Sleep and Oxidative Stress: Current Perspectives on the Role of NRF2.

Sleep is a fundamental conserved physiological state across evolution, suggesting vital biological functions that are yet to be fully clarified. However, our understanding of the neural and molecular basis of sleep regulation has increased rapidly in recent years. Among various processes implicated in controlling sleep homeostasis, a bidirectional relationship between sleep and oxidative stress has recently emerged. One proposed function of sleep may be the mitigation of oxidative stress in both brain and peripheral tissues, contributing to the clearance of reactive species that accumulate during wakefulness. Conversely, reactive species, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), at physiological levels, may act as signaling agents to regulate redox-sensitive transcriptional factors, enzymes, and other effectors involved in the regulation of sleep. As a primary sensor of intracellular oxidation, the transcription factor NRF2 is emerging as an indispensable component to maintain cellular redox homeostasis during sleep. Indeed, a number of studies have revealed an association between NRF2 dysfunction and the most common sleep conditions, including sleep loss, obstructive sleep apnea, and circadian sleep disturbances. This review examines the evidence of the intricate link between oxidative stress and NRF2 function in the context of sleep, and highlights the potential of NRF2 modulators to alleviate sleep disturbances.

NRF2 signaling pathway and telomere length in aging and age-related diseases.

The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is well recognized as a critical regulator of redox, metabolic, and protein homeostasis, as well as the regulation of inflammation. An age-associated decline in NRF2 activity may allow oxidative stress to remain unmitigated and affect key features associated with the aging phenotype, including telomere shortening. Telomeres, the protective caps of eukaryotic chromosomes, are highly susceptible to oxidative DNA damage, which can accelerate telomere shortening and, consequently, lead to premature senescence and genomic instability. In this review, we explore how the dysregulation of NRF2, coupled with an increase in oxidative stress, might be a major determinant of telomere shortening and age-related diseases. We discuss the relevance of the connection between NRF2 deficiency in aging and telomere attrition, emphasizing the importance of studying this functional link to enhance our understanding of aging pathologies. Finally, we present a number of compounds that possess the ability to restore NRF2 function, maintain a proper redox balance, and preserve telomere length during aging.

Relationship between monounsaturated fatty acids and sarcopenia: a systematic review and meta-analysis of observational studies.

Accumulating evidence suggests that fatty acids (FAs) play an essential role in regulating skeletal muscle mass and function throughout life. This systematic review and meta-analysis aimed to examine the relationship between dietary or circulatory levels of monounsaturated FAs (MUFAs) and sarcopenia in observational studies. A comprehensive literature search was performed in three databases (PubMed, Scopus, and Web of Science) from inception until August 2022. Of 414 records, a total of 12 observational studies were identified for this review. Ten studies were meta-analysed, comprising a total of 3704 participants. The results revealed that MUFA intake is inversely associated with sarcopenia (standardized mean difference = - 0.28, 95% CI - 0.46 to - 0.11; p < 0.01). Despite the limited number of studies, our results suggest that lower MUFA intake is associated with a higher risk of sarcopenia. However, the available evidence is still insufficient and further investigations are needed to demonstrate this relationship.

Dietary Astaxanthin: A Promising Antioxidant and Anti-Inflammatory Agent for Brain Aging and Adult Neurogenesis.

Decreased adult neurogenesis, or the gradual depletion of neural stem cells in adult neurogenic niches, is considered a hallmark of brain aging. This review provides a comprehensive overview of the intricate relationship between aging, adult neurogenesis, and the potential neuroregenerative properties of astaxanthin, a carotenoid principally extracted from the microalga Haematococcus pluvialis. The unique chemical structure of astaxanthin enables it to cross the blood-brain barrier and easily reach the brain, where it may positively influence adult neurogenesis. Astaxanthin can affect molecular pathways involved in the homeostasis, through the activation of FOXO3-related genetic pathways, growth, and regeneration of adult brain neurons, enhancing cell proliferation and the potency of stem cells in neural progenitor cells. Furthermore, astaxanthin appears to modulate neuroinflammation by suppressing the NF-κB pathway, reducing the production of pro-inflammatory cytokines, and limiting neuroinflammation associated with aging and chronic microglial activation. By modulating these pathways, along with its potent antioxidant properties, astaxanthin may contribute to the restoration of a healthy neurogenic microenvironment, thereby preserving the activity of neurogenic niches during both normal and pathological aging.

Equol and Resveratrol Improve Bone Turnover Biomarkers in Postmenopausal Women: A Clinical Trial.

Estrogen deficiency is a major cause of loss of postmenopausal bone mineral density (BMD). This study aimed to evaluate the effects of equol and resveratrol on bone turnover biomarkers in postmenopausal women. Sixty healthy postmenopausal women were randomly assigned to receive 200 mg fermented soy containing 10 mg equol and 25 mg resveratrol or a placebo for 12 months. Whole-body BMD and bone turnover biomarkers, such as deoxypyridinoline (DPD), tartrate-resistant acid phosphatase 5b (TRACP-5b), osteocalcin, and bone-specific alkaline phosphatase (BAP), were measured at baseline and after 12 months of treatment. At the end of treatment, DPD, osteocalcin, and BAP significantly improved in the active group (p < 0.0001 for all) compared to the placebo group. Conversely, TRACP-5b levels were unaffected by supplementation (p = 0.051). Statistically significant changes in the concentrations of DPD (p < 0.0001), osteocalcin (p = 0.0001), and BAP (p < 0.0001) compared to baseline were also identified. Overall, the intervention significantly increased BMD measured in the whole body (p = 0.0220) compared with the placebo. These data indicate that the combination of equol and resveratrol may positively modulate bone turnover biomarkers and BMD, representing a potential approach to prevent age-related bone loss in postmenopausal women.

Ozonated Oil in Liposome Eyedrops Reduces the Formation of Biofilm, Selection of Antibiotic-Resistant Bacteria, and Adhesion of Bacteria to Human Corneal Cells.

The recent attention to the risk of potential permanent eye damage triggered by ocular infections has been leading to a deeper investigation of the current antimicrobials. An antimicrobial agent used in ophthalmology should possess the following characteristics: a broad antimicrobial spectrum, prompt action even in the presence of organic matter, and nontoxicity. The objective of this study is to compare the antimicrobial efficacy of widely used ophthalmic antiseptics containing povidone-iodine, chlorhexidine, and liposomes containing ozonated sunflower oil. We determined the minimum inhibitory concentration (MIC) on various microbial strains: Staphylococcus aureus (ATCC 6538), methicillin-resistant Staphylococcus aureus (ATCC 33591), Staphylococcus epidermidis (ATCC 12228), Pseudomonas aeruginosa (ATCC 9027), and Escherichia coli (ATCC 873). Furthermore, we assessed its efficacy in controlling antibiotic resistance, biofilm formation, and bacterial adhesion. All three antiseptic ophthalmic preparations showed significant anti-microbicidal and anti-biofilm activity, with the liposomes containing ozonated sunflower oil with the highest ability to control antibiotic resistance and bacteria adhesion to human corneal cells.

Sex Differences in Cardiovascular Diseases: A Matter of Estrogens, Ceramides, and Sphingosine 1-Phosphate.

The medical community recognizes sex-related differences in pathophysiology and cardiovascular disease outcomes (CVD), culminating with heart failure. In general, pre-menopausal women tend to have a better prognosis than men. Explaining why this occurs is not a simple matter. For decades, sex hormones like estrogens (Es) have been identified as one of the leading factors driving these sex differences. Indeed, Es seem protective in women as their decline, during and after menopause, coincides with an increased CV risk and HF development. However, clinical trials demonstrated that E replacement in post-menopause women results in adverse cardiac events and increased risk of breast cancer. Thus, a deeper understanding of E-related mechanisms is needed to provide a vital gateway toward better CVD prevention and treatment in women. Of note, sphingolipids (SLs) and their metabolism are strictly related to E activities. Among the SLs, ceramide and sphingosine 1-phosphate play essential roles in mammalian physiology, particularly in the CV system, and appear differently modulated in males and females. In keeping with this view, here we explore the most recent experimental and clinical observations about the role of E and SL metabolism, emphasizing how these factors impact the CV system.

Astaxanthin as a Modulator of Nrf2, NF-κB, and Their Crosstalk: Molecular Mechanisms and Possible Clinical Applications.

Astaxanthin (AST) is a dietary xanthophyll predominantly found in marine organisms and seafood. Due to its unique molecular features, AST has an excellent antioxidant activity with a wide range of applications in the nutraceutical and pharmaceutical industries. In the past decade, mounting evidence has suggested a protective role for AST against a wide range of diseases where oxidative stress and inflammation participate in a self-perpetuating cycle. Here, we review the underlying molecular mechanisms by which AST regulates two relevant redox-sensitive transcription factors, such as nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor κB (NF-κB). Nrf2 is a cellular sensor of electrophilic stress that coordinates the expression of a battery of defensive genes encoding antioxidant proteins and detoxifying enzymes. Likewise, NF-κB acts as a mediator of cellular stress and induces the expression of various pro-inflammatory genes, including those encoding cytokines, chemokines, and adhesion molecules. The effects of AST on the crosstalk between these transcription factors have also been discussed. Besides this, we summarize the current clinical studies elucidating how AST may alleviate the etiopathogenesis of oxidative stress and inflammation.

Metabolic indices of polyunsaturated fatty acids: current evidence, research controversies, and clinical utility.

The n-3 and n-6 polyunsaturated fatty acids (PUFA) are among the most studied nutrients in human metabolism. In the past few decades, prospective studies and controlled trials have supported the view that the effects of these essential fatty acids are clinically relevant. PUFA profiles in different blood compartments are reflections of both diet and metabolism, and their levels may be related to disease risk. Despite widespread interest, there is no consensus regarding which biomarkers best reflect PUFA status in the body. The measurement of PUFA levels is not straight-forward, and a wide variety of indices have been used in clinical studies, producing conflicting results. A major source of heterogeneity among studies is associated with research design, sampling, and laboratory analyses. To date, the n-3 index, n-6/n-3 ratio, and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio are the most promising biomarkers associated with PUFA metabolism. Although hotly debated, these indices may be considered at least markers, if not risk factors, for several diseases, especially cardiovascular events and brain disorders. Here, we summarize the most updated evidence of n-3 and n-6 PUFA effects on human health, reviewing current controversies on the aforementioned indices and whether they can be considered valuable predictors of clinical outcomes.

Crosslinked Hyaluronic Acid with Liposomes and Crocin Confers Cytoprotection in an Experimental Model of Dry Eye.

Dry eye disease (DED) is a multifactorial condition caused by tear deficiency and accompanied by ocular surface damage. Recent data support a key role of oxidative and inflammatory processes in the pathogenesis of DED. Hyaluronic acid (HA) is widely used in artificial tears to treat DED by improving ocular hydration and reducing surface friction. Crocin (Cr), the main constituent of saffron, is a renowned compound that exhibits potent antioxidant and anti-inflammatory effects. The present study was undertaken to assess the viscosity and muco-adhesiveness of a photoactivated formulation with crosslinked HA (cHA), Cr, and liposomes (cHA-Cr-L). Our aim was also to evaluate whether cHA-Cr-L may exert cytoprotective effects against oxidative and inflammatory processes in human corneal epithelial cells (HCECs). Viscosity was measured using a rotational rheometer, and then the muco-adhesiveness was evaluated. Under hyperosmolarity (450 mOsm), the HCECs were treated with cHA-Cr-L. Interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNFα) were quantified by quantitative real-time polymerase chain reaction (RT-qPCR). The levels of reactive oxygen species (ROS) were measured using the DCF assay. The combined action of cHA-Cr-L produced a higher viscosity and muco-adhesiveness compared to the control. The anti-inflammatory effect of cHA-Cr-L was achieved through a significant reduction of IL-1ß and TNFα (p < 0.001). The results also showed that cHA-Cr-L reduces ROS production under conditions of hyperosmolarity (p < 0.001). We conclude that cHA-Cr-L has potential as a therapeutic agent in DED, which should be further investigated.

Astaxanthin as a Putative Geroprotector: Molecular Basis and Focus on Brain Aging.

In recent years, the scientific interest in natural compounds with geroprotective activities has grown exponentially. Among the various naturally derived molecules, astaxanthin (ASX) represents a highly promising candidate geroprotector. By virtue of the central polyene chain, ASX acts as a scavenger of free radicals in the internal membrane layer and simultaneously controls oxidation on the membrane surface. Moreover, several studies have highlighted ASX's ability to modulate numerous biological mechanisms at the cellular level, including the modulation of transcription factors and genes directly linked to longevity-related pathways. One of the main relevant evolutionarily-conserved transcription factors modulated by astaxanthin is the forkhead box O3 gene (FOXO3), which has been recognized as a critical controller of cell fate and function. Moreover, FOXO3 is one of only two genes shown to robustly affect human longevity. Due to its tropism in the brain, ASX has recently been studied as a putative neuroprotective molecule capable of delaying or preventing brain aging in different experimental models of brain damage or neurodegenerative diseases. Astaxanthin has been observed to slow down brain aging by increasing brain-derived neurotrophic factor (BDNF) levels in the brain, attenuating oxidative damage to lipids, protein, and DNA and protecting mitochondrial functions. Emerging data now suggest that ASX can modulate Nrf2, FOXO3, Sirt1, and Klotho proteins that are linked to longevity. Together, these mechanisms provide support for a role of ASX as a potential geroneuroprotector.

Astaxanthin from Shrimp Cephalothorax Stimulates the Immune Response by Enhancing IFN-γ, IL-10, and IL-2 Secretion in Splenocytes of Helicobacter Pylori-Infected Mice.

Infection with Helicobacter pylori is a critical cause of gastrointestinal diseases. A crucial host response associated with H. pylori infection includes gastric inflammation, which is characterized by a sustained recruitment of T-helper (Th) cells to the site of infection and distinct patterns of cytokine production. Adequate nutritional status, especially frequent consumption of dietary antioxidants, appears to protect against infection with H. pylori. The aim of the present study was to investigate whether astaxanthin (AXT) from shrimp cephalothorax may modulate cytokine release of splenocytes in H. pylori-infected mice (n = 60). Six- to eight-week-old female mice were divided into three groups (n = 20 per group) to receive a daily oral dose of 10 or 40 mg of AXT for six weeks. After six weeks, a trend toward interferon gamma (IFN-γ) upregulation was found (40 mg; p < 0.05) and a significant dose-dependent increase of interleukin 2 (IL-2) and IL-10 (both p < 0.05) was observed. These results suggest that AXT induces higher levels of IL-2 and a shift to a balanced Th1/Th2 response by increasing IFN-γ and augmenting IL-10. We concluded that AXT may influence the pattern of cytokines during H. pylori infection.

Anti-inflammatory effects of H2S during acute bacterial infection: a review.

Hydrogen sulfide (H2S), previously only considered a toxic environmental air pollutant, is now increasingly recognized as an important signaling molecule able to modulate several cellular pathways in many human tissues. As demonstrated in recent studies, H2S is produced endogenously in response to different cellular stimuli and plays different roles in controlling a number of physiological responses. The precise role of H2S in inflammation is still largely unknown. In particular, the role of H2S in the regulation of the inflammatory response in acute and chronic infections is being actively investigated because of its potential therapeutic use. To study the effect of H2S as an anti-inflammatory mediator during bacterial infections, we developed an ex vivo model of primary cells and cell lines infected with Mycoplasma. Our data demonstrate a dichotomic effect of H2S on the NF-kB and Nrf-2 molecular pathways, which were inhibited and stimulated, respectively.

Dietary phytochemicals and neuro-inflammaging: from mechanistic insights to translational challenges.

An extensive literature describes the positive impact of dietary phytochemicals on overall health and longevity. Dietary phytochemicals include a large group of non-nutrients compounds from a wide range of plant-derived foods and chemical classes. Over the last decade, remarkable progress has been made to realize that oxidative and nitrosative stress (O&NS) and chronic, low-grade inflammation are major risk factors underlying brain aging. Accumulated data strongly suggest that phytochemicals from fruits, vegetables, herbs, and spices may exert relevant negative immunoregulatory, and/or anti-O&NS activities in the context of brain aging. Despite the translational gap between basic and clinical research, the current understanding of the molecular interactions between phytochemicals and immune-inflammatory and O&NS (IO&NS) pathways could help in designing effective nutritional strategies to delay brain aging and improve cognitive function. This review attempts to summarise recent evidence indicating that specific phytochemicals may act as positive modulators of IO&NS pathways by attenuating pro-inflammatory pathways associated with the age-related redox imbalance that occurs in brain aging. We will also discuss the need to initiate long-term nutrition intervention studies in healthy subjects. Hence, we will highlight crucial aspects that require further study to determine effective physiological concentrations and explore the real impact of dietary phytochemicals in preserving brain health before the onset of symptoms leading to cognitive decline and inflammatory neurodegeneration.

Nutrigerontology: a key for achieving successful ageing and longevity.

During the last two centuries the average lifespan has increased at a rate of approximately 3 months/year in both sexes, hence oldest old people are becoming the population with the fastest growth in Western World. Although the average life expectancy is increasing dramatically, the healthy lifespan is not going at the same pace. This underscores the importance of studies on the prevention of age-related diseases, in order to satisfactorily decrease the medical, economic and social problems associated to advancing age, related to an increased number of individuals not autonomous and affected by invalidating pathologies. In particular, data from experimental studies in model organisms have consistently shown that nutrient signalling pathways are involved in longevity, affecting the prevalence of age-related loss of function, including age-related diseases. Accordingly, nutrigerontology is defined as the scientific discipline that studies the impact of nutrients, foods, macronutrient ratios, and diets on lifespan, ageing process, and age-related diseases. To discuss the potential relevance of this new science in the attainment of successful ageing and longevity, three original studies performed in Sicily with local foods and two reviews have been assembled in this series. Data clearly demonstrate the positive effects of nutraceuticals, functional foods and Mediterranean Diet on several biological parameters. In fact, they could represent a prevention for many age-related diseases, and, although not a solution for this social plague, at least a remedy to alleviate it. Thus, the possibility to create a dietary pattern, based on the combined strategy of the use of both nutraceuticals and functional foods should permit to create a new therapeutic strategy, based not only on a specific bioactive molecule or on a specific food but on a integrated approach that, starting from the local dietary habits, can be led to a "nutrafunctional diet" applicable worldwide.

A Randomized Clinical Trial Evaluating the Efficacy of an Anthocyanin-Maqui Berry Extract (Delphinol®) on Oxidative Stress Biomarkers.

OBJECTIVE: Berries are a rich source of anthocyanins, and clinical data suggest that a polyphenol-rich diet may exert health-promoting effects by reducing oxidative stress. The aim of this study was to elucidate the effects of dietary supplementation with Delphinol (trademark owned by MNL Chile) standardized maqui berry (Aristotelia chilensis) extract on products of lipid peroxidation in healthy, overweight, and smoker subjects. METHODS: In a double-blind, placebo-controlled design, 42 participants (age 45-65 years) consumed in random order either a standardized extract of maqui berry (162 mg anthocyanins) or a matched placebo, given 3 times daily for 4 weeks. The samples were collected at baseline, after the end of the supplementation, and 40 days after the end of the study. Primary outcome was the measure of oxidized low-density lipoprotein (Ox-LDL) and F2-isoprostanes in plasma and urine, respectively. Secondary outcomes included anthropometric measures, blood pressure, and lipid profile. RESULTS: Delphinol supplementation was associated with reduced levels of Ox-LDL in the anthocyanin group compared to baseline (p < 0.05). There was also a decrease in urinary F2-isoprostanes (8-iso-prostaglandin F2α) at 4 weeks versus baseline in the Delphinol-supplemented group (p < 0.05). However, no differences in primary outcomes were evident at 40 days of follow-up. In the fourth week of the intervention, no significant differences were noted for anthropometric characteristics, ambulatory blood pressure, and lipid profile. CONCLUSIONS: Our observations suggest that dietary interventions with maqui berry extract may improve oxidative status (Ox-LDL and F2-isoprostanes) in healthy adults, overweight adults, and adult smokers.

Sulfur compounds block MCP-1 production by Mycoplasma fermentans-infected macrophages through NF-κB inhibition.

BACKGROUND AND AIMS: Hydrogen sulfide (H2S), together with nitric oxide (NO) and carbon monoxide (CO), belongs to a family of endogenous signaling mediators termed "gasotransmitters". Recent studies suggest that H2S modulates many cellular processes and it has been recognized to play a central role in inflammation, in the cardiovascular and nervous systems. By infecting monocytes/macrophages with Mycoplasma fermentans (M.F.), a well-known pro-inflammatory agent, we evaluated the effects of H2S. METHODS: M.F.-infected cells were analyzed by ELISA and real time RT-PCR to detect the M.F. effects on MCP-1 and on MMP-12 expression. The role of two different H2S donors (NaHS and GYY4137) on MF-infected cells was determined by treating infected cells with H2S and then testing the culture supernatants for MCP-1 and on MMP-12 production by ELISA assay. In order to identify the pathway/s mediating H2S- anti-inflammatory activity, cells were also treated with specific pharmaceutical inhibitors. Cytoplasmic and nuclear accumulation of NF-κB heterodimers was analyzed. RESULTS: We show that H2S was able to reduce the production of pro-inflammatory cytokine MCP-1, that was induced in monocytes/macrophages during M.F. infection. Moreover, MCP-1 was induced by M.F. through Toll-like receptor (TLR)-mediated nuclear factor-κB (NF-κB) activation, as demonstrated by the fact that TLR inhibitors TIRAP and MyD88 and NF-κB inhibitor IKK were able to block the cytokine production. In contrast H2S treatment of M.F. infected macrophages reduced nuclear accumulation of NF-κB heterodimer p65/p52. CONCLUSIONS: Our data demonstrate that under the present conditions H2S is effective in reducing Mycoplasma-induced inflammation by targeting the NF-κB pathway. This supports further studies for possible clinical applications.

Altered expression pattern of Nrf2/HO-1 axis during accelerated-senescence in HIV-1 transgenic rat.

Chronic oxidative stress plays a central role in the pathogenesis of many diseases, including HIV-1 associated disorders. Concomitantly with the decline of endogenous antioxidant systems, it was reported that HIV-1-related proteins increase the production of radical species in cells and tissues that are not directly infected by the virus. In the context of HIV-1 infection, the role of Nrf2, a key transcription factor that contributes to the maintenance of cellular redox homeostasis, remains largely uncharacterized. One of the major stress-responsive player regulated by Nrf2 is the antioxidant enzyme HO-1. The Nrf2/HO-1 axis constitutes a crucial cell survival mechanism to counteract oxidative stress and inflammation. The present study aims to investigate the age-related patterns of Nrf2 and HO-1 in different brain regions and tissues of HIV-1 transgenic rat. Since HIV-1 induces an accelerated aging and the redox imbalance may actively promote senescence, we also evaluated the senescence phenotype-switching by quantifying levels of ß-galactosidase activity. Our results showed changes in gene expression, with different trends depending on the brain regions and tissues examined. However, compared to age-matched controls, we observed in HIV-1 transgenic rats a significant reduction in the protein levels of Nrf2 and HO-1, suggesting a weakening in the protection exerted by Nrf2/HO-1 system. Moreover, we show that senescence occurs more rapidly in HIV-1 transgenic rats than in control animals. To our knowledge this is the first in vivo report showing the involvement of Nrf2/HO-1 pathway in a rat model of HIV-1.

Omega-3 Index as a Sport Biomarker: Implications for Cardiovascular Health, Injury Prevention, and Athletic Performance.

The composition of polyunsaturated fatty acids (PUFA) in the cell membrane plays a crucial role in cell signaling and function. Physical activity can induce shifts in PUFA metabolism, potentially altering their membrane composition. Given the multifaceted regulatory and structural roles of PUFA, training-related fluctuations in PUFA concentrations may impact health and athletic performance in both elite and non-elite athletes, highlighting the critical role of these fatty acids' nutritional intake. The ω-3 index (O3I), a biomarker reflecting the proportion of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in red blood cell membranes, is considered a marker of cardiovascular risk, gaining increasing interest in sports medicine. Dietary interventions aimed at maintaining an optimal O3I may offer several benefits for elite and non-elite athletes, including cardiovascular health performance optimization, recovery, and injury prevention. Here, we discuss emerging evidence on the application of O3I in sports and physical exercise, highlighting its promising role as a biomarker in a wide range of sports practices.