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Nutrition Reviews Sep 2009In recent years, nuts have received special attention because of their potential role in preventing cardiovascular disease. Because nuts are very rich in total fat that... (Review)
Review
In recent years, nuts have received special attention because of their potential role in preventing cardiovascular disease. Because nuts are very rich in total fat that can potentially be oxidized and their skins contain several antioxidants, studies have been conducted to evaluate the potential effect of nut consumption on oxidative stress. This review evaluates the in vitro and in vivo studies conducted in animals or humans to analyze the effect of nuts on oxidation.
Topics: Animals; Antioxidants; Biomarkers; Cardiovascular Diseases; Diet; Eating; Fatty Acids; Humans; Lipid Peroxidation; Nuts; Oxidation-Reduction; Oxidative Stress; Plant Extracts
PubMed: 19703258
DOI: 10.1111/j.1753-4887.2009.00223.x -
International Journal of Environmental... May 2022Over the past two decades, scientists have attempted to evaluate whether the point of maximal fat oxidation (FAT) and the aerobic threshold (AerT) are connected. The... (Meta-Analysis)
Meta-Analysis Review
Over the past two decades, scientists have attempted to evaluate whether the point of maximal fat oxidation (FAT) and the aerobic threshold (AerT) are connected. The existence of such a relationship would allow a more tailored training approach for athletes while improving the efficacy of individualized exercise prescriptions when treating numerous health-related issues. However, studies have reported conflicting results, and this issue remains unresolved. This systematic review and meta-analysis aimed: (i) to examine the strength of the association between FAT and AerT by using the effect size (ES) of correlation coefficient (r) and standardized mean difference (SMD); (ii) to identify potential moderators and their influence on ES variability. This study was registered with PROSPERO (CRD42021239351) and ClinicalTrials (NCT03789045). PubMed and Google Scholar were searched and fourteen articles, consisting of overall 35 ES for and 26 ES for SMD were included. Obtained ESs were analyzed using a multilevel random-effects meta-analysis. Our results support the presence of a significant association between FAT and AerT exercise intensities. In conclusion, due to the large ES variance caused by clinical and methodological differences among the studies, we recommend that future studies follow strict standardization of data collection and analysis of FAT and AerT-related outcomes.
Topics: Athletes; Exercise; Exercise Test; Humans; Oxidation-Reduction
PubMed: 35682065
DOI: 10.3390/ijerph19116479 -
Arab Journal of Urology 2019: To review and present the most distinct concepts on the association of reactive oxygen species (ROS) with male reproduction. : The Preferred Reporting Items for... (Review)
Review
: To review and present the most distinct concepts on the association of reactive oxygen species (ROS) with male reproduction. : The Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines were used to search PubMed, Medline, EMBASE, and the Cochrane electronic databases for studies investigating the role of oxidative stress (OS) on sperm function. : The literature search yielded 1857 studies, of which 1791 articles were excluded because of irrelevance of data, non-English language, non-human nature or because they were case reports or commentaries. All included studies were reviews (46), meta-analyses (one), original research studies (18) and guideline articles (one). The studies were published between 1984 and 2018. Under normal physiological conditions, ROS are vital for sperm maturation, hyperactivation, capacitation, acrosome reaction, as well as fertilisation. However, a number of endogenous and exogenous causes may induce supra-physiological levels of ROS resulting in lipid peroxidation, sperm DNA fragmentation and apoptosis, and consequently infertility. Several laboratory testing methods can be used in infertile men to diagnose OS. Treatment usually involves antioxidant supplementation and, when possible, elimination of the causative factor. : OS is an important cause of male factor infertility. Its assessment provides essential information that can guide treatment strategies aimed at improving the male's reproductive potential. bp: base-pair; CAT: catalase; LPO: lipid peroxidation; MDA: malondialdehyde; MiOXSYS: Male Infertility Oxidative System; mtDNA: mitochondrial DNA; NAD(PH): nicotinamide adenine dinucleotide (phosphate); NO: nitric oxide; 8-OHdG: 8-hydroxy-2'-deoxyguanosine; ORP: oxidation-reduction potential; OS: oxidative stress; PKA: protein kinase A; PLA2: phospholipase A2; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PUFA: poly-unsaturated fatty acid; ROS: reactive oxygen species; SOD: superoxide dismutase; TAC: total antioxidant capacity; TBA: thiobarbituric acid.
PubMed: 31285919
DOI: 10.1080/2090598X.2019.1599624 -
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 -
International Journal of Environmental... Dec 2022Regular exercise at the intensity matching maximal fat oxidation (FAT) has been proposed as a key element in both athletes and clinical populations when aiming to... (Meta-Analysis)
Meta-Analysis Review
Regular exercise at the intensity matching maximal fat oxidation (FAT) has been proposed as a key element in both athletes and clinical populations when aiming to enhance the body's ability to oxidize fat. In order to allow a more standardized and tailored training approach, the connection between FAT and the individual aerobic thresholds (AerT) has been examined. Although recent findings strongly suggest that a relationship exists between these two intensities, correlation alone is not sufficient to confirm that the intensities necessarily coincide and that the error between the two measures is small. Thus, this systematic review and meta-analysis aim to examine the agreement levels between the exercise intensities matching FAT and AerT by pooling limits of agreement in a function of three parameters: (i) the average difference, (ii) the average within-study variation, and (iii) the variation in bias across studies, and to examine the influence of clinical and methodological inter- and intra-study differences on agreement levels. This study was registered with PROSPERO (CRD42021239351) and ClinicalTrials (NCT03789045). PubMed and Google Scholar were searched for studies examining FAT and AerT connection. Overall, 12 studies with forty-five effect sizes and a total of 774 subjects fulfilled the inclusion criteria. The ROBIS tool for risk of bias assessment was used to determine the quality of included studies. In conclusion, the overall 95% limits of agreement of the differences between FAT and AerT exercise intensities were larger than the a priori determined acceptable agreement due to the large variance caused by clinical and methodological differences among the studies. Therefore, we recommend that future studies follow a strict standardization of data collection and analysis of FAT- and AerT-related outcomes.
Topics: Humans; Follow-Up Studies; Lipid Metabolism; Oxygen Consumption; Calorimetry, Indirect; Oxidation-Reduction; Exercise Test
PubMed: 36612784
DOI: 10.3390/ijerph20010453 -
Cells Apr 2023Betel quid and areca nut are complex mixture carcinogens, but little is known about whether their derived single-agent arecoline or arecoline -oxide (ANO) is...
Betel quid and areca nut are complex mixture carcinogens, but little is known about whether their derived single-agent arecoline or arecoline -oxide (ANO) is carcinogenic, and the underlying mechanisms remain unclear. In this systematic review, we analyzed recent studies on the roles of arecoline and ANO in cancer and strategies to block carcinogenesis. In the oral cavity, flavin-containing monooxygenase 3 oxidizes arecoline to ANO, and both alkaloids conjugate with -acetylcysteine to form mercapturic acid compounds, which are excreted in urine, reducing arecoline and ANO toxicity. However, detoxification may not be complete. Arecoline and ANO upregulated protein expression in oral cancer tissue from areca nut users compared to expression levels in adjacent normal tissue, suggesting a causal relationship between these compounds and oral cancer. Sublingual fibrosis, hyperplasia, and oral leukoplakia were diagnosed in mice subjected to oral mucosal smearing of ANO. ANO is more cytotoxic and genotoxic than arecoline. During carcinogenesis and metastasis, these compounds increase the expression of epithelial-mesenchymal transition (EMT) inducers such as reactive oxygen species, transforming growth factor-β1, Notch receptor-1, and inflammatory cytokines, and they activate EMT-related proteins. Arecoline-induced epigenetic markers such as sirtuin-1 hypermethylation, low protein expression of miR-22, and miR-886-3-p accelerate oral cancer progression. Antioxidants and targeted inhibitors of the EMT inducers used reduce the risk of oral cancer development and progression. Our review findings substantiate the association of arecoline and ANO with oral cancer. Both of these single compounds are likely carcinogenic to humans, and their mechanisms and pathways of carcinogenesis are useful indicators for cancer therapy and prognosis.
Topics: Arecoline; Cyclic N-Oxides; Mouth Neoplasms; Carcinogenesis; Humans; Animals; Mice; Areca; Oxygenases; Oxidation-Reduction; Acetylcysteine; Epigenesis, Genetic; Carcinogens
PubMed: 37190117
DOI: 10.3390/cells12081208 -
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 -
Brain, Behavior, and Immunity Oct 2023Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses.
OBJECTIVES
To systematically review and meta-analyze all data concerning biomarkers of reverse cholesterol transport (RCT), lipid-associated antioxidants, lipid peroxidation products, and autoimmune responses to oxidatively modified lipid epitopes in MDD and BD.
METHODS
Databases including PubMed, Google scholar and SciFinder were searched to identify eligible studies from inception to January 10th, 2023. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.
RESULTS
The current meta-analysis included 176 studies (60 BD and 116 MDD) and examined 34,051 participants, namely 17,094 with affective disorders and 16,957 healthy controls. Patients with MDD and BD showed a) significantly decreased RCT (mainly lowered high-density lipoprotein cholesterol and paraoxonase 1); b) lowered lipid soluble vitamins (including vitamin A, D, and coenzyme Q10); c) increased lipid peroxidation and aldehyde formation, mainly increased malondialdehyde (MDA), 4-hydroxynonenal, peroxides, and 8-isoprostanes; and d) Immunoglobulin (Ig)G responses to oxidized low-density lipoprotein and IgM responses to MDA. The ratio of all lipid peroxidation biomarkers/all lipid-associated antioxidant defenses was significantly increased in MDD (standardized mean difference or SMD = 0.433; 95% confidence intervals (CI): 0.312; 0.554) and BD (SMD = 0.653; CI: 0.501-0.806). This ratio was significantly greater in BD than MDD (p = 0.027).
CONCLUSION
In MDD/BD, lowered RCT, a key antioxidant and anti-inflammatory pathway, may drive increased lipid peroxidation, aldehyde formation, and autoimmune responses to oxidative specific epitopes, which all together cause increased immune-inflammatory responses and neuro-affective toxicity.
Topics: Humans; Bipolar Disorder; Lipid Peroxidation; Depression; Antioxidants; Depressive Disorder, Major; Aldehydes; Biomarkers; Cholesterol; Lipids
PubMed: 37557967
DOI: 10.1016/j.bbi.2023.08.007 -
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 -
RSC Advances Sep 20212,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is the most widely used quinone with a high reduction potential, and it commonly mediates hydride transfer reactions and... (Review)
Review
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is the most widely used quinone with a high reduction potential, and it commonly mediates hydride transfer reactions and shows three accessible oxidation states: quinone (oxidized), semiquinone (one-electron-reduced), and hydroquinone (two-electron-reduced). DDQ has found broad utility as a stoichiometric oxidant in the functionalization of activated C-H bonds and the dehydrogenation of saturated C-C, C-O, and C-N bonds. The cost and toxicity of DDQ triggered recent efforts to develop methods that employ catalytic quantities of DDQ in combination with alternative stoichiometric oxidants. The aerobic catalytic approach was established for the selective oxidation of non-sterically hindered electron-rich benzyl methyl ethers and benzylic alcohols, and effectively extended to the oxidative deprotection of -methoxybenzyl ethers to generate the alcohols in high selectivity. A combination of DDQ and protic acid is known to oxidize several aromatic donors to the corresponding cation radicals. The excited-state DDQ converts benzyls, heteroarenes, fluoroarenes, benzene, and olefins into their radical cation forms as well as chloride and other anions into their respective radicals. These reactive intermediates have been employed for the generation of C-C and C-X (N, O, or Cl) bonds in the synthesis of valuable natural products and organic compounds. To the best of our knowledge, however, there is still no review article exclusively describing the applications of DDQ in organic synthesis. Therefore, in the present review, we provide an overview of DDQ-induced organic transformations with their scope, limitations and the proposed reaction mechanisms.
PubMed: 35479576
DOI: 10.1039/d1ra04575j