA. Apocynin exerted a myoprotective effect by mitigating muscle atrophy in diabetic rats. Its effects were differentially mediated on TG accumulation and muscle fiber size, reducing oxidative stress, atrogene expression, and positively regulating PGC-1α. Full article

Obesity has been implicated in the induction of oxidative stress, which is thought to contribute to the pathogenesis of various cardiovascular diseases, including cardiac hypertrophy. However, the redox status during the early stages of cardiac hypertrophy remains inadequately characterized. In this study, we administered a high-fat diet (HFD) to C57BL/6N mice for 12 weeks. We investigated the expression of biomarkers associated with hypertrophy and oxidative stress, including lipid peroxidation, protein carbonylation, and the redox couples NADH/NAD⁺, NADPH/NADP⁺, and GSH/GSSG. Additionally, we assessed the expression levels and enzymatic activities of catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase. Following 12 weeks on a HFD, mice exhibited obesity and a 10% increase in the heart weight/tibia length ratio, together with an upregulation in the mRNA levels of β-myosin heavy chain, brain natriuretic peptide, and regulator of calcineurin 1, isoform 4. There was also a significant increase in NOX4 content in the heart of these animals; however, we observed no rise in protein carbonylation and a decrease in lipid peroxidation products. As for the redox couples, the GSH/GSSG ratio nearly doubled, while the NADH/NAD⁺ and NADPH/NADP⁺ ratios remained stable. All antioxidant enzyme mRNAs examined showed increased expression; however, only glutathione reductase showed higher activity. Our findings suggest that reductive stress is predominant within the cardiac environment of these animals. Full article

Background/Objectives: Strawberries are highly appreciated for their rich phytochemical composition, but rapid postharvest deterioration limits their shelf life and nutritional quality. This study aimed to investigate the metabolic changes occurring in both strawberry fruits and leaves during storage and to evaluate the NADPH oxidase 2 (NOX2) inhibitory potential of strawberry-derived metabolites. Methods: Untargeted LC-MS/MS analysis was conducted on fruit and leaf tissues stored at 8 ± 0.5 °C. A total of 37 metabolites were identified, including organic acids, phenolic acids, flavonoids, and hydroxycinnamic acid derivatives. Multivariate statistical analyses (ANOVA, PLS-DA, and volcano plots) were used to assess temporal and tissue-specific metabolic shifts. Additionally, a machine learning-based predictive model was applied to evaluate the NOX2 inhibitory potential of 24 structurally characterized metabolites. Results: Storage induced significant and tissue-specific metabolic changes. In fruits, malic acid, caffeic acid, and quercetin-3-glucuronide showed notable variations, while ellagic acid aglycone and galloylquinic acid emerged as prominent markers in leaves. The predictive model identified 21 out of 24 metabolites as likely NOX2 inhibitors, suggesting potential antioxidant and anti-inflammatory bioactivity. Conclusions: These findings provide new insights into postharvest biochemical dynamics in both strawberry fruits and leaves. The results highlight the value of leaves as a source of bioactive compounds and support their potential valorization in functional food and nutraceutical applications. Full article

Triterpenoids are the bioactive components in Inonotus obliquus with extensive medicinal prospects, but their low content in fermentation production is the main limiting factor for their application. This study focuses on nitric oxide (NO), an important signaling molecule within organisms, aiming to explore its inducing effect on the synthesis of triterpenes in I. obliquus and the potential signaling transduction mechanisms involved. Compared with the control group, the content of representative triterpenoid betulin increased by 70.59% after adding the NO donor sodium nitroprusside. Gene expression level detection revealed that NO mainly promotes its biosynthesis by activating the transcription of key enzyme genes in the downstream pathway of betulin biosynthesis, thereby increasing its abundance. Tracing upstream, the NO signal was found to induce the upregulation of genes related to cellular antioxidant and calcium ion signaling pathways. Notably, IoCAMP responded strongly to the NO signal, participating in the regulation of cytoplasmic Ca²⁺ concentration by altering the Ca²⁺ concentration of mitochondria together with IoCATP and IoCALM. Additionally, the signaling of changes in Ca²⁺ concentrations is likely to crosstalk with the reactive oxygen species (ROS) signaling pathway. The increase in enzyme activity of IoNOX after NO induction confirmed the activation of the ROS signaling pathway. It works in synergy with IoSOD and IoCAT to reduce oxidative damage and promote downstream triterpenoid biosynthesis. This study not only contributes to clarify the signaling pathways regulating NO-mediated triterpenoid biosynthesis but also provides a theoretical basis for the efficient production of triterpenoid active components in I. obliquus. Full article

Endometritis poses a significant challenge to the dairy industry, impairing bovine reproductive performance and causing substantial economic losses. Although Morinda officinalis oligosaccharides (MOO) exhibit anti-inflammatory properties, their therapeutic potential against endometritis remains unclear. This study investigated MOO’s protective effects against LPS-induced uterine injury in mice and inflammation in bovine endometrial epithelial cells (BENDs), and explored the underlying mechanisms. In mice, MOO attenuated uterine inflammation by improving histopathology, reducing pro-inflammatory cytokines and decreasing oxidative stress. In BEND cells, MOO alleviated LPS-induced inflammation, oxidative stress, and apoptosis via downregulating pro-inflammatory mediators (IL-1β, IL-6, TNF-α, IL-8, TLR4, RELA), restoring antioxidant enzymes (HMOX1, NQO1, Nrf2, NOX4), and modulating apoptosis markers (BAX, cleaved CASP3, CASP9, BCL2). MOO reduced ROS accumulation, preserved mitochondrial membrane potential, and inhibited calcium influx. Critically, the calcium channel agonist Bay K 8644 reversed MOO’s protective effects, confirming calcium signaling modulation as a key mechanism. This study provides the first evidence that MOO mitigates LPS-induced uterine damage and BENDs inflammation through calcium signaling regulation, suggesting its potential for treating inflammation-related reproductive disorders in livestock. Full article

Damp-heat diarrhea (DHD) in piglets presents as diarrhea and intestinal bleeding, significantly affecting both piglet health and the pig industry. Pulsatilla powder (PP), a herbal formulation composed of Pulsatilla, Rhizoma Coptidis, Phellodendron Bark, and Fraxini Cortex, has proven to be an effective treatment for DHD. Although the pentose phosphate pathway (PPP) has been associated with its therapeutic effects, the exact mechanism of action remains unclear. In this study, the DHD model in piglets was established to evaluate clinical symptoms, organ index, serum index, histological changes, colonic metabolites, and molecular mechanisms using techniques such as QPCR, ELISA, WB and metabolomics. PP improved intestinal health by restoring spleen and lung index, increasing LDL-C and HDL-C levels (HDL-C: p < 0.05), decreasing mRNA expression levels of IFN-γ and TNF-α mRNA (p < 0.01), and increasing MUC1 and MUC2 expression. Metabolomics analysis has identified 44 pathways, including pentose phosphate and glutathione pathways, and 132 differential metabolites have involved in DHD treatment. PP significantly reduced G6PD (p < 0.01), inhibited the pentose phosphate pathway, reduced NOX production (p < 0.01), and suppressed ROS production (p < 0.01). These effects alleviated oxidative stress and intestinal damage, demonstrating PP’s effectiveness in treating DHD by targeting critical enzymes and ROS levels. Full article

Hyperphosphataemia is a key contributor to oxidative stress (OS) and cellular dysfunction across various pathological conditions. While numerous studies have associated phosphate overload with redox imbalances, the role of NADPH oxidase (NOX) in this process has received limited attention. NOX enzymes are major enzymatic sources of reactive oxygen species (ROS), and their activation has been implicated in the progression of chronic kidney disease, vascular calcification, metabolic disorders, and cancer development. Under hyperphosphataemic conditions, excessive ROS production exacerbates endothelial dysfunction, promotes vascular smooth muscle cell transdifferentiation, induces chronic inflammation, and facilitates tumour progression. Despite increasing evidence linking phosphate metabolism to NOX activation, the underlying molecular mechanisms remain poorly characterised. This review critically examines the relationship between hyperphosphataemia and NADPH oxidase-mediated OS and explores its impact on disease pathophysiology. By providing an integrated analysis of the current findings, this work aims to highlight the pathological consequences of phosphate-induced OS and identify potential therapeutic strategies to mitigate its effects. Full article

NADPH oxidase enzymes (NOXs) are a family of enzymes generating superoxide, which form reactive oxygen species. NOX2 activity is a causative agent for the progression of many diseases: neurodegenerative, cardiovascular, immune dysregulations, and even hereditary diseases and cancer. Administering antioxidants helps in inhibiting NOX2 activity; however, the development of selective inhibitors may provide greater improvement in the therapy of diseases. Here, an optimized synthesis of two most promising NOX2 inhibitors based on the 3-(indolin-6-yl)-4-(N-pyrazole-sulfonamide)-1H-pyrrolo [2,3-b]pyridine structure, namely, GSK2795039 and NCATS-SM7270, and an isomeric derivative of the same class, IMBIOC-1, is reported. The new modified procedures simplify the isolation, reduce byproduct formation, and improve the yields in 0.1–1 g scale preparations. Molecular modeling of the structures of NOX2 complexes with inhibitors validated their binding at the same site as NADPH, with IMBIOC-1 forming the largest number of intermolecular interactions with the NOX2 active site. Testing the effects of the compounds on amyloid beta-induced oxidative stress and toxicity in HMC3 microglial cells showed that all three inhibitors completely prevented the pathological amyloid-beta effect. At the same time, NCATS-SM7270 and IMBIOC-1 provided a stronger protective effect on microglial cell survival than GSK2795039, which allowed us to assert the potential of those compounds as neuroprotective agents. Full article

Oxidative stress, a pivotal driver of neurodegenerative diseases, results from an imbalance between the generation of reactive oxygen species (ROS) and cellular antioxidant defenses. This review provides a comprehensive analysis of key oxidative stress sources, focusing on NADPH oxidase (NOX) hyperactivity and mitochondrial Uncoupling Protein (UCP) downregulation. Critically, we examine the therapeutic potential of phytochemicals in mitigating NOX-mediated ROS generation through direct enzyme inhibition, including impacts on NOX subunit assembly and gene expression. Furthermore, we explore the ability of phytochemicals to bolster cellular antioxidant defenses by activating the Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway, elucidating the upregulation of antioxidant genes, such as GPx, SOD, CAT, and HO-1. This review expands beyond confined overviews; emphasizes specific molecular interactions between phytochemicals and target proteins, including NOX isoforms; and provides an in-depth analysis of the specific antioxidant genes upregulated via Nrf2. This approach aims to pave the way for targeted and translatable therapeutic strategies in neurodegenerative diseases. Ultimately, this review illuminates the intricate molecular dynamics of oxidative stress in neurodegenerative diseases; underscores the potential of phytochemicals to restore redox homeostasis and reverse pathological conditions through precise modulation of key signaling pathways. Full article

Macrophage mitochondrial dysfunction, caused by oxidative stress, has been proposed as an essential event in the progression of chronic inflammation diseases, such as atherosclerosis. The cluster of differentiation-36 (CD36) and lectin-like oxLDL receptor-1 (LOX-1) scavenger receptors mediate macrophage uptake of oxidized low-density lipoprotein (oxLDL), which contributes to mitochondrial dysfunction by sustained production of mitochondrial reactive oxygen species (mtROS), as well as membrane depolarization. In the present study, the antioxidant mechanisms of action of the selective synthetic azapeptide CD36 ligand MPE-298 have been revealed. After binding to CD36, MPE-298 was rapidly internalized by and simultaneously induced CD36 endocytosis through activation of the Lyn and Syk (spleen) tyrosine kinases. Within this internalized complex, MPE-298 inhibited oxLDL/LOX-1-induced chemokine ligand 2 (CCL2) secretion, abolished the production of mtROS, and prevented mitochondrial membrane potential depolarization in macrophages. This occurred through the inhibition of the multiple-component enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) by oxLDL-activated LOX-1, which was further supported by the reduced recruitment of the p47phox subunit and small GTPase (Rac) 1/2/3 into the plasma membrane. A new mechanism for alleviating oxLDL-induced oxidative stress and inflammation in macrophages is highlighted using the CD36 ligand MPE-298. Full article