Key Antioxidant Research Articles

The Role of Superoxide Dismutase in Kidney Aging: A Meta-Analysis of Oxidative Stress, Inflammation, and Renal Function

Background: Kidney aging is an inevitable physiological process characterized by a progressive decline in renal function, increased oxidative stress, and chronic low-grade inflammation. Superoxide dismutase (SOD), a key antioxidant enzyme, plays a crucial role in mitigating oxidative damage. This meta-analysis aimed to comprehensively evaluate the association between SOD levels/activity and markers of oxidative stress, inflammation, and renal function in the context of kidney aging. Methods: A systematic search of PubMed, Scopus, and Web of Science databases was conducted for relevant studies published between 2013 and 2024. Studies investigating the relationship between SOD (SOD1, SOD2, SOD3) and kidney aging in humans were included. Data on SOD levels/activity, oxidative stress markers, inflammatory markers, and renal function parameters were extracted. Random-effects models were used to pool the standardized mean differences (SMD) and 95% confidence intervals (CI). Results: Nine studies with a total of 1,245 participants were included in the meta-analysis. Pooled analysis revealed a significant negative association between SOD activity and markers of oxidative stress (SMD = -0.85, 95% CI: -1.20 to -0.50, p < 0.001). Similarly, SOD activity was inversely associated with inflammatory markers (SMD = -0.62, 95% CI: -0.95 to -0.29, p < 0.001). Furthermore, a significant positive association was observed between SOD activity and eGFR (SMD = 0.78, 95% CI: 0.41 to 1.15, p < 0.001). Conclusion: This meta-analysis provides compelling evidence that SOD plays a critical role in mitigating oxidative stress and inflammation in kidney aging, contributing to the preservation of renal function. These findings highlight the potential of SOD as a therapeutic target for age-related kidney diseases.

Resveratrol mitigates heat stress-induced testicular injury in rats: enhancing male fertility via antioxidant, antiapoptotic, pro-proliferative, and anti-inflammatory mechanisms.

This study investigates the protective effects of resveratrol (RSV) against heat stress (HS)-induced testicular injury in rats. Climate change has exacerbated heat stress, particularly affecting male fertility by impairing testicular function and sexual behavior. A total of 32 rats were allocated into four experimental groups: control, RSV control, HS control, and RSV + HS. The HS groups were subjected to a 43°C water bath for 20 min to induce testicular hyperthermia, while the RSV + HS group received 20 mg/kg of RSV starting just before HS and continuing for eight weeks. Our findings reveal that HS significantly impairs male sexual behavior, evidenced by reduced mount and intromission numbers, and increased latencies. It also negatively affects the reproductive system, decreasing the weights of testes (Cohen's d = 1.8), epididymis, and accessory sex glands, and deteriorating sperm profile parameters such as motility (Cohen's d = 2.1), viability, and morphology. Furthermore, HS notably decreases reproductive performance in female rats, reducing litter size, live births, and conception rates. Biochemically, HS decreases activities of key antioxidant enzymes in the testes-glutathione peroxidase, superoxide dismutase, and catalase-while increasing lipid peroxidation, nitrite levels, and proinflammatory cytokines (IL-1β and TNF-α). It also reduces serum levels of reproductive hormones like testosterone (Cohen's d = 2.0) and 17β-estradiol.These results were affirmed with the histopathological evaluation and the immunohistochemistry staining (Ki-67, PCNA, Bax 5, and caspase-3 protein expression). Remarkably, RSV treatment mitigated these adverse effects, restoring both physiological and biochemical parameters toward normal levels (e.g., testicular weight Cohen's d = 1.6, sperm motility Cohen's d = 1.9, and testosterone levels Cohen's d = 1.7). This suggests that RSV's antioxidative, anti-inflammatory, antiapoptotic, and androgenic properties could effectively counteract the degenerative impacts of testicular hyperthermia. This highlights the potential of RSV as a therapeutic agent against climate change-induced fertility issues in males.

High Selectivity Fluorescence and Electrochemical Dual-Mode Detection of Glutathione in the Serum of Parkinson's Disease Model Mice and Humans.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons and the accumulation of alpha-synuclein. Glutathione (GSH), a key antioxidant, is significantly depleted in PD patients. This study presents a dual-mode detection strategy for selectively determining GSH using a single probe. A series of "turn-on" electrochemical and fluorescent probes were developed, with resorufin (Re) serving as the reporting unit and featuring specific GSH recognition sites. Among these, the 7-(3,5-dinitrophenoxy)-3H-phenoxazin-3-one (Re-DNP) probe was selected for its high selectivity as both a fluorescent and electrochemical probe. Its response to GSH was superior in comparison to that observed for hydrogen sulfide (H2S) and cysteine (Cys). For electrochemical detection using screen-printed carbon electrode (SPCE)/carbon nanotube (CNT) modified electrodes, the detection limit for GSH was 5 μM, with a linear range of 25-500 μM. In fluorescence detection, the probe produced a 78-fold increase in emission at 630 nm in the presence of GSH, with a strong linear correlation between fluorescence intensity and GSH concentration in the range of 10-700 μM, and a detection limit of 2 μM. When applied to real clinical serum samples, the probe demonstrated significantly lower GSH levels in both PD mice and human patients compared to healthy controls. This dual-mode detection method provides a sensitive and accurate tool for GSH detection, with potential applications in understanding GSH's role in PD and related neurodegenerative diseases.

Toxicological effects of Mercury in Radish (Raphanus Sativus) plants – Biochemical Analysis

Mercury is one of the major toxic heavy metal, poses significant risks to both the environment and human health due to its persistence and its capability to accumulate within ecosystems. The primary route of mercury exposure is through contaminated soil, water and food sources, which can lead to substantial damage to living organisms. In particular, mercury exposure adversely affecting the kidneys, nervous system and other important organs. This study investigates the toxicological effects of Mercury in Radish (Raphanus Sativus) plants through biochemical analysis. The experimental plants were divided into four groups, Group 1, the control group, received no mercury treatment, while Groups 2, 3 and 4 were subjected to mercury concentrations of 50, 100 and 200 mg, respectively. The results demonstrated that mercury exposure led to a significant reduction in important growth parameters. Specifically, the germination percentage, root and shoot lengths, fresh and dry weight, and vigor index were all markedly decreased in the mercury treated groups compared to the control. Biochemical analysis revealed the mercury’s clear negative impact on the metabolic processes in radish plants. Mercury at higher concentrations was associated with a notable reduction in carbohydrate and protein levels, reflecting the plant’s impaired physiological functions. Additionally, the activities of key enzymic antioxidants, such as catalase and superoxide dismutase, were significantly reduced under mercury induced stress. By exploring the biochemical and physiological effects of mercury exposure, this research provides valuable insights into how mercury accumulation impacts plant health.

Selenoprotein-Mediated Redox Regulation Shapes the Cell Fate of HSCs and Mature Lineages.

The maintenance of cellular redox balance is crucial for cell survival and homeostasis and is disrupted with aging. Selenoproteins, comprising essential antioxidant enzymes, raise intriguing questions about their involvement in hematopoietic aging and potential reversibility. Motivated by our observation of mRNA downregulation of key antioxidant selenoproteins in aged human hematopoietic stem cells (HSCs) and previous findings of increased lipid peroxidation in aged hematopoiesis, we employed tRNASec gene (Trsp) knockout (KO) mouse model to simulate disrupted selenoprotein synthesis. This revealed insights into the protective roles of selenoproteins in preserving HSC stemness and B-lineage maturation, despite negligible effects on myeloid cells. Notably, Trsp KO exhibited B lymphocytopenia and reduced HSCs' self-renewal capacity, recapitulating certain aspects of aged phenotypes, along with the upregulation of aging-related genes in both HSCs and pre-B cells. While Trsp KO activated an antioxidant response transcription factor NRF2, we delineated a lineage-dependent phenotype driven by lipid peroxidation, which was exacerbated with aging yet ameliorated by ferroptosis inhibitors such as vitamin E. Interestingly, the myeloid genes were ectopically expressed in pre-B cells of Trsp KO mice, and KO pro-B/pre-B cells displayed differentiation potential toward functional CD11b+ fraction in the transplant model, suggesting that disrupted selenoprotein synthesis induces the potential of B-to-myeloid switch. Given the similarities between the KO model and aged wild-type mice, including ferroptosis vulnerability, impaired HSC self-renewal and B-lineage maturation, and characteristic lineage switch, our findings underscore the critical role of selenoprotein-mediated redox regulation in maintaining balanced hematopoiesis and suggest the preventive potential of selenoproteins against aging-related alterations.

Depression and the Glutamate/GABA-Glutamine Cycle.

Many features of major depressive disorder are mirrored in rodent models of psychological stress. These models have been used to examine the relationship between the activation of the hypothalamic- pituitary axis in response to stress, the development of oxidative stress and neuroinflammation, the dominance of cholinergic neurotransmission and the associated increase in REM sleep pressure. Rodent models have also provided valuable insights into the impairment of glycolysis and brain glucose utilization by the brain under stress, the resulting decrease in brain energy production and the reduction in glutamate/GABA-glutamine cycling. The rapidly acting antidepressants, scopolamine, ketamine and ECT, all raise extracellular glutamate and scopolamine and ketamine have specifically been shown to increase glutamate/GABA-glutamine cycling in men and rodents with corresponding short-term relief of depression. The nightly use of gammahydroxybutyrate (GHB) may achieve more permanent results and may even act prophylactically to prevent the development or recurrence of depression. GHB is a GABAB agonist and restores the normal balance between cholinergic and monoaminergic neurotransmission by inhibiting cholinergic neurotransmission. It relieves REM sleep pressure. GHB's metabolism generates NADPH, a key antioxidant cofactor. Its metabolism also generates succinate, the tricarboxylic acid cycle intermediate, to provide energy to the cell and to synthesize glutamate. In both animals and man, GHB increases the level of brain glutamate.

5-(3-(N-(Carboxymethyl)naphthalene-2-sulfonamido)phenyl)-1-ethyl-1H-pyrrole-2-carboxylic acid as a Keap1-Nrf2 inhibitor for cerebral ischemia/reperfusion injury treatment.

The Keap1 (Kelch-like ECH-Associating Protein 1)-Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2)-ARE (Antioxidant Response Element) signaling pathway plays a crucial role in the oxidative stress response and has been linked to the development and progression of various diseases. Its influence on cerebral ischemia/reperfusion (I/R) injury has garnered significant attention. In our study, we investigated the effect of compound 2, a non-covalent inhibitor of the Keap1-Nrf2 interaction, which was previously discovered by our research group. Specifically, we used 5-(3-(N-(carboxymethyl)naphthalene-2-sulfonamido)phenyl)-1-ethyl-1H-pyrrole-2-carboxylic acid (compound 2) to assess its therapeutic potential in a cerebral I/R injury model. The results demonstrated that compound 2 had a significant therapeutic effect, promoting the translocation of Nrf2 from the cytoplasm to the nucleus in diseased tissue. Additionally, it increased the production of key antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH).

Exogenous 2,4-Epibrassinolide Alleviates Alkaline Stress in Cucumber by Modulating Photosynthetic Performance.

Brassinosteroids (BRs) are recognized for their ability to enhance plant salt tolerance. While considerable research has focused on their effects under neutral salt conditions, the mechanisms through which BRs regulate photosynthesis under alkaline salt stress are less well understood. This study investigates these mechanisms, examining plant growth, photosynthetic electron transport, gas exchange parameters, Calvin cycle dynamics, and the expression of key antioxidant and Calvin cycle genes under alkaline stress conditions induced by NaHCO3. The findings indicate that NaHCO3 stress substantially impairs cucumber growth and photosynthesis, significantly reducing chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), maximum photochemical efficiency (Fv/Fm), actual photochemical efficiency (ΦPSII), antenna conversion efficiency (Fv'/Fm'), and photochemical quenching coefficient (qP). This disruption suggests a severe dysregulation of the photosynthetic electron transport system, impairing electron transfer from photosystem II (PSII) to photosystem I (PSI) and subsequently the Calvin cycle. Application of exogenous 24-epibrassinolide (EBR) alleviated these effects, reducing leaf chlorosis and growth inhibition and significantly enhancing the expression of key genes within the antioxidant system (AsA-GSH cycle) and the Calvin cycle. This intervention also led to a reduction in reactive oxygen species (ROS) accumulation and improved photosynthetic performance, as evidenced by enhancements in Pn, Gs, E, Fv/Fm, ΦPSII, Fv'/Fm', and qP. Moreover, NaHCO3 stress hindered chlorophyll synthesis, primarily by blocking the conversion from porphobilinogen (PBG) to uroporphyrinogen III (UroIII) and by increasing chlorophyllase (Chlase) and decreasing porphobilinogen deaminase (PBGD) activity. Exogenous EBR countered these effects by enhancing PBGD activity and reducing Chlase activity, thereby increasing chlorophyll content under stress conditions. In summary, EBR markedly mitigated the adverse effects of alkaline stress on cucumber leaf photosynthesis by stabilizing the photosynthetic electron transport system, accelerating photosynthetic electron transport, and promoting the Calvin cycle. This study provides valuable insights into the regulatory roles of BRs in enhancing plant resilience to alkaline stress.

Morphology-dependent nanoplasmonic assay: a powerful signaling platform for multiplexed total antioxidant capacity analysis.

Assessing the total antioxidant capacity (TAC) in biological samples, such as saliva, is essential for health monitoring and disease prevention. TAC plays a critical role in protecting cells from damage caused by free radicals and oxidative stress, which are associated with various conditions, including cancer, cardiovascular diseases, and aging. Key antioxidants, including ascorbic acid (AA), cysteine (CYS), glutathione (GSH), and uric acid (UA), significantly contribute to this protective effect, with salivary levels of these antioxidants reflecting their concentrations in the bloodstream. Therefore, there is a strong demand for a robust, non-toxic colorimetric sensor that can effectively monitor these antioxidants using an innovative approach. This study introduces a multi-colorimetric probe capable of generating high-resolution, naked-eye-detectable color readouts for evaluating salivary TAC. The probe utilizes the morphology-dependent properties of plasmonic nanostructures as recently developed colorimetric sensors, enabling precise and efficient analysis of salivary antioxidants. The assessment of antioxidants was conducted using the probe in combination with pattern recognition analysis for accurate identification and regression analysis for quantification. The probe exhibited linear responses to pure antioxidants and TAC over a broad concentration range: 3.1-60.0, 2.6-60.0, 1.2-20.0, 0.8-20.0, and 0.7-14.0 μmol L-1, with detection limits of 1.1, 0.9, 0.4, 0.3, and 0.2 μmol L-1 for AA, CYS, GSH, UA, and TAC-mixture, respectively. Moreover, performance metrics highlight the robustness and efficacy of the probe in detecting and quantifying antioxidant levels in saliva samples. The efficacy of the developed multi-colorimetric probe was rigorously validated through the analysis of real saliva samples for on-site TAC monitoring. This rapid, cost-effective, user-friendly, non-toxic, and non-invasive method allows for a comprehensive analysis of both individual and total antioxidants, making it highly applicable for health monitoring and disease prevention. Additionally, the probe generates unique response profiles based on varying ratios of endogenous antioxidants, enabling precise TAC quantification in saliva-an essential factor for clinical diagnostics.

2,4-Dinitrophenol is toxic on a low caloric diet but extends lifespan of Drosophila melanogaster on nutrient-rich diets without an impact on metabolism.

Uncouplers of mitochondrial electron transport chain, such as 2,4-dinitrophehol (DNP), can mimic calorie restriction by decreasing efficiency of adenosine triphosphate (ATP) synthesis. However, DNP is also a toxic substance, whose overdosage can be lethal. In the fruit fly, Drosophila melanogaster model, we have found that DNP in concentrations of 0.05-0.2g/L, led to a drastic decrease in fruit fly survival on a low caloric diet (1% sucrose and 1% yeast; 1S-1Y). On the 5S-5Y diet, DNP decreased lifespan of flies reared only in concentration 0.2g/L, whilst on the diet 15S-15Y DNP either did not significantly shortened fruit fly lifespan or extended it. The lifespan extension on the high caloric 15S-15Y diet with DNP was accompanied by lower activity of lactate dehydrogenase and a decrease in activities of mitochondrial respiratory chain complexes I, II, and V, determined by blue native electrophoresis followed by in-gel activity assays. The exposure to DNP also did not affect key glycolytic enzymes, antioxidant and related enzymes, and markers of oxidative stress, such as aconitase activity and amount protein carbonyls. Consumption of DNP-supplemented diet did not affect flies' resistance to heat stress, though made male flies slightly more resistant to starvation compared with males reared on the control food. We also did not observe substantial changes in the contents of metabolic stores, triacylglycerols and glycogen, in the DNP-treated flies. All this suggest that a nutrient-rich diets provide effective protection against DNP, providing a mild uncoupling of the respiratory chain that allows lifespan extension without considerable changes in metabolism.

Sulforaphane treatment mimics contractile activity-induced mitochondrial adaptations in muscle myotubes.

Mitochondria are metabolic hubs that govern skeletal muscle health. While exercise has been established as a powerful inducer of quality control processes that ultimately enhance mitochondrial function, there are currently limited pharmaceutical interventions available that emulate exercise-induced mitochondrial adaptations. To investigate a novel candidate for this role, we examined Sulforaphane (SFN), a naturally occurring compound found in cruciferous vegetables. SFN has been documented as a potent antioxidant inducer through its activation of the nuclear factor erythroid 2-related factor 2 (Nrf-2) antioxidant response pathway. However, its effects on muscle health have been underexplored. To investigate the interplay between chronic exercise and SFN, C2C12 myotubes were electrically stimulated to model chronic contractile activity (CCA) in the presence or absence of SFN. SFN promoted Nrf-2 nuclear translocation, enhanced mitochondrial respiration, and upregulated key antioxidant proteins including catalase and glutathione reductase. These adaptations were accompanied by reductions in cellular and mitochondrial ROS emission. Signaling towards biogenesis was enhanced, demonstrated by increases in mitochondrial transcription factor A (TFAM), Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α nuclear translocation, PGC-1α promoter activity, mitochondrial content, and organelle branching, suggestive of a larger, more interconnected mitochondrial pool. These mitochondrial adaptations were accompanied by an increase in lysosomal proteins, suggesting coordinated regulation. There was no difference in mitochondrial and antioxidant-related proteins between CCA and non-CCA SFN-treated cells. Our data suggests that SFN activates signaling cascades that are common to those produced by contractile activity, indicating that SFN-centered therapeutic strategies may improve the mitochondrial phenotype in skeletal muscle.

Comparative effectiveness of Moringa leaf extract, a natural biostimulant, with inorganic NPK fertilizer for regulating growth and the activities of enzymatic antioxidants in wheat (Triticum aestivum L.)

Bio-stimulants include a range of compounds effective enough to enhance certain physiological processes that promote crop ontogeny and development, so that the use of synthetic fertilizers can be greatly decreased. Moringa Leaf Extract (MLE) is a good source of fertilizers alterative to NPK and other macro- and micro-nutrients. MLE has the ability of promoting healthy and safe foods that are environment-friendly. Therefore, the use of safe natural bio-stimulants such as MLE to enhance the growth and productivity of food crops is indispensable these days. The present study was designed to examine the efficiency and effectiveness of MLE with respect to NPK fertilizers on two spring wheat varieties, Akbar-2019 and Ujala-2016. Pot experiments were conducted in the Botanical Garden of the University of Gujrat, Gujrat., Pakistan. The experiments were laid down in a completely randomized design (CRD) with four replications. Three levels of Moringa leaf extract (0%, 10%, and 20%) and three levels of NPK fertilizers (0%, 10%, and 20%) were applied after two weeks of seed germination. It was found that 10% and 20 % of both MLE and NPK enhanced the crop growth by increasing foliage growth, and antioxidative enzymes activities. MLE applied as 10% showed better results in terms of enhancing the crop growth as compared to NPK. MLE was also more effective than NPK in promoting the activities of key enzymatic antioxidants such as SOD, CAT and POD. Of the two varieties of wheat, Ujala-2016 had better response to MLE 10% in terms of growth and biochemical attributes measured in this study. It was concluded that MLE, being cost-effective and eco-friendly, can be applied as a potential source of fertilizers to improve growth and yield of wheat.

The Role of Dietary Antioxidants, Food Supplements and Functional Foods for Energy Enhancement in Healthcare Professionals.

Healthcare professionals frequently experience significant work overload, which often leads to substantial physical and psychological stress. This stress is closely linked to increased oxidative stress and a corresponding decline in energy levels. This scoping review investigates the potential impact of dietary antioxidants and food supplements in conjunction with diet in controlling these negative effects. Through an analysis of the biochemical pathways involved in oxidative stress and energy metabolism, the paper emphasizes the effectiveness of targeted dietary interventions. Key dietary antioxidants, such as vitamins C and E, polyphenols, and carotenoids, are evaluated for their ability to counteract oxidative stress and enhance energy levels. Additionally, the review assesses various food supplements, including omega-3 fatty acids, coenzyme Q10, and ginseng, and their mechanisms of action in energy enhancement. Practical guidelines for incorporating energy-boost dietary strategies into the routine of healthcare professionals are provided, emphasizing the importance of dietary modifications in reducing oxidative stress and improving overall well-being and performance in high-stress healthcare environments. The review concludes by suggesting directions for future research to validate these findings and to explore new dietary interventions that may further support healthcare professionals under work overload.

Insight into the Amelioration Effect of Nitric Acid-Modified Biochar on Saline Soil Physicochemical Properties and Plant Growth.

Soil salinization is a major factor threatening global food security. Soil improvement strategies are therefore of great importance in mitigating the adverse effect of salt stress. Our study aimed to evaluate the effect of biochar (BC) and nitric acid-modified biochar (HBC) (1%, 2%, and 3%; m/m) on the properties of salinized soils and the morphological and physiological characteristics of pakchoi. Compared with BC, HBC exhibited a lower pH and released more alkaline elements, reflected in reduced contents of K+, Ca2+, and Mg2+, while its hydrophilicity and polarity increased. Additionally, the microporous structure of HBC was altered, showing a rougher surface, larger pore size, pore volume, specific surface area, and carboxyl and aliphatic carbon content, along with lower aromatic carbon content and crystallinity. Moreover, HBC application abated the pH of saline soil. Both BC and HBC treatments decreased the sodium absorption rate (SAR) of saline soil as their concentration increased. Conversely, both types of biochar enhanced the cation exchange capacity (CEC), organic matter, alkali-hydrolyzable nitrogen, and available phosphorus and potassium content in saline soils, with HBC demonstrating a more potent improvement effect. Furthermore, biochar application promoted the growth-related parameters in pakchoi, and reduced proline and Na+ content, whilst increasing leaf K+ content under salt stress. Biochar also enhanced the activity of key antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) in leaves, and reduced hydrogen peroxide (H2O2) and malondialdehyde (MDA) content. Collectively, modified biochar can enhance soil quality and promote plant growth in saline soils.

Global Insights into the Lysine Acetylome Reveal the Role of Lysine Acetylation in the Adaptation of Bacillus altitudinis to Salt Stress.

Bacillus altitudinis is a well-known beneficial microorganism in plant rhizosphere, capable of enhancing plant growth and salt tolerance in saline soils. However, the mechanistic changes underlying salt tolerance in B. altitudinis at the level of post-translational modifications remain unclear. Here, diverse lysine modifications including acetylation, succinylation, crotonylation, and malonylation were determined in the B. altitudinis response to salt stress by immunodetection, and the acetylation level greatly increased under salt stress. The in-depth acetylome landscape showed that 1032 proteins in B. altitudinis were differentially acetylated under salt stress. These proteins were involved in many physiological aspects closely related to salt tolerance like energy generation and conversion, amino acid synthesis and transport, cell motility, signal transduction, secretion system, and repair system. Moreover, we also identified the differential acetylation of key enzymes involved in the major osmolyte biosynthesis and conversion and antioxidant defenses. Thiol peroxidase (TPX), a key protective antioxidant enzyme, had 3 upregulated acetylation sites (K7/139/157) under salt stress. Site-specific mutations demonstrated that K7/139/157 acetylation strongly regulated TPX function in scavenging intracellular ROS, thereby impacting bacterial growth under salt stress. To our knowledge, this is the first study showing that bacteria adaptation to salt stress occurs at the level of PTMs.

Ubiquitin Ligase U-Box51 Positively Regulates Drought Stress in Potato (Solanum tuberosum L.).

The ubiquitin-proteasome system (UPS) is a key protein degradation pathway in eukaryotes, in which E3 ubiquitin ligases mediate protein ubiquitination, directly or indirectly targeting substrate proteins to regulate various biological processes, including plant growth, hormone signaling, immune responses, and adaptation to abiotic stress. In this study, we identified plant U-box protein 51 in Solanum tuberosum (StPUB51) as an E3 ubiquitin ligase through transcriptomic analysis, and used it as a candidate gene for gene-function analysis. Quantitative real-time PCR (qRT-PCR) was used to examine StPUB51 expression across different tissues, and its expression patterns under simulated drought stress induced by polyethylene glycol (PEG 6000) were assessed. Transgenic plants overexpressing StPUB51 and plants with down-regulated StPUB51 expression were generated to evaluate drought tolerance. The activities of key antioxidant enzymes-superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) as well as malondialdehyde (MDA) content in transgenic plants' leaves were measured under drought conditions. Protein-protein interactions involving StPUB51 were explored via yeast two-hybrid (Y2H) screening, with interaction verification by bimolecular fluorescence complementation (BiFC). StPUB51 was predominantly expressed in stems, with lower expression observed in tubers, and its expression was significantly upregulated in response to 20% PEG-6000 simulated drought. Subcellular localization assays revealed nuclear localization of the StPUB51 protein. Under drought stress, StPUB51-overexpressing plants exhibited enhanced SOD, POD, and CAT activities and reduced MDA levels, in contrast to plants with suppressed StPUB51 expression. Y2H and BiFC analyses identified two interacting proteins, StSKP2A and StGATA1, which may be functionally linked to StPUB51. Collectively, these findings suggest that StPUB51 plays a positive regulatory role in drought tolerance, enhancing resilience in potato growth and stress adaptation.

Cupressus torulosa, a Source of Antioxidant Polyphenols: An Analytical and Pharmacological Study.

Cupressus torulosa (family Cupressaceae), widely distributed in the northwestern Himalayan region of India, is a coniferous aromatic tree traditionally used for its aerial parts. Its needles are renowned for their anti-inflammatory, anticonvulsant, antimicrobial, and wound-healing properties. Antioxidants from this plant are vital in combating oxidative stress, which are implicated in these diseases. This study employed a range of methods, including in vitro, in vivo, and ex vivo assays; biochemical estimations such as Total Phenolics Content and Total Flavonoids Content; and UPLC-QTOF-MS analysis, to evaluate the antioxidant potential of Cupressus torulosa needles. Initial screenings demonstrated promising antioxidant activity of 25% aqueous methanol extract of the needles, with SGOT and SGPT values of 55.28±57.07 and 52.27±19.50 IU/L, respectively, when compared to the positive control glibenclamide. Fractionation of the extract into ethyl acetate and butanol fractions revealed that the ethyl acetate fraction showed notable activity, with an EC50 value of 85.6 μg/mL in the DPPH assay, indicating effective free radical scavenging and reduced oxidative damage. UPLC-QTOF-MS characterization of ethyl acetate fraction in negative ion mode identified 34 metabolites, including 10 key antioxidant compounds. These findings underscore C. torulosa's potential as a source of bioactive antioxidants, highlighting its value for pharmaceutical and nutraceutical applications. The research provides a foundation for further isolation, characterization, and clinical testing of these compounds, enhancing our understanding of natural antioxidants in addressing oxidative stress-related conditions.

Oxidative pathways of apo, partially, and fully Zn(II)‐ and Cd(II)‐metalated human metallothionein‐3 are dominated by disulfide bond formation

Oxidative stress is a key component of many diseases, including neurodegenerative diseases such as Alzheimer's disease. Reactive oxygen species (ROS) such as hydrogen peroxide and nitric oxide lead to disease progression by binding to proteins and causing their dysregulation. Metallothionein‐3 (MT3), a cysteine‐rich brain‐located metalloprotein, has been proposed to be a key player in controlling oxidative stress in the central nervous system. We report data from a combination of electrospray ionization mass spectrometry (ESI‐MS), ultraviolet (UV)‐visible absorption spectroscopy, and circular dichroism spectroscopy that identify the oxidation pathway of MT3 fully bound to endogenous Zn(II) or exogenous Cd(II) together with the partially metalated species. We characterize the intermediate species formed during the oxidation of MT3, which is dominated by disulfide bond formation. We report the rates of oxidation. For both fully and partially metalated MT3, MT3 is oxidized at 5 to 10 times the rate of MT1, a similar but kidney‐expressed isoform of MT. As oxidation progresses, MT3 follows a domain‐specific demetallation pathway when it is fully metalated, and a domain‐independent pathway when partially metalated. This suggests the presence of a significant susceptibility toward oxidation when MT3 is partially metalated, and, therefore, a possible protective role of Zn(II) when fully metalated. With the evidence for the rapid oxidation rate, our data support the proposals of MT3 as a key antioxidant in physiology.

Therapeutic Effects of Liposomal Resveratrol in the Mitigation of Diabetic Nephropathy via Modulating Inflammatory Response, Oxidative Stress, and Apoptosis.

An important factor in the development of diabetes and its associated consequences is prolonged chronic hyperglycemia, which weakens the antioxidant defense system and produces reactive oxygen species. Phytochemicals have been found to scavenge free radicals and exhibit antioxidant effects necessary to increase insulin sensitivity and reduce the development of diabetes-related complications. Current treatments for managing diabetes and diabetic nephropathy are often not very effective and come with several limitations and side effects. Resveratrol, for example, has shown therapeutic potential in mitigating kidney damage induced by high glucose levels, but its short bioavailability is a significant limitation. This accentuates the need for alternatives that not only improve the disease but also reduce the side effects associated with treatment. To enhance the therapeutic efficacy of resveratrol, we investigated the protective effects of liposomal resveratrol (LR) in a streptozotocin-induced diabetic rat model at doses of 20 and 40mg/kg. We compared the impact of LR to that of resveratrol alone (at a dose of 40mg/kg) on various parameters, including serum levels of biochemical markers, tissue levels of pro-inflammatory cytokines, nuclear transcription factor, oxidative stress indices, and apoptotic markers. LR, as a highly absorbable and metabolized form of resveratrol, has demonstrated beneficial effects in diabetic rats. Administered at both 20mg/kg and 40mg/kg dosages over a 5-week period, it demonstrated notable efficacy in alleviating inflammation. This was accomplished by diminishing the levels of pro-inflammatory mediators, TNF-α and IL-6, through the inhibition of NF-κB translocation. Additionally, LR influenced apoptotic markers, specifically caspase, BCL-2, and BAX. Furthermore, it enhanced the expression of key antioxidant enzymes such as catalase and glutathione peroxidase while significantly lowering malondialdehyde levels. These significant biochemical and immunological protective effects correlated with improved histological integrity and overall kidney architecture. Notably, resveratrol alone was not as effective as LR in restoring kidney function, highlighting its potential as a therapeutic candidate for the treatment of diabetic nephropathy. However, more in-depth studies are needed to explore its mechanism of action and improved bioavailability.

Physiological and ecological responses of flue-cured tobacco to field chilling stress: insights from metabolomics and proteomics.

Currently, research on tobacco's response to chilling stress is mostly limited to laboratory simulations, where temperature is controlled to study physiological and molecular responses. However, laboratory conditions cannot fully replicate the complex environment of field chilling stress, so conducting research under field conditions is crucial for understanding the multi-level adaptive mechanisms of tobacco to chilling stress in natural environments. This study aims to use field trials, starting from physiological responses, combined with proteomics and untargeted metabolomics, to systematically reveal the physiological and biochemical characteristics and key molecular mechanisms of tobacco leaves under chilling stress. It provides new insights into tobacco's adaptation strategies under chilling stress. The results showed that (1) chilling stress damages the appearance of tobacco leaves, reduces the chlorophyll content, increases H2O2 and malondialdehyde (MDA) levels in cold-injured tobacco leaves, and damages the plasma membrane system. Although catalase (CAT) activity increases to cope with the accumulation of reactive oxygen species (ROS), the activities of key antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) significantly decrease, indicating that the antioxidant system of tobacco leaves fails in environments with sudden temperature drops. (2) Proteomics analysis indicated that 410 differentially expressed proteins were identified in cold-stressed tobacco leaves, with 176 upregulated and 234 downregulated. Tobacco leaves under chilling stress attempt to maintain energy supply and physiological stability by enhancing glycolysis, starch, and sucrose metabolism pathways. Concurrently, chilling stress triggers the expression of proteins related to cell wall reinforcement and antioxidant defense. However, due to impaired ribosomal function, protein synthesis is significantly inhibited, which aggravates damage to photosynthesis and cellular functions. (3) Metabolomics analysis revealed that the differential metabolites in cold-stressed tobacco leaves were mainly enriched in tyrosine metabolism, isoquinoline alkaloid biosynthesis, and fatty acid degradation pathways. This indicates that under chilling stress, tobacco leaves enhance adaptability by regulating energy metabolism, increasing antioxidant capacity, and stabilizing cell membrane structure. Therefore, under chilling stress, tobacco leaves exhibit complex physiological adaptability through multiple regulatory mechanisms involving proteins and metabolites. The research results provide important insights into the metabolic regulatory mechanisms of tobacco in response to extreme environments and also enhance the theoretical foundation for addressing low-temperature stress in practical production.