PubMed HealthSearch

SEARCH · PubMed Health

Results for “Antioxidant enzyme”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Oxygen toxicity in neonatal and adult animals of various species.

Neonatal and adult animals of five species were exposed to 95+% O2. Survival time and changes in lung antioxidant enzyme activity (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GP)) in response to hyperoxia were determined. Adult animals succumbed to O2 lung toxicity in 3--5 days. Neonatal rats, mice and rabbits showed minimal lung changes after 7 days of hyperoxic exposure and these same neonatal animals showed rapid and significant increases in lung antioxidant enzyme activities. In contrast, neonatal guinea pigs and hamsters had no lung antioxidant enzyme response to hyperoxia and these neonates died in 95+% O2 as readily as their respective parent animals. Results from an in vitro hyperoxic exposure system suggest that the lack of enzymic response of the guinea pig (and hamster) neonates to O2 challenge is due to an inherent pulmonary biochemical unresponsiveness rather than to a deficiency of a necessary "serum factor." The results of this species and age study support the important role of the lung antioxidant enzyme defense system in protection of the lung from O2-induced injury.

Animals

Caeruloplasmin: a plasma protein, enzyme, and antioxidant.

Multifunctional roles of the plasma protein, caeruloplasmin, have been briefly reviewed under three main headings. These are protein functions, enzymic activity, and antioxidant protection. As a plasma protein it is said to play a role in the transport of copper. Since some 95% of serum copper is associated with caeruloplasmin, measurement of the protein provides a useful guide to copper levels. Enzymic functions are related to its oxidase activity. Substrates commonly used for laboratory assay include non-biologically occurring aromatic amines and polyphenols. More recently, a physiological function has been proposed in which the enzyme oxidases iron from the ferrous to ferric state for binding to apotransferrin. This enzymic function of caeruloplasmin has been designated 'ferroxidase'. In vitro studies have shown that caeruloplasmin can inhibit the peroxidation of polyunsaturated fatty-acids. This function is in part related to its ferroxidase activity. No antioxidant activity has yet been demonstrated in vivo but this possibility is speculatively discussed.

Biogenic Amines

Pre-transport dietary chitosan improves the physiological robustness of juvenile largemouth bass (Micropterus salmoides) by modulating antioxidant and inflammatory responses.

The acute stress caused by long-distance transport can lead to oxidative damage, immune dysfunction, and health deterioration in fish. This study evaluated dietary chitosan as a pre-transport nutritional strategy for juvenile largemouth bass (Micropterus salmoides). Five experimental diets contained chitosan at 0, 2.5, 5.0, 7.5, or 10.0 g/kg, designated as p0, p25, p50, p75, and p100, respectively, for 56 d. The effects of dietary chitosan were evaluated using growth performance, feed utilization, digestive function, antioxidant capacity, nonspecific immunity, and resistance to Aeromonas hydrophila infection. Then, fish from the p0 and p50 groups underwent a 12-h transport stress test, with samples collected before, during, and 7 d after transport. Dietary chitosan improved most of these parameters. Among the treatment groups, p50 and p75 showed the best overall performance. The dose-response analysis further indicated that the appropriate dietary inclusion range was 5.0-7.5 g/kg. Under transport stress, fish in the p50 group exhibited more stable antioxidant enzyme responses and lower lipid peroxidation, as indicated by reduced MDA levels. Consistent with these enzyme responses, antioxidant-related genes remained relatively stable. At the same time, expression patterns related to the Nrf2-Keap1 and NF-κB signaling pathways suggested that 5.0 g/kg chitosan alleviated transport-induced oxidative damage and inflammation. Dietary chitosan also attenuated pro-inflammatory gene induction and altered the temporal expression patterns of anti-inflammatory genes. Overall, 5.0-7.5 g/kg dietary chitosan is suitable for juvenile largemouth bass, and 5.0 g/kg may serve as an effective pre-transport dietary inclusion level.

Animals

Integrated physiological and transcriptomic analyses reveal coordinated gill responses to heat stress in pikeperch (Sander lucioperca).

Climate change-driven warming of aquatic environments has made thermal stress an increasingly important factor influencing fish physiological homeostasis. Given their central roles in respiration and osmoregulation, gills are particularly responsive to variations in ambient temperature. Histological examination, physiological measurements, and transcriptome profiling were integrated to investigate the mechanisms associated with heat stress-induced gill injury in pikeperch (Sander lucioperca). Histological analysis revealed that exposure to 29 °C directly caused structural damage to the gills of pikeperch. Oxidative status was evaluated by measuring malondialdehyde (MDA) levels and the activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). MDA accumulation was significantly enhanced under heat stress, while antioxidant enzyme activities (SOD, POD, and CAT) displayed a transient increase followed by a subsequent decline. Transcriptome profiling showed marked enrichment of the protein processing in endoplasmic reticulum pathway after heat stress, suggesting activation of endoplasmic reticulum (ER) stress in pikeperch gills. With increasing stress duration, the unfolded protein response (UPR) appeared unable to re-establish ER homeostasis, shifting ire1 and atf6 toward a pro-apoptotic state. Protein-protein interaction (PPI) analysis further highlighted hub genes potentially involved in heat stress-induced ER stress and apoptosis. TUNEL staining and western blotting collectively confirmed that heat stress triggered apoptosis in pikeperch gill tissue. Overall, this study provides new insights into the physiological and molecular responses of pikeperch gills to heat stress and enhances our understanding of thermal stress adaptation in cold-water aquaculture species under climate change.

Animals

Tumor-derived antioxidants suppress immunity by depriving T cells of reactive oxygen species.

Reactive oxygen species (ROS) promote genomic instability and fuel oncogenic signaling in cancer, but antioxidant therapies have so far failed to improve, or worsen, cancer outcomes. Emerging data suggest that T cells depend on ROS for signal transduction. In this study, we show that tumors exploit this dependency, releasing antioxidant enzymes into the tumor environment to suppress T cell-mediated antitumor immunity. The interstitial fluid of tumors possesses potent antioxidant activity, associated with enrichment of the antioxidant enzyme peroxiredoxin 1 (PRDX1). Extracellular PRDX1 deprives T cells of ROS, preventing oxidative inactivation of phosphatases required for T cell receptor-driven kinase signaling and effector function. Prdx1 is up-regulated upon cancer immunoediting, and loss of PRDX1 within tumors enhances antitumor immunity and immunotherapy responses. These findings define a redox-dependent mechanism of tumor immunosuppression that is potentially amenable to therapeutic intervention.

Animals

Heterologous expression of DobHLH25 from Dendrobium officinale enhances drought tolerance in Arabidopsis.

Drought stress severely constrains the growth, yield, and accumulation of bioactive compounds in Dendrobium officinale (D. officinale), a valuable medicinal orchid, and this challenge is exacerbated under simulated wild cultivation where plants are inevitably exposed to recurring water deficits. Basic helix-loop-helix (bHLH) transcription factors are well-established regulators of plant abiotic stress responses. However, the molecular mechanisms by which bHLH transcription factors respond to drought stress in this species remain largely unknown. In this study, a bHLH transcription factor gene, DobHLH25, was cloned from D. officinale. Phylogenetic analysis revealed that DobHLH25 shares the highest sequence identity with its ortholog in Dendrobium nobile. Additionally, subcellular localization analysis indicated that DobHLH25 is targeted to the nucleus and possesses a functional transcriptional activation domain. Expression pattern analysis showed that DobHLH25 is most abundantly expressed in old leaves, and its expression in roots, stems, and leaves is induced by polyethylene glycol treatments. Heterologous expression of DobHLH25 in Arabidopsis thaliana resulted in higher seed germination rates and longer root lengths under mannitol-induced osmotic stress compared to wild-type plants. Under drought stress, DobHLH25 heterologous expression lines exhibited higher survival rates, reduced leaf water loss, lower malondialdehyde accumulation, and increased proline content. Moreover, the activities of antioxidant enzymes such as superoxide dismutase and peroxidase were significantly enhanced, and the expression levels of multiple drought-responsive genes were markedly upregulated. Collectively, these findings suggest a correlation between DobHLH25 expression and plant drought tolerance, as evidenced by reduced oxidative damage, increased osmolyte accumulation, enhanced antioxidant enzyme activities, and upregulation of drought-responsive genes. Together, these results suggest that DobHLH25 plays a positive role in drought tolerance, and provides a basis for future dissection of its regulatory network in D. officinale.

Drought Resistance

Physiological and transcriptomic responses of sunflower to combined saline-alkali stress.

BACKGROUND: Sunflower (Helianthus annuus L.), an important oilseed crop, is often used as a pioneer species for improving saline-alkali soils. However, the molecular mechanisms underlying sunflower seedling responses to combined saline-alkali stress remain unclear. This study aimed to elucidate the molecular basis of saline-alkali tolerance at the seedling stage by comparing physiological and transcriptomic responses between tolerant and sensitive sunflower hybrids. The saline-alkali tolerant hybrid K-27 and the sensitive hybrid K-7 were used as experimental materials. Root samples were collected at 0, 3, 12, 24, 48, and 96 h after exposure to combined saline-alkali stress (0.5% NaCl + Na2CO3, adjusted to pH 9.0). Physiological parameters, including antioxidant enzyme activities, osmolyte contents, ion concentrations, membrane damage levels, and cell wall components, were measured, followed by transcriptome sequencing analysis. RESULTS: Phenotypic analysis showed that the root length inhibition rate and fresh weight loss rate of K-27 were significantly lower than those of K-7, indicating stronger tolerance. Physiological analysis revealed that K-27 exhibited an inducible antioxidant enzyme response pattern. In addition, K-27 achieved osmotic adjustment through sustained proline accumulation (peaking at 12 h and remaining significantly higher than that of K-7 at 96 h) and exhibited higher basal levels of lignin and hemicellulose. Transcriptome analysis showed that the number of upregulated genes in K-27 was consistently higher than in K-7 at all time points, with 5,283 genes upregulated as early as 3 h after stress exposure. Venn analysis identified 44 core differentially expressed genes (cDEGs) shared between the two genotypes, which were mainly enriched in auxin biosynthesis regulation, phenylpropanoid biosynthesis, and glutathione metabolism. Among them, the benzoic acid carboxyl methyltransferase gene (BAMT) was continuously upregulated in K-27 but persistently downregulated in K-7. In addition, five other genes (encoding fatty aldehyde dehydrogenase, pectin methylesterase inhibitor, glutathione S-transferase, INPP5E, and HXXXD-type acyltransferase) exhibited significantly higher expression levels in K-27. CONCLUSION: K-27 tolerates combined saline-alkali stress through coordinated multi-layered response mechanisms, including inducible antioxidant defense, maintenance of ion homeostasis, sustained osmotic adjustment, and activation of the phenylpropanoid metabolic pathway. Candidate genes such as BAMT may provide potential targets for molecular breeding of saline-alkali tolerant sunflower, although their functions require further experimental validation.

Helianthus

Phenotypic, physiological and transcriptomic analysis of graded salt stress responses in Pyrus betulifolia Bunge and functional characterization of the hub gene PbSTY46.

Pyrus betulifolia Bunge is a salt‑tolerant rootstock for pear, but its salt‑tolerance mechanisms remain largely unknown. In this study, P. betulifolia seedlings were subjected to graded NaCl stress at concentrations of 0 (CK), 50 (T1), 100 (T2), and 200 (T3) mM. We integrated phenotypic observation, physiological assessment, transcriptomic profiling, and functional gene validation to systematically elucidate its salt tolerance mechanisms. Salt stress inhibited seedling growth and root traits in a concentration-dependent manner, and T3 caused the most severe damage. Osmotic solutes responded differentially: soluble sugars peaked under T2, while proline peaked under T3. Antioxidant enzymes showed tissue-specific biphasic responses and declined after prolonged T3 stress. Meanwhile, chlorophyll and photosynthesis decreased, whereas anthocyanin increased, indicating a metabolic shift from photosynthesis to photoprotection. Transcriptome analysis revealed distinct responses depending on stress intensity: mild stress induced membrane lipid remodeling, moderate stress activated circadian rhythm and hormone signaling, and severe stress enhanced phenylpropanoid biosynthesis and thiamine metabolism. Gene Set Enrichment Analysis (GSEA) further highlighted progressive enrichment of phenylpropanoid biosynthesis, heme binding, and oxidoreductase activity. Weighted Gene Co‑expression Network Analysis (WGCNA) identified a blue module significantly positively correlated with root traits, from which the hub gene PbSTY46 was identified. Functional validation via overexpression, loss‑of‑function mutants, and pharmacological interventions (MeJA/DIECA) confirmed that PbSTY46 acts through JA signaling to enhance antioxidant enzyme activities and thereby confer salt tolerance. Collectively, P. betulifolia adopts a "survival‑first" strategy that coordinates growth arrest, osmotic homeostasis, and ROS scavenging. These findings establish PbSTY46 as a key regulator that links JA signaling to antioxidant defense. Thus, PbSTY46 represents a promising candidate for marker‑assisted breeding of salt‑tolerant pear cultivars.

Salt Stress

[The presence of antioxidative defense enzymes in the ascarid Ascaris lumbricoides].

Superoxide dismutase, glutathione peroxidase and glutathione have been discovered in muscles of the ringworm A. lumbricoides. Superoxide dismutase activity was also revealed in eggs and larvae. Using polyacrylamide gel electrophoresis and electrofocusing, it was shown that this enzyme exists in ringworm muscles in multiple molecular forms. Oxygen poisoning of the ringworm and aerobic incubation of muscle homogenates in the presence of Fe+2 do not result in accumulation of malonyldialdehyde. Biochemical defence mechanisms are discussed against oxygen poisoning of the organisms which live under the conditions of reduced and changing pO2.

Animals

Functional Characterization of the Oat (Avena sativa L.) TCP Transcription Factor AsTCP38 Reveals Its Role in Low-Nitrogen Stress Tolerance.

Nitrogen limitation restricts plant growth, development, and yield in crops and forage species. Although TCP transcription factors are implicated in diverse abiotic-stress responses, the functions of most TCP genes in oat remain unclear. Here, we cloned and characterized the AsTCP38 gene, which is 1215 bp long and encodes a 405-amino-acid protein. The predicted protein contains a conserved TCP domain and shares its highest sequence similarity with Arabidopsis thaliana (A. thaliana) AtTCP15. The AsTCP38 protein localized to the nucleus, and promoter analysis identified cis-elements associated with light, hormone, and stress responses. We generated AsTCP38-overexpressing A. thaliana and wheat plants and screened an oat leaf yeast cDNA library for candidate interacting proteins. In these heterologous overexpression lines, AsTCP38 overexpression was associated with greater abscisic acid (ABA) sensitivity and improved seedling growth under low-nitrogen conditions. Changes in antioxidant-enzyme activities, nitrogen-metabolism-related enzyme activities, and endogenous hormone contents were also observed. Together, these findings suggest that AsTCP38 may participate in low-nitrogen responses and provide a basis for further functional studies in oat. Direct regulatory targets and the contribution of AsTCP38 to low-nitrogen adaptation in oat remain to be established.

Avena

Comparative Responses of Invasive and Native Plant Species to Combined Cd and Microplastic Pollution.

The co-occurrence of heavy metal contamination and biodegradable microplastic (polylactic acid, PLA) pollution poses increasing risks to terrestrial plant communities and soil functioning, yet species-specific responses to combined stress remain poorly understood. Cd and microplastics frequently co-occur in agricultural soils, where microplastics can alter cadmium mobility, bioavailability, and transport pathways, potentially modifying metal toxicity and plant stress responses compared with single-pollutant exposure. We investigated the responses of the invasive Bidens pilosa and the native Solanum nigrum grown in monoculture and mixed culture under combined cadmium (Cd) and biodegradable microplastic (PLA) stress by integrating plant growth, photosynthetic performance, oxidative physiology, and rhizosphere biochemical processes. Combined Cd-MP exposure markedly reduced plant growth, chlorophyll content (SPAD), photosystem II efficiency (Fv/Fm), nitrogen accumulation, biomass production, and rhizosphere enzyme activities associated with carbon, nitrogen, and phosphorus cycling. However, B. pilosa maintained greater physiological stability under stress, characterized by higher antioxidant enzyme activities (SOD, CAT, POD), lower reactive oxygen species (H2O2, O2˙-) accumulation, and reduced lipid peroxidation (MDA), whereas S. nigrum exhibited stronger oxidative damage and functional impairment. Multivariate analyses further revealed that root antioxidant capacity was closely associated with rhizosphere microbial enzyme activity, suggesting a root-centered regulatory mechanism linking plant stress tolerance to soil functioning. Overall, the invasive species showed greater tolerance to combined contamination and maintained relatively higher rhizosphere functional activity than the native species, indicating that multi-pollutant stress may alter competitive interactions between invasive and native plants in contaminated environments.

Cadmium

CRISPR/Cas9-Mediated Generation and Characterization of an Ent2*/CyO Drosophila melanogaster Strain.

In this study, a CRISPR/Cas9-based genome-editing approach was used to introduce mutations in the equilibrative nucleoside transporter 2 (Ent2) gene in Drosophila melanogaster. Guide RNAs targeting the coding region of Ent2 were designed and co-injected with Cas9 mRNA into w1118 embryos. Mutant alleles were identified by Sanger sequencing and maintained as a stable Ent2*/CyO heterozygous line using a balancer chromosome. Subsequently, we evaluated body weight, climbing ability, survival rate, and the activities of superoxide dismutase (SOD) and catalase (CAT) in fruit flies at 22 °C and 25 °C, respectively. The results indicate that at both 22 °C and 25 °C, the body length and weight of Ent2*/CyO fruit flies were significantly reduced compared to the w1118, and their development was delayed. At 22 °C, the overall lifespan of Ent2*/CyO flies was slightly longer than that of the w1118, whereas at 25 °C, no significant difference was observed. Regarding locomotor ability, the climbing performance of heterozygous flies was significantly lower than that of the w1118 at both temperatures, with males being more severely affected. In addition, the antioxidant enzyme activities of CAT and SOD in Ent2*/CyO fruit flies were significantly reduced, indicating a clear impairment of antioxidant capacity. These results describe the phenotypic profile of a CRISPR-generated Ent2 mutant line and demonstrate the feasibility of combining genome editing with balancer chromosome strategies in Drosophila. This study provides a methodological framework and a genetic resource for future investigations of genes associated with metabolism and environmental responses.

Animals

Characterization of oxidative status in maize protoplasts under temperature and saline-alkali stresses.

BACKGROUND: Protoplasts have emerged as a powerful model system in plant functional genomics, offering significant utility in functional gene analysis, protein interaction studies, and transient expression platforms for gene editing. Despite their versatility, inherent limitations restrict their broader application, highlighting the need for systematic investigations into their responses to abiotic stressors, such as temperature fluctuations and saline-alkali conditions (200 mM saline mixture: 170mM NaCl and 30mM Na2CO3, pH = 9.1). RESULTS: In this study, we comprehensively examined the effects of varying temperatures and saline-alkali stress on the integrity, viability, and reactive oxygen species (ROS) metabolism of maize protoplasts. Key markers of oxidative stress-including ROS accumulation, lipid peroxidation (measured as malondialdehyde, MDA), antioxidant enzyme activity (superoxide dismutase, SOD), and hydrogen peroxide (H2O2) levels-were quantified to assess the oxidative stress response. Protoplasts maintained at 4 °C demonstrated enhanced stability and antioxidant capacity, preserving cell viability and endogenous protein integrity for up to 16 h. Conversely, exposure to 37 °C significantly compromised protoplast viability, while incubation at 28 °C exerted minimal effects within 16 h. CONCLUSIONS: Our study investigated the effects of various temperature stresses and salt-alkali stress on maize protoplasts. The results demonstrated that both temperature and salt-alkali stress significantly impacted protoplast production, viability, and the expression of endogenous proteins. These findings not only characterize the redox response of maize protoplasts, but also provide guidance for protoplast isolation and other procedures: 4 °C is suitable for short-term maintenance, 25-28 °C for routine functional assays, and 37 °C should be avoided. These findings provide valuable insights into the stress responses of protoplasts and establish a foundation for future research aimed at improving plant stress tolerance through protoplast-based techniques.

Zea mays

Immunomodulatory effects of palm-derived tocotrienol-rich fraction in healthy volunteers following influenza vaccination: A randomised clinical trial.

Most studies on vitamin E and immunity have focused on tocopherols, but the tocotrienol-rich fraction (TRF) from palm oil may exert stronger immunomodulatory effects. This study investigated the effect of various TRF doses on the immune response to influenza immunisation in healthy adults. We hypothesized daily supplementation with lower doses of TRF can boost immune response to the influenza vaccine in healthy Individuals. In a double-blind placebo-controlled trial, 150 participants (≥18 years) were randomised to receive placebo or TRF (50, 100, 200, or 400 mg) daily for 2 months, with vaccination on day 28. Blood samples collected on days 0, 28, and 56 were analyzed for humoral and cellular immunity, antioxidant status, and plasma concentrations of vitamin E. TRF significantly augmented anti-influenza antibody production across all doses, with the 400 mg group exhibiting the highest titers. A selective Th1-type immune response was observed, characterized by significant IFN-γ production upon restimulation in all TRF-supplemented groups compared with placebo. Plasma IL-12 was elevated in the highest dose, whereas the amount of EBI3 produced increased across a broader range of doses compared to placebo. TRF supplementation was associated with increased antioxidant enzyme activities and stable malondialdehyde activity. Elevated α-tocopherol concentrations observed, primarily at higher doses. Supplementation with TRF can enhance immune response to influenza immunisation by modulating humoral, Th1 responses and improving antioxidant status. Critically, antibody production increased similarly across all TRF doses, suggesting that lower doses may offer a cost-effective strategy for supporting humoral immunity, while higher doses provide broader immunomodulatory benefits.

Humans

The role of endotoxin in protection of adult rats from oxygen-induced lung toxicity.

Adult rats show evidence of severe lung damage after 72h of continuous exposure to hyperoxia (96-98% O2). Treatment of adult rats with a solution of Plasmanate, inadvertently contaminated with endotoxin-producing organisms, or with purified endotoxin itself markedly altered the lung toxicity associated with hyperoxic exposure (survival in treated animals = 110/113 [97%] versus survival in untreated animals = 56/172 [33%]). After 72h of hyperoxic exposure, the endotoxin-treated rats demonstrated significant increases in lung superoxide dismutase, catalase, and glutathione peroxidase activity, a protectant enzyme response not seen in untreated adult rats. The basis for endotoxin's protective effect from hyperoxic lung damage is believed to be related to the stimulated increase in activity of the pulmonary antioxidant enzyme defense system. Some previously known actions of endotoxin are speculated to also serve a protective function by opposing some of the usual detrimental effects of high concentrations of O2 on the lung.

Animals

β-carotene enhances drought tolerance in fenugreek by modulating antioxidant defense and redox homeostasis.

Drought stress is one of the main abiotic factors that modulates the morphology and physiology of crops. This study investigated the effect of foliar application of β-carotene on the growth, physiological, and biochemical responses of fenugreek (Trigonella foenum-graecum L.) under drought stress conditions. A pot experiment was conducted using two varieties, Kasuri and Local, under two drought stress levels (control and 50% field capacity), and three β-carotene concentrations (0, 100, and 200 ppm) were applied. Drought stress significantly declined shoot fresh weight up to 35.02% and 58.04%, and shoot length to 17.12% and 17.14%, while increasing the root fresh weight by 133% and 26.2% and the root length to 109.1% and 13.4%, respectively, in the Kasuri methi and Local. Drought stress decreases the total Chl. by 55.4% and 59.3% and carotenoids 42.1% and 59.3% and increased the MDA by 6.35% and 24.2%, respectively, and the content of hydrogen peroxides increased by 12.05% and 44.2% in Kasuri and Local as compared to control. By the application of 200  ppm β-carotene, the shoot fresh weight increased by 95.06% and 66.7%, the shoot length increased by 49.6% and 44.5%, and the total Chl. increased by 194.3% and 144.3%, and carotenoids 71.6% and 63%, and MDA decreased by 14.7% and 15.8%, hydrogen peroxides 26.6% and 27.8%, in Kasuri methi and Local under drought stress conditions. Additionally, with the application of β-carotene, antioxidant enzyme activities (SOD, POD, and CAT) and osmoprotectants (total soluble proteins and sugars) improved significantly, indicating enhanced oxidative defense. Overall, foliar β-carotene application, especially at 200 ppm, proved highly effective in improving fenugreek's drought tolerance by enhancing antioxidant capacity, maintaining pigment stability, and supporting metabolic homeostasis, thereby highlighting its potential role in sustainable crop management under water-limited conditions.

beta Carotene

Association between sirtuin 1 and markers of oxidative stress in master athletes.

BACKGROUND: Lifelong training in master athletes confers protective effects, promoting higher sirtuin levels and enhanced antioxidant capacity. Although Sirtuin 1 (SIRT1) is well studied, no previous study has examined the relationship between circulating SIRT1 levels and antioxidant defense variables in master athletes. PURPOSE: To compare and analyze the relationships between circulating levels of SIRT1 and variables related to antioxidant defense in master athletes (MA) and untrained middle-aged individuals (UMA). METHODS: Male MA (n&#x2009;=&#x2009;42; 51.62&#x2009;&#xb1;&#x2009;7.33 years; &#x2265;10 years of training and competition in running) and UMA (n&#x2009;=&#x2009;15; 47.73&#x2009;&#xb1;&#x2009;8.52 years) were evaluated. Venous blood samples were collected for biochemical analyses of SIRT1, antioxidant enzymes, TBARS and F2-isoprostanes, 8-OHdG, and redox balance indexes. RESULTS: MA showed higher levels of SIRT1 (18.22&#x2009;&#xb1;&#x2009;4.53 vs. 6.08&#x2009;&#xb1;&#x2009;2.11 ng/mL; p&#x2009;<&#x2009;0.0001), as well as of SOD, CAT, and GSH (p&#x2009;<&#x2009;0.001), indicating a more favorable antioxidant profile. After adjustment for body fat percentage, differences in SOD, CAT, GSH and TBARS, remained significant. SIRT1 was positively correlated with SOD (r&#x2009;=&#x2009;0.279; p&#x2009;=&#x2009;0.031), CAT (r&#x2009;=&#x2009;0.485; p&#x2009;<&#x2009;0.001), GSH (r&#x2009;=&#x2009;0.476; p&#x2009;<&#x2009;0.001) and CAT/8-OHdG (r&#x2009;=&#x2009;0.430; p&#x2009;=&#x2009;0.032), and negatively correlated with TBARS (r&#x2009;=&#x2009;-&#x2009;0.518; p&#x2009;<&#x2009;0.001). CONCLUSION: Master athletes exhibited higher circulating SIRT1 concentrations and a more favorable systemic redox profile than untrained individuals, with SIRT1 being associated with markers of antioxidant defense, lipid peroxidation, and redox balance.

Aging