Expression Levels Of Antioxidant Enzymes Research Articles

Korean Mint (Agastache rugosa) Extract and Its Bioactive Compound Tilianin Alleviate Muscle Atrophy via the PI3K/Akt/FoxO3 Pathway in C2C12 Myotubes.

Skeletal muscle atrophy, which is characterized by diminished muscle mass, strength, and function, is caused by malnutrition, physical inactivity, aging, and diseases. Korean mint (Agastache rugosa Kuntze) possesses various biological functions, including anti-inflammatory, antioxidant, anticancer, and antiosteoporosis activities. Moreover, it contains tilianin, which is a glycosylated flavone that exerts antioxidant, anti-inflammatory, antidiabetic, and neuroprotective activities. However, no studies have analyzed the inhibitory activity of A. rugosa extract (ARE) and tilianin on muscle atrophy. Thus, the present study investigated the potential of ARE and tilianin on muscle atrophy and their underlying mechanisms of action in C2C12 myotubes treated with tumor necrosis factor-α (TNF-α). The results showed that ARE and tilianin promoted the phosphatidylinositol 3-kinase/protein kinase B pathway, thereby activating mammalian target of rapamycin (a protein anabolism-related factor) and its downstream factors. Moreover, ARE and tilianin inhibited the mRNA expression of muscle RING-finger protein-1 and atrogin-1 (protein catabolism-related factors) by blocking Forkhead box class O3 translocation. ARE and tilianin also mitigated inflammatory responses by downregulating nuclear factor-kappa B expression levels, thereby diminishing the expression levels of inflammatory cytokines, including TNF-α and interleukin-6. Additionally, ARE and tilianin enhanced the expression levels of antioxidant enzymes, including catalase, superoxide dismutase, and glutathione peroxidase. Overall, these results suggest that ARE and tilianin are potential functional ingredients for preventing or improving muscle atrophy.

Antioxidant and Anti-Fatigue Effects of a Standardized Botanical Extract Fraction (HemoHIM) in Forced-Exercised Aged Mice.

HemoHIM is a standardized medicinal herbal preparation consisting of extracts of Angelica gigas Nakai, Cnidium officinale Makino, and Paeonia lactiflora Pallas that possesses immune regulatory activities. This study aimed to research the potential antioxidant effects of HemoHIM and its capacity for reducing fatigue in aged mice subjected to forced exercise. After administering HemoHIM 125 (500 mg/kg orally) for 4 weeks in 8-month-old female C57BL/6 mice (4 groups of 10 mice), various parameters were evaluated. The analyses revealed that HemoHIM enhanced swimming time and grip strength. In addition, it significantly reduced serum lactate levels and increased liver glutathione peroxidase (GPx) levels after exercise challenge. The expression levels of antioxidant enzymes and factors, including nuclear factor erythroid 2-related factor-2 (Nrf-2), heme oxygenase 1, superoxide dismutase, GPx, and glutathione reductase, were significantly higher in liver and muscle tissues of mice treated with HemoHIM. These results indicate that HemoHIM might function as an anti-fatigue and antioxidant agent by modulating the Nrf-2 signaling pathway.

The 14-3-3 Protein BdGF14a Increases the Transcriptional Regulation Activity of BdbZIP62 to Confer Drought and Salt Resistance in Tobacco.

BdGF14a, a 14-3-3 gene from Brachypodium distachyon, induced by salt, H2O2, and abscisic acid (ABA), improved tolerance to drought and salt in tobacco, with a higher survival rate and longer roots under these stresses. Additionally, physiological index analyses showed that the heterologous expression of BdGF14a induced higher expression levels of antioxidant enzymes and their activities, leading to lighter DAB and NBT staining, denoting decreased H2O2 content. Additionally, the lower MDA content and ion leakage indicated enhanced cell membrane stability. Moreover, exogenous ABA resulted in shorter roots and a lower stomatal aperture in BdGF14a transgenic plants. BdGF14a interacted with NtABF2 and regulated the expression of stress-related genes. However, adding an ABA biosynthesis inhibitor suppressed most of these changes. Furthermore, similar salt and drought resistance phenotypes and physiological indicators were characterized in tobacco plants expressing BdbZIP62, an ABRE/ABF that interacts with BdGF14a. And Y1H and LUC assays showed that BdGF14a could enhance the transcription regulation activity of NtABF2 and BdbZIP62, targeting NtNECD1 by binding to the ABRE cis-element. Thus, BdGF14a confers resistance to drought and salinity through interaction with BdbZIP62 and enhances its transcriptional regulation activity via an ABA-mediated signaling pathway. Therefore, this work offers novel target genes for breeding salt- and drought-tolerant plants.

Overexpression of PavbHLH28 from Prunus avium enhances tolerance to cold stress in transgenic Arabidopsis

BackgroundThe basic helix-loop-helix (bHLH) gene family is one of plants’ largest transcription factor families. It plays an important role in regulating plant growth and abiotic stress response.ResultsIn this study, we determined that the PavbHLH28 gene participated in cold resistance. The PavbHLH28 gene was located in the nucleus and could be induced by low temperature. Under the treatment of ABA, PEG, and GA3, the transcript level of PavbHLH28 was affected. At low temperature, overexpression of the PavbHLH28 gene enhanced the cold resistance of plants with higher proline content, lower electrolyte leakage (EL) and malondialdehyde (MDA) content. Compared with the WT plants, the transgenic plants accumulated fewer reactive oxygen species (ROS), and the activity and expression levels of antioxidant enzymes were significantly increased. The expression of proline synthesis enzyme genes was up-regulated, and the transcripts levels of degradation genes were significantly down-regulated. The transcripts abundance of the cold stressed-related genes in the C-repeat binding factor (CBF) pathway was not significantly different between WT plants and transgenic plants after cold stress. Moreover, the PavbHLH28 could directly bind to the POD2 gene promoter and promote its gene expression.ConclusionsOverall, PavbHLH28 enhanced the cold resistance of transgenic plants through a CBF-independent pathway, which may be partly related to ROS scavenging.

Label-Free Quantitative Proteomics Reveal the Mechanisms of Young Wheat (Triticum aestivum L.) Ears’ Response to Spring Freezing

Late spring frost is an important meteorological factor threatening the safe production of winter wheat in China. The young ear is the most vulnerable organ of the wheat plant to spring frost. To gain an insight into the mechanisms underpinning young wheat ears’ tolerance to freezing, we performed a comparative proteome analysis of wheat varieties Xumai33 (XM33, freezing-sensitive) and Jimai22 (JM22, freezing-tolerant) under normal and freezing conditions using label-free quantitative proteomic techniques during the anther connective tissue formation phase (ACFP). Under freezing stress, 392 and 103 differently expressed proteins (DEPs) were identified in the young ears of XM33 and JM22, respectively, and among these, 30 proteins were common in both varieties. A functional characterization analysis revealed that these DEPs were associated with antioxidant capacity, cell wall modification, protein folding, dehydration response, and plant–pathogen interactions. The young ears of JM22 showed significantly higher expression levels of antioxidant enzymes, heat shock proteins, and dehydrin under normal conditions compared to those of XM33, which might help to prepare the young ears of JM22 for freezing stress. Our results lead to new insights into understanding the mechanisms in young wheat ears’ response to freezing stress and provide pivotal potential candidate proteins required for improving young wheat ears’ tolerance to spring frost.

Understanding how high stocking densities and concurrent limited oxygen availability drive social cohesion and adaptive features in regulatory growth, antioxidant defense and lipid metabolism in farmed gilthead sea bream (Sparus aurata).

The study combined the use of biometric, behavioral, physiological and external tissue damage scoring systems to better understand how high stocking densities drive schooling behavior and other adaptive features during the finishing growing phase of farmed gilthead sea bream in the Western Mediterranean. Fish were grown at three different final stocking densities (LD, 8.5kg/m3; MD, 17kg/m3; HD, 25kg/m3). Water oxygen concentration varied between 5 and 6ppm in LD fish to 3-4ppm in HD fish with the summer rise of water temperature from 19°C to 26°C (May-July). HD fish showed a reduction of feed intake and growth rates, but they also showed a reinforced social cohesion with a well-defined endogenous swimming activity rhythm with feeding time as a main synchronization factor. The monitored decrease of the breathing/swimming activity ratio by means of the AEFishBIT data-logger also indicated a decreased energy partitioning for growth in the HD environment with a limited oxygen availability. Plasma glucose and cortisol levels increased with the rise of stocking density, and the close association of glycaemia with the expression level of antioxidant enzymes (mn-sod, gpx4, prdx5) in liver and molecular chaperones (grp170, grp75) in skeletal muscle highlighted the involvement of glucose in redox processes via rerouting in the pentose-phosphate-pathway. Other adaptive features included the depletion of oxidative metabolism that favored lipid storage rather than fatty acid oxidation to decrease the oxygen demand as last electron acceptor in the mitochondrial respiratory chain. This was coincident with the metabolic readjustment of the Gh/Igf endocrine-growth cascade that promoted the regulation of muscle growth at the local level rather than a systemic action via the liver Gh/Igf axis. Moreover, correlation analyses within HD fish displayed negative correlations of hepatic transcripts of igf1 and igf2 with the data-logger measurements of activity and respiration, whereas the opposite was found for muscle igf2, ghr1 and ghr2. This was indicative of a growth-regulatory transition that supported a proactive instead of a reactive behavior in HD fish, which was considered adaptive to preserve an active and synchronized feeding behavior with a minimized risk of oxidative stress and epidermal skin damage.

Smoking Induces a Decline in Semen Quality and the Activation of Stress Response Pathways in Sperm.

Male infertility is a prevalent concern affecting couples worldwide. While genetic factors, hormonal imbalances, and reproductive system defects play significant roles, emerging evidence suggests that lifestyle choices also profoundly impact male fertility. This study aimed to explore the effects of several lifestyle factors, including tobacco and alcohol consumption, physical activity, and dietary habits, on semen quality parameters and molecular biomarkers. Thirty healthy male volunteers were recruited in the Urology service at Hospital Infante D. Pedro, Aveiro, Portugal. Participants completed lifestyle questionnaires and provided semen samples, which were analyzed according to the World Health Organization criteria by experienced technicians. We also analyzed the expression levels of antioxidant enzymes and heat-shock response-related proteins to explore the activation of signaling pathways involved in stress response within sperm cells. Our results revealed that tobacco consumption reduced semen volume and total sperm count. Although the changes in the percentage of total motility and normal morphology in the smokers' group did not reach statistical significance, a slight decrease was observed. Moreover, we identified for the first time a significant association between tobacco consumption and increased levels of heat shock protein 27 (HSP27) and phosphorylated HSP27 (p-HSP27) in sperm cells, indicating the potential detrimental effects of tobacco on the reproductive system. This study highlights that lifestyle factors reduce semen quality, possibly by inducing stress in sperm, raising awareness about the effects of these risk factors among populations at risk of male infertility.

EbbHLH80 Enhances Salt Responses by Up-Regulating Flavonoid Accumulation and Modulating ROS Levels.

bHLH transcription factors are involved in multiple aspects of plant biology, such as the response to abiotic stress. Erigeron breviscapus is a composite plant, and its rich flavonoids have strong preventive and therapeutic effects on cardio cerebral vascular disease. EbbHLH80, a gene from E. breviscapus that positively regulates flavonoid synthesis, was previously characterized. However, it is unclear whether EbbHLH80 increases flavonoid accumulation, which affects salt tolerance. The function of EbbHLH80 in transgenic tobacco seeds was identified by phylogenetic analysis and metabolome-transcriptome analysis. We investigated the role of EbbHLH80 in salt stress response. Our results showed that the expression of EbbHLH80 increased following salt treatment. Integrating the metabolome and transcriptome analysis of EbbHLH80-OE and Yunyan 87 (WT) seeds, we identified several genes and metabolites related to flavonoid biosynthesis and salt stress. Moreover, EbbHLH80-OE plants displayed higher salt tolerance than wild-type plants during seed germination and seedling growth. After salt treatment, transgenic tobacco had significantly lower levels of reactive oxygen species (ROS) than WT, with enhanced levels of antioxidant enzyme expression. Altogether, our results demonstrated that EbbHLH80 might be a positive regulator, promoting salt tolerance by modulating ROS scavenging and increasing stress-responsive genes.

Dihydromyricetin attenuates cisplatin-induced acute kidney injury by reducing oxidative stress, inflammation and ferroptosis

BackgroundCisplatin is effective against various types of cancers. However, its clinical application is limited owing to its adverse effects, especially acute kidney injury (AKI). Dihydromyricetin (DHM), a flavonoid derived from Ampelopsis grossedentata, has varied pharmacological activities. This research aimed to determine the molecular mechanism for cisplatin-induced AKI. MethodsA murine model of cisplatin-induced AKI (22 mg/kg, I.P.) and a HK-2 cell model of cisplatin-induced damage (30 μM) were established to evaluate the protective function of DHM. Renal dysfunction markers, renal morphology and potential signaling pathways were investigated. ResultsDHM decreased the levels of renal function biomarkers (blood urea nitrogen and serum creatinine), mitigated renal morphological damage, and downregulated the protein levels of kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin. It upregulated the expression levels of antioxidant enzymes (superoxide dismutase and catalase expression), nuclear factor-erythroid-2-related factor 2 (Nrf2) and its downstream proteins, including heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunits, thus eventually reducing cisplatin-induced reactive oxygen species (ROS) production. Moreover, DHM partially inhibited the phosphorylation of the active fragments of caspase-8 and -3 and mitogen-activated protein kinase and restored glutathione peroxidase 4 expression, which attenuated renal apoptosis and ferroptosis in cisplatin-treated animals. DHM also mitigated the activation of NLRP3 inflammasome and nuclear factor (NF)-κB, attenuating the inflammatory response. In addition, it reduced cisplatin-induced HK-2 cell apoptosis and ROS production, both of which were blocked by the Nrf2 inhibitor ML385. ConclusionsDHM suppressed cisplatin-induced oxidative stress, inflammation and ferroptosis probably through regulating of Nrf2/HO-1, MAPK and NF-κB signaling pathways.

A non-specific lipid transfer protein, NtLTPI.38, positively mediates heat tolerance by regulating photosynthetic ability and antioxidant capacity in tobacco

Non-specific lipid transfer proteins (nsLTPs) play an important role in plant growth and stress resistance; however, their function in tobacco remains poorly understood. Therefore, to explore the function of NtLTP in response to high temperature, we identified an NtLTPI.38 from tobacco, obtained its overexpression and knockout transgenic plants, and further studied their response to heat stress (42 °C). The results showed that NtLTPI.38 overexpression in tobacco reduced chlorophyll degradation, alleviated the high temperature damage to photosynthetic organs, and enhanced the photosynthetic capacity of tobacco under heat stress. NtLTPI.38 overexpression in heat-stressed tobacco increased the contents of soluble sugar and protein, proline, and flavonoid substances, reduced the relative conductivity, and decreased H2O2, O2•−, and MDA accumulation, and increased the enzymatic antioxidant activities, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), compared to wild type (WT) and knockout mutant plants. RT-PCR confirmed that the expression levels of antioxidant enzymes and thermal stress-related genes were significantly upregulated under thermal stress in overexpression plants. Therefore, NtLTPI.38 enhanced heat tolerance in tobacco by mitigating photosynthetic damage and improving osmoregulation and antioxidant capacity. These results provided the theoretical basis and a potential resource for further breeding projects to improve heat tolerance in plants.

Effect of PPARγ on oxidative stress in diabetes-related dry eye

Oxidative stress is closely associated with diabetes and can cause free radical accumulation and eventually lead to ocular surface tissue damage. The purpose of this study was to investigate peroxisome proliferator-activated receptor-γ (PPARγ) expression in the lacrimal gland (LG), meibomian gland, and cornea of diabetes-related dry eye mice and whether the PPARγ agonist rosiglitazone can alleviate the oxidative stress of the ocular surface, thereby improving the condition of diabetes-related dry eye. Quantitative RT-PCR (Q-PCR) showed that the PPARγ, catalase, glutathione peroxidase 3, and heme oxygenase-1 (HO-1) mRNA expression levels in the LG of diabetes-related dry eye mice decreased at 8 and 12 weeks. In addition, the increased levels of oxidative stress were confirmed by western blot. Although the mRNA expression levels of antioxidant enzymes in the cornea and meibomian gland decreased at 8 weeks, some of them recovered by 12 weeks. Rosiglitazone alleviated ocular surface damage and increased corneal sensitivity and tear production in diabetes-related dry eye mice. Moreover, the reactive oxygen species accumulation was reduced and the PPARγ, HO-1, and glutathione peroxidase 3 mRNA expression levels were increased in the LG. The PPARγ, HO-1, translocase of the outer membrane 20, and mitochondrial transcription factor A protein levels were also significantly increased. These results demonstrated that rosiglitazone reduced oxidative stress in the LG of diabetes-related dry eye mice, at least in part, by activating PPARγ to up-regulate antioxidant enzyme expression.

Oxygen nanobubble water affects wound healing of fibroblast WI-38 cells.

This study investigated the usefulness of oxygen nanobubble water (O2NBW) for wound repair by analyzing its effect on the wound-healing process in human lung fibroblasts (WI-38 cells). The WI-38 cells were treated with 0%, 50%, and 100% O2NBW. The cell viability, reactive oxygen species (ROS) production, and wound healing following treatment were determined to elucidate the effects of O2NBW. Our findings revealed that O2NBW had no cytotoxic effects on WI-38 cells, but instead increased cell numbers. The production of ROS was inhibited in the presence of O2NBW. Further, O2NBW induced migration and wound closure in WI-38 cells. In addition, the mRNA expression levels of antioxidant enzymes and wound-healing-related genes were evaluated. The results demonstrated that O2NBW enhanced the expression levels of all representative genes. In conclusion, our findings suggest that O2NBW could affect ROS production and wound healing in WI-38 cells and genes associated with the antioxidant system and wound healing.

Nitric oxide promotes adventitious root formation in cucumber under cadmium stress through improving antioxidant system, regulating glycolysis pathway and polyamine homeostasis.

Cadmium (Cd) as a potentially toxic heavy metal that not only pollutes the environment but also interferes with plant growth. Nitric oxide (NO) regulates plant growth and development as well as abiotic stress response. However, the mechanism underpinning NO-induced adventitious root development under Cd stress remains unclear. In this study, cucumber (Cucumis sativus 'Xinchun No. 4') was used as the experimental material to investigate the effect of NO on the development of adventitious roots in cucumber under Cd stress. Our results revealed that, as compared to Cd stress, 10 μM SNP (a NO donor) could considerably increase the number and length of adventitious roots by 127.9% and 289.3%, respectively. Simultaneously, exogenous SNP significantly increased the level of endogenous NO in cucumber explants under Cd stress. Our results revealed that supplementation of Cd with SNP significantly increased endogenous NO content by 65.6% compared with Cd treatment at 48 h. Furthermore, our study indicated that SNP treatment could improve the antioxidant capacity of cucumber explants under Cd stress by up-regulating the gene expression level of antioxidant enzymes, as well as reducing the levels of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion ( ) to alleviate oxidative damage and membrane lipid peroxidation. Application of NO resulted in a decrease of the , MDA, and H2O2 level by 39.6%, 31.4% and 60.8% as compared to Cd-alone treatment, respectively. Besides that, SNP treatment significantly increased the expression level of related genes involved in glycolysis processes and polyamine homeostasis. However, application of NO scavenger 2-(4-carboxy -2-phenyl)-4, 4, 5, 5-tetramethy limidazoline -1-oxyl -3-oxide (cPTIO) and the inhibitor tungstate significantly reversed the positive role of NO in promoting the adventitious root formation under Cd stress. These results suggest that exogenous NO can increase the level of endogenous NO, improve antioxidation ability, promote glycolysis pathway and polyamine homeostasis to enhance the occurrence of adventitious roots in cucumber under Cd stress. In summary, NO can effectively alleviate the damage of Cd stress and significantly promote the development of adventitious root of cucumber under Cd stress.

Berberine Alleviates the Damage, Oxidative Stress and Mitochondrial Dysfunction of PC12 Cells Induced by High Glucose by Activating the KEAP1/Nrf2/ARE Pathway.

Diabetic encephalopathy (DE) is one of the major chronic complications of diabetes mellitus. This study aims to investigate the inhibitory effect of berberine (BBR) on the damage of PC12 cells induced by high glucose (HG). Differentiated PC12 cells were treated with different concentrations of glucose/BBR. The cell morphology, cell viability, lactate dehydrogenase (LDH) activity, apoptosis, oxidative stress (OS), mitochondrial structure, mitochondrial membrane potential (MMP), mitochondrial complex I-V activity, and adenosine triphosphate (ATP) levels were evaluated. The mRNA and protein levels of the Keap1/Nrf2/ARE pathway-related genes were assessed by RT-qPCR and Western blot. High-dose BBR and HG jointly treated-PC12 cells were treated with Nrf2-specific inhibitor ML385 to further verify whether Nrf2 was the target of BBR. The results showed that BBR inhibited cell damage, OS, and mitochondrial dysfunction induced by HG. The inhibitory effect of high BBR was more significant. The Keap1/Nrf2/ARE pathway was inhibited in PC12 cells induced by HG. BBR could activate the Keap1/Nrf2/ARE pathway, thus up-regulating the expression levels of antioxidant enzymes. ML385 antagonized the ameliorating effect of BBR on OS and mitochondrial dysfunction. The conclusion is that BBR can activate the Keap1/Nrf2/ARE pathway, upregulate the expression patterns of antioxidant enzymes, and reduce cell damage, OS, and mitochondrial dysfunction of PC12 cells induced by HG.

Changes of antioxidant enzymes in the kidney after cardiac arrest in the rat model.

Globally, cardiac arrest (CA) is a leading cause of death and disability. Asphyxial CA (ACA)-induced kidney damage is a crucial factor in reducing the survival rate. The purpose of this study was to investigate the role of antioxidant enzymes in histopathological renal damage in an ACA rat model at different time points. A total of 88 rats were divided into five groups and exposed to ACA except for the sham group. To evaluate glomerular function and oxidative stress, serum levels of blood urea nitrogen (BUN) and creatinine (Crtn) and malondialdehyde (MDA) levels in renal tissues were measured. To determine histopathological damage, hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson's trichrome staining were performed. Expression levels of antioxidant enzymes including superoxide dismutase-1 (SOD-1), superoxide dismutase-2 (SOD-2), catalase (CAT), and glutathione peroxidase (GPx) were measured by immunohistochemistry (IHC). Survival rate of the experimental rats was reduced to 80% at 6 h, 55% at 12 h, 42.9% at 1 day, and 33% at 2 days after return of spontaneous circulation. Levels of BUN, Crtn, and MDA started to increase significantly in the early period of CA induction. Renal histopathological damage increased markedly from 6 h until two days post-CA. Additionally, expression levels of antioxidant enzymes were significantly decreased at 6 h, 12 h, 1 day, and 2 days after CA. CA-induced oxidative stress and decreased levels of antioxidant enzymes (SOD-1, SOD-2, CAT, GPx) from 6 h to two days could be possible mediators of severe renal tissue damage and increased mortality rate.

Deuterohemin-Ala-His-Thr-Val-Glu-Lys (DhHP-6) Mimicking Enzyme as Synergistic Antioxidant and Anti-Inflammatory Material for Periodontitis Therapy.

Periodontitis is an inflammatory disease induced by plaque microorganisms. In the clinic, antibiotic assistant periodontal mechanical therapy is the most effective therapy for the treatment of periodontitis. However, the drug resistance of the antibiotics and the repeated coming and diminishing of the disorder of oxidation-reduction balance in the inflammatory tissue could not meet the high requirements for periodontic health control in long periods. Deuterohemin-ala-his-thr-val-glu-lys (DhHP-6) is a biomimetic oxidase-mimicking enzyme that simulates the reactive oxygen radical scavenger function of heme by synthesizing the new molecular material following the key structure and amino acid sequence of heme. In this article, we report the antioxidant and anti-inflammatory properties of DhHP-6 by building a inflammatory model for human gingival fibroblasts (HGFs) stimulated by lipolysaccharide (LPS) and its effects on periodontitis in Wistar rats. DhHP-6 reduced the oxidative stress of HGFs by increasing the amount of the reductase species of glutathione (GSH) and catalase (CAT) while decreasing the amount of oxidase species of malonaldehyde (MDA) and reactive oxygen species (ROS). DhHP-6 had a dose-dependent protective effect on alveolar bone absorption in rats with periodontitis, enhanced antioxidant capacity, and reduced inflammation. As determined by Micro-CT scanning, DhHP-6 reduced alveolar bone loss and improved the bone structure of the left maxillary first molar of rats. There were no obvious morphological and histological differences in the rat organs with or without DhHP-6 treatment. These results suggest that DhHP-6 can be used to treat periodontitis by increasing the expression levels of antioxidant enzymes and antioxidants in systemic and local tissues, thereby reducing levels of oxidation products and cyto-inflammatory factors. The synergistic antioxidant and anti-inflammatory effects of DhHP-6 suggest that there are promising applications of this biomimetic enzyme molecular material for the next generation of agents for periodontitis therapy.

N-acetylcysteine attenuates oxidative stress-mediated cell viability loss induced by dimethyl sulfoxide in cryopreservation of human nucleus pulposus cells: A potential solution for mass production.

Cell therapy is considered a promising strategy for intervertebral disc (IVD) regeneration. However, cell products often require long-term cryopreservation, which compromises cell viability and potency, thus potentially hindering commercialization and off-the-shelf availability. Dimethyl sulfoxide (DMSO) is a commonly used cryoprotectant, however, DMSO is associated with cytotoxicity and cell viability loss. This study aimed to investigate the effects of DMSO on human nucleus pulposus cells (NPC) and the role of oxidative stress in DMSO-induced cytotoxicity. Furthermore, we examined the potential of antioxidant N-acetylcysteine (NAC) supplementation to mitigate the negative effects of DMSO. NPC were exposed to various concentrations of DMSO with or without a freezing cycle. Cell viability, cell apoptosis and necrosis rates, intracellular reactive oxygen species (ROS) levels, and gene expression of major antioxidant enzymes were evaluated. In addition, NAC was added to cryopreservation medium containing 10% DMSO and its effects on ROS levels and cell viability were assessed. DMSO concentrations ≤1% for 24 h did not significantly affect the NPC viability, whereas exposure to 5 and 10% DMSO (most commonly used concentration) caused cell viability loss (loss of 57% and 68% respectively after 24 h) and cell death in a dose- and time-dependent manner. DMSO increased intracellular and mitochondrial ROS (1.9-fold and 3.6-fold respectively after 12 h exposure to 10% DMSO) and downregulated gene expression levels of antioxidant enzymes in a dose-dependent manner. Tempering ROS through NAC treatment significantly attenuated DMSO-induced oxidative stress and supported maintenance of cell viability. This study demonstrated dose- and time-dependent cytotoxic effects of DMSO on human NPC. The addition of NAC to the cryopreservation medium ameliorated cell viability loss by reducing DMSO-induced oxidative stress in the freeze-thawing cycle. These findings may be useful for future clinical applications of whole cells and cellular products.

Cleistocalyx nervosum var. paniala Berry Promotes Antioxidant Response and Suppresses Glutamate-Induced Cell Death via SIRT1/Nrf2 Survival Pathway in Hippocampal HT22 Neuronal Cells.

Excessive glutamate neurotransmitters result in oxidative neurotoxicity, similar to neurodegeneration. An indigenous berry of Thailand, Cleistocalyx nervosum var. paniala (CNP), has been recognized for its robust antioxidants. We investigated the effects and mechanisms of CNP fruit extracts on antioxidant-related survival pathways against glutamate-induced neurotoxicity. The extract showed strong antioxidant capability and had high total phenolic and flavonoid contents, particularly resveratrol. Next, the protective effects of the CNP extract or resveratrol on the glutamate-induced neurotoxicity were examined in HT22 hippocampal cells. Our investigation showed that the pretreatment of cells with the CNP extract or resveratrol attenuated glutamate-induced neuronal death via suppression of apoptosis cascade by inhibiting the levels of cleaved- and pro-caspase-3 proteins. The CNP extract and resveratrol suppressed the intracellular ROS by increasing the mRNA expression level of antioxidant enzymes (SODs, GPx1, and CAT). We found that this extract and resveratrol significantly increased SIRT1 expression as a survival-related protein. Moreover, they also promoted the activity of the Nrf2 protein translocation into the nucleus and could bind to the promoter containing the antioxidant response element, inducing the expression of the downstream GPx1-antioxidant protein. Our data illustrate that the CNP extract and resveratrol inhibit apoptotic neuronal death via glutamate-induced oxidative neurotoxicity in HT22 cells through the activation of the SIRT1/Nrf2 survival mechanism.

Fast regulation of the NF-κB signalling pathway in human skeletal muscle revealed by high-intensity exercise and ischaemia at exhaustion: Role of oxygenation and metabolite accumulation

The NF-κB signalling pathway plays a critical role in inflammation, immunity, cell proliferation, apoptosis, and muscle metabolism. NF-κB is activated by extracellular signals and intracellular changes in Ca2+, Pi, H+, metabolites and reactive oxygen and nitrogen species (RONS). However, it remains unknown how NF-κB signalling is activated during exercise and how metabolite accumulation and PO2 influence this process. Eleven active men performed incremental exercise to exhaustion (IE) in normoxia and hypoxia (PIO2:73 mmHg). Immediately after IE, the circulation of one leg was instantaneously occluded (300 mmHg). Muscle biopsies from m. vastus lateralis were taken before (Pre), and 10s (Post, occluded leg) and 60s after exercise from the occluded (Oc1m) and free circulation (FC1m) legs simultaneously together with femoral vein blood samples. NF-κB signalling was activated by exercise to exhaustion, with similar responses in normoxia and acute hypoxia, as reflected by the increase of p105, p50, IKKα, IκBβ and glutathione reductase (GR) protein levels, and the activation of the main kinases implicated, particularly IKKα and CaMKII δD, while IKKβ remained unchanged. Postexercise ischaemia maintained and stimulated further NF-κB signalling by impeding muscle reoxygenation. These changes were quickly reverted at the end of exercise when the muscles recovered with open circulation. Finally, we have shown that Thioredoxin 1 (Trx1) protein expression was reduced immediately after IE and after 1 min of occlusion while the protein expression levels of glutathione peroxidase 1 (Gpx1) and thioredoxin reductase 1 (TrxR1) remained unchanged. These novel data demonstrate that exercising to exhaustion activates NF-κB signalling in human skeletal muscle and regulates the expression levels of antioxidant enzymes in human skeletal muscle. The fast regulation of NF-κB at exercise cessation has implications for the interpretation of published studies and the design of new experiments.

An orally administered gold nanocluster with ROS scavenging for inflammatory bowel disease treatment

Oxidative stress that is induced by excessive reactive oxygen species (ROS) is considered to be a key pathophysiological mechanism of inflammatory bowel disease (IBD), and restoring redox homeostasis in the inflammatory region by eliminating ROS is an effective way to treat IBD. Herein, ultrasmall Au25 nanoclusters (Au25 NCs) were synthesized using a simple improved protocol, which has good physiological stability and biosafety and can be noninvasively monitored by clinical computed tomography (CT) after oral administration. Au25 NCs can eliminate ROS such as ABTS radicals, superoxide free radicals (•O2−), and hydroxyl free radicals (•OH), upregulate the expression level of antioxidant enzymes, inhibit the expression of proinflammatory cytokines, and finally interrupt the inflammatory circuit of IBD to achieve the effective prevention and delayed treatment of IBD. This work will demonstrate the protective effect of Au25 NCs on IBD in living animals, which suggests a new nanomedicine strategy for IBD treatment.