Aging related changes in circulating reactive oxygen species (ROS) and protein carbonyls are indicative of liver oxidative injury

Nicotine-mediated therapy for Parkinson's disease in transgenic Caenorhabditis elegans model

Parkinson's disease resultant in the degeneration of Dopaminergic neurons and accumulation of α-synuclein in the substantia nigra pars compacta. The synthetic therapeutics for Parkinson's disease have moderate symptomatic benefits but cannot prevent or delay disease progression. In this study, nicotine was employed by using transgenic Caenorhabditis elegans Parkinson's disease models to minimize the Parkinson's disease symptoms. The results showed that the nicotine at 100, 150, and 200 μM doses reduced degeneration of Dopaminergic neurons caused by 6-hydroxydopamine (14, 33, and 40%), lowered the aggregative toxicity of α-synuclein by 53, 56, and 78%, respectively. The reduction in food-sensing behavioral disabilities of BZ555 was observed to be 18, 49, and 86%, respectively, with nicotine concentrations of 100 μM, 150 μM, and 200 μM. Additionally, nicotine was found to enhance Daf-16 nuclear translocation by 14, 31, and 49%, and dose-dependently increased SOD-3 expression by 10, 19, and 23%. In summary, the nicotine might a promising therapy option for Parkinson's disease.

Protein Oxidation in Aging and Alzheimer's Disease Brain

Proteins are essential molecules that play crucial roles in maintaining cellular homeostasis and carrying out biological functions such as catalyzing biochemical reactions, structural proteins, immune response, etc. However, proteins also are highly susceptible to damage by reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this review, we summarize the role of protein oxidation in normal aging and Alzheimer's disease (AD). The major emphasis of this review article is on the carbonylation and nitration of proteins in AD and mild cognitive impairment (MCI). The oxidatively modified proteins showed a strong correlation with the reported changes in brain structure, carbohydrate metabolism, synaptic transmission, cellular energetics, etc., of both MCI and AD brains compared to the controls. Some proteins were found to be common targets of oxidation and were observed during the early stages of AD, suggesting that those changes might be critical in the onset of symptoms and/or formation of the pathological hallmarks of AD. Further studies are required to fully elucidate the role of protein oxidation and nitration in the progression and pathogenesis of AD.

Effects of Phytosterol Ester Supplementation on Egg Characteristics, Eggshell Ultrastructure, Antioxidant Capacity, Liver Function and Hepatic Metabolites of Laying Hens during Peak Laying Period

The aim of this experiment was to investigate the effects of dietary Phytosterol Ester (PSE) supplementation on egg characteristics, eggshell ultrastructure, antioxidant capacity, liver function, hepatic metabolites, and its mechanism of action in Hy-Line Brown laying hens during peak laying period. A total of 256 healthy Hy-Line Brown laying hens were randomly allocated into four groups. The hens in the control group were fed a basal diet, while those in the experimental groups were fed a basal diet further supplemented with 10, 20, and 40 mg/kg PSE, respectively. It was found that the addition of 20 mg/kg and 40 mg/kg PSE to the diets increased egg weight, but decreased egg breaking strength (p < 0.05). The addition of PSEs to the diets increased albumen height and Haugh unit in all experimental groups (p < 0.05). Electron microscopic observation revealed that the mammillary thickness increased significantly at doses of 20 and 40 mg/kg, but the total thickness decreased, and the effective thickness also thinned (p < 0.05). The mammillary width narrowed in all experimental groups (p < 0.001). Dietary supplementation with 40 mg/kg PSE significantly increased egg yolk Phenylalanine, Leucine, and Isoleucine levels (p < 0.05). In untargeted liver metabolomic analyses, L-Phenylalanine increased significantly in all experimental groups. Leucyl-Lysine, Glutamyl-Leucyl-Arginine, and L-Tryptophan increased significantly at doses of 10 and 20 mg/kg (p < 0.05), and L-Tyrosine increased significantly at doses of 10 and 40 mg/kg (p = 0.033). Aspartyl-Isoleucine also increased significantly at a dose of 10 mg/kg (p = 0.044). The concentration of total protein in the liver was significantly higher at doses of 20 and 40 mg/kg than that of the control group, and the concentrations of total cholesterol and low-density lipoprotein cholesterol were significantly reduced (p < 0.05). The concentration of triglyceride and alkaline phosphatase were significantly reduced in all experimental groups (p < 0.05). Steatosis and hemorrhage in the liver were also improved by observing the H&E-stained sections of the liver. Concerning the antioxidant capacity in the liver, malondialdehyde concentration was significantly reduced (p < 0.05) at a dose of 40 mg/kg. In the ovary, malondialdehyde and nitric oxide concentrations were significantly reduced (p < 0.001). In all the experimental groups, plasma nitric oxide concentration was significantly decreased while superoxide dismutase was significantly increased, and total antioxidant capacity concentration was significantly increased (p < 0.05) in the 10 mg/kg and 40 mg/kg doses. Metabolomics analyses revealed that PSEs play a role in promoting protein synthesis by promoting Aminoacyl-tRNA biosynthesis and amino acid metabolism, among other pathways. This study showed that the dietary addition of PSEs improved egg characteristics, antioxidant capacity, liver function, and symptoms of fatty liver hemorrhagic syndrome in Hy-Line Brown laying hens at peak laying stage. The changes in liver metabolism suggest that the mechanism of action may be related to pathways such as Aminoacyl-tRNA biosynthesis and amino acid metabolism. In conclusion, the present study demonstrated that PSEs are safe and effective dietary additives as an alternative to antibiotics.

Integrated biomarker responses in wild populations of the intertidal sea anemone Bunodosoma zamponii living under different anthropogenic pressures

Bunodosoma zamponii is the most abundant anemone in Mar del Plata (Buenos Aires, Argentina). Given that the presence of persistent organic pollutants (organochlorine pesticides and PCBs) and the organophosphate pesticide chlorpyrifos has recently been reported in this species, two wild populations living under different anthropogenic pressures were studied and compared regarding basic aspects of their ecology and physiological response to oxidative stress. A population from an impacted site (Las Delicias, LD) and another from a reference site (Punta Cantera, PC) were monitored seasonally (spring, summer, autumn, and winter), for one year. Anemones from PC were larger and more abundant than those from LD for most sampling periods. During winter, glutathione-S-transferase and catalase activities were higher in LD. Moreover, protein content and antioxidant defenses were higher in anemones from PC during winter as well. Taking into account their ecology (size and abundance) and biomarker responses, the population from PC was comparatively healthier. Furthermore, such differences are in agreement with recent studies indicating a higher concentration of pollutants in anemones from LD (specially during the winter sampling). In this sense, considering that B. zamponii can bioaccumulate the aforementioned pollutants, its resilience to their presence, and the fact that biomarker response differed between sites, this species can be regarded as a proper sentinel species of environmental pollution. Overall, this anemone seems to be a good bioindicator to be considered in future biomonitoring and ecotoxicological studies.

17-Oxime ethers of oxidized ecdysteroid derivatives modulate oxidative stress in human brain endothelial cells and dose-dependently might protect or damage the blood-brain barrier

20-Hydroxyecdysone and several of its oxidized derivatives exert cytoprotective effect in mammals including humans. Inspired by this bioactivity of ecdysteroids, in the current study it was our aim to prepare a set of sidechain-modified derivatives and to evaluate their potential to protect the blood-brain barrier (BBB) from oxidative stress. Six novel ecdysteroids, including an oxime and five oxime ethers, were obtained through regioselective synthesis from a sidechain-cleaved calonysterone derivative 2 and fully characterized by comprehensive NMR techniques revealing their complete 1H and 13C signal assignments. Surprisingly, several compounds sensitized hCMEC/D3 brain microvascular endothelial cells to tert-butyl hydroperoxide (tBHP)-induced oxidative damage as recorded by impedance measurements. Compound 8, containing a benzyloxime ether moiety in its sidechain, was the only one that exerted a protective effect at a higher, 10 μM concentration, while at lower (10 nM- 1 μM) concentrations it promoted tBHP-induced cellular damage. Brain endothelial cells were protected from tBHP-induced barrier integrity decrease by treatment with 10 μM of compound 8, which also mitigated the intracellular reactive oxygen species production elevated by tBHP. Based on our results, 17-oxime ethers of oxidized ecdysteroids modulate oxidative stress of the BBB in a way that may point towards unexpected toxicity. Further studies are needed to evaluate any possible risk connected to dietary ecdysteroid consumption and CNS pathologies in which BBB damage plays an important role.

Old muscle, new tricks: a clinician perspective on sarcopenia and where to next

PURPOSE OF REVIEW

This review offers a contemporary clinical approach to the recognition, prevention and management of sarcopenia, and discusses recent clinically relevant advances in the aetiopathogenesis of muscle ageing that may lead to future therapeutic targets.

RECENT FINDINGS

The key recent directions for sarcopenia are in the diagnosis, understanding molecular mechanisms and management. Regarding the recognition of the condition, it has become increasingly clear that different definitions hamper progress in understanding. Therefore, the Global Leadership in Sarcopenia has been established in 2022 to develop a universally accepted definition. Moreover, substantial work is occurring to understand the various roles and contribution of inflammation, oxidative stress, mitochondrial dysfunction and metabolic dysregulation on skeletal muscle function and ageing. Finally, the role of resistance-based exercise regimes has been continually emphasised. However, the role of protein supplementation and hormone replacement therapy (HRT) are still under debate, and current clinical trials are underway.

SUMMARY

With the global ageing of our population, there is increasing emphasis on maintaining good health. Maintenance of skeletal muscle strength and function are key to preventing frailty, morbidity and death.

Ameliorative effects of camel milk and silymarin upon aflatoxin B1 induced hepatic injury in rats

Aflatoxin B1 (AFB1) poses a major risk to both human and animal health because it contaminates food, feed, and grains. These dangerous effects can be mitigated using natural components. The purpose of this study was to examine the ameliorative effects of camel milk and silymarin supplementation upon aflatoxin B1 induced hepatic injury in rats. This improvement was assessed by measuring leukocytic and deferential counts, serum biochemical parameters, and gene expression of Tumor Necrosis Factor (TNF-α), antioxidant gene (NAD(P)H quinone oxidoreductase 1 (NQO1)), and base excision repair genes (APE1 and OGG1) in the liver tissue, in addition to liver histopathology. Sixty mature males Wister white rats were used to perform the present study; the rats were distributed in six groups (ten rats/group). The control group (without any treatment) received saline by gavage. The camel milk group received 1 ml of camel milk/kg body weight. The silymarin group received 1 ml of silymarin suspension solution at a dose of 20 mg of silymarin/kg of b.wt. The aflatoxin group received an aflatoxin-contaminated diet at a dose of 1.4 mg of aflatoxin /kg of diet and received saline. The camel milk + aflatoxin group received the same previous oral doses of camel milk and an aflatoxin-contaminated diet at the same time. The silymarin + aflatoxin group received the same previous doses of silymarin orally and an aflatoxin-contaminated diet at the same time. The obtained data indicated the deleterious effect of aflatoxin B1 on the leukocytic count, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and the expression of the studied genes. However, these deleterious effects were mitigated by camel milk and silymarin supplementation. Thus, we could conclude that the ingestion of camel milk and silymarin mitigated the negative effects of AFB1 on the hematology, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and gene expression in the rat model.

EEPD1 promotes repair of oxidatively-stressed replication forks

Unrepaired oxidatively-stressed replication forks can lead to chromosomal instability and neoplastic transformation or cell death. To meet these challenges cells have evolved a robust mechanism to repair oxidative genomic DNA damage through the base excision repair (BER) pathway, but less is known about repair of oxidative damage at replication forks. We found that depletion or genetic deletion of EEPD1 decreases clonogenic cell survival after oxidative DNA damage. We demonstrate that EEPD1 is recruited to replication forks stressed by oxidative damage induced by H2O2 and that EEPD1 promotes replication fork repair and restart and decreases chromosomal abnormalities after such damage. EEPD1 binds to abasic DNA structures and promotes resolution of genomic abasic sites after oxidative stress. We further observed that restoration of expression of EEPD1 via expression vector transfection restores cell survival and suppresses chromosomal abnormalities induced by oxidative stress in EEPD1-depleted cells. Consistent with this, we found that EEPD1 preserves replication fork integrity by preventing oxidatively-stressed unrepaired fork fusion, thereby decreasing chromosome instability and mitotic abnormalities. Our results indicate a novel role for EEPD1 in replication fork preservation and maintenance of chromosomal stability during oxidative stress.

Nrf2 and Oxidative Stress: A General Overview of Mechanisms and Implications in Human Disease

Organisms are continually exposed to exogenous and endogenous sources of reactive oxygen species (ROS) and other oxidants that have both beneficial and deleterious effects on the cell. ROS have important roles in a wide range of physiological processes; however, high ROS levels are associated with oxidative stress and disease progression. Oxidative stress has been implicated in nearly all major human diseases, from neurogenerative diseases and neuropsychiatric disorders to cardiovascular disease, diabetes, and cancer. Antioxidant defence systems have evolved as a means of protection against oxidative stress, with the transcription factor Nrf2 as the key regulator. Nrf2 is responsible for regulating an extensive panel of antioxidant enzymes involved in the detoxification and elimination of oxidative stress and has been extensively studied in the disease contexts. This review aims to provide the reader with a general overview of oxidative stress and Nrf2, including basic mechanisms of Nrf2 activation and regulation, and implications in various major human diseases.

Glycyrrhizic acid Poly(D,L-lactide-co-glycolide) nanoparticles: anti-aging cosmeceutical formulation for topical applications

Glycyrrhizic acid (GA) is one of the components of licorice roots (Glycyrrhiza glabra L.). GA is a triterpenoid saponin can be used as a medicinal plant with its antiallergic, antiviral, anti-inflammatory, anti-ulcer, hepatoprotective, anticancer, anti-oxidation activities and several other therapeutic properties. The aim of this study is to develop an anti-aging formulation for topical application containing GA. In this context, GA-loaded Poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were prepared using the double emulsion method, and were characterized by various spectroscopic methods. The efficacy of GA-PLGA NPs was evaluated with in vitro and in silico methods. The encapsulation efficiency and loading capacity were calculated. The in vitro release study was conducted, and the GA release profile was determined. The genotoxic activity of GA and GA-PLGA NPs was evaluated by the Ames test using TA98 and TA100 mutant strains of Salmonella typhimurium. The cytotoxic potential of GA-PLGA NPs was evaluated on the HaCaT cell line using the MTT assay. According to the genotoxicity and cytotoxicity results, it was found that the GA-PLGA NP formulation did not exhibit genotoxic and cytotoxic effects. Moreover, the efficacy of GA in preventing UVB-induced photo-aging in HaCaT cells and the clarification of the molecular mechanism of GA binding to MMPs were revealed by molecular docking analysis. In addition, through molecular dynamics (MD) analysis, the binding interaction of GA with MMPs in a dynamic system, and protein-ligand stability were predicted as a result of 50 ns MD simulation studies considering various analysis parameters. Finally, it was evaluated that GA-PLGA nanoformulation might be used as an alternative anti-aging skin care product candidate via topical application.

Tea Polyphenols as Prospective Natural Attenuators of Brain Aging

No organism can avoid the process of aging, which is often accompanied by chronic disease. The process of biological aging is driven by a series of interrelated mechanisms through different signal pathways, including oxidative stress, inflammatory states, autophagy and others. In addition, the intestinal microbiota play a key role in regulating oxidative stress of microglia, maintaining homeostasis of microglia and alleviating age-related diseases. Tea polyphenols can effectively regulate the composition of the intestinal microbiota. In recent years, the potential anti-aging benefits of tea polyphenols have attracted increasing attention because they can inhibit neuroinflammation and prevent degenerative effects in the brain. The interaction between human neurological function and the gut microbiota suggests that intervention with tea polyphenols is a possible way to alleviate brain-aging. Studies have been undertaken into the possible mechanisms underpinning the preventative effect of tea polyphenols on brain-aging mediated by the intestinal microbiota. Tea polyphenols may be regarded as potential neuroprotective substances which can act with high efficiency and low toxicity.

Metabolic reprogramming: a bridge between aging and tumorigenesis

Aging is the most robust risk factor for cancer development, with more than 60% of cancers occurring in those aged 60 and above. However, how aging and tumorigenesis are intertwined is poorly understood and a matter of significant debate. Metabolic changes are hallmarks of both aging and tumorigenesis. The deleterious consequences of aging include dysfunctional cellular processes, the build‐up of metabolic byproducts and waste molecules in circulation and within tissues, and stiffer connective tissues that impede blood flow and oxygenation. Collectively, these age‐driven changes lead to metabolic reprogramming in different cell types of a given tissue that significantly affects their cellular functions. Here, we put forward the idea that metabolic changes that happen during aging help create a favorable environment for tumorigenesis. We review parallels in metabolic changes that happen during aging and how these changes function both as adaptive mechanisms that enable the development of malignant phenotypes in a cell‐autonomous manner and as mechanisms that suppress immune surveillance, collectively creating the perfect environment for cancers to thrive. Hence, antiaging therapeutic strategies that target the metabolic reprogramming that occurs as we age might provide new opportunities to prevent cancer initiation and/or improve responses to standard‐of‐care anticancer therapies.

Altered Metabolism in Alzheimer Disease Brain: Role of Oxidative Stress

Significance: Alzheimer disease (AD) is an all-too-common condition in the aging population. However, aging does not automatically equal neurodegeneration and memory decline. Recent Advances: This review article involves metabolic changes in the AD brain that are related to oxidative stress. Selected pathways are identified as potential targets for intervention in AD. Critical Issues: One of the main factors of AD is the oxidative imbalance within the central nervous system, causing a disruption in metabolic processes. Reactive oxygen species (ROS) are a natural consequence of many cellular processes, especially those associated with mitochondria, such as the electron transport chain. Some ROS, when kept under control and maintained at reasonable levels, often play roles in cell signaling. The cellular damage of ROS arises when oxidative imbalance occurs, in which case ROS are not controlled, leading to a myriad of alterations in cellular metabolic processes. These altered pathways include, among others, dysfunctional glycolysis, calcium regulation, lipid metabolism, mitochondrial processes, and mammalian target of rapamycin pathway dysregulation. Future Directions: Understanding how ROS can lead to these alterations can, ideally, elucidate therapeutic options for retarding AD progression in the aging population. Antioxid. Redox Signal. 36, 1289-1305.

Effects of acute and chronic oxidative stress on the blood-brain barrier in 2D and 3D in vitro models

Oxidative stress is a shared pathology of neurodegenerative disease and brain injuries, and is derived from perturbations to normal cell processes by aging or environmental factors such as UV exposure and air pollution. As oxidative cues are often present in systemic circulation, the blood-brain barrier (BBB) plays a key role in mediating the effect of these cues on brain dysfunction. Therefore, oxidative damage and disruption of the BBB is an emergent focus of neurodegenerative disease etiology and progression. We assessed barrier dysfunction in response to chronic and acute oxidative stress in 2D and 3D in vitro models of the BBB with human iPSC-derived brain microvascular endothelial-like cells (iBMECs). We first established doses of hydrogen peroxide to induce chronic damage (modeling aging and neurodegenerative disease) and acute damage (modeling the response to traumatic brain injury) by assessing barrier function via transendothelial electrical resistance in 2D iBMEC monolayers and permeability and monolayer integrity in 3D tissue-engineered iBMEC microvessels. Following application of these chronic and acute doses in our in vitro models, we found local, discrete structural changes were the most prevalent responses (rather than global barrier loss). Additionally, we validated unique functional changes in response to oxidative stress, including dysfunctional cell turnover dynamics and immune cell adhesion that were consistent with changes in gene expression.

ROS-Activated nanoscale coordination polymers for enhanced ultrasound-mediated therapy for the treatment of cancer

Stimuli-responsive nanoplatforms for efficient delivery of drugs in an on-demand manner show promising potential for killing cancer cells with high accuracy and minimal invasiveness. Herein, taking advantage of the good tissue-penetrating depth of sonodynamic therapy (SDT), reactive oxygen species (ROS)-responsive nanoscale coordination polymers (NCPs) were designed through self-assembly of porphyrins (PP) and platinum, which contained ROS-cleavable thioketal (TK) linkers to enhance the release of doxorubicin (Dox) during SDT. Upon exposure to the ultrasound (US), the Dox-loaded NCPs (PTK@PEG/Dox) could generate high amounts of cytotoxic ROS and heat, which not only induced the apoptosis of MCF-7 cells but also facilitated the efficient release of Dox due to the decomposition of the ROS-sensitive TK linkers, achieving the synergistic therapy of US-induced therapy and chemotherapy. After being modified with Arg-Gly-Asp (RGD) peptide, RGD/PTK@PEG exhibited a good targeting ability to cancer cells. Importantly, using the multicellular tumor spheroids (MCTS) derived from MCF-7 cells as a model, the RGD/PTK@PEG/Dox exhibited an efficient and controlled release behavior of Dox under the US irradiation, accompanying a tremendous anti-cancer effect for inducing apoptosis in the solid tumor tissues. This work provided a potential strategy to design controllable and stimuli-responsive nanoplatforms for synergistic/enhanced US-induced cancer therapy. STATEMENT OF SIGNIFICANCE: Stimulus-responsive nanoplatforms can deliver drugs efficiently in an on-demand manner, showing the potential to kill cancer cells with high accuracy and minimal invasiveness. Taking advantage of the good penetration ability of ultrasound (US), nanoscale coordination polymers (NCP) composed of porphyrin (PP), thioketal (TK) linkers, and platinum(II) were prepared via a coordination-driven self-assembly procedure. After doxorubicin (Dox) was loaded on the NCP (PTK@PEG/Dox), the nanoplatform responded to reactive oxygen species (ROS) under the stimulation of US, and induced the on-demand release of Dox, thereby achieving the combined therapeutic effect of sonodynamic therapy (SDT) and chemotherapy for cancer. This work provides a potential strategy for the development of controllable and stimuli-responsive nanoplatforms for enhanced ultrasound-induced cancer therapy.

Gut microbiota drives age-related oxidative stress and mitochondrial damage in microglia via the metabolite N6-carboxymethyllysine

Microglial function declines during aging. The interaction of microglia with the gut microbiota has been well characterized during development and adulthood but not in aging. Here, we compared microglial transcriptomes from young-adult and aged mice housed under germ-free and specific pathogen-free conditions and found that the microbiota influenced aging associated-changes in microglial gene expression. The absence of gut microbiota diminished oxidative stress and ameliorated mitochondrial dysfunction in microglia from the brains of aged mice. Unbiased metabolomic analyses of serum and brain tissue revealed the accumulation of N⁶-carboxymethyllysine (CML) in the microglia of the aging brain. CML mediated a burst of reactive oxygen species and impeded mitochondrial activity and ATP reservoirs in microglia. We validated the age-dependent rise in CML levels in the sera and brains of humans. Finally, a microbiota-dependent increase in intestinal permeability in aged mice mediated the elevated levels of CML. This study adds insight into how specific features of microglia from aged mice are regulated by the gut microbiota.

Age-related changes in liver metabolism and antioxidant capacity of laying hens

This study aimed to investigate the age-related changes of hepatic metabolism and antioxidant capacity of laying hens at 3 different ages. A total of 192 Hy-line Brown laying hens were assigned into 3 groups: 1) 195-day-old (D195 group); 2) 340-day-old (D340 group); 3) 525-day-old (D525 group). Each group replicated 8 times with 8 hens at the same age. Higher activity of aspartate aminotransferase and lower contents of total protein and globulin were observed in the serum of 525-day-old hens in comparison with their 195-day-old counterparts (P < 0.05). The 525-day-old hens accumulated higher contents of total cholesterol and triglyceride in the liver than 195-day-old birds. Additionally, compared with hens from D195 or D340 group, 525-day-old birds exhibited a lower circulating estradiol level (P < 0.05). For antioxidant capacity, birds in the D525 group showed a higher malondialdehyde concentration in both serum and liver as compared with D195 or D340 group (P < 0.05). The 525-day-old hens also exhibited lower glutathione peroxidase activities in both serum and liver when compared with 195-day-old birds (P < 0.05). Simultaneously, there was a decline of hepatic superoxide dismutase activity in the D525 group in comparison with D195 group (P < 0.05). Compared with 195-day-old counterparts, 340-day-old birds upregulated the mRNA abundance of nuclear factor erythroid-2 related factor 2 and glutathione peroxidase 1 in the liver (P < 0.05). In contrast, hens from D525 group showed the downregulation of hepatic nuclear factor erythroid-2 related factor 2, NAD(P)H quinone dehydrogenase 1, and superoxide dismutase 1 when compared with D340 group (P < 0.05). These results indicated that increasing age can adversely affect liver metabolism and function of laying hens.

Erinacine A-Enriched Hericium erinaceus Mycelium Delays Progression of Age-Related Cognitive Decline in Senescence Accelerated Mouse Prone 8 (SAMP8) Mice

There have been many reports on the neuroprotective effects of Hericium erinaceus mycelium, in which the most well-known active compounds found are diterpenoids, such as erinacine A. Previously, erinacine A-enriched Hericeum erinaceus mycelium (EAHEM) was shown to decrease amyloid plaque aggregation and improve cognitive disability in Alzheimer’s disease model APP/PS1 mice. However, its effects on brain aging have not yet been touched upon. Here, we used senescence accelerated mouse prone 8 (SAMP8) mice as a model to elucidate the mechanism by which EAHEM delays the aging of the brain. Three-month-old SAMP8 mice were divided into three EAHEM dosage groups, administered at 108, 215 and 431 mg/kg/BW/day, respectively. During the 12th week of EAHEM feeding, learning and memory of the mice were evaluated by single-trial passive avoidance and active avoidance test. After sacrifice, the amyloid plaques, induced nitric oxidase synthase (iNOS) activity, thiobarbituric acid-reactive substances (TBARS) and 8-OHdG levels were analyzed. We found that the lowest dose of 108 mg/kg/BW EAHEM was sufficient to significantly improve learning and memory in the passive and active avoidance tests. In all three EAHEM dose groups, iNOS, TBARS and 8-OHdG levels all decreased significantly and showed a dose-dependent response. The results indicate that EAHEM improved learning and memory and delayed degenerative aging in mice brains.

Exploring the Protective and Reparative Mechanisms of G. lucidum Polysaccharides Against H2O2-Induced Oxidative Stress in Human Skin Fibroblasts

BACKGROUND

Ganoderma lucidum (G. lucidum) is one of China's traditional medicinal materials. G. lucidum polysaccharide has a wide range of promising pharmacological applications. However, there are many kinds of G. lucidum and they contain different kinds of polysaccharides. The biological mechanism through which Ganoderma lucidum polysaccharides (GLP) is able to protect human skin fibroblasts (HSFs) from H2O2-induced oxidative damage is still unclear.

METHODS

Six polysaccharides were obtained from G. lucidum to evaluate their free radical scavenging ability (DPPH free radical, ABTS free radical, hydroxyl-free radical, superoxide anion-free radical) in vitro, and their protective and reparative effects on oxidative damage induced by H2O2 in human skin fibroblasts. One polysaccharide was selected to detect oxidative damage markers and gene expression in the Keap1-Nrf2/ARE signaling pathway in HSFs.

RESULTS

All six polysaccharides showed the ability to scavenge free radicals and enhance the tolerance of human skin fibroblasts to H2O2 damage. Among them, GLP1 was selected and separated into two components (GLP1I and GLP1II). The results showed that GLP1, GLP1I and GLPII could significantly reduce the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). The protective effect of GLP1II was stronger than that of positive control vitamin C. In addition, GLP1, GLP1I and GLP1II could significantly increase the levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). And GLP1I works best in both ways. Meanwhile, Nrf2, a key regulator of keAP1-NRF2/ARE signaling pathway, was activated, while Keap1, a negative regulator, was inhibited, thus promoting the expression of downstream antioxidant enzyme genes (GSTs, GCLs, Nqo1, and Ho-1).

CONCLUSION

The results showed that GLP could protect human skin fibroblasts from oxidative damage caused by H2O2 peroxide by enhancing enzyme activity and activating Keap1-Nrf2/ARE signaling pathway. GLP will act as a natural antioxidant to protect the skin from oxidative stress damage.

Variation in resistance to oxidative stress in Oregon-(R)R-flare and Canton-S strains of Drosophila melanogaster

All aerobic organisms are susceptible to damage by reactive oxygen species (ROS). ROS-induced damage has been associated with aging and diseases such as metabolic syndrome and cancer. However, not all organisms develop these diseases, nor do they age at the same rate; this is partially due to resistance to oxidative stress, a quantitative trait attributable to the interaction of factors including genetics and environmental. Drosophila melanogaster represents an ideal system to study how genetic variation can affect resistance to oxidative stress. In this work, oxidative stress (total and mitochondrial ROS), antioxidant response, and Cap 'n' collar isoform C and Spineless gene expression, one pesticide resistant (Oregon R(R)-flare) and wild-type (Canton-S) strains of D. melanogaster, were analyzed to test resistance to basal oxidative stress. ROS, catalase, and superoxide dismutase were determined by flow cytometry, and Cap 'n' collar isoform C and Spineless expression by qRT-PCR. The intensity of oxidative stress due to the pro-oxidant zearalenone in both was evaluated by flow cytometry. Data confirm expected differences in oxidative stress between strains that differ in Cyp450s levels. The Oregon (R)R-flare showed greater ROS, total and mitochondrial, compared to Canton-S. Regarding oxidative stress genes expression Cap 'n' collar isoform C and Spineless (Ss), Oregon R(R)-flare strain showed higher expression. In terms of response to zearalenone mycotoxin, Canton-S showed higher ROS concentration. Our data show variation in the resistance to oxidative stress among these strains of D. melanogaster.

Genetically Encoded Fluorescent Redox Indicators for Unveiling Redox Signaling and Oxidative Toxicity

Redox-active molecules play essential roles in cell homeostasis, signaling, and other biological processes. Dysregulation of redox signaling can lead to toxic effects and subsequently cause diseases. Therefore, real-time tracking of specific redox-signaling molecules in live cells would be critical for deciphering their functional roles in pathophysiology. Fluorescent protein (FP)-based genetically encoded redox indicators (GERIs) have emerged as valuable tools for monitoring the redox states of various redox-active molecules from subcellular compartments to live organisms. In the first section of this review, we overview the background, focusing on the sensing mechanisms of various GERIs. Next, we review a list of selected GERIs according to their analytical targets and discuss their key biophysical and biochemical properties. In the third section, we provide several examples which applied GERIs to understanding redox signaling and oxidative toxicology in pathophysiological processes. Lastly, a summary and outlook section is included.

New Multi-Walled carbon nanotube of industrial interest induce cell death in murine fibroblast cells

The search for new nanomaterials has brought to the multifactorial industry several opportunities for use and applications for existing materials. Carbon nanotubes (CNT), for example, present excellent properties which allow us to assume a series of applications, however there is concern in the industrial scope about possible adverse health effects related to constant exposure for inhalation or direct skin contact. Thus, using cell models is the fastest and safest way to assess the effects of a new material. The aim of this study was to investigate the cytotoxic profile in LA9 murine fibroblast lineage, of a new multi-walled carbon nanotube (MWCNT) that was functionalized with tetraethylenepentamine (TEPA) to obtain better physical-chemical characteristics for industrial use. The modifications presented in the CNT cause concern, as they can change its initial characteristics, making this nanomaterial harmful. HR-TEM, FE-SEM and zeta potential were used for the characterization. Cytotoxicity and cell proliferation tests, oxidative and nitrosative stress analyzes and inflammatory cytokine assay (TNF-α) were performed. The main findings demonstrated a reduction in cell viability, increased release of intracellular ROS, accompanied by an increase in TNF-α, indicating an important inflammatory profile. Confirmation of the data was performed by flow cytometry and ImageXpress with apoptosis/necrosis markers. These data provide initial evidence that OCNT-TEPA has a cytotoxic profile dependent on the concentration of LA9 fibroblasts, since there was an increase in free radicals, inflammation induction and cell death, suggesting that continuous exposure to this nanoparticle can cause damage to different tissues in the organism.

Loss of Fis1 impairs proteostasis during skeletal muscle aging in Drosophila

Increased levels of dysfunctional mitochondria within skeletal muscle are correlated with numerous age‐related physiopathological conditions. Improving our understanding of the links between mitochondrial function and muscle proteostasis, and the role played by individual genes and regulatory networks, is essential to develop treatments for these conditions. One potential player is the mitochondrial outer membrane protein Fis1, a crucial fission factor heavily involved in mitochondrial dynamics in yeast but with an unknown role in higher‐order organisms. By using Drosophila melanogaster as a model, we explored the effect of Fis1 mutations generated by transposon Minos‐mediated integration. Mutants exhibited a higher ratio of damaged mitochondria with age as well as elevated reactive oxygen species levels compared with controls. This caused an increase in oxidative stress, resulting in large accumulations of ubiquitinated proteins, accelerated muscle function decline, and mitochondrial myopathies in young mutant flies. Ectopic expression of Fis1 isoforms was sufficient to suppress this phenotype. Loss of Fis1 led to unbalanced mitochondrial proteostasis within fly muscle, decreasing both flight capabilities and lifespan. Fis1 thus clearly plays a role in fly mitochondrial dynamics. Further investigations into the detailed function of Fis1 are necessary for exploring how mitochondrial function correlates with muscle health during aging.

The Keap1-Nrf2 System: A Mediator between Oxidative Stress and Aging

Oxidative stress, a term that describes the imbalance between oxidants and antioxidants, leads to the disruption of redox signals and causes molecular damage. Increased oxidative stress from diverse sources has been implicated in most senescence-related diseases and in aging itself. The Kelch-like ECH-associated protein 1- (Keap1-) nuclear factor-erythroid 2-related factor 2 (Nrf2) system can be used to monitor oxidative stress; Keap1-Nrf2 is closely associated with aging and controls the transcription of multiple antioxidant enzymes. Simultaneously, Keap1-Nrf2 signaling is also modulated by a more complex regulatory network, including phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), protein kinase C, and mitogen-activated protein kinase. This review presents more information on aging-related molecular mechanisms involving Keap1-Nrf2. Furthermore, we highlight several major signals involved in Nrf2 unbinding from Keap1, including cysteine modification of Keap1 and phosphorylation of Nrf2, PI3K/Akt/glycogen synthase kinase 3β, sequestosome 1, Bach1, and c-Myc. Additionally, we discuss the direct interaction between Keap1-Nrf2 and the mammalian target of rapamycin pathway. In summary, we focus on recent progress in research on the Keap1-Nrf2 system involving oxidative stress and aging, providing an empirical basis for the development of antiaging drugs.

Beyond Antioxidant Effects: Nature-Based Templates Unveil New Strategies for Neurodegenerative Diseases

The complex network of malfunctioning pathways occurring in the pathogenesis of neurodegenerative diseases (NDDs) represents a huge hurdle in the development of new effective drugs to be used in therapy. In this context, redox reactions act as crucial regulators in the maintenance of neuronal microenvironment homeostasis. Particularly, their imbalance results in the severe compromising of organism’s natural defense systems and subsequently, in the instauration of deleterious OS, that plays a fundamental role in the insurgence and progress of NDDs. Despite the huge efforts in drug discovery programs, the identification process of new therapeutic agents able to counteract the relentless progress of neurodegenerative processes has produced low or no effective therapies. Consequently, a paradigm-shift in the drug discovery approach for these diseases is gradually occurring, paving the way for innovative therapeutical approaches, such as polypharmacology. The aim of this review is to provide an overview of the main pharmacological features of most promising nature-based scaffolds for a possible application in drug discovery, especially for NDDs, highlighting their multifaceted effects against OS and neuronal disorders.

Plasma from Young Rats Injected into Old Rats Induce Antiaging Effects

An experimental novel antiaging intervention strategy is based on the concept of parabiosis, which involves long-term treatment with factors derived from young blood facilitating rejuvenation of old individuals. In this study, we employed blood plasma from young rats as an intervention strategy to evaluate whether this could impact aging biomarkers in aged rats. The biomarkers studied include: reactive oxygen species, the ferric reducing ability of plasma, plasma membrane redox system, reduced glutathione, malondialdehyde, protein carbonyl, and advanced oxidation protein products in blood. Additionally, the level of tumor necrosis factor-α and interleukin-6 were also estimated in blood. We found that old rats injected with plasma from young rats were protected from oxidative stress. Thus, this study provides some evidence of the rejuvenating effects of young plasma. We hypothesize that young plasma may contain certain "factors," which may be responsible for the observed effects. The mechanism of action is not clearly understood and is open to further studies.

Mitochondrial transformations in the aging human placenta

Mitochondria play a key role in homeostasis and are central to one of the leading hypotheses of aging, the free radical theory. Mitochondria function as a reticulated network, constantly adapting to the cellular environment through fusion (joining), biogenesis (formation of new mitochondria), and fission (separation). This adaptive response is particularly important in response to oxidative stress, cellular damage, and aging, when mitochondria are selectively removed through mitophagy, a mitochondrial equivalent of autophagy. During this complex process, mitochondria influence surrounding cell biology and organelles through the release of signaling molecules. Given that the human placenta is a unique organ having a transient and somewhat defined life span of ∼280 days, any adaption or dysfunction associated with mitochondrial physiology as a result of aging will have a dramatic impact on the health and function of both the placenta and the fetus. Additionally, a defective placenta during gestation, resulting in reduced fetal growth, has been shown to influence the development of chronic disease in later life. In this review we focus on the mitochondrial adaptions and transformations that accompany gestational length and share similarities with age-related diseases. In addition, we discuss the role of such changes in regulating placental function throughout gestation, the etiology of gestational complications, and the development of chronic diseases later in life.

Age-Related Changes in the Thermoregulatory Properties in Bank Voles From a Selection Experiment

As with many physiological performance traits, the capacity of endotherms to thermoregulate declines with age. Aging compromises both the capacity to conserve or dissipate heat and the thermogenesis, which is fueled by aerobic metabolism. The rate of metabolism, however, not only determines thermogenic capacity but can also affect the process of aging. Therefore, we hypothesized that selection for an increased aerobic exercise metabolism, which has presumably been a crucial factor in the evolution of endothermic physiology in the mammalian and avian lineages, affects not only the thermoregulatory traits but also the age-related changes of these traits. Here, we test this hypothesis on bank voles (Myodes glareolus) from an experimental evolution model system: four lines selected for high swim-induced aerobic metabolism (A lines), which have also increased the basal, average daily, and maximum cold-induced metabolic rates, and four unselected control (C) lines. We measured the resting metabolic rate (RMR), evaporative water loss (EWL), and body temperature in 72 young adult (4 months) and 65 old (22 months) voles at seven ambient temperatures (13-32°C). The RMR was 6% higher in the A than in the C lines, but, regardless of the selection group or temperature, it did not change with age. However, EWL was 12% higher in the old voles. An increased EWL/RMR ratio implies either a compromised efficiency of oxygen extraction in the lungs or increased skin permeability. This effect was more profound in the A lines, which may indicate their increased vulnerability to aging. Body temperature did not differ between the selection and age groups below 32°C, but at 32°C it was markedly higher in the old A-line voles than in those from other groups. As expected, the thermogenic capacity, measured as the maximum cold-induced oxygen consumption, was decreased by about 13% in the old voles from both selection groups, but the performance of old A-line voles was the same as that of the young C-line ones. Thus, the selection for high aerobic exercise metabolism attenuated the adverse effects of aging on cold tolerance, but this advantage has been traded off by a compromised coping with hot conditions by aged voles.

Dietary Antioxidants and the Mitochondrial Quality Control: Their Potential Roles in Parkinson's Disease Treatment

Advances in medicine and dietary standards over recent decades have remarkably increased human life expectancy. Unfortunately, the chance of developing age-related diseases, including neurodegenerative diseases (NDDs), increases with increased life expectancy. High metabolic demands of neurons are met by mitochondria, damage of which is thought to contribute to the development of many NDDs including Parkinson’s disease (PD). Mitochondrial damage is closely associated with the abnormal production of reactive oxygen species (ROS), which are widely known to be toxic in various cellular environments, including NDD contexts. Thus, ways to prevent or slow mitochondrial dysfunction are needed for the treatment of these NDDs. In this review, we first detail how ROS are associated with mitochondrial dysfunction and review the cellular mechanisms, such as the mitochondrial quality control (MQC) system, by which neurons defend against both abnormal production of ROS and the subsequent accumulation of damaged mitochondria. We next highlight previous studies that link mitochondrial dysfunction with PD and how dietary antioxidants might provide reinforcement of the MQC system. Finally, we discuss how aging plays a role in mitochondrial dysfunction and PD before considering how healthy aging through proper diet and exercise may be salutary.

Effects of Different Doses of Excessive Iron in Diets on Oxidative Stress in Immune Organs of Sheep

The aim of this work is to investigate the relationship between iron and oxidative stress in the immune organs of excessive iron-fed sheep. Sixteen German Mutton Merino rams were randomly divided into 4 groups, which were fed the basal diets supplemented with 50 (CON), 500 (L-iron), 1000 (M-iron), and 1500 (H-iron) mg Fe/kg as ferrous sulfate monohydrate (FeSO₄·H₂O), respectively. The actual iron content in the diet was determined to be 457.68 (CON), 816.42 (L-iron), 1256.78 (M-iron), and 1725.63 (H-iron) mg/kg, respectively. The consequences of oxidative damage were tested in 4 groups. The results showed that the contents of malondialdehyde (MDA), nitric oxide (NO), hydrogen peroxide (H₂O₂), and the activity of nitric oxide synthase (iNOS) were increased in excessive iron-fed sheep. Moreover, the present results revealed that excess iron was associated with a significant decrease in the activities of antioxidant capacity, such as glutathione peroxidase (GPx) activity and total antioxidant capacity (T-AOC) levels. The iNOS mRNA expression declined in excessive iron-fed sheep, indicating that down-regulation is likely to occur at the transcription level, which is consistent with the studies of iron blockades iNOS transcription. Surprisingly, the activity of glutathione peroxidase 1 (GPx1) continued to decline, but the expression levels of GPX1 mRNA and protein increased first and then decreased. This suggests that at the transcriptional and translation levels, the body compensatively increases the amount of GPx1 to maintain the balance of the oxidation-antioxidant system to resist peroxidation. Hematoxylin-eosin (HE) staining revealed histopathological changes in immune organs, such as lymphocyte infiltration and cell death, indicating that excessive iron-induced oxidative damage indirectly affects the body's immune function. These findings confirm the role of iron in regulating the homeostasis of the oxidation-antioxidant system.

Interrelation between ROS and Ca2+ in aging and age-related diseases

Calcium (Ca2+) and reactive oxygen species (ROS) are versatile signaling molecules coordinating physiological and pathophysiological processes. While channels and pumps shuttle Ca2+ ions between extracellular space, cytosol and cellular compartments, short-lived and highly reactive ROS are constantly generated by various production sites within the cell. Ca2+ controls membrane potential, modulates mitochondrial adenosine triphosphate (ATP) production and affects proteins like calcineurin (CaN) or calmodulin (CaM), which, in turn, have a wide area of action. Overwhelming Ca2+ levels within mitochondria efficiently induce and trigger cell death. In contrast, ROS comprise a diverse group of relatively unstable molecules with an odd number of electrons that abstract electrons from other molecules to gain stability. Depending on the type and produced amount, ROS act either as signaling molecules by affecting target proteins or as harmful oxidative stressors by damaging cellular components. Due to their wide range of actions, it is little wonder that Ca2+ and ROS signaling pathways overlap and impact one another. Growing evidence suggests a crucial implication of this mutual interplay on the development and enhancement of age-related disorders, including cardiovascular and neurodegenerative diseases as well as cancer.

Fenugreek (Trigonella foenum-graecum L.) Seeds Dietary Supplementation Regulates Liver Antioxidant Defense Systems in Aging Mice

Fenugreek seeds are widely used in Asia and other places of the world for their nutritive and medicinal properties. In Asia, fenugreek seeds are also recommended for geriatric populations. Here, we evaluated for the first time the effect of fenugreek seed feed supplementation on the liver antioxidant defense systems in aging mice. The study was conducted on 12-months aged mice which were given fenugreek seed dietary supplement. We evaluated the activities of various antioxidant defense enzymes such as superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx), and also estimated the phenolics and free radical scavenging properties in mice liver upon fenugreek supplementation. The estimation of SOD, GPx, and GR activities in aged mice liver revealed a significant (p < 0.01) difference among all the liver enzymes. Overall, this study reveals that fenugreek seed dietary supplementation has a positive effect on the activities of the hepatic antioxidant defense enzymes in the aged mice.

Oligosaccharide attenuates aging-related liver dysfunction by activating Nrf2 antioxidant signaling

Chitosan oligosaccharide (COS) is the depolymerized product of chitosan possessing various biological activities and protective effects against inflammation and oxidative injury. The aim of the present study was to investigate the antioxidant effects of COS supplements on aging-related liver dysfunction. We found that COS treatment significantly attenuated elevated liver function biomarkers and oxidative stress biomarkers and decreased antioxidative enzyme activities in liver tissues in D-galactose (D-gal)-treated mice. Furthermore, COS treatment significantly upregulated the expression of Nrf2 and its downstream target genes HO-1, NQO1, and CAT. Moreover, in vitro experiments showed that COS treatment played a vital role in protecting H2O2-exposed L02 cells against oxidative stress by activating Nrf2 antioxidant signaling. These data indicate that COS could protect against D-gal-induced hepatic aging by activating Nrf2 antioxidant signaling, which may provide novel applications for the prevention and treatment of aging-related hepatic dysfunction.

Swertiamarin, a secoiridoid glycoside modulates nAChR and AChE activity

The ailments related to a malfunction in cholinergic functioning currently employ the use of inhibitors for acetylcholinesterase (AChE) and N-methyl-d-aspartate (NMDA) receptors. The present study was designed to elucidate the potential of swertiamarin (SW), a secoiridoidal glycoside isolated from Enicostemma littorale in curtailing the cholinergic dysfunction. Using Caenorhabditis elegans as a model, SW was found to enhance neurotransmission by modulating AChE and nicotinic acetylcholine receptor (nAChR) activity; being orchestrated through up-regulation of unc-17 and unc-50. SW exhibited AChE inhibition both in vivo and cell-free system. The in silico molecular docking of SW and human AChE (hAChE) displayed good binding energy of -6.02. Interestingly, the increase in aldicarb and levamisole sensitivity post SW treatment was curtailed to a significant level in daf-16 and skn-1 mutants. SW raised the level of the endogenous antioxidant enzymes through up-regulation of sod-3 and gst-4 that act downstream to DAF-16 and SKN-1, imparting protection against neurodegeneration. The outcome of our study displays SW as a potential natural molecule for the amelioration of cholinergic dysfunction. Moreover, the study also indicates that SW elicits antioxidant response via up-modulation of daf-16 possibly through unc-17 upregulation. Further research on SW pertaining to the underlying mechanism and potential is expected to significantly advance the current understanding and design of possible ameliorative or near ameliorative regimens for cholinergic dysfunction.

Inhibition effect of thiol-type antioxidants on protein oxidative aggregation caused by free radicals

This study was aimed to investigate the inhibition effect of thiol-type antioxidants on protein oxidative aggregation caused by free radicals and the underlying mechanisms using six different thiol-type antioxidants (N-acetyl-L-cysteine, methionine, taurine, alpha-lipoic acid, glutathione and thioproline), Cu²⁺-H₂O₂ as a free radical generator (mainly a hydroxyl radical generator) and bovine serum albumin as the model protein. The inhibition effect of these antioxidants on protein oxidative aggregation and protective effect against oxidative damage in mouse brain tissues were investigated using SDS-PAGE, intrinsic fluorescence, simultaneous fluorescence, thioflavin T fluorescence, Congo red absorbance and inverted microscope. The results showed that all six antioxidants could inhibit protein oxidative aggregation by scavenging free radicals. In addition, alpha-lipoic acid could also bind to proteins via hydrophobic interactions and thioproline could bind to proteins via hydrogen bonds and van der Waals forces, thereby showing much stronger inhibition effect than others. Moreover, alpha-lipoic acid and thioproline could effectively prevent oxidative damage of mouse brain tissues. These results suggest that alpha-lipoic acid and thioproline can effectively inhibit free radical-induced protein aggregation and brain damage, which are worth testing for further anti-Alzheimer properties.

Urinary 8-Hydroxy-2'-Deoxyguanosine Levels and Cardiovascular Disease Incidence in Japan

Aim: The association between urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative stress marker, and the incidence of cardiovascular disease (CVD) has not been confirmed because no previous studies evaluated 24-hour 8-OHdG excretion levels in the general population. We aimed to confirm the association between 24-hour urinary 8-OHdG levels and CVD risk among Japanese men and women.

Methods: A nested case-control study was performed based on a 24-hour urine collection in a community-based cohort study performed from 1996 to 2005. Seventy-six cases (55 men and 21 women) who experienced their first CVD incidence during the follow-up period (median: 5.9 years) were recruited. The controls were frequency-matched 1:2, with each case for sex, age, area of residence, and baseline year. The 8-OHdG level was measured by enzyme-linked immunosorbent assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression models adjusted for body mass index, ethanol intake, smoking status, and estimated glomerular filtration rate.

Results: The geometric mean and geometric standard deviation (SD) of 8-OHdG levels (nmol/day) for cases and controls were 35.5 (1.55) and 35.5 (1.54) for men and 32.1 (1.35) and 25.0 (1.39) for women, respectively. The multivariable OR (95% CI) of CVD incidence according to the 1-SD increment of the log-transformed 8-OHdG level was 2.08 (0.99–4.37) for women. The multivariable ORs (95% CIs) for the 1st (lowest) and 4th versus 2nd quartile according to 8-OHdG for men were 3.29 (1.02–10.61) and 2.77 (0.96–7.96), respectively.

Conclusion: A high 8-OHdG level tended to be associated with CVD incidence among women.

Cellular Turnover: A Potential Metabolic Rate-Driven Mechanism to Mitigate Accumulation of DNA Damage

Oxidative stress, the imbalance of reactive oxygen species and antioxidant capacity, may cause damage to biomolecules pivotal for cellular processes (e.g., DNA). This may impair physiological performance and, therefore, drive life-history variation and aging rate. Because aerobic metabolism is supposed to be the main source of such oxidative risk, the rate of oxygen consumption should be positively associated with the level of damage and/or antioxidants. Empirical support for such relationships remains unclear, and recent considerations suggest even a negative relationship between metabolic rate and oxidative stress. We investigated the relationship between standard metabolic rate (SMR), antioxidants, and damage in blood plasma and erythrocytes for 35 grass snakes (Natrix natrix). Reactive oxygen metabolites (dROMs) and nonenzymatic antioxidants were assessed in plasma, while two measures of DNA damage and the capacity to neutralize H₂O₂ were measured in erythrocytes. Plasma antioxidants showed no correlation to SMR, and the level of dROMs was positively related to SMR. A negative relationship between antioxidant capacity and SMR was found in erythrocytes, but no association of SMR with either measure of DNA damage was detected. No increase in DNA damage, despite lower antioxidant capacity at high SMR, indicates an upregulation in other defense mechanisms (e.g., damage repair and/or removal). Indeed, we observed a higher frequency of immature red blood cells in individuals with higher SMR, which indicates that highly metabolic individuals had increased erythrocyte turnover, a mechanism of damage removal. Such DNA protection through upregulated cellular turnover might explain the negligible senescence observed in some ectotherm taxa.

N-Carbamylglutamate and l-arginine supplementation improve hepatic antioxidant status in intrauterine growth-retarded suckling lambs

The influence of dietary supplementation of l-arginine (Arg) or N-carbamylglutamate (NCG) on the hepatic antioxidant status in intrauterine-growth-retarded (IUGR) suckling lambs remains unclear. The current work aimed to investigate the regulatory mechanisms whereby dietary Arg or NCG alter hepatic antioxidant status in suckling lambs suffering from IUGR. Forty-eight newborn Hu lambs of normal birth weight (CON) and IUGR were allocated randomly into four groups of 12 animals each: CON (4.25 ± 0.14 kg), IUGR (3.01 ± 0.12 kg), IUGR + 1% Arg (2.99 ± 0.13 kg), or IUGR + 0.1% NCG (3.03 ± 0.11 kg). All lambs were raised for a period of 21 days from 7 to 28 days after birth. Compared with the IUGR suckling animals, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and reduced glutathione (GSH) content were greater (P < 0.05), and protein carbonyl and malondialdehyde (MDA) levels were reduced (P < 0.05) in the livers of both IUGR + 1% Arg and 0.1% NCG suckling animals. Relative to IUGR suckling lambs, supplementing with Arg or NCG markedly reduced (P < 0.05) reactive oxygen species (ROS) levels, apoptosis, and necrosis in liver. Relative to IUGR suckling lambs, protein and mRNA expression of GSH-Px1, SOD2, catalase (CAT), heme oxygenase-1 (HO-1), inducible nitric oxide (NO) synthase (iNOS), and epithelial NO synthase (eNOS) increased in IUGR animals receiving Arg or NCG (P < 0.05). Both Arg and NCG can protect neonates from IUGR-induced hepatic oxidative damage through promoting the expression of antioxidative enzymes (including SOD, CAT, and GSH-Px), phase II metabolizing enzymes, and activation of the NO pathway.

The influence of dietary supplementation of l-arginine (Arg) or N-carbamylglutamate (NCG) on the hepatic antioxidant status in intrauterine-growth-retarded (IUGR) suckling lambs remains unclear.

Toxicity of Carbon Nanotubes as Anti-Tumor Drug Carriers

Nanoparticle drug formulations have enormous application prospects owing to achievement of targeted and sustained release drug delivery, improvement in drug solubility and reduction of adverse drug reactions. Recently, a variety of efficient drug nanometer carriers have been developed, among which carbon nanotubes (CNT) have been increasingly utilized in the field of cancer therapy. However, these nanotubes exert various toxic effects on the body due to their unique physical and chemical properties. CNT-induced toxicity is related to surface modification, degree of aggregation in vivo, and nanoparticle concentration. This review has focused on the potential toxic effects of CNTs utilized as anti-tumor drug carriers. The main modes by which CNTs enter target sites, the toxicity expressive types and the factors affecting toxicity are discussed.

The splicing component ISY1 regulates APE1 in base excision repair

The integrity of cellular genome is continuously challenged by endogenous and exogenous DNA damaging agents. If DNA damage is not removed in a timely fashion the replisome may stall at DNA lesions, causing fork collapse and genetic instability. Base excision DNA repair (BER) is the most important pathway for the removal of oxidized or mono-alkylated DNA. While the main components of the BER pathway are well defined, its regulatory mechanism is not yet understood. We report here that the splicing factor ISY1 enhances apurinic/apyrimidinic endonuclease 1 (APE1) activity, the multifunctional enzyme in BER, by promoting its 5'-3' endonuclease activity. ISY1 expression is induced by oxidative damage, which would provide an immediate up-regulation of APE1 activity in vivo and enhance BER of oxidized bases. We further found that APE1 and ISY1 interact, and ISY1 enhances the ability of APE1 to recognize abasic sites in DNA. Using purified recombinant proteins, we reconstituted BER and demonstrated that ISY1 markedly promoted APE1 activity in both the short- and long-patch BER pathways. Our study identified ISY1 as a regulator of the BER pathway, which would be of physiological relevance where suboptimal levels of APE1 are present. The interaction of ISY1 and APE1 also establishes a connection between DNA damage repair and pre-mRNA splicing.

Ageing enhances the shedding of splenocyte microvesicles with endothelial pro-senescent effect that is prevented by a short-term intake of omega-3 PUFA EPA:DHA 6:1

BACKGROUND

Ageing is associated with progressive endothelial senescence and dysfunction, and cardiovascular risk. Circulating endothelial microvesicles (MVs) are pro-senescent and pro-inflammatory endothelial effectors in acute coronary syndrome. Omega-3 PUFA intake was claimed beneficial in cardiovascular prevention.

PURPOSE

To investigate whether the intake of the omega-3 formulation EPA:DHA 6:1 by middle-aged and old rats reduces the shedding of pro-senescent microvesicles from cultured spleen leukocytes (SMVs) and clarify the underlying mechanisms in target coronary primary endothelial cells (ECs).

METHODS

Middle-aged male Wistar rats (M, 48-week old) received 500 mg/kg/d of either EPA:DHA 6:1, EPA:DHA 1:1, or vehicle (CTL) for 7 days, old rats (72-week old) for 14 days. Spleen-derived leukocytes were prepared and cultured for 24 h and MVs collected from supernatants (SMVs). Cultured ECs were prepared from freshly isolated porcine coronary arteries. Senescence-associated β-galactosidase activity (SA-β-gal) was assessed by C12FDG, protein expression by Western blot analysis, oxidative stress by dihydroethidium using confocal microscopy, and procoagulant MVs by prothrombinase assay. The pro-senescent potential of SMVs from middle-aged rats (M-SMVs) was analyzed by comparison with young (Y, 12-week) and old (O) rats.

RESULTS

The shedding of SMVs significantly increased with age and was inhibited by EPA:DHA 6:1 intake that also prevented ROS accumulation in spleen. Incubation of ECs with 10 nM SMVs from middle-aged and old but not those from young rats induced premature senescence after 48 h. The pro-senescent effect of M-SMVs was prevented by Losartan and associated with endothelial oxidative stress. M-SMVs induced an up-regulation of senescence markers (p16, p21, p53), pro-atherothrombotic (VCAM-1, ICAM-1, tissue factor) and pro-inflammatory markers (pNF-κB, COX-2) and proteins of the angiotensin system (ACE, AT1-R). Conversely, endothelial NO synthase was down-regulated. Intake of EPA:DHA 1:1 and 6:1 by middle-aged rats decreased SMV shedding by 14% and 24%, respectively. Only EPA:DHA 6:1 intake abolished the M-SMVs-induced endothelial senescence and reduced the pro-senescent action of O-SMVs by 45%. Protection of ECs was not observed in response to SMVs from EPA:DHA 1:1 treated rats.

CONCLUSION

Ingestion of EPA:DHA 6:1 by middle-aged or old rats, respectively abolished or limited both the shedding of SMVs and their pro-senescent, pro-thrombotic and pro-inflammatory effects in ECs, most likely by triggering the local angiotensin system. EPA:DHA 6:1 may help to delay ageing-related endothelial dysfunction.

Electrochemical Sensor for Carbonyl Groups in Oxidized Proteins

The interaction of proteins with free radicals leads, among other types of damages, to the production of stable carbonyl groups, which can be used as a quantification of oxidative stress at proteins level. The aim of this study was the development of an electrochemical sensor for the detection of carbonyl groups in proteins oxidized by reactive oxygen species. Its working principle is based on the redox properties of dinitrophenylhydrazine (DNPH). BSA was used as a model protein and its oxidation achieved through Fenton reactions. Using differential pulse voltammetry at glassy carbon electrode, the electrochemical behavior of DNPH and of the native and oxidized BSA was investigated in solution. It has been shown that the hydrazine moiety of the DNPH is the electroactive center and is responsible for carbonyl complexation. Special attention was paid to the immobilization of the DNPH in order to retain its redox properties, and this was achieved on a mixed 4-styrenesulfonic acid-nafion matrix. The sensor's surface characterization and the detection of carbonyl groups in oxidized protein were performed by voltammetry, Fourier-transformed infrared spectroscopy and scanning electron microscopy while the voltammetric results were confirmed by surface plasmon resonance measurements. It has been shown that upon interaction with carbonyl groups of the oxidized protein, the oxidation peak of the hydrazine moiety of DNPH decreases as a function of incubation time and protein concentration. The sensor sensitivity was 0.015 nmol carbonyl per mg of oxidized protein and detection limits of 50 μg oxidized BSA and 0.75 pmol carbonyls.

Protective Effects and Mechanisms of N-Phenethyl Caffeamide from UVA-Induced Skin Damage in Human Epidermal Keratinocytes through Nrf2/HO-1 Regulation

The skin provides an effective barrier against physical, chemical, and microbial invasion; however, overexposure to ultraviolet (UV) radiation causes excessive cellular oxidative stress, which leads to skin damage, DNA damage, mutations, and skin cancer. This study investigated the protective effects of N-phenethyl caffeamide (K36) from UVA damage on human epidermal keratinocytes. We found that K36 reduced UVA-induced intracellular reactive oxygen species (ROS) production and induced the expression of the intrinsic antioxidant enzyme heme oxygenase-1 (HO-1) by increasing the translocation of nuclear factor erythroid 2⁻related factor 2 (Nrf2). K36 could inhibit the phosphorylation of extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinases (JNK) and reduce UVA-induced matrix metalloproteinase (MMP)-1 and MMP-2 overexpression; it could also elevate the expression of tissue inhibitors of metalloproteinases (TIMP). In addition, K36 ameliorated 8-hydroxy-2'-deoxyguanosine (8-OHdG) induced by UVA irradiation. Furthermore, K36 could downregulate the expression of inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) and the subsequent production of nitric oxide (NO) and prostaglandin E₂ (PGE₂). Based on our findings, K36 possessed potent antioxidant, anti-inflammatory, antiphotodamage, and even antiphotocarcinogenesis activities. Thus, K36 has the potential to be used to multifunctional skin care products and drugs.