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Molecules (Basel, Switzerland) Jun 2024Our hypothesis that controlled ozone applications interfere with the redox balance of a biological organism (first published in 1998 with a preclinical trial on... (Review)
Review
Our hypothesis that controlled ozone applications interfere with the redox balance of a biological organism (first published in 1998 with a preclinical trial on protecting the liver from CCl intoxication) has been verified over the past two decades in reactive oxygen species (ROS)-induced mitochondrial pathologies, such as rheumatoid arthritis, osteoarthritis, aging processes and type 2 diabetes, and in the prevention of intoxications. Low-dose ozone acts as a redox bioregulator: the restoration of the disturbed redox balance is comprehensible in a number of preclinical and clinical studies by a remarkable increase in the antioxidant repair markers, here mainly shown as a glutathione increase and a reduction in oxidative stress markers, mainly malondialdehyde. The mechanism of action is shown, and relevant data are displayed, evaluated and comprehensively discussed: the repair side of the equilibrium increases by 21% up to 140% compared to the non-ozone-treated groups and depending on the indication, the stress markers are simultaneously reduced, and the redox system regains its balance.
Topics: Oxidative Stress; Ozone; Oxidation-Reduction; Humans; Mitochondria; Reactive Oxygen Species; Animals; Antioxidants; Biomarkers
PubMed: 38930804
DOI: 10.3390/molecules29122738 -
The ISME Journal Jan 2024Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing... (Review)
Review
Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing microbial ecology. Since their first application for aerobic gammaproteobacterial methane oxidizers less than a decade ago, GEMs have substantially increased our understanding of the metabolism of methanotrophs, a microbial guild of high relevance for the natural and biotechnological mitigation of methane efflux to the atmosphere. Particularly, GEMs helped to elucidate critical metabolic and regulatory pathways of several methanotrophic strains, predicted microbial responses to environmental perturbations, and were used to model metabolic interactions in cocultures. Here, we conducted a systematic review of GEMs exploring aerobic methanotrophy, summarizing recent advances, pointing out weaknesses, and drawing out probable future uses of GEMs to improve our understanding of the ecology of methane oxidizers. We also focus on their potential to unravel causes and consequences when studying interactions of methane-oxidizing bacteria with other methanotrophs or members of microbial communities in general. This review aims to bridge the gap between applied sciences and microbial ecology research on methane oxidizers as model organisms and to provide an outlook for future studies.
Topics: Methane; Oxidation-Reduction; Aerobiosis; Metabolic Networks and Pathways; Models, Biological
PubMed: 38861460
DOI: 10.1093/ismejo/wrae102 -
Nutrients Apr 2024Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease... (Meta-Analysis)
Meta-Analysis
Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1β, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.
Topics: Animals; Humans; Antioxidants; Cytochrome P-450 CYP2E1; Cytokines; Disease Models, Animal; Fatty Liver, Alcoholic; Lipid Peroxidation; Liver; NF-E2-Related Factor 2; Oxidative Stress; Reactive Oxygen Species
PubMed: 38674865
DOI: 10.3390/nu16081174 -
Nutrients Jan 2024Pre-exercise intake of caffeine (from ~3 to 9 mg/kg) has been demonstrated as an effective supplementation strategy to increase fat oxidation during fasted exercise.... (Meta-Analysis)
Meta-Analysis Review
Pre-exercise intake of caffeine (from ~3 to 9 mg/kg) has been demonstrated as an effective supplementation strategy to increase fat oxidation during fasted exercise. However, a pre-exercise meal can alter the potential effect of caffeine on fat oxidation during exercise as caffeine modifies postprandial glycaemic and insulinemic responses. Hypothetically, the effect of caffeine on fat oxidation may be reduced or even withdrawn during fed-state exercise. The present systematic review aimed to meta-analyse investigations on the effect of acute caffeine intake on the rate of fat oxidation during submaximal aerobic exercise performed in the fed state (last meal < 5 h before exercise). A total of 18 crossover trials with randomised and placebo-controlled protocols and published between 1982 and 2021 were included, with a total of 228 participants (185 males and 43 females). Data were extracted to compare rates of fat oxidation during exercise with placebo and caffeine at the same exercise intensity, which reported 20 placebo-caffeine pairwise comparisons. A meta-analysis of the studies was performed, using the standardised mean difference (SMD) estimated from Hedges' , with 95% confidence intervals (CI). In comparison with the placebo, caffeine increased the rate of fat oxidation during fed-state exercise (number of comparisons (n) = 20; = 0.020, SMD = 0.65, 95% CI = 0.20 to 1.20). Only studies with a dose < 6 mg/kg of caffeine (n = 13) increased the rate of fat oxidation during fed-state exercise ( = 0.004, SMD = 0.86, 95% CI = 0.27 to 1.45), while no such effect was observed in studies with doses ≥6 mg/kg (n = 7; = 0.97, SMD = -0.03, 95% CI = -1.40 to 1.35). The effect of caffeine on fat oxidation during fed-state exercise was observed in active untrained individuals (n = 13; < 0.001, SMD = 0.84, 95% CI = 0.39 to 1.30) but not in aerobically trained participants (n = 7; = 0.27, SMD = 0.50, 95% CI = -0.39 to 1.39). Likewise, the effect of caffeine on fat oxidation was observed in caffeine-naïve participants (n = 9; < 0.001, SMD = 0.82, 95% CI = 0.45 to 1.19) but not in caffeine consumers (n = 3; = 0.54, SMD = 0.57, 95% CI = -1.23 to 2.37). In conclusion, acute caffeine intake in combination with a meal ingested within 5 h before the onset of exercise increased the rate of fat oxidation during submaximal aerobic exercise. The magnitude of the effect of caffeine on fat oxidation during fed-state exercise may be modulated by the dose of caffeine administered (higher with <6 mg/kg than with ≥6 mg/kg), participants' aerobic fitness level (higher in active than in aerobically trained individuals), and habituation to caffeine (higher in caffeine-naïve than in caffeine consumers).
Topics: Female; Male; Humans; Caffeine; Exercise; Fasting; Meals; Oxidation-Reduction
PubMed: 38257100
DOI: 10.3390/nu16020207 -
Brain, Behavior, and Immunity Mar 2024While genetic and cohort studies suggest immune and reduction/oxidation (redox) alterations occur in psychosis, less is known about potential alterations in children and... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
While genetic and cohort studies suggest immune and reduction/oxidation (redox) alterations occur in psychosis, less is known about potential alterations in children and adolescents.
METHODS
We conducted a systematic review to identify immune and redox biomarker studies in children and adolescents (mean age ≤ 18 years old) across the psychosis spectrum: from psychotic like experiences, which are common in children, to threshold psychotic disorders like schizophrenia. We conducted meta-analyses when at least three studies measured the same biomarker.
RESULTS
The systematic review includes 38 pediatric psychosis studies. The meta-analyses found that youth with threshold psychotic disorders had higher neutrophil/lymphocyte ratio (Hedge's g = 0.40, 95 % CI 0.17 - 0.64), tumor necrosis factor (Hedge's g = 0.38, 95 % CI 0.06 - 0.69), C-reactive protein (Hedge's g = 0.38, 95 % CI 0.05 - 0.70), interleukin-6 (Hedge's g = 0.35; 95 % CI 0.11 - 0.64), and total white blood cell count (Hedge's g = 0.29, 95 % CI 0.12 - 0.46) compared to youth without psychosis. Other immune and oxidative stress meta-analytic findings were very heterogeneous.
CONCLUSION
Results from several studies are consistent with the hypothesis that signals often classified as "proinflammatory" are elevated in threshold pediatric psychotic disorders. Data are less clear for immune markers in subthreshold psychosis and redox markers across the subthreshold and threshold psychosis spectrum. Immune and redox biomarker intervention studies are lacking, and research investigating interventions targeting the immune system in threshold pediatric psychosis is especially warranted.
Topics: Adolescent; Humans; Child; Psychotic Disorders; Biomarkers; C-Reactive Protein; Interleukin-6; Oxidative Stress
PubMed: 38141839
DOI: 10.1016/j.bbi.2023.12.019 -
Frontiers in Nutrition 2023Central nervous system (CNS) disorders present a growing and costly global health challenge, accounting for over 11% of the diseases burden in high-income countries.... (Review)
Review
Central nervous system (CNS) disorders present a growing and costly global health challenge, accounting for over 11% of the diseases burden in high-income countries. Despite current treatments, patients often experience persistent symptoms that significantly affect their quality of life. Dietary polysaccharides have garnered attention for their potential as interventions for CNS disorders due to their diverse mechanisms of action, including antioxidant, anti-inflammatory, and neuroprotective effects. Through an analysis of research articles published between January 5, 2013 and August 30, 2023, encompassing the intervention effects of dietary polysaccharides on Alzheimer's disease, Parkinson's disease, depression, anxiety disorders, autism spectrum disorder, epilepsy, and stroke, we have conducted a comprehensive review with the aim of elucidating the role and mechanisms of dietary polysaccharides in various CNS diseases, spanning neurodegenerative, psychiatric, neurodevelopmental disorders, and neurological dysfunctions. At least four categories of mechanistic bases are included in the dietary polysaccharides' intervention against CNS disease, which involves oxidative stress reduction, neuronal production, metabolic regulation, and gut barrier integrity. Notably, the ability of dietary polysaccharides to resist oxidation and modulate gut microbiota not only helps to curb the development of these diseases at an early stage, but also holds promise for the development of novel therapeutic agents for CNS diseases. In conclusion, this comprehensive review strives to advance therapeutic strategies for CNS disorders by elucidating the potential of dietary polysaccharides and advocating interdisciplinary collaboration to propel further research in this realm.
PubMed: 38075226
DOI: 10.3389/fnut.2023.1299117 -
Frontiers in Immunology 2023Novel biomarkers of inflammation and oxidative stress might enhance the early recognition, management, and clinical outcomes of patients with rheumatic diseases (RDs).... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Novel biomarkers of inflammation and oxidative stress might enhance the early recognition, management, and clinical outcomes of patients with rheumatic diseases (RDs). We assessed the available evidence regarding the pathophysiological role of neopterin, the oxidation product of 7,8-dihydroneopterin, a pteridine generated in macrophages activated by interferon-γ, by conducting a systematic review and meta-analysis of studies reporting its concentrations in biological fluids in RD patients and healthy controls.
METHODS
We searched electronic databases for relevant articles published between inception and 31 August 2023. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development and Evaluation Working Group system, respectively.
RESULTS
In 37 studies, when compared to healthy controls, RD patients had significantly higher concentrations of neopterin both in plasma or serum (standard mean difference, SMD=1.31, 95% CI 1.01 to 1.61; p<0.001; moderate certainty of evidence) and in the urine (SMD=1.65, 95% CI 0.86 to 2.43, p<0.001; I = 94.2%, p<0.001; low certainty of evidence). The results were stable in sensitivity analysis. There were non-significant associations in meta-regression and subgroup analysis between the effect size and age, male to female ratio, year of publication, sample size, RD duration, C-reactive protein, erythrocyte sedimentation rate, specific type of RD, presence of connective tissue disease, analytical method used, or biological matrix investigated (plasma . serum). By contrast, the effect size was significantly associated with the geographical area in studies assessing serum or plasma and with the type of RD in studies assessing urine.
DISCUSSION
Pending additional studies that also focus on early forms of disease, our systematic review and meta-analysis supports the proposition that neopterin, a biomarker of inflammation and oxidative stress, can be useful for the identification of RDs. (PROSPERO registration number: CRD42023450209).
SYSTEMATIC REVIEW REGISTRATION
PROSPERO, identifier CRD42023450209.
Topics: Humans; Male; Female; Neopterin; Inflammation; Oxidation-Reduction; Oxidative Stress; Rheumatic Diseases; Biomarkers
PubMed: 37799718
DOI: 10.3389/fimmu.2023.1271383 -
World Journal of Microbiology &... Jul 2023Tellurium is a super-trace metalloid on Earth. Owing to its excellent physical and chemical properties, it is used in industries such as metallurgy and manufacturing,... (Review)
Review
Tellurium is a super-trace metalloid on Earth. Owing to its excellent physical and chemical properties, it is used in industries such as metallurgy and manufacturing, particularly of semiconductors and - more recently - solar panels. As the global demand for tellurium rises, environmental issues surrounding tellurium have recently aroused concern due to its high toxicity. The amount of tellurium released to the environment is increasing, and microorganisms play an important role in the biogeochemical cycling of environmental tellurium. This review focuses on novel developments on tellurium transformations driven by microbes and includes the following sections: (1) history and applications of tellurium; (2) toxicity of tellurium; (3) microbial detoxification mechanisms against soluble tellurium anions including uptake, efflux and methods of reduction, and reduced ability to cope with oxidation stress or repair damaged DNA; and (4) the characteristics and applications of tellurium nanoparticles (TeNPs) produced by microbes. This review raises the awareness of microorganisms in tellurium biogeochemical cycling and the growing applications for microbial tellurium nanoparticles.
Topics: Trace Elements; Tellurium; Nanoparticles
PubMed: 37507604
DOI: 10.1007/s11274-023-03704-2