Search Results (245)

Oxidative stress caused by excessive reactive oxygen species (ROS) disrupts skin and oral epithelial homeostasis and contributes to skin aging, inflammation, periodontitis, and mucosal injury. As the principal defenders in both skin and oral mucosal tissues, keratinocytes are important responders to oxidative stress. However, most existing studies have examined skin or oral keratinocytes in isolation, with few comparative investigations of their tolerance, repair capacity, and antioxidant mechanisms under oxidative stress. In this study, we systematically compared immortalized oral keratinocytes (TIGK) and skin keratinocytes (HaCaT) under hydrogen peroxide (H₂O₂)-induced oxidative stress. Functional analyses, including cell survival, ROS accumulation, stress granule formation, in vitro wound healing, and proliferation recovery assays, were combined with transcriptomic profiling to evaluate differences in antioxidant and pro-oxidant systems. TIGK exhibited significantly higher survival rates, lower ROS accumulation, and superior migratory and proliferative recovery compared with HaCaT after oxidative insult. Transcriptomic analysis further revealed that TIGK consistently expressed higher levels of antioxidant genes and enzymes. In contrast, HaCaT showed greater ROS accumulation and relatively limited antioxidant defenses. The results show that oral and skin keratinocytes adopt distinct adaptive mechanisms under oxidative stress. The intrinsic redox advantage of oral keratinocytes provides new insights into their rapid wound-healing capacity and may inform strategies to enhance epithelial resilience. Full article

Background and Objectives: Oxidative stress plays a central role in numerous pathological and toxicological processes, and in vivo investigations are essential for understanding integrated systemic responses. Methylxanthines have been reported to modulate redox homeostasis through multiple mechanisms, but their effects in aquatic vertebrate models under metal nanoparticle-induced oxidative stress remain poorly characterized. Materials and Methods: In the present study, adult zebrafish were exposed for 15 days to ZnO nanoparticles (0.69 mg/L) as a pro-oxidant model, and to methylxanthines (caffeine, theobromine, theophylline; 50 mg/L). Oxidative stress biomarkers were assessed by measuring the levels of glutathione peroxidase 1 (GPx1), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) in whole-body homogenates using ELISA. Complementary molecular docking was performed to investigate methylxanthine–enzyme interactions. Results: The most substantial change was observed for SOD level, which significant increased compared to the control group (from 0.122 to 1.090 ng/g; p = 0.001), followed by CAT, which rose from 38.3 pg/g to 100.8 pg/g; p = 0.001), and GPX1 which increased from 84.3 pg/g to 142.2 pg/g; p = 0.011). In parallel, GSH levels decreased by 58.7% (p = 0.001). Co-exposure to methylxanthines significantly modulated the ZnO-NPs exposure response, by mitigating the increase in antioxidant enzyme levels and restoring glutathione. Among the tested compounds, theobromine exerted the strongest protective effect on GPx1 and GSH and caffeine primarily influenced CAT and SOD, whereas theophylline showed overall weaker responses. The molecular docking investigation indicated that all tested methylxanthines can attach to different cavities of the antioxidant enzymes. Theophylline and theobromine established hydrogen bonds and π-stacking interactions with the interfacing amino acids, potentially contributing to the modulation of enzymes stabilization and function under physiological conditions. Conclusions: ZnO-NPs trigger a robust systemic response in zebrafish, whereas methylxanthines display distinct compound-specific modulating effects. Full article

Heme, a protoporphyrin IX iron complex, functions as an essential prosthetic group in hemoglobin and myoglobin, mediating oxygen storage and transport. Additionally, heme serves as a critical cofactor in various enzymes such as cytochrome c, enabling electron transfer within the mitochondrial respiratory chain. Unlike protein-bound heme, free or labile heme exhibits cytotoxic, pro-oxidant, and pro-inflammatory properties. Elevated levels of free heme are associated with various pathophysiological conditions, including hemolytic disorders such as sickle cell disease, malaria, and sepsis. In this review, we introduce the physiological roles of heme and its involvement in human health and disease. We also examine the mechanisms of heme sensing and regulation in bacterial cells. A variety of analytical methods have been developed to detect and quantify heme, enabling differentiation between protein-bound and free forms. These tools are discussed in the context of their applications in studying cellular heme regulation and their use in monitoring pathological conditions in humans. In particular, we describe examples of biosensors employing bacterial heme sensor proteins as recognition elements. Full article

Ochratoxin A (OTA), Zearalenone (ZEA), and Fumonisins (FB) are common contaminants of poultry feed associated with oxidative damage and potentially dangerous residues in products from exposed animals. We investigated the molecular effects in broilers of a short-term (10 days) dietary exposure to OTA (0.26 mg/kg), ZEA (2.9 mg/kg), or FB (60 mg/kg) on cytochrome P450 enzymes (CYP), drug transporters (DT) and the antioxidant defence system. OTA markedly decreased serum antioxidant capacity, while all mycotoxins depressed reduced glutathione content and increased lipid peroxidation in the liver, indicating a hepatic pro-oxidant effect. All the tested mycotoxins also reduced both the activities and the gene expression of selected antioxidant enzymes in the liver and duodenum as a result of the modulation of the Nrf2/Keap1 pathway. Moreover, mycotoxins differentially altered the hepatic and intestinal gene expression of CYP enzymes (i.e., CYP2A6, CYP2C45, CYP3A4, and CYP1A isoforms). Finally, the transcription of selected DT (i.e., ABCB1, ABCC2 and ABCG2) was generally enhanced in both the liver and duodenum. In conclusion, short-term exposure to OTA, ZEA, or FB at dietary concentrations higher than those recommended in the EU, but occurring in third countries, not only disrupt the antioxidant defence but also affect the expression of CYP and DT, which might potentially alter the kinetics of drugs and toxicants. Our results provide new insights into mycotoxin adverse effects in the light to assess the effectiveness of new mitigation strategies that contribute to food and feed safety. Full article

Vitamin A (VA) is an essential micronutrient that improves growth, immune activity, and antioxidant responses in fish. This study focuses on optimizing VA dietary levels for Oncorhynchus kisutch (Coho salmon) alevins. A 12-week trial was conducted using seven diets containing graded dietary VA levels of 244, 957, 1902, 3494, 6906, 10,248, and 25,213 IU/kg. A total of 2100 fish were reared in 21 tanks; 100 fish were housed in each tank, and 3 tanks represented one treatment. Peak (SGR) and FBW were observed at 6906 IU/kg. Excess VA levels (>15,000 IU/kg) compromised feed conversion efficacy and led to oxidative stress. Analysis of proximate composition resulted in protein and lipid deposition at optimal VA levels. However, excess may have led to metabolic disturbances and reduced ash content. The activity of the antioxidant enzymes catalase (CA), acid phosphatase (ACP), alkaline phosphatase (AKP), and total superoxide dismutase (T-SOD) revealed biphasic patterns, peaking at 6906 IU/kg and dropping when VA levels were exceeded, inducing pro-oxidant effects. Malondialdehyde (MDA), the indicator of toxicity, had a minimal value of 15,000 IU/kg. VA accumulation in the liver showed a dose-dependent relationship, while excess storage (>25,000 IU/kg) induced hepatotoxicity. Quadratic regression was used to identify the optimum VA levels required in Coho salmon alevins, ranging from 6906 to 10,248 IU/kg. Polynomial quadratic regression results indicated that the predicted dietary inclusion of VA at 3000 IU/kg and 15,000 IU/kg may yield better results of T-SOD and MDA. Real-world experimentation is recommended to explore long-term VA optimization with other nutrients and promote better feed utilization and sustainable aquaculture practices. Full article

Background: Familial hypercholesterolemia (FH) is a monogenic disorder causing markedly elevated low-density lipoprotein cholesterol (LDL-C) and premature atherosclerosis. Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme in antioxidant defense via NADPH production. G6PD deficiency, an X-linked disorder impairing redox homeostasis, may contribute to cardiovascular disease (CVD) risk. This study examined whether G6PD deficiency increases CVD risk in FH patients. Methods: We retrospectively analyzed 217 FH patients. Clinical data included demographics, lipid profiles, G6PD status, and atherosclerotic CVD outcomes (coronary, cerebrovascular, or peripheral arterial disease). In a subset, FH was confirmed by LDLR gene sequencing, and G6PD Mediterranean and Seattle variants were genotyped. Cumulative CVD prevalence was compared between G6PD-deficient and G6PD-normal FH patients. Multivariable logistic regression was adjusted for age, sex, body mass index, high blood pressure, and smoking. Results: Participants (mean age 47 years, 60% female) had markedly elevated LDL-C (mean 292 mg/dL at diagnosis). Atherosclerotic CVD was present in 119 (55%) patients. G6PD-deficient FH patients had a significantly higher CVD prevalence than those with normal G6PD activity (77.4% vs. 39.8%, p < 0.0001). LDL-C levels were higher in the G6PD-deficient group than in the non-deficient group, and this difference reached statistical significance in the univariate analysis. In the multivariable analysis, G6PD deficiency remained an independent CVD predictor (adjusted OR 3.57, 95% CI 1.30–9.83) after controlling for conventional risk factors. Conclusions: In FH, hereditary G6PD deficiency is associated with a markedly increased risk of atherosclerotic CVD. A pro-oxidative state in G6PD-deficient FH patients may play a role in premature atherogenesis. G6PD status may represent a cardiovascular risk modifier in FH, warranting further research into underlying mechanisms and targeted management. Full article

Both primary and secondary hemostasis consist of finely regulated pathways, forming a blood clot to stop bleeding. These orchestrated mechanisms involve multiple plasma- and platelet/endothelial-derived receptors, factors, enzymes, and proteins, such as the von Willebrand factor (vWF), fibrinogen, and thrombin. Over-activation or improper resolution of the coagulation cascade leads to severe pathological disorders, arterial and venous. Despite the fact that the genetic etiology of thrombophilia has gained the main research interest, there is growing evidence that the disturbed redox network of key hemostatic pathways signals thrombus formation. Oxidized LDL in dyslipidemias and many endogenous and exogenous compounds act as pro-oxidant stimuli that lead to post-translational modifications of proteins, such as sulfenylation, nitrosation, disulfide formation, glutathionylation, etc. Oxidation of cysteine and methionine residues of vWF, fibrinogen, and thrombomodulin has been detected at thrombotic episodes. Increased homocysteine levels due to, but not restricted to, methylenetetrahydrofolate reductase gene (MTHFR) mutations have been incriminated as a causative factor for oxidative stress, leading to a pro-thrombotic phenotype. Alterations in the vascular architecture, impaired vascular relaxation through decreased bioavailability of NO, accumulation of Nε-homocysteinylated proteins, ER stress, and endothelial cells’ apoptosis are among the pro-oxidant mechanisms of homocysteine. This review article focuses on describing key concepts on the oxidant-based molecular pathways that contribute to thrombotic episodes, with emphasis on the endogenous compound, homocysteine, aiming to promote further molecular, clinical, and pharmacological research in this field. Full article

The reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) is a primary electron donor for both antioxidant enzymes, such as glutathione reductase, and pro-oxidant enzymes, such as NADPH oxidases that produce reactive oxygen species (ROS) and nitric oxide synthases that generate nitric oxide which act as signaling molecules. Monitoring NADPH levels, NADPH/NADP⁺ ratio, and especially distinguishing from NADH, provides vital information about cellular redox status, energy generation, survival, lineage specification, and death pathway selection. NADPH detection is key to understanding metabolic reprogramming in cancer, aging, and cardiovascular, hormonal, neurodegenerative, and autoimmune diseases. Liquid chromatography combined with mass spectrometry (LC-MS) is crucial for NADPH detection in redox signaling because it offers the high sensitivity, specificity, and comprehensive profiling needed to quantify this vital but labile redox cofactor in complex biological samples. Using hepatoma cell lines, liver tissues, and primary hepatocytes from mice lacking transaldolase or nicotinamide nucleotide transhydrogenase, or having lupus, this study demonstrates that accurate measurement of NADPH depends on its preservation in reduced form which can be optimally achieved by extraction of metabolites in alkaline solution, such as 0.1 M potassium hydroxide (KOH) in comparison to 80% methanol (MeOH) alone or 40:40:20 methanol/acetonitrile/formic acid solution. While KOH extraction coupled with hydrophilic interaction liquid chromatography (HILIC) and mass spectrometry most reliably detects NADPH, NADP, NADH, NAD, polyamines, and polyols, MeOH extraction is best suited for detection of glutathione and overall discrimination between complex metabolite extracts. This study therefore supports performing parallel KOH and MeOH extractions to enable comprehensive metabolomic analysis of redox signaling. Full article

Objectives: Our study aimed to examine the antioxidative and anti-inflammatory potential of the lyophilized aqueous leaf extract of Vitis vinifera. Methods: The antioxidant capacity of the extract was evaluated using the DPPH and FRAP assays. The in vivo phase of the study included 40 male Wistar albino rats. One half of the animals were used to induce the carrageenan model of acute inflammation, while the other half were used for examination of the extract effect on the redox state. Rats from the experimental group drank tap water containing 150 mg/kg Vitis vinifera extract for 14 days, while control animals received saline at the same volume. The molecular docking studies of polyphenols present in the leaf extract were conducted in AutoDock Vina. Results: In vitro assessment of the antioxidative capacity of the applied extract revealed significant free radical scavenging activity (IC₅₀ value 11.63 µg/mL), along with a pronounced ferric reducing ability (0.143 at 700 nm). Moreover, animal treatment with the extract led to significant paw edema inhibition (30.34%, 35.06%, and 41.54% in the second, third, and fourth hours, respectively) and to pro-oxidative marker reduction. Additionally, Vitis vinifera extract significantly increased catalase activity and glutathione levels. The in silico results showed that rutin binds to cyclooxygenase 1 (−8.2 kcal/mol) and 2 (−8.3 kcal/mol), as well as to antioxidant enzymes (catalase: −8.6 kcal/mol, SOD: −7.4 kcal/mol), indicating its key role in mediating the biological activity of the tested extract. Conclusions: This study highlights the significant antioxidant and anti-inflammatory potential of V. vinifera lyophilized aqueous leaf extract from the Serbian market, supported by both in vivo and in silico analyses. Full article

Background/Objectives: In the fight against ovarian cancer, various therapies have been employed, with a strong focus on developing novel derivatives of existing substances. Methods: In this study, we continue our research on novel xanthone derivatives in combination with mild hyperthermia, targeting ovarian cancer cell lines TOV-21G and SK-OV-3. Using qPCR arrays, we analyzed 84 cellular stress-related genes categorized into anti-oxidant and pro-oxidant enzymes, molecular chaperones, and xenobiotic metabolism including the cytochrome P450 group. Furthermore, we conducted in silico analyses to investigate the pathways of the most affected genes, gene set enrichment, and gene ontology. Results: The most significant changes were observed in SOD2, SOD3, CYP2F1, CYP1B1, and HMOX1. Additional changes related to drug toxicity and the postulated mechanism of action were also identified. Based on in silico analyses, we concluded that the primary node of hyperthermia-induced changes is HSPA1A. Heat-induced alterations predominantly revolve around misfolded proteins, monooxygenase activity, and ATPase activity. Conclusions: To summarize, the combined therapy of novel xanthone derivatives and mild hyperthermia shows promising results and warrants further investigation to fully elucidate the mechanisms of action underlying these effects. Full article

Chronic injuries and diseases related to oxidative stress are major global concerns as they impose a great medical burden and lead to serious public health issues. Antioxidant peptides derived from pea protein can serve as potent antioxidants and food additives, contributing to address the challenges posed by oxidative stress. This review will focus on the antioxidant effects of pea peptides demonstrated in various in vitro chemical, cellular, and in vivo antioxidant models. Additionally, this review also summarizes the regulatory role of pea peptides on the Nrf2 (NF-E2-related factor 2)/Kelch-like ECH-associated protein 1 (Keap1) pathway, aiming to elucidate their antioxidant mechanisms. Our review found that pea peptides with smaller molecular weights (<1 kDa) obtained through enzymatic hydrolysis or fermentation and/or those containing amino acids such as Glu, Asp, Gly, Pro, and Leu tend to exhibit higher antioxidant activity. These pea peptides exert their antioxidant effects by scavenging free radicals, chelating pro-oxidative transition metals, reducing hydrogen peroxide, inactivating reactive oxygen species, enhancing the expression of antioxidant enzymes, and reducing the accumulation of lipid peroxides. Our study provides a theoretical foundation for the development of pea resources and the processing of pea-related functional foods. Full article

Amiodarone (AMD) is an effective antiarrhythmic drug whose long-term use is limited by multi-organ toxicities linked to oxidative stress. This review synthesizes current evidence on how AMD induces reactive oxygen species (ROS) generation in vitro and in vivo, and the mechanistic pathways involved. AMD promotes ROS production through both direct and indirect mechanisms. Directly, AMD accumulates in mitochondria and impairs the electron transport chain, leading to electron leakage and superoxide formation. It also undergoes redox cycling, forming radical intermediates that trigger lipid peroxidation and deplete cellular antioxidants. AMD and its metabolites inhibit antioxidant enzymes (SOD, CAT, GPx) expression and/or activities and reduce glutathione level, compounding oxidative injury. Indirectly, AMD activates signaling pathways that exacerbate ROS generation. This compound can induce pro-inflammatory mediators such as TNF-α and modulate nuclear receptors such as AhR, PXR, CAR, and PPARs, altering the expression of metabolic enzymes and endogenous antioxidants. These processes are time- and dose-dependent: short exposures at low concentrations may transiently scavenge radicals, whereas chronic or higher-dose exposures consistently lead to net ROS accumulation. The oxidative effects of AMD vary by tissue and experimental models. In chronic models, organs such as the lung and liver show pronounced ROS-mediated injury, whereas acute or cell-based systems typically exhibit subtler changes. AMD-induced toxicity arises from multifactorial oxidative stress involving mitochondrial dysfunction, increased radical formation, depletion of antioxidant defenses, and activation of pro-oxidant signaling pathways. Recognizing these pathways suggests that antioxidant and mitochondria-targeted co-therapies could ameliorate the side effects of AMD. Full article

The renin-angiotensin system (RAS) has evolved from being considered solely a peripheral endocrine system for cardiovascular control to being recognized as a complex molecular network with important functions in the central nervous system (CNS) and peripheral nervous system (PNS). Here we examine the organization, mechanisms of action, and clinical implications of cerebral RAS in physiological conditions and in various neurological pathologies. The cerebral RAS operates autonomously, synthesizing its main components locally due to restrictions imposed by the blood–brain barrier. The key elements of the system are (pro)renin; (pro)renin receptor (PRR); angiotensinogen; angiotensin-converting enzyme types 1 and 2 (ACE1 and ACE2); angiotensin I (AngI), angiotensin II (AngII), angiotensin III (AngIII), angiotensin IV (AngIV), angiotensin A (AngA), and angiotensin 1-7 (Ang(1-7)) peptides; RAS-regulating aminopeptidases; and AT1 (AT1R), AT2 (AT2R), AT4 (AT4R/IRAP), and Mas (MasR) receptors. More recently, alamandine and its MrgD receptor have been included. They are distributed in specific brain regions such as the hypothalamus, hippocampus, cerebral cortex, and brainstem. The system is organized into two opposing axes: the classical axis (renin/ACE1/AngII/AT1R) with vasoconstrictive, proinflammatory, and prooxidative effects, and the alternative axes AngII/AT2R, AngIV/AT4R/IRAP, ACE2/Ang(1-7)/MasR and alamandine/MrgD receptor, with vasodilatory, anti-inflammatory, and neuroprotective properties. This functional duality allows us to understand its role in neurological physiopathology. RAS dysregulation is implicated in multiple neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and neuropsychiatric disorders such as depression and anxiety. In brain aging, an imbalance toward hyperactivation of the renin/ACE1/AngII/AT1R axis is observed, contributing to cognitive impairment and neuroinflammation. Epidemiological studies and clinical trials have shown that pharmacological modulation of the RAS using ACE inhibitors (ACEIs) and AT1R antagonists (ARA-II) not only controls blood pressure but also offers neuroprotective benefits, reducing the incidence of cognitive decline and dementia. These effects are attributed to direct mechanisms on the CNS, including reduction of oxidative stress, decreased neuroinflammation, and improved cerebral blood flow. Full article

Despite their crucial biological role as metabolites, reactive oxygen and reactive nitrogen species (ROS and RNS) can have a negative effect on organisms when their cellular contents overwhelm the normal equilibrium provided by antioxidant defenses. Important biomolecules, such as lipids, proteins, and nucleic acids (i.e., DNA), can be damaged by their oxidative effects, resulting in malfunction or a shorter lifespan of cells and, eventually, of the whole organism. Oxidative stress can be defined as the consequence of an imbalance of pro-oxidants and antioxidants due to external stress sources (e.g., exposure to xenobiotics, UV radiation, or thermic stress). It can be evaluated by monitoring specific biomarkers to determine the state of health of breathing organisms. Assessments of ROS, RNS, specific degenerative oxidative reaction products, and antioxidant system efficiency (antioxidant enzyme activities and antioxidant compound contents) have been extensively performed for this purpose. A wide variety of analytical methods for measuring these biomarkers exist in the literature; most of these methods involve indirect determination via spectrophotometric and spectrofluorometric techniques. This review reports a collection of studies from the last decade regarding contaminant-induced oxidative stress in insects, with a brief description of the analytical methods utilized. Full article

Oxidative stress (OS), defined as an imbalance between pro-oxidant and antioxidant mechanisms, contributes to DNA and protein oxidation as well as cellular injury, and plays a pivotal role in the pathogenesis of chronic kidney disease (CKD). Peroxiredoxins (PRDXs) are key antioxidant enzymes that regulate intracellular peroxide levels and maintain redox homeostasis. Beyond its renal implications, OS is closely intertwined with hypertension and atherosclerosis, both common comorbidities that accelerate CKD progression. As previously reported, serum concentrations of PRDXs 1-5 may help to differentiate between IgA nephropathy (IgAN), membranous nephropathy (MN), and lupus nephritis (LN). This study aimed to assess the utility of baseline serum PRDX levels in predicting longitudinal changes in kidney function and proteinuria in patients with IgAN, MN, and LN. We analyzed data from 80 patients (IgAN, n = 36; MN, n = 23; LN, n = 21) drawn from an initial cohort of 108 in whom baseline serum concentrations of PRDX 1–5 were measured. Patients were stratified into low, medium, and high PRDX level groups at baseline, and associations between these strata and longitudinal changes in eGFR and proteinuria were assessed over a follow-up period of up to five years. Across all groups, the follow-up eGFR was significantly associated with low baseline serum PRDX 1, 2, 3, and 5 (p = 0.043; p = 0.001; p = 0.036; p = 0.007, respectively). Significant associations were also observed between 24 h follow-up proteinuria and low baseline serum PRDX 2, 3, and 5 (p = 0.025; p = 0.025; p = 0.005, respectively), medium PRDX 4 (p = 0.010), and high PRDX 2 (p = 0.019). No significant associations were found within the study groups; however, these associations were more pronounced in IgAN and MN patients. These findings suggest a potential role for PRDXs in predicting and monitoring CKD progression, especially eGFR decline. Full article