The wanderings of a free radical

Exploring Therapeutic Potential of Catalase: Strategies in Disease Prevention and Management

The antioxidant defense mechanisms play a critical role in mitigating the deleterious effects of reactive oxygen species (ROS). Catalase stands out as a paramount enzymatic antioxidant. It efficiently catalyzes the decomposition of hydrogen peroxide (H2O2) into water and oxygen, a potentially harmful byproduct of cellular metabolism. This reaction detoxifies H2O2 and prevents oxidative damage. Catalase has been extensively studied as a therapeutic antioxidant. Its applications range from direct supplementation in conditions characterized by oxidative stress to gene therapy approaches to enhance endogenous catalase activity. The enzyme's stability, bioavailability, and the specificity of its delivery to target tissues are significant hurdles. Furthermore, studies employing conventional catalase formulations often face issues related to enzyme purity, activity, and longevity in the biological milieu. Addressing these challenges necessitates rigorous scientific inquiry and well-designed clinical trials. Such trials must be underpinned by sound experimental designs, incorporating advanced catalase formulations or novel delivery systems that can overcome existing limitations. Enhancing catalase's stability, specificity, and longevity in vivo could unlock its full therapeutic potential. It is necessary to understand the role of catalase in disease-specific contexts, paving the way for precision antioxidant therapy that could significantly impact the treatment of diseases associated with oxidative stress.

Chemical Investigation and Antinociceptive Activity Evaluation of Marrubium Vulgare L. Aqueous Extract

Marrubium vulgare L. (Lamiaceae) has a long history of use in traditional herbal medicine for the treatment of respiratory tract infections, inflammatory conditions, and pain. This study aimed to investigate the chemical composition, acute toxicity, and antinociceptive effects of the aqueous extract from M. vulgare leaves (AEMV). Antioxidant activity was evaluated using DPPH and reducing power assays. The chemical composition of AEMV was determined through LC-MS/MS, and the levels of total phenolics, flavonoids, and condensed tannins were quantified. Acute oral toxicity was assessed in male Swiss mice with a single oral dose of AEMV (1, 2, 5 g/kg). The analgesic impact was examined through writhing, hot plate, and formalin tests. Our findings not only confirmed the safety of the extract in animal models but also revealed significant antioxidant activity in AEMV. High-performance liquid chromatography (HPLC) analysis identified important bioactive compounds, with marrubiin being a major component. Furthermore, AEMV demonstrated robust antinociceptive properties in all conducted tests, highlighting its potential as a valuable natural source of bioactive compounds suitable for a wide range of therapeutic applications.

An organic extract from ascidian Ciona robusta induces cytotoxic autophagy in human malignant cell lines

The last decades have seen an increase in the isolation and characterization of anticancer compounds derived from marine organisms, especially invertebrates, and their use in clinical trials. In this regard, ascidians, which are included in the subphylum Tunicata, represent successful examples with two drugs, Aplidine© and Yondelis© that reached the market as orphan drugs against several malignancies. Here, we report that an organic extract prepared from homogenized tissues of the Mediterranean ascidian Ciona robusta inhibited cell proliferation in HT-29, HepG2, and U2OS human cells with the former being the most sensitive to the extract (EC50 = 250 μg/mL). We demonstrated that the ascidian organic extract was not cytotoxic on HT-29 cells that were induced to differentiate with sodium butyrate, suggesting a preference for the mixture for the malignant phenotype. Finally, we report that cell death induced by the organic extract was mediated by the activation of a process of cytotoxic autophagy as a result of the increased expression of the LC3-II marker and number of autophagic vacuoles, which almost doubled in the treated HT-29 cells. In summary, although the detailed chemical composition of the Ciona robusta extract is still undetermined, our data suggest the presence of bioactive compounds possessing anticancer activity.

Integrated Redox-Metabolic Orchestration Sustains Life in Hibernating Ground Squirrels

Significance: The ultimate manifestations of life, birth, survival under various environmental pressures and death are based on bioenergetics. Hibernation is a unique survival strategy for many small mammals that is characterised by severe metabolic depression and transition from euthermia to hypothermia (torpor) at body temperatures close to 0°C. These manifestations of life were made possible by the remarkable "social" behavior of biomolecules during billions of years of evolution: the evolution of life with oxygen. Oxygen was necessary for energy production and the evolutionary explosion of aerobic organisms. Recent Advances: Nevertheless, reactive oxygen species, formed through oxidative metabolism, are dangerous-they can kill a cell and, on the other hand, play a plethora of fundamentally valuable roles. Therefore, the evolution of life depended on energy metabolism and redox-metabolic adaptations. The more extreme the conditions for survival are, the more sophisticated the adaptive responses of organisms become. Hibernation is a beautiful illustration of this principle. Hibernating animals use evolutionarily conserved molecular mechanisms to survive adverse environmental conditions, including reducing body temperature to ambient levels (often to ∼0°C) and severe metabolic depression. This long-built secret of life lies at the intersection of oxygen, metabolism, and bioenergetics, and hibernating organisms have learned to exploit all the underlying capacities of molecular pathways to survive. Critical Issues: Despite such drastic changes in phenotype, tissues and organs of hibernators sustain no metabolic or histological damage during hibernation or upon awakening from hibernation. This was made possible by the fascinating integration of redox-metabolic regulatory networks whose molecular mechanisms remain undisclosed to this day. Future Directions: Discovering these molecular mechanisms is not warranted only to understand hibernation in itself but to help explain complex medical conditions (hypoxia/reoxygenation, organ transplantation, diabetes, and cancer) and to even help overcome limitations associated with space travel. This is a review of integrated redox-metabolic orchestration in hibernation. Antioxid. Redox Signal. 40, 345-368.

Understanding mechanisms of antioxidant action in health and disease

Several different reactive oxygen species (ROS) are generated in vivo. They have roles in the development of certain human diseases whilst also performing physiological functions. ROS are counterbalanced by an antioxidant defence network, which functions to modulate ROS levels to allow their physiological roles whilst minimizing the oxidative damage they cause that can contribute to disease development. This Review describes the mechanisms of action of antioxidants synthesized in vivo, antioxidants derived from the human diet and synthetic antioxidants developed as therapeutic agents, with a focus on the gaps in our current knowledge and the approaches needed to close them. The Review also explores the reasons behind the successes and failures of antioxidants in treating or preventing human disease. Antioxidants may have special roles in the gastrointestinal tract, and many lifestyle features known to promote health (especially diet, exercise and the control of blood glucose and cholesterol levels) may be acting, at least in part, by antioxidant mechanisms. Certain reactive sulfur species may be important antioxidants but more accurate determinations of their concentrations in vivo are needed to help assess their contributions.

Antioxidant effects of LEDT in dystrophic muscle cells: involvement of PGC-1α and UCP-3 pathways

PURPOSE

Reactive oxygen species and mitochondrial dysfunction play a crucial role in the pathophysiology of Duchenne muscular dystrophy (DMD). The light-emitting diode therapy (LEDT) showed beneficial effects on the dystrophic muscles. However, the mechanisms of this therapy influence the molecular pathways in the dystrophic muscles, particularly related to antioxidant effects, which still needs to be elucidated. The current study provides muscle cell-specific insights into the effect of LEDT, 48 h post-irradiation, on oxidative stress and mitochondrial parameters in the dystrophic primary muscle cells in culture.

METHODS

Dystrophic primary muscle cells were submitted to LEDT, at multiple wavelengths (420 nm, 470 nm, 660 nm and 850 nm), 0.5 J dose, and evaluated after 48 h based on oxidative stress markers, antioxidant enzymatic system and biogenesis, and functional mitochondrial parameters.

RESULTS

The mdx muscle cells treated with LEDT showed a significant reduction of H2O2 production and 4-HNE, catalase, SOD-2, and GR levels. Upregulation of UCP3 was observed with all wavelengths while upregulation of PGC-1α and a slight upregulation of electron transport chain complexes III and V was only observed following 850 nm LEDT. In addition, the mitochondrial membrane potential and mitochondrial mass mostly tended to be increased following LEDT, while parameters like O2·- production tended to be decreased.

CONCLUSION

The data shown here highlight the potential of LEDT as a therapeutic agent for DMD through its antioxidant action by modulating PGC-1α and UCP3 levels.

Iron and atherosclerosis: Lessons learned from rabbits relevant to human disease

The role of iron in promoting atherosclerosis, and hence the cardiovascular, neurodegenerative and other diseases that result from atherosclerosis, has been fiercely controversial. Many studies have been carried out on various rodent models of atherosclerosis, especially on apoE-knockout (apoE-/-) mice, which develop atherosclerosis more readily than normal mice. These apoE-/- mouse studies generally support a role for iron in atherosclerosis development, although there are conflicting results. The purpose of the current article is to describe studies on another animal model that is not genetically manipulated; New Zealand White (NZW) rabbits fed a high-cholesterol diet. This may be a better model than the apoE-/- mice for human atherosclerosis, although it has been given much less attention. Studies on NZW rabbits support the view that iron promotes atherosclerosis, although some uncertainties remain, which need to be resolved by further experimentation.

50 shades of oxidative stress: A state-specific cysteine redox pattern hypothesis

Oxidative stress is biochemically complex. Like primary colours, specific reactive oxygen species (ROS) and antioxidant inputs can be mixed to create unique "shades" of oxidative stress. Even a minimal redox module comprised of just 12 (ROS & antioxidant) inputs and 3 outputs (oxidative damage, cysteine-dependent redox-regulation, or both) yields over half a million "shades" of oxidative stress. The present paper proposes the novel hypothesis that: state-specific shades of oxidative stress, such as a discrete disease, are associated with distinct tell-tale cysteine oxidation patterns. The patterns are encoded by many parameters, from the identity of the oxidised proteins, the cysteine oxidation type, and magnitude. The hypothesis is conceptually grounded in distinct ROS and antioxidant inputs coalescing to produce unique cysteine oxidation outputs. And considers the potential biological significance of the holistic cysteine oxidation outputs. The literature supports the existence of state-specific cysteine oxidation patterns. Measuring and manipulating these patterns offer promising avenues for advancing oxidative stress research. The pattern inspired hypothesis provides a framework for understanding the complex biochemical nature of state-specific oxidative stress.

Interplay of hypoxia-inducible factors and oxygen therapy in cardiovascular medicine

Mammals have evolved to adapt to differences in oxygen availability. Although systemic oxygen homeostasis relies on respiratory and circulatory responses, cellular adaptation to hypoxia involves the transcription factor hypoxia-inducible factor (HIF). Given that many cardiovascular diseases involve some degree of systemic or local tissue hypoxia, oxygen therapy has been used liberally over many decades for the treatment of cardiovascular disorders. However, preclinical research has revealed the detrimental effects of excessive use of oxygen therapy, including the generation of toxic oxygen radicals or attenuation of endogenous protection by HIFs. In addition, investigators in clinical trials conducted in the past decade have questioned the excessive use of oxygen therapy and have identified specific cardiovascular diseases in which a more conservative approach to oxygen therapy could be beneficial compared with a more liberal approach. In this Review, we provide numerous perspectives on systemic and molecular oxygen homeostasis and the pathophysiological consequences of excessive oxygen use. In addition, we provide an overview of findings from clinical studies on oxygen therapy for myocardial ischaemia, cardiac arrest, heart failure and cardiac surgery. These clinical studies have prompted a shift from liberal oxygen supplementation to a more conservative and vigilant approach to oxygen therapy. Furthermore, we discuss the alternative therapeutic strategies that target oxygen-sensing pathways, including various preconditioning approaches and pharmacological HIF activators, that can be used regardless of the level of oxygen therapy that a patient is already receiving.

Gut microbiota interacts with inflammatory responses in acute pancreatitis

Acute pancreatitis (AP) is one of the most common acute abdominal conditions, and its incidence has been increasing for years. Approximately 15-20% of patients develop severe AP (SAP), which is complicated by critical inflammatory injury and intestinal dysfunction. AP-associated inflammation can lead to the gut barrier and function damage, causing dysbacteriosis and facilitating intestinal microbiota migration. Pancreatic exocrine deficiency and decreased levels of antimicrobial peptides in AP can also lead to abnormal growth of intestinal bacteria. Meanwhile, intestinal microbiota migration influences the pancreatic microenvironment and affects the severity of AP, which, in turn, exacerbates the systemic inflammatory response. Thus, the interaction between the gut microbiota (GM) and the inflammatory response may be a key pathogenic feature of SAP. Treating either of these factors or breaking their interaction may offer some benefits for SAP treatment. In this review, we discuss the mechanisms of interaction of the GM and inflammation in AP and factors that can deteriorate or even cure both, including some traditional Chinese medicine treatments, to provide new methods for studying AP pathogenesis and developing therapies.

Oxidative Stress in Type 2 Diabetes: Impacts from Pathogenesis to Lifestyle Modifications

Oxidative stress is a critical factor in the pathogenesis and progression of diabetes and its associated complications. The imbalance between reactive oxygen species (ROS) production and the body's antioxidant defence mechanisms leads to cellular damage and dysfunction. In diabetes, chronic hyperglycaemia and mitochondrial dysfunction contribute to increased ROS production, further exacerbating oxidative stress. This oxidative burden adversely affects various aspects of diabetes, including impaired beta-cell function and insulin resistance, leading to disrupted glucose regulation. Additionally, oxidative stress-induced damage to blood vessels and impaired endothelial function contribute to the development of diabetic vascular complications such as retinopathy, nephropathy, and cardiovascular diseases. Moreover, organs and tissues throughout the body, including the kidneys, nerves, and eyes, are vulnerable to oxidative stress, resulting in diabetic nephropathy, neuropathy, and retinopathy. Strategies to mitigate oxidative stress in diabetes include antioxidant therapy, lifestyle modifications, and effective management of hyperglycaemia. However, further research is necessary to comprehensively understand the underlying mechanisms of oxidative stress in diabetes and to evaluate the efficacy of antioxidant interventions in preventing and treating diabetic complications. By addressing oxidative stress, it might be possible to alleviate the burden of diabetes and improve patient outcomes.

The Emerging Importance of Cirsimaritin in Type 2 Diabetes Treatment

Cirsimaritin is a dimethoxy flavon that has different biological activities such as antiproliferative, antimicrobial, and antioxidant activities. This study aims to investigate the anti-diabetic effects of cirsimaritin in a high-fat diet and streptozotocin-(HFD/STZ)-induced rat model of type 2 diabetes mellitus (T2D). Rats were fed HFD, followed by a single low dose of STZ (40 mg/kg). HFD/STZ diabetic rats were treated orally with cirsimaritin (50 mg/kg) or metformin (200 mg/kg) for 10 days before terminating the experiment and collecting plasma, soleus muscle, adipose tissue, and liver for further downstream analysis. Cirsimaritin reduced the elevated levels of serum glucose in diabetic rats compared to the vehicle control group (p < 0.001). Cirsimaritin abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control rats (p < 0.01). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in the diabetic rats treated with cirsimaritin compared to the vehicle controls. The skeletal muscle and adipose tissue protein contents of GLUT4 (p < 0.01 and p < 0.05, respectively) and pAMPK-α1 (p < 0.05) were upregulated following treatment with cirsimaritin. Cirsimaritin was able to upregulate GLUT2 and AMPK protein expression in the liver (p < 0.01, <0.05, respectively). LDL, triglyceride, and cholesterol were reduced in diabetic rats treated with cirsimaritin compared to the vehicle controls (p < 0.001). Cirsimaritin reduced MDA, and IL-6 levels (p < 0.001), increased GSH levels (p < 0.001), and reduced GSSG levels (p < 0.001) in diabetic rats compared to the vehicle control. Cirsimaritin could represent a promising therapeutic agent to treat T2D.

Aspirin-Triggered Resolvin D1 (AT-RvD1) Protects Mouse Skin against UVB-Induced Inflammation and Oxidative Stress

Intense exposure to UVB radiation incites excessive production of reactive oxygen species (ROS) and inflammation. The resolution of inflammation is an active process orchestrated by a family of lipid molecules that includes AT-RvD1, a specialized proresolving lipid mediator (SPM). AT-RvD1 is derived from omega-3, which presents anti-inflammatory activity and reduces oxidative stress markers. The present work aims to investigate the protective effect of AT-RvD1 on UVB-induced inflammation and oxidative stress in hairless mice. Animals were first treated with 30, 100, and 300 pg/animal AT-RvD1 (i.v.) and then exposed to UVB (4.14 J/cm²). The results showed that 300 pg/animal of AT-RvD1 could restrict skin edema, neutrophil and mast cell infiltration, COX-2 mRNA expression, cytokine release, and MMP-9 activity and restore skin antioxidant capacity as per FRAP and ABTS assays and control O₂^•- production, lipoperoxidation, epidermal thickening, and sunburn cells development. AT-RvD1 could reverse the UVB-induced downregulation of Nrf2 and its downstream targets GSH, catalase, and NOQ-1. Our results suggest that by upregulating the Nrf2 pathway, AT-RvD1 promotes the expression of ARE genes, restoring the skin's natural antioxidant defense against UVB exposition to avoid oxidative stress, inflammation, and tissue damage.

Soluble ST2 as a New Oxidative Stress and Inflammation Marker in Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MS) is a complex and prevalent disorder. Oxidative stress and inflammation might contribute to the progression of MS. Soluble ST2 (sST2) is an attractive and druggable molecule that sits at the interface between inflammation, oxidative stress and fibrosis. This study aims to analyze the relationship among sST2, oxidative stress, inflammation and echocardiographic parameters in MS patients.

METHODS

Fifty-eight patients with MS were recruited and underwent physical, laboratory and transthoracic echocardiography examinations. Commercial ELISA and appropriate colorimetric assays were used to quantify serum levels of oxidative stress and inflammation markers and sST2.

RESULTS

Circulating sST2 was increased in MS patients and was significantly correlated with the oxidative stress markers nitrotyrosine and 8-hydroxy-2'-deoxyguanosine as well as with peroxide levels. The inflammatory parameters interleukin-6, intercellular adhesion molecule-1 and myeloperoxidase were positively correlated with sST2. Noteworthy, sST2 was positively correlated with left ventricular mass, filling pressures and pulmonary arterial pressures.

CONCLUSION

Circulating levels of sST2 are associated with oxidative stress and inflammation burden and may underlie the pathological remodeling and dysfunction of the heart in MS patients. Our results suggest that sST2 elevation precedes diastolic dysfunction, emerging as an attractive biotarget in MS.

Personalized redox medicine in inflammatory bowel diseases: an emerging role for HIF-1α and NRF2 as therapeutic targets

Inflammatory bowel diseases (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), are intimately associated with inflammation and overproduction of reactive oxygen species (ROS). Temporal and inter-individual variabilities in disease activity and response to therapy pose significant challenges to diagnosis and patient care. Discovery and validation of truly integrative biomarkers would benefit from embracing redox metabolomics approaches with prioritization of central regulatory hubs. We here make a case for applying a personalized redox medicine approach that aims to selectively inhibit pathological overproduction and/or altered expression of specific enzymatic sources of ROS without compromising physiological function. To this end, improved 'clinical-omics integration' may help to better understand which particular redox signaling pathways are disrupted in what patient. Pharmacological interventions capable of activating endogenous antioxidant defense systems may represent viable therapeutic options to restore local/systemic redox status, with HIF-1α and NRF2 holding particular promise in this context. Achieving the implementation of clinically meaningful mechanism-based biomarkers requires development of easy-to-use, robust and cost-effective tools for secure diagnosis and monitoring of treatment efficacy. Ultimately, matching redox-directed pharmacological interventions to individual patient phenotypes using predictive biomarkers may offer new opportunities to break the therapeutic ceiling in IBD.

Degradation of soybean meal proteins by wheat malt endopeptidase and the antioxidant capacity of the enzymolytic products

This study investigated the hydrolysis effect of the endopeptidase from wheat malt on the soybean meal proteins. The results indicated that the endopeptidase broke the peptide bonds of soybean meal proteins and converted the alcohol- and alkali-soluble proteins into water-soluble and salt-soluble proteins. In addition, wheat malt endopeptidase did not break the disulfide bonds between proteins but affected the conformation of disulfide bonds between substrate protein molecules, which were changed from the gauche-gauche-trans (g-g-t) vibrational mode to the trans-gauche-trans (t-g-t) vibrational mode. Wheat malt endopeptidase exhibited the highest enzymatic activity at 2 h of enzymatic digestion, demonstrating the fastest hydrolytic rate of soybean meal proteins. Compared with the samples before enzymatic hydrolysis, the total alcohol- and alkali-soluble proteins were decreased by 11.89% but the water- and salt-soluble proteins were increased by 11.99%, indicating the hydrolytic effect of endopeptidase. The corresponding water-soluble proteins had molecular weights of 66.4-97.2, 29-44.3, and 20.1 kDa, while the salt-soluble proteins had molecular weights of 44.3-66.4, 29-44.3, and 20.1 kDa, respectively. The degree of enzymatic hydrolysis of soybean meal reached the maximum at 8 h. The newly created proteins exhibited significantly antioxidant properties, which were inversely related to the molecular weight. Proteins with molecular weight <3 kDa had the highest antioxidant performance with an antioxidant capacity of 1.72 ± 0.03 mM, hydroxyl radical scavenging rate of 98.04%, and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging capacity of 0.44 ± 0.04 mM.

Effects of N-acetylcysteine on Growth, Viability, and Ultrastructure of In Vitro Cultured Bovine Secondary Follicles

This study aimed to investigate the effects of different concentrations of N-acetylcysteine (NAC) on the growth, antrum formation, viability, and ultrastructure of bovine secondary follicles cultured in vitro for 18 days. To this end, the follicles were cultured in TCM-199+ medium alone or supplemented with 1.0, 5.0, or 25.0 mM NAC. Follicular growth, antrum formation, viability (calcein-AM and ethidium homodimer-1) and ultrastructure were evaluated at the end of culture period. The results showed that 1.0 mM NAC increased the percentage of growing follicles and the fluorescence intensity for calcein-AM when compared to other treatments (p < 0.05). On the other hand, follicles cultured with 25.0 mM NAC had higher fluorescence intensity for ethidium homodimer-1, which is a sign of degeneration. Ultrastructural analysis showed that oocytes from follicles cultured in control medium alone or with 1 mM NAC had intact zonae pellucidae in close association with oolemmae, but the ooplasm showed mitochondria with a reduced number of cristae. On the other hand, oocytes from follicles cultured with 5 or 25 mM NAC had extremely vacuolated cytoplasm and no recognizable organelles. In conclusion, 1 mM NAC increases cytoplasmic calcein staining and the growth rate in bovine secondary follicles cultured in vitro, but the presence of 5 or 25 mM NAC causes damage in cellular membranes and organelles, as well as reducing the percentages of growing follicles.

Associations of alkaline water with metabolic risks, sleep quality, muscle strength: A cross-sectional study among postmenopausal women

Much has been claimed on the health benefits of alkaline water including metabolic syndrome (MetS) and its features with scarcity of scientific evidence. Methods: This cross-sectional comparative study was conducted to determine whether regular consumption of alkaline water confers health advantage on blood metabolites, anthropometric measures, sleep quality and muscle strength among postmenopausal women. A total of 304 community-dwelling postmenopausal women were recruited with comparable proportion of regular drinkers of alkaline water and non-drinkers. Participants were ascertained on dietary intake, lifestyle factors, anthropometric and biochemical measurements. Diagnosis of MetS was made according to Joint Interim Statement definition. A total of 47.7% of the participants met MS criteria, with a significant lower proportion of MetS among the alkaline water drinkers. The observed lower fasting plasma glucose (F(1,294) = 24.20, p = 0.025, partial η2 = 0.435), triglyceride/high-density lipoprotein concentration ratio (F(1,294) = 21.06, p = 0.023, partial η2 = 0.360), diastolic blood pressure (F(1,294) = 7.85, p = 0.046, partial η2 = 0.258) and waist circumference (F(1,294) = 9.261, p = 0.038, partial η2 = 0.263) in the alkaline water drinkers could be considered as favourable outcomes of regular consumption of alkaline water. In addition, water alkalization improved duration of sleep (F(1,294) = 32.05, p = 0.007, partial η2 = 0.451) and handgrip strength F(1,294) = 27.51, p = 0.011, partial η2 = 0.448). Low density lipoprotein cholesterol concentration (F(1,294) = 1.772, p = 0.287, partial η2 = 0.014), body weight (F(1,294) = 1.985, p = 0.145, partial η2 = 0.013) and systolic blood pressure (F(1,294) = 1.656, p = 0.301, partial η2 = 0.010) were comparable between the two different water drinking behaviours. In conclusion, drinking adequate of water is paramount for public health with access to good quality drinking water remains a critical issue. While consumption of alkaline water may be considered as a source of easy-to implement lifestyle to modulate metabolic features, sleep duration and muscle strength, further studies are warranted for unravelling the precise mechanism of alkaline water consumption on the improvement and prevention of MetS and its individual features, muscle strength and sleep duration as well as identification of full spectrum of individuals that could benefit from its consumption.

Oxidative Stress in Traumatic Brain Injury

Traumatic Brain Injury (TBI) remains a major cause of disability worldwide. It involves a complex neurometabolic cascade, including oxidative stress. The products of this manuscript is examining the underlying pathophysiological mechanism, including reactive oxygen species (ROS) and reactive nitrogen species (RNS). This process in turn leads to secondary injury cascade, which includes lipid peroxidation products. These reactions ultimately play a key role in chronic inflammation and synaptic dysfunction in a synergistic fashion. Although there are no FDA approved antioxidant therapy for TBI, there is a number of antioxidant therapies that have been tested and include free radical scavengers, activators of antioxidant systems, inhibitors of free radical generating enzymes, and antioxidant enzymes. Antioxidant therapies have led to cognitive and functional recovery post TBI, and they offer a promising treatment option for patients recovering from TBI. Current major challenges in treatment of TBI symptoms include heterogenous nature of injury, as well as access to timely treatment post injury. The inherent benefits of antioxidant therapies include minimally reported side effects, and relative ease of use in the clinical setting. The current review also provides a highlight of the more studied anti-oxidant regimen with applicability for TBI treatment with potential use in the real clinical setting.

Reflections of an Aging Free Radical Part 2: Meeting Inspirational People

Significance: During my long career in the field of redox biology, I met many inspiring people, especially Lester Packer. Recent Advances: This special issue of Antioxidants & Redox Signaling is dedicated to Lester Packer. Critical Issues: In this short review, I explore how Lester and other pioneers helped to develop the redox biology field and how I interacted with them. Future Directions: In our research to advance the field of redox biology, we stand on the shoulders of giants, including Lester Packer.

Biogenetic and biomimetic synthesis of natural bisditerpenoids: hypothesis and practices

Covering: up to March 2022Bisditerpenoids, or diterpenoid dimers, are a group of natural products with high structural variance, deriving from homo- or hetero-dimeric coupling of two diterpenoid units. They usually possess complex architectures resulting from the diversity of monomeric diterpenoids as building blocks and the dimerization processes. These compounds have attracted the attention of synthetic and biological scientists owing to the rarity of their natural origin and their significant biological activities. Herein, we provide a review highlighting some of the interesting bisditerpenoids reported since 1961 and showcase the chemical diversity in both their structures and biosynthesis, as well as their biological functions. This review focuses on the biosynthetic dimerization pathways of interesting molecules and their biomimetic synthesis, which may act as useful inspiration for the discovery and synthesis of more bisditerpenoids and further pharmacological investigations.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Synthesis, Characterization, and the Antioxidant Activity of Phenolic Acid Chitooligosaccharide Derivatives

A series of phenolic acid chitooligosaccharide (COS) derivatives synthesized by two mild and green methods were illuminated in this paper. Seven phenolic acids were selected to combine two kinds of COS derivatives: the phenolic acid chitooligosaccharide salt derivatives and the phenolic-acid-acylated chitooligosaccharide derivatives. The structures of the derivatives were characterized by FT-IR and 1H NMR spectra. The antioxidant experiment results in vitro (including DPPH-radical scavenging activity, superoxide-radical scavenging activity, hydroxyl-radical scavenging ability, and reducing power) demonstrated that the derivatives exhibited significantly enhanced antioxidant activity compared to COS. Moreover, the study showed that the phenolic acid chitooligosaccharide salts had stronger antioxidant activity than phenolic-acid-acylated chitooligosaccharide. The cytotoxicity assay of L929 cells in vitro indicated that the derivatives had low cytotoxicity and good biocompatibility. In conclusion, this study provides a possible synthetic method for developing novel and nontoxic antioxidant agents which can be used in the food and cosmetics industry.

Association of Oxidative Stress with Neurological Disorders

BACKGORUND

Oxidative stress is one of the main contributing factors involved in cerebral biochemical impairment. The higher susceptibility of the central nervous system to reactive oxygen species mediated damage could be attributed to several factors. For example, neurons use a greater quantity of oxygen, many parts of the brain have higher concentraton of iron, and neuronal mitochondria produce huge content of hydrogen peroxide. In addition, neuronal membranes have polyunsaturated fatty acids, which are predominantly vulnerable to oxidative stress (OS). OS is the imbalance between reactive oxygen species generation and cellular antioxidant potential. This may lead to various pathological conditions and diseases, especially neurodegenerative diseases such as, Parkinson's, Alzheimer's, and Huntington's diseases.

OBJECTIVES

In this study, we explored the involvement of OS in neurodegenerative diseases.

METHODS

We used different search terms like "oxidative stress and neurological disorders" "free radicals and neurodegenerative disorders" "oxidative stress, free radicals, and neurological disorders" and "association of oxidative stress with the name of disorders taken from the list of neurological disorders. We tried to summarize the source, biological effects, and physiologic functions of ROS.

RESULTS

Finally, it was noted that more than 190 neurological disorders are associated with oxidative stress.

CONCLUSION

More elaborated studies in the future will certainly help in understanding the exact mechanism involved in neurological diseases and provide insight into revelation of therapeutic targets.

Effects of riboflavin on boar sperm motility, sperm quality, enzyme activity and antioxidant status during cryopreservation

Objectives

This study was conducted to evaluate the effect of adding riboflavin to boar sperm freezing extender on the challenge of cryopreservation.

Methods

Different concentrations (0, 5, 10, 15, 20 or 25 μM) of riboflavin were added to the freezing extender. Spermatozoa motility, membrane integrity, acrosomal integrity, mitochondrial membrane potential and enzyme activities were analysed once 10 min after thawing. Q‐PCR was used to detect the mRNA expression of Caspase3, Bcl‐2 and Bax.

Results

The results showed that the addition of 10 μM riboflavin to boar sperm freezing extender significantly increased the frozen‐thawed sperm progressive motility compared with the control group (p < 0.05). Activities of superoxide dismutase, glutathione peroxidase and catalase improved after adding riboflavin to the extender (p < 0.05). During freezing‐thawing, the boar sperm mitochondrial membrane potential, acrosomal integrity, plasma membrane and DNA at 10 μM in the riboflavin group increased by 6.6%, 9.6%, 5.49% and 5.62% (p < 0.05), respectively, compared with the control group. The addition of 10 μM riboflavin to the extender significantly decreased the malondialdehyde (p < 0.05) content, whereas it increased the ATP content (p < 0.05) of boar sperm during freezing‐thawing. Furthermore, the expression of Caspase‐3 and Bax (p < 0.05) were significantly lower, whereas the expression of BCL‐2 (p < 0.05) was greater than the control group when adding 10 μM riboflavin to the extender.

Conclusions

Riboflavin showed cryoprotective capacity to the freezing extender used for boar sperm during the process of freezing‐thawing, and the optimal concentration of riboflavin for the frozen extender was 10 μM.

Phytochemical Screening, Antioxidant, and Inhibition Activity of Picrorhiza kurroa Against α-Amylase and α-Glucosidase

Picrorhiza kurroa (P.K) usually familiar as kutki is a well-known plant in the Ayurvedic system of medicine due to its reported activities including antidiabetic, antibacterial, antioxidant, antitumor, anti-inflammatory, and hepatoprotective. The current research was intended to evaluate the antioxidant, inhibition activity of the ethanolic, methanolic, and aqueous extracts of P.K roots against α-amylase and α-glucosidase in vitro, after the phytochemical analysis. For this purpose, P.K roots were extracted with ethanol (EthPk), methanol (MthPk), and distilled water (AqPk) and phytochemical study of the extracts were performed to recognize the total phenolic content (TPC) and total flavonoids content (TFC). Antioxidant capability of the extracts was assessed by FRAP, ABTS, and DPPH assay. α-amylase inhibitory and α-glucosidase inhibitory activities were also determined. Software SPSS-23 was used to statistically analyze with One Way ANOVA and results were stated as mean standard deviation. Result of the study showed that MthPk contained the maximum concentration of TPC and TFC than EthPk and AqEh. Antioxidants in terms of DPPH (lowest IC₅₀ = .894 ± .57), FRAP (612.54 ± 11.73) and ABTS (406.42 ± 4.02) assay was also maximum in MthPk. MthPk was also showed maximum inhibition activity against α-amylase and α-glucosidase with lowest IC₅₀ (.39 ± .41; .61 ± .24), respectively. The extracts α-amylase and α-glucosidase inhibitory activities order was as MthPk > EthPk> AqPk. Results clearly specified that the methanolic extract of Picrorhiza kurroa have the maximum antioxidant, α-amylase, and α-glucosidase inhibitory activities. A positive correlation of TPC, TFC with antioxidant, and α-amylase and α-glucosidase inhibition activities of the P.K roots were also shown. The plant has capability to diminish the oxidative stress and can be used to treat diabetes by inhibiting α-amylase and α-glucosidase actions.

Evaluation of an extracorporeal ozone-based bactericide system for the treatment of Escherichia coli sepsis

BACKGROUND

Sepsis is associated with substantial mortality rates. Antibiotic treatment is crucial, but global antibiotic resistance is now classified as one of the top ten global public health risks facing humanity. Ozone (O₃) is an inorganic molecule with no evident function in the body. We investigated the bactericide properties of ozone, using a novel system of extracorporeal ozone blood treatment. We hypothesized that ozone would decrease the concentration of viable Escherichia coli (E. coli) in human whole blood and that the system would be technically feasible and physiologically tolerable in a clinically relevant model of E. coli sepsis in swine.

METHODS

The E. coli strain B09-11822, a clinical isolate from a patient with septic shock was used. The in vitro study treated E. coli infected human whole blood (n = 6) with ozone. The in vivo 3.5-h sepsis model randomized swine to E. coli infusion and ozone treatment (n = 5) or E. coli infusion and no ozone treatment (n = 5). Live E. coli, 5 × 10⁷ colony-forming units (CFU/mL) was infused in a peripheral vein. Ozone treatment was initiated with a duration of 30 min after 1.5 h.

RESULTS

The single pass in vitro treatment decreased E. coli by 27%, mean 1941 to 1422 CFU/mL, mean of differences - 519.0 (95% CI - 955.0 to - 82.98, P = 0.0281). pO₂ increased (95% CI 31.35 to 48.80, P = 0.0007), pCO₂ decreased (95% CI - 3.203 to - 1.134, P = 0.0069), oxyhemoglobin increased (95% CI 1.010 to 3.669, P = 0.0113). Methemoglobin was not affected. In the sepsis model, 9/10 swine survived. One swine randomized to ozone treatment died from septic shock before initiation of the treatment. Circulatory, respiratory, and metabolic parameters were not affected by the ozone treatment. E. coli in arterial blood, in organs and in aerobic and anaerobic blood cultures did not differ. Hemoglobin, leucocytes, and methemoglobin were not affected by the treatment.

CONCLUSIONS

Ozone decreased the concentration of viable E. coli in human whole blood. The system was technically feasible and physiologically tolerable in porcine sepsis/septic shock and should be considered for further studies towards clinical applications.

Flavonoids, alkaloids and terpenoids: a new hope for the treatment of diabetes mellitus

Diabetes mellitus is a metabolic syndrome characterized by a hyperglycemic state and multi-organ failure. Millions of people worldwide are suffering from this deadly disease taking a hit on their pocket and mental health in the name of its treatment. Modern medical practices with new technological advancements and discoveries have made revolutionary changes in the treatment. But, unfortunately, Glucose-lowering drugs used have many accompanying effects such as chronic vascular disease, renal malfunction, liver disease and, many skin problems. These complications have made us think about alternative treatments for diabetes with minimum or no side effects. Nowadays, in addition to modern medicine, herbal treatment has been suggested to treat diabetes mellitus. These herbal medicines contain biological macromolecules such as flavonoids, Terpenoids, glycosides, and alkaloids, which show versatile anti-diabetic effects. These phytochemicals are generally considered safe, and naturally occurring compounds have a potential role in preventing or controlling diabetes mellitus. The underlying mechanism of their anti-diabetic effects includes improvement in insulin secretion, decrease in insulin resistance, enhanced liver glycogen synthesis, antioxidant and anti-inflammatory activities. In this review, we have focused on the mechanism of various phytochemicals targeting hyperglycemia and its underlying pathogenesis.

Diabetes and Colorectal Cancer Risk: A New Look at Molecular Mechanisms and Potential Role of Novel Antidiabetic Agents

Epidemiological data have demonstrated a significant association between the presence of type 2 diabetes mellitus (T2DM) and the development of colorectal cancer (CRC). Chronic hyperglycemia, insulin resistance, oxidative stress, and inflammation, the processes inherent to T2DM, also play active roles in the onset and progression of CRC. Recently, small dense low-density lipoprotein (LDL) particles, a typical characteristic of diabetic dyslipidemia, emerged as another possible underlying link between T2DM and CRC. Growing evidence suggests that antidiabetic medications may have beneficial effects in CRC prevention. According to findings from a limited number of preclinical and clinical studies, glucagon-like peptide-1 receptor agonists (GLP-1RAs) could be a promising strategy in reducing the incidence of CRC in patients with diabetes. However, available findings are inconclusive, and further studies are required. In this review, novel evidence on molecular mechanisms linking T2DM with CRC development, progression, and survival will be discussed. In addition, the potential role of GLP-1RAs therapies in CRC prevention will also be evaluated.

Redox Dysregulation in Aging and COPD: Role of NOX Enzymes and Implications for Antioxidant Strategies

With a rapidly growing elderly human population, the incidence of age-related lung diseases such as chronic obstructive pulmonary disease (COPD) continues to rise. It is widely believed that reactive oxygen species (ROS) play an important role in ageing and in age-related disease, and approaches of antioxidant supplementation have been touted as useful strategies to mitigate age-related disease progression, although success of such strategies has been very limited to date. Involvement of ROS in ageing is largely attributed to mitochondrial dysfunction and impaired adaptive antioxidant responses. NADPH oxidase (NOX) enzymes represent an important enzyme family that generates ROS in a regulated fashion for purposes of oxidative host defense and redox-based signalling, however, the associations of NOX enzymes with lung ageing or age-related lung disease have to date only been minimally addressed. The present review will focus on our current understanding of the impact of ageing on NOX biology and its consequences for age-related lung disease, particularly COPD, and will also discuss the implications of altered NOX biology for current and future antioxidant-based strategies aimed at treating these diseases.

The Molecular Mechanism of Antioxidation of Huolisu Oral Liquid Based on Serum Analysis and Network Analysis

Huolisu Oral Liquid (HLS), a well-known traditional Chinese medicine (TCM) prescription, is an over-the-counter drug that is registered and approved by the State Food and Drug Administration (Approval No. Z51020381). HLS has been widely applied in the clinical treatment of cognitive disorders and has effects on delaying aging. The antioxidant effects of HLS are closely related to its antiaging activities, but the underlying mechanisms are unclear. In this study, the potential antioxidant ingredients of HLS were screened based on serum pharmacochemistry and network pharmacology, and the potential mechanisms involved in HLS antioxidant effects were preliminarily explored. Further, the antioxidant effects of HLS were verified by in vivo and in vitro experiments. The results showed that potential antioxidant ingredients could affect the toxic advanced glycation end products-receptor for advanced glycation end products (TAGE-RAGE) signaling, mitogen-activated protein kinase (MAPK) signaling, interleukin (IL)-17 signaling, tumor necrosis factor (TNF) signaling, toll-like receptors (TLRs), cyclic adenosine monophosphate (cAMP) signaling, hypoxia-inducible factor (HIF)-1 signaling, and other related pathways by regulating GAPDH, AKT1, TP53, MAPK1, JUN, and other associated targets. Thus, HLS may reduce inflammation, control the release of inflammatory cytokines, and regulate mitochondrial autophagy and metabolic abnormalities to ultimately play an antioxidant role. This is the first study attempting to construct a multilevel network of "HLS-antioxidant targets" based on serum pharmacochemistry and network pharmacology to explore the relationship between HLS and antioxidation and the molecular mechanisms of antioxidation combined with bioinformatics functional analysis and lays a foundation for further elucidating the antioxidant mechanisms of HLS.

Protection against UVB deleterious skin effects in a mouse model: effect of a topical emulsion containing Cordia verbenacea extract

Cordia verbenacea DC (Boraginaceae) is a flowering shrub found along the Brazilian Atlantic Forest, Brazilian coast, and low areas of the Amazon. The crude extract of its leaves is widely used in Brazilian folk medicine as an anti-inflammatory, both topically and orally. The aim of this study is to evaluate the activity of C. verbenacea ethanolic leaves extract (CVE) against UVB-triggered cutaneous inflammation and oxidative damage in hairless mice. CVE treatment recovered cutaneous antioxidant capacity demonstrated by scavenging ABTS⁺ free radical and iron-reducing antioxidant potential evaluated by FRAP. CVE also controlled the following UV-triggered events in the skin: reduced glutathione (GSH) depletion, catalase activity decrease, and superoxide anion (O^⋅-) build-up. Furthermore, mice treated with CVE exhibited less inflammation, shown by the reduction in COX-2 expression, TNF-α, IL-1β, IL-6, edema, and neutrophil infiltration. CVE also regulated epidermal thickening and sunburn cells, reduced dermal mast cells, and preserved collagen integrity. The best results were obtained using 5% CVE-added emulsion. The present data demonstrate that topical administration of CVE presents photochemoprotective activity in a mouse model of UVB inflammation and oxidative stress. Because of the intricate network linking inflammation, oxidative stress, and skin cancer, these results also indicate the importance of further studies elucidating a possible role of C. verbenacea in the prevention of UVB-induced skin cancer and evaluating a potential synergy between CVE and sunscreens in topical products against UVB damaging effects to the skin.

Redox changes in obesity, metabolic syndrome, and diabetes

"Life is an instantaneous encounter of circulating matter and flowing energy" (Jean Giaja, Serbian physiologist), is one of the most elegant definitions not only of life but the relationship of redox biology and metabolism. Their evolutionary liaison has created inseparable yet dynamic homeostasis in health, which, when disrupted, leads to disease. This interconnection is even more pertinent today, in an era of increasing metabolic diseases of epidemic proportions such as obesity, metabolic syndrome, and diabetes. Despite great advances in understanding the molecular mechanisms of redox and metabolic regulation, we face significant challenges in preventing, diagnosing, and treating metabolic diseases. The etiological association and temporal overlap of these syndromes present significant challenges for the discrimination of appropriate clinical biomarkers for diagnosis, treatment, and outcome prediction. These multifactorial, multiorgan metabolic syndromes with complex etiopathogenic mechanisms are accompanied by disturbed redox equilibrium in target tissues and circulation. Free radicals and reactive species are considered both a causal factor and a consequence of disease status. Thus, determining the subtypes and levels of free radicals and reactive species, oxidatively damaged biomolecules (lipids, proteins, and nucleic acids) and antioxidant defense components as well as redox-sensitive transcription factors and fluxes of redox-dependent metabolic pathways will help define existing and establish novel redox biomarkers for stratifying metabolic diseases. This review aims to discuss diverse redox/metabolic aspects in obesity, metabolic syndrome, and diabetes, with the imperative to help establish a platform for emerging and future redox-metabolic biomarkers research in precision medicine. Future research warrants detailed investigations into the status of redox biomarkers in healthy subjects and patients, including the use of emerging 'omic' profiling technologies (e.g., redox proteomes, lipidomes, metabolomes, and transcriptomes), taking into account the influence of lifestyle (diet, physical activity, sleep, work patterns) as well as circadian ~24h fluctuations in circulatory factors and metabolites.

Naringin Supplementation during Pregnancy Induces Sex and Region-Specific Alterations in the Offspring's Brain Redox Status

Research has shown the beneficial effects of naringin supplementation to adult rodents, which can ameliorate oxidative stress in disease models. However, evidence has demonstrated that polyphenol supplementation induced detrimental effects when consumed during sensitive periods of development, such as pregnancy. Therefore, we investigated the effect of maternal naringin supplementation during pregnancy on the offspring’s cerebral redox status. Pregnant Wistar rats were divided into control and naringin groups and supplemented from gestational day 15 to gestational day 21. On postnatal days 1, 7, and 21, offspring were euthanized, and the prefrontal cortex, hippocampus, striatum, and cerebellum dissected. On postnatal day 1, maternal naringin supplementation positively modulated the pups’ brain redox status. On postnatal day 7, a pro-oxidative milieu was observed in the offspring’s striatum and cerebellum in a sex-dependent manner, even though the prefrontal cortex and hippocampus were not negatively affected. Besides, the alterations observed on postnatal day 7 did not persist up to weaning. Our findings demonstrated that the effect induced by naringin supplementation in the brain redox status differed according to the period of development in which naringin was consumed since the beneficial effects usually found in the adult rodents became detrimental when the supplementation was applied during pregnancy.

Impacts of Heat Stress-Induced Oxidative Stress on the Milk Protein Biosynthesis of Dairy Cows

Heat stress (HS) is one of the most important factors posing harm to the economic wellbeing of dairy industries, as it reduces milk yield as well as milk protein content. Recent studies suggest that HS participates in the induction of tissue oxidative stress (OS), as elevated levels of reactive oxygen species (ROS) and mitochondrial dysfunction were observed in dairy cows exposed to hot conditions. The OS induced by HS likely contributes to the reduction in milk protein content, since insulin resistance and apoptosis are promoted by OS and are negatively associated with the synthesis of milk proteins. The apoptosis in the mammary gland directly decreases the amount of mammary epithelial cells, while the insulin resistance affects the regulation of insulin on mTOR pathways. To alleviate OS damages, strategies including antioxidants supplementation have been adopted, but caution needs to be applied as an inappropriate supplement with antioxidants can be harmful. Furthermore, the complete mechanisms by which HS induces OS and OS influences milk protein synthesis are still unclear and further investigation is needed.

Protective effect of oral treatment with Cordia verbenacea extract against UVB irradiation deleterious effects in the skin of hairless mouse

Photochemoprotection of the skin can be achieved by inhibiting inflammation and oxidative stress, which we tested using Cordia verbenacea extract, a medicinal plant known for its rich content of antioxidant molecules and anti-inflammatory activity. In vitro antioxidant evaluation of Cordia verbenacea leaves ethanolic extract (CVE) presented the following results: ferric reducing antioxidant power (886.32 μM equivalent of Trolox/g extract); IC50 of 19.128 μg/ml for scavenging 2,2-diphenyl-1-picrylhydrazyl; IC50 of 12.48 μg/mL for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); decrease of hydroperoxides from linoleic acid (IC50 of 10.20 μg/mL); inhibition of thiobarbituric acid reactive substances (IC50 8.90 μg/mL); iron-chelating ability in bathophenanthroline iron assay (IC50 47.35 μg/mL); chemiluminescence triggered by free radicals in the H2O2/horseradish peroxidase/luminol (IC50 0.286 μg/mL) and xanthine/xanthine oxidase/luminol (IC50 0.42 μg/mL) methods. CVE (10-100 mg per kg, 30 min before and immediately after UVB exposure) treatment was performed by gavage in hairless mice. CVE inhibited skin edema, neutrophil infiltration, and overproduction of MMP-9; reduced levels of TNF-α, IL-1β, and IL- 6; numbers of skin mast cells, epidermal thickening, number of epidermal apoptotic keratinocytes, and collagen degradation. CVE increased the skin's natural antioxidant defenses as observed by Nrf-2, NAD(P)H quinone oxidoreductase 1, and heme oxygenase 1 mRNA expression enhancement. Furthermore, CVE inhibited lipid peroxidation and superoxide anion production and recovered antioxidant reduced glutathione, catalase activity, and ROS scavenging capacity of the skin. Concluding, CVE downregulates the skin inflammatory and oxidative damages triggered by UVB, demonstrating its potentialities as a therapeutic approach.

Creation of an adequate animal model of hyperuricemia (acute and chronic hyperuricemia); study of its reversibility and its maintenance

AIM

Hyperuricemia is defined by the European Rheumatology Society as a uric acid level greater than 6 mg/dl (60 mg/l or 360 μmol/l). Our goal was to evaluate the hypouricemic effect of nettle. For this reason, we have first of all try to create an hyperuricemic animal model which is very suitable because at the level of literature there is not an exact model, there are many models and our objective is to set an adequate model.

MATERIALS AND METHODS

An attempt has been made to test acute and chronic hyperuricemia by varying the duration and method of induction of potassium oxonate. Similarly, attempts have been made to induce chronic hyperuricemia through an animal and vegetable diet. The reversibility of hyperuricemia was tested with a maintenance protocol.

KEY FINDINGS

For the creation of the hyperuricemia model, it has been shown that acute hyperuricemia cannot be induced by short administration of potassium oxonate and persistent chronic hyperuricemia can be induced only after daily administration of oxonate of potassium by intraperitoneal injection for 15 days. Indeed, hyperuricemia was reversible after stopping the administration of potassium oxonate. The high-purine diet is also capable of inducing chronic hyperuricemia but to a less extent.

SIGNIFICANCE

After creating an adequate model of hyperuricemia while setting the dose of potassium oxonate, route of administration and duration. A maintenance protocol was followed which subsequently made it possible to deduce that the daily administration of potassium oxonate must be continued to maintain the hyperuricemia.

Beneficial and Detrimental Effects of Reactive Oxygen Species on Lifespan: A Comprehensive Review of Comparative and Experimental Studies

Aging is the greatest risk factor for a multitude of diseases including cardiovascular disease, neurodegeneration and cancer. Despite decades of research dedicated to understanding aging, the mechanisms underlying the aging process remain incompletely understood. The widely-accepted free radical theory of aging (FRTA) proposes that the accumulation of oxidative damage caused by reactive oxygen species (ROS) is one of the primary causes of aging. To define the relationship between ROS and aging, there have been two main approaches: comparative studies that measure outcomes related to ROS across species with different lifespans, and experimental studies that modulate ROS levels within a single species using either a genetic or pharmacologic approach. Comparative studies have shown that levels of ROS and oxidative damage are inversely correlated with lifespan. While these studies in general support the FRTA, this type of experiment can only demonstrate correlation, not causation. Experimental studies involving the manipulation of ROS levels in model organisms have generally shown that interventions that increase ROS tend to decrease lifespan, while interventions that decrease ROS tend to increase lifespan. However, there are also multiple examples in which the opposite is observed: increasing ROS levels results in extended longevity, and decreasing ROS levels results in shortened lifespan. While these studies contradict the predictions of the FRTA, these experiments have been performed in a very limited number of species, all of which have a relatively short lifespan. Overall, the data suggest that the relationship between ROS and lifespan is complex, and that ROS can have both beneficial or detrimental effects on longevity depending on the species and conditions. Accordingly, the relationship between ROS and aging is difficult to generalize across the tree of life.

Role of Oxidative Stress in the Mechanisms of Anthracycline-Induced Cardiotoxicity: Effects of Preventive Strategies

Anthracycline-induced cardiotoxicity (AIC) persists as a significant cause of morbidity and mortality in cancer survivors. Although many protective strategies have been evaluated, cardiotoxicity remains an ongoing threat. The mechanisms of AIC remain unclear; however, several pathways have been proposed, suggesting a multifactorial origin. When the central role of topoisomerase 2β in the pathophysiology of AIC was described some years ago, the classical reactive oxygen species (ROS) hypothesis shifted to a secondary position. However, new insights have reemphasized the importance of the role of oxidative stress-mediated signaling as a common pathway and a critical modulator of the different mechanisms involved in AIC. A better understanding of the mechanisms of cardiotoxicity is crucial for the development of treatment strategies. It has been suggested that the available therapeutic interventions for AIC could act on the modulation of oxidative balance, leading to a reduction in oxidative stress injury. These indirect antioxidant effects make them an option for the primary prevention of AIC. In this review, our objective is to provide an update of the accumulated knowledge on the role of oxidative stress in AIC and the modulation of the redox balance by potential preventive strategies.

Reflections of an aging free radical

In this mini-reflection, I explain how during my doctoral work in a Botany Department I first became interested in H2O2 and later in my career in other reactive oxygen species, especially the role of "catalytic" iron and haem compounds (including leghaemoglobin) in promoting oxidative damage. The important roles that H2O2, other ROS and dietary plants play in respect to humans are discussed. I also review the roles of diet-derived antioxidants in relation to human disease, presenting reasons why clinical trials using high doses of natural antioxidants have generally given disappointing results. Iron chelators and ergothioneine are reviewed as potential cytoprotective agents with antioxidant properties that may be useful therapeutically. The discovery of ferroptosis may also lead to novel agents that can be used to treat certain diseases.

Are Flavonoids Effective Antioxidants in Plants? Twenty Years of Our Investigation

Whether flavonoids play significant antioxidant roles in plants challenged by photooxidative stress of different origin has been largely debated over the last few decades. A critical review of the pertinent literature and our experimentation as well, based on a free-of-scale approach, support an important antioxidant function served by flavonoids in plants exposed to a wide range of environmental stressors, the significance of which increases with the severity of stress. On the other side, some questions need conclusive answers when the putative antioxidant functions of plant flavonoids are examined at the level of both the whole-cell and cellular organelles. This partly depends upon a conclusive, robust, and unbiased definition of "a plant antioxidant", which is still missing, and the need of considering the subcellular re-organization that occurs in plant cells in response to severe stress conditions. This likely makes our deterministic-based approach unsuitable to unveil the relevance of flavonoids as antioxidants in extremely complex biological systems, such as a plant cell exposed to an ever-changing stressful environment. This still poses open questions about how to measure the occurred antioxidant action of flavonoids. Our reasoning also evidences the need of contemporarily evaluating the changes in key primary and secondary components of the antioxidant defense network imposed by stress events of increasing severity to properly estimate the relevance of the antioxidant functions of flavonoids in an in planta situation. In turn, this calls for an in-depth analysis of the sub-cellular distribution of primary and secondary antioxidants to solve this still intricate matter.

Plants as Sources of Anti-Inflammatory Agents

Plants represent the main source of molecules for the development of new drugs, which intensifies the interest of transnational industries in searching for substances obtained from plant sources, especially since the vast majority of species have not yet been studied chemically or biologically, particularly concerning anti-inflammatory action. Anti-inflammatory drugs can interfere in the pathophysiological process of inflammation, to minimize tissue damage and provide greater comfort to the patient. Therefore, it is important to note that due to the existence of a large number of species available for research, the successful development of new naturally occurring anti-inflammatory drugs depends mainly on a multidisciplinary effort to find new molecules. Although many review articles have been published in this regard, the majority presented the subject from a limited regional perspective. Thus, the current article presents highlights from the published literature on plants as sources of anti-inflammatory agents.

Oxidative Stress and Redox-Modulating Therapeutics in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with the production of reactive species that target cysteine redox switches in proteins, thereby affecting gene regulation, DNA damage, ion transport, intermediary metabolism, and mitochondrial function. Precursors of reactive species are derived from organic and inorganic compounds and their cofactors, including amino acids, vitamins, oxygen, nitrite, and sulfate. Nutrition and the gut microbiome fuel this process to a significant extent. The production of reactive species in IBD is reflected by a reduction in systemic free thiols, the major components of the antioxidant machinery. Systemic free thiols are amenable to nutritional or therapeutic intervention. This opens up future avenues for therapeutic modulation of redox status in IBD.

Capsaicin Exerts Anti-convulsant and Neuroprotective Effects in Pentylenetetrazole-Induced Seizures

The transient receptor potential vanilloid-1 (TRPV1) receptor has been implicated in the development of epileptic seizures. We examined the effect of the TRPV1 agonist capsaicin on epileptic seizures, neuronal injury and oxidative stress in a model of status epilepticus induced in the rat by intraperitoneal (i.p.) injections of pentylenetetrazole (PTZ). Capsaicin was i.p. given at 1 or 2 mg/kg, 30 min before the first PTZ injection. Other groups were i.p. treated with the vehicle or the anti-epileptic drug phenytoin (30 mg/kg) alone or co-administered with capsaicin at 2 mg/kg. Brain levels of malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide, and paraoxonase-1 (PON-1) activity, seizure scores, latency time and PTZ dose required to reach status epilepticus were determined. Histopathological assessment of neuronal damage was done. Results showed that brain MDA decreased by treatment with capsaicin, phenytoin or capsaicin/phenytoin. Nitric oxide decreased by capsaicin or capsaicin/phenytoin. GSH and PON-1 activity increased after capsaicin, phenytoin or capsaicin/phenytoin. Mean total seizure score decreased by 48.8% and 66.3% by capsaicin compared with 78.7% for phenytoin and 69.8% for capsaicin/phenytoin treatment. Only phenytoin increased the latency (115.7%) and threshold dose of PTZ (78.3%). Capsaicin did not decrease the anti-convulsive effect of phenytoin but prevented the phenytoin-induced increase in latency time and threshold dose. Neuronal damage decreased by phenytoin or capsaicin at 2 mg/kg but almost completely prevented by capsaicin/phenytoin. Thus in this model of status epilepticus, capsaicin decreased brain oxidative stress, the severity of seizures and neuronal injury and its co-administration with phenytoin afforded neuronal protection.

Knockdown of macrophage migration inhibitory factor (MIF), a novel target to protect neurons from parthanatos induced by simulated post-spinal cord injury oxidative stress

Parthanatos is a form of regulated cell death (RCD) that is closely linked to DNA damage, which is a common consequence of oxidative stress due to central nervous trauma, such as spinal cord injury (SCI). The mechanism by which apoptosis-inducing factor (AIF) mediates DNA strand breaks in parthanatos was not clear until the discovery of the nuclease function of MIF. A previous study suggested that observed results may not be reliable if the oxidative stress induced in cells observed under experimental pathological conditions does not accurately replicate the specific pathologies being studied. According to an earlier direct measurement of extracellular oxidative stress in a rat SCI model, post-SCI oxidative stress was approximately the same as exposure to 150 μM H₂O₂. However, this concentration has been reported as sublethal oxidative stress in other cell types related to senescence, apoptosis, and parthanatos. Using sublethal H₂O₂ concentrations to induce oxidative stress is equivocal. Also, different cell types have diverse tolerances and responses to oxidative stress, and, therefore, exposure to H₂O₂. To avoid these limitations, the present study explored the mechanism of neuronal death under this simulated post-SCI oxidative stress and determined the effects of MIF knockdown in parthanatos associated with SCI. Immunofluorescence and flow cytometry were used to reveal typical characteristics of parthanatos that were blocked by PARP-1 inhibitors but not caspase inhibitors. In addition to classic features like PARP-1 and caspase-3 cleavage that were absent, we determined that parthanatos instead of apoptosis played a major role in the cell death caused by oxidative stress following SCI. Flow cytometry analysis of cells transfected by adenovirus with MIF-shRNA then exposed to H₂O₂ showed a significant decrease in cell death for MIF knockdown cells, even after AIF nuclear translocation. The comet assay also displayed significantly fewer DNA strand breaks after MIF knockdown. This is the first study has verified that MIF knockdown enables to protect neurons from parthanatos under a simulated in vivo oxidative stress following SCI. It suggests that MIF knockdown is a promising therapy to rescue neurons suffering from oxidative stress-induced SCI pathology.

Plasma concentrations of vitamin A and E and risk of dysglycemia in first-trimester pregnant Saudi women

BACKGROUND

Existing evidence suggest that low concentrations of vitamin A and E may have a contribution to the development of diabetes complications; however, data regarding the status of vitamin A and E among individuals with prediabetes are lacking. This study aimed to examine the association of plasma concentrations of vitamin A and E with the glycemic control status among first trimester pregnant Saudi women.

METHODS

In this cross-sectional study, 1102 first trimester pregnant Saudi women were recruited from antenatal clinics. Sociodemographic and anthropometric information were collected, and laboratory analyses of blood glycated hemoglobin (A1C) and plasma vitamins A and E were performed. Subjects were classified as normoglycemic, prediabetic, or undiagnosed diabetic. Multinomial regression models adjusted for age estimated the adjusted odds ratios (aORs) and [95% confidence intervals (CIs)].

RESULTS

Among the sample, 78.8% (n = 868) had normal glycemic control, while 19.1% (n = 211) had prediabetes and 2.1% (n = 23) had undiagnosed diabetes. Plasma concentrations of vitamin A and E of prediabetic participants were at a level midway between that of normoglycemic and diabetic participants (p < 0.01). Compared to subjects with normoglycemic status, those with higher concentrations of vitamin A and E had lower odds of being prediabetic (aOR = 0.27 [0.21-0.35] and aOR = 0.95 [0.94-0.96], respectively) or diabetic (aOR = 0.18 [0.13-0.24] and aOR = 0.93 [0.92-0.94], respectively).

CONCLUSIONS

Our findings indicate a possible contribution of vitamins A and E to the progression of prediabetes to diabetes. Future longitudinal studies are needed to elucidate the association between the antioxidant status and dysglycemia. Clinicians should monitor the glycemic and the antioxidant status closely and provide dietary guidance where needed.