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Antioxidants (Basel, Switzerland) Feb 2022Tree nuts, including Brazil nuts, have been hypothesized to impact cardiovascular health through the modulation of oxidative stress and inflammation. Nonetheless, a... (Review)
Review
Effect of Brazil Nuts on Selenium Status, Blood Lipids, and Biomarkers of Oxidative Stress and Inflammation: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Tree nuts, including Brazil nuts, have been hypothesized to impact cardiovascular health through the modulation of oxidative stress and inflammation. Nonetheless, a quantitative analysis of these effects has not been performed. Therefore, the aim of this study was to systematically revise and quantify the effect of Brazil nut intervention on selenium status, blood lipids, and biomarkers of oxidative stress and inflammation using a meta-analytical approach. To meet the goals of this study, a systematic search of PubMed, EMBASE, and Web of Science databases of published randomised clinical trials reporting on dietary interventions with Brazil nuts and their effects on selenium status, blood lipids, and markers of oxidative stress and inflammation was performed. Eight articles were included for systematic review and meta-analysis. Based on the conducted analysis, a significant positive effect of Brazil nuts on selenium blood concentration (SMD = 6.93, 95% CI: 3.99; 9.87) was found. Additionally, a positive effect of Brazil nut intervention on glutathione peroxidase activity (SMD = 0.53, 95% CI: 0.07; 0.99) was observed. However, no significant results were found when considering blood lipid levels, including results for total cholesterol (SMD = -0.22, 95% CI: -0.57; 0.14), HDL cholesterol (SMD = -0.04, 95% CI: -0.28; 0.19) and LDL cholesterol (SMD = -0.15; 95% CI: -0.43; 0.13). In conclusion, the findings from this study suggest that Brazil nut consumption improves selenium status and exerts antioxidant effects, which could be considered a potential pathway for the prevention of metabolic disorders related to altered blood lipid profiles. However, further studies are needed to elucidate the effect of Brazil nuts toward blood lipid profile, also preferably controlling for other biomarkers.
PubMed: 35204285
DOI: 10.3390/antiox11020403 -
Frontiers in Pharmacology 2020Fatigue, as a complex, multidimensional symptom, is associated with many physical illnesses. C. A. Mey (PG) is an important herbal drug which has been used for...
BACKGROUND
Fatigue, as a complex, multidimensional symptom, is associated with many physical illnesses. C. A. Mey (PG) is an important herbal drug which has been used for benefiting Qi for thousand years. C. A. Mey and its compounds (PGC) possess various pharmacological activities, including anti-fatigue. Here, we conducted a systematic review of both randomized clinical trials (RCTs) and preclinical animal studies to investigate the efficacy and safety of PGC for fatigue.
METHODS
Electronic searches were performed in 7 databases from the time of each database's inception to August 2019. The methodological quality of RCTs was assessed using 7-item checklist recommended by Cochrane Collaboration or by the CAMARADES 10-item quality checklist. All the data were analyzed using Rev-Man 5.3 and Stata SE software.
RESULTS
Eight eligible RCTs and 30 animal studies were identified. The risk of bias scores in RCTs ranged from 4/7 to 7/7, and of animal studies varied from 4/10 to 7/10. Meta-analyses showed that PGC was superior to placebo according to their respective fatigue scales, heart rate recovery, and clinical effect (P < 0.05). There were a similar number of adverse effects between PGC and placebo group (P > 0.05). Meta-analyses showed that PGC can significantly decrease level of blood lactate, blood urea nitrogen, creatine kinase, malondialdehyde, and lactic dehydrogenase in serum, level of malondialdehyde in liver and level of gamma-aminobutyric acid, 5-hydroxytryptamine in brain tissue, and increase swimming time, level of glutathione peroxidase, glucose, superoxide dismutase in serum, level of glycogen and activity of superoxide dismutase, glutathione peroxidase, and catalase in skeletal muscle, level of hepatic glycogen in liver and level of dopamine, acetylcholine in brain tissue, compared with control (P < 0.05). Meta-analyses showed no significant difference in animal body weight between PGC and control (P > 0.05).
CONCLUSION
The present findings supported, to a certain degree, that PGC can be recommended for routine use in fatigue. The possible mechanism of PGC resists fatigue, mainly through antioxidant stress, regulating carbohydrate metabolism, delaying the accumulation of metabolites, promoting mitochondrial function, neuroprotection, antiapoptosis, and regulating neurotransmitter disorder in central nervous system.
PubMed: 32765262
DOI: 10.3389/fphar.2020.01031 -
Foods (Basel, Switzerland) May 2022This study adopted systematic literature review and meta-analysis methodology to explored anti-oxidative effect of pu-erh tea. Study authors have systemically searched... (Review)
Review
This study adopted systematic literature review and meta-analysis methodology to explored anti-oxidative effect of pu-erh tea. Study authors have systemically searched seven databases up until 21 February 2020. In performing the literature search on the above-mentioned databases, the authors used keywords of pu-erh AND (superoxide dismutase OR glutathione peroxidase OR malondialdehyde). Results derived from meta-analyses showed statistically significant effects of pu-erh tea on reducing serum MDA levels (SMD, −4.19; 95% CI, −5.22 to −3.15; p < 0.001; I2 = 93.67%); increasing serum SOD levels (SMD, 2.41; 95% CI, 1.61 to 3.20; p < 0.001; I2 = 91.36%); and increasing serum GSH-Px levels (SMD, 4.23; 95% CI, 3.10 to 5.36; p < 0.001; I2 = 93.69%). Results from systematic review and meta-analyses validated that various ingredients found in pu-erh tea extracts had anti-oxidation effects, a long-held conventional wisdom with limited supporting evidence.
PubMed: 35564056
DOI: 10.3390/foods11091333 -
Annals of Palliative Medicine Apr 2021This investigation systematically evaluated the selenium levels and the effects of selenium supplementation in patients with autoimmune thyroid disease (AITD). (Meta-Analysis)
Meta-Analysis
BACKGROUND
This investigation systematically evaluated the selenium levels and the effects of selenium supplementation in patients with autoimmune thyroid disease (AITD).
METHODS
Randomized controlled trials (RCTs) related to selenium supplementation in patients with AITD were selected from the PubMed, Medline, Web of Sciences, Embase, Cochrane Library, and Spring databases. All related literature published between January 2000 and November 2020 were included. The RCT bias risk assessment was conducted according to the Cochrane Handbook 5.0.2. The Review Manager 5.3 software was applied for meta-analysis of the included literature.
RESULTS
A total of 17 articles meeting the requirements were selected, including a total of 1,911 subjects. Meta-analysis results showed that the serum free triiodothyronine (FT3) levels in patients was greatly reduced after selenium supplementation compared to placebo treatment (MD =-0.40; 95% confidential interval (CI): -0.70--0.10; Z=2.61; P=0.009). Serum free thyroxine (FT4) levels and anti-thyroid peroxidase antibody (TPOAb) levels were also significantly reduced (MD = -0.76; 95% CI: -1.58--0.07; Z=1.79; P=0.07), and anti-thyroid peroxidase antibody (TPOAb) level was decreased observably (MD =-150.25; 95% CI: -04.06--96.43; Z=5.47; P<0.00001). The thyroid stimulating hormone (TSH) levels (MD =0.06; 95% CI: -0.53-0.66; Z=0.21; P=0.83) and anti-thyroglobulin antibody (TGAb) levels (MD =17.19; 95% CI: -254.86-289.25; Z=0.12; P=0.90) were not significantly different between the experimental group and the control group.
CONCLUSIONS
Selenium-containing drugs were effective in treating AITD patients, and greatly reduced the levels of FT3, FT4, and TPOAb in AITD patients. These results suggested that selenium level had a great effect on AITD and selenium supplementation showed a very important effect on AITD.
Topics: Hashimoto Disease; Humans; Pharmaceutical Preparations; Selenium; Thyroid Hormones
PubMed: 33894732
DOI: 10.21037/apm-21-449 -
International Journal of Molecular... Dec 2022Aim: The single-nucleotide polymorphism (SNP) rs713041, located in the regulatory region, is required to incorporate selenium into the selenoprotein glutathione... (Meta-Analysis)
Meta-Analysis Review
Aim: The single-nucleotide polymorphism (SNP) rs713041, located in the regulatory region, is required to incorporate selenium into the selenoprotein glutathione peroxidase 4 (GPX4) and has been found to have functional consequences. This systematic review aimed to conduct a meta-analysis to determine whether there is an association between GPX4 (rs713041) SNP and the risk of diseases in humans and its correlation with selenium status. Material and methods: A systematic search for English-language manuscripts published between January 1990 and November 2022 was carried out using six databases: CINAHL, Cochrane, Medline, PubMed, Scopus and Web of Science. Odds ratios (ORs) and 95% confidence intervals (CIs) were applied to assess a relationship between GPX4 (rs713041) SNP and the risk of different diseases based on three genetic models. Review Manager 5.4 and Comprehensive Meta-Analysis 4 software were used to perform the meta-analysis and carry out Egger’s test for publication bias. Results: Data from 21 articles were included in the systematic review. Diseases were clustered according to the physiological system affected to understand better the role of GPX4 (rs713041) SNP in developing different diseases. Carriers of the GPX4 (rs173041) T allele were associated with an increased risk of developing colorectal cancer in additive and dominant models (p = 0.02 and p = 0.004, respectively). In addition, carriers of the T allele were associated with an increased risk of developing stroke and hypertension in the additive, dominant and recessive models (p = 0.002, p = 0.004 and p = 0.01, respectively). On the other hand, the GPX4 (rs713041) T allele was associated with a decreased risk of developing pre-eclampsia in the additive, dominant and recessive models (p < 0.0001, p = 0.002 and p = 0.0005, respectively). Moreover, selenium levels presented lower mean values in cancer patients relative to control groups (SMD = −0.39 µg/L; 95% CI: −0.64, −0.14; p = 0.002, I2 = 85%). Conclusion: GPX4 (rs713041) T allele may influence colorectal cancer risk, stroke, hypertension and pre-eclampsia. In addition, low selenium levels may play a role in the increased risk of cancer.
Topics: Female; Humans; Pregnancy; Colorectal Neoplasms; Genetic Predisposition to Disease; Glutathione Peroxidase; Hypertension; Phospholipid Hydroperoxide Glutathione Peroxidase; Polymorphism, Single Nucleotide; Pre-Eclampsia; Selenium; Stroke
PubMed: 36555402
DOI: 10.3390/ijms232415762 -
Clinical and Experimental Dental... Jun 2024The present systematic review explored the involvement of enzymatic and nonenzymatic antioxidants in periodontitis, drawing from established literature. (Meta-Analysis)
Meta-Analysis Review
The assessment of glutathione, glutathione peroxidase, glutathione reductase, and oxidized glutathione in patients with periodontitis-A systematic review and meta-analysis.
OBJECTIVE
The present systematic review explored the involvement of enzymatic and nonenzymatic antioxidants in periodontitis, drawing from established literature.
MATERIALS AND METHODS
The research approach encompassed an extensive electronic search from 2000 to 2023 across databases such as PubMed, Science Direct, and Wiley Online Library and cross-referencing using specific keywords.
RESULTS
The initial literature exploration generated a total of 766 articles. After thoroughly examining the abstracts, 693 articles were excluded from consideration due to duplication and lack of relevance to the central research inquiry. Following that, 73 articles were left for in-depth evaluation. Following a qualitative assessment, 35 studies that satisfied the inclusion criteria were chosen, while 38 were removed for not meeting the necessary standards. Within this selection, a meta-analysis was conducted on 11 articles that provided consistent data for quantitative synthesis. Specifically, the analysis of glutathione (GSH) levels in serum samples revealed a standardized mean difference (SMD) of -5.552 µg/mL (CI 95%: -9.078 to -2.026; P-0.002). In contrast, the analysis of glutathione peroxidase (GPx) enzymes in gingival crevicular fluid (GCF) samples displayed an overall SMD of 2.918 ng/µL (CI 95%: 0.372-5.465; P-0.025), while salivary samples exhibited an overall SMD value of 0.709 U/l (95% CI: -1.907-3.325; P-0.596) which is of insignificant.
CONCLUSION
The systematic review findings suggest a notable decrease in antioxidant enzymes across various systemic biological samples among patients with periodontitis, contrasting with the results from gingival tissue samples meta-analysis of GPx enzyme.
Topics: Humans; Periodontitis; Glutathione Peroxidase; Glutathione; Glutathione Reductase; Glutathione Disulfide; Gingival Crevicular Fluid; Antioxidants
PubMed: 38881240
DOI: 10.1002/cre2.907 -
Alpha Psychiatry Mar 2022Brain's aerobic energy metabolism, abundance of the fatty acids and unsaturated lipids, generation of Reactive Oxygen Species (ROS) by hormones, physiological roles of... (Review)
Review
OBJECTIVE
Brain's aerobic energy metabolism, abundance of the fatty acids and unsaturated lipids, generation of Reactive Oxygen Species (ROS) by hormones, physiological roles of transition metals (i.e., iron and copper), and free radicals in the nervous system may cause inclination to oxidative stress in psychiatric disorders. Electroconvulsive therapy (ECT) may cause oxidative stress by the electrical field or by the induced seizure. It was aimed to review the literature in terms of the influence of ECT on levels of oxidant and antioxidant compounds.
METHODS
The literature search was performed with the keywords that were oxidative stress or "DNA damage" or "RNA damage" or "lipid peroxidase" or "superoxide dismutase" or "catalase" or "glutathione" or "nitrite" or "nitric oxide" and "electroconvulsive therapy" or "electroconvulsive shock" or "electroconvulsive seizure". Twenty of 1480 records were included.
RESULTS
Eleven studies were performed in human subjects, whereas 9 studies were performed in rats. Human studies are conducted with serum, plasma, or urine samples; rat studies include brain tissues from various sites. In rats, four independent studies showed increased levels of lipid oxidation markers, and four independent studies reported increased levels of oxidative stress markers in brain samples. In human studies, studies were performed with circulating blood samples and the results were more inconsistent.
CONCLUSION
Although some markers like superoxide dismutase or thioredoxin imply that ECT may increase the balance for oxidative stress, this notion is not supported by other markers of ECT. The current literature does not clearly suggest that the ECT is associated with oxidative stress in psychiatric disorders. Further studies with similar methods should be performed in big samples.
PubMed: 36426296
DOI: 10.5152/alphapsychiatry.2021.21584 -
Antioxidants (Basel, Switzerland) Oct 2021Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by a state of persistent inflammation and oxidative stress. The presence of... (Review)
Review
Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by a state of persistent inflammation and oxidative stress. The presence of oxidative stress in COPD is the result of an imbalance between pro-oxidant and antioxidant mechanisms. The aim of this review was to investigate a possible association between glutathione peroxidase (GPx), a key component of antioxidant defense mechanisms, and COPD. A systematic search for relevant studies was conducted in the electronic databases PubMed, Web of Science, Scopus, and Google Scholar, from inception to June 2021. Standardized mean differences (SMDs) were used to express the differences in GPx concentrations between COPD patients and non-COPD subjects. Twenty-four studies were identified. In 15 studies assessing whole blood/erythrocytes (GPx isoform 1), the pooled results showed that GPx concentrations were significantly lower in patients with COPD (SMD = -1.91, 95% CI -2.55 to -1.28, < 0.001; moderate certainty of evidence). By contrast, in 10 studies assessing serum/plasma (GPx isoform 3), the pooled results showed that GPx concentrations were not significantly different between the two groups (very low certainty of evidence). The concentration of GPx-1, but not GPx-3, is significantly lower in COPD patients, suggesting an impairment of antioxidant defense mechanisms in this group.
PubMed: 34829616
DOI: 10.3390/antiox10111745 -
Reproductive Biology and Endocrinology... Nov 2020Thyroid autoimmunity (TAI) - the presence of anti-thyroid peroxidase and/or anti-thyroglobulin antibodies - affects 8-14% of reproductively-aged women. It is hotly... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Thyroid autoimmunity (TAI) - the presence of anti-thyroid peroxidase and/or anti-thyroglobulin antibodies - affects 8-14% of reproductively-aged women. It is hotly debated whether TAI adversely affects IVF/ICSI outcomes. This systematic review and meta-analysis evaluated the relationship between thyroid autoimmunity (TAI) and IVF/ICSI outcomes, both overall and amongst euthyroid women of known age using strict criteria for grouping pregnancy outcomes.
METHODS
The review was registered with PROSPERO: CRD42019120947. Searches were undertaken in MEDLINE, EMBASE, Web of Science and Cochrane Database from Inception-March 2020. Primary outcomes were clinical pregnancy rate, clinical miscarriage rate, biochemical pregnancy loss, livebirth rate per-cycle and live birth rate per clinical pregnancy (CP).
RESULTS
14 studies were included in the meta-analysis. Compared with women who tested negative for thyroid autoantibodies (TAI-), there was no significant difference in clinical pregnancy rate overall (OR 0.86; 95%CI [0.70, 1.05]; P = 0.14; 11 studies; I = 29.0%), or in euthyroid women (OR 0.88; 95%CI [0.69, 1.12]; P = 0.29; 10 studies; I = 32.0%). There was also no significant difference in clinical miscarriage rate overall (OR 1.04; 95%CI [0.52, 2.07]; P = 0.908; 8 studies; I = 53%), or in euthyroid women (OR 1.18; 95%CI [0.52, 2.64]; P = 0.69; 7 studies; I = 54%). There was no significant difference in biochemical pregnancy loss (OR 1.14; 95%CI [0.48, 2.72]; P = 0.769; 4 studies; I2 = 0.0%), live birth rate per cycle (OR 0.84; 95%CI [0.67, 1.06]; P = 0.145; I = 1.7%), live birth rate per clinical pregnancy (OR 0.67; 95%CI [0.28, 1.60]; P = 0.369; I = 69.2%), both overall and in euthyroid women as all studies included consisted of euthyroid women only. There was also no significant difference in number of embryos transferred, number of oocytes retrieved, mean maternal age or TSH levels overall or in euthyroid women.
CONCLUSION
The findings of the present study suggest that thyroid autoimmunity has no effect on pregnancy outcomes in euthyroid women alone, or in euthyroid women and women with subclinical hypothyroidism.
Topics: Adult; Autoimmunity; Female; Fertilization in Vitro; Humans; Pregnancy; Pregnancy Outcome; Sperm Injections, Intracytoplasmic; Thyroid Gland; Treatment Outcome
PubMed: 33239046
DOI: 10.1186/s12958-020-00671-3 -
Antioxidants (Basel, Switzerland) Apr 2024Melatonin is an indoleamine with crucial antioxidant properties that are used to combat inflammatory and neoplastic processes, as well as control transplants. However,... (Review)
Review
UNLABELLED
Melatonin is an indoleamine with crucial antioxidant properties that are used to combat inflammatory and neoplastic processes, as well as control transplants. However, the clinical applications of melatonin have not yet been fully consolidated in the literature and require in-depth analysis.
OBJECTIVES
This study reviewed the literature on the antioxidant properties of melatonin in rat models.
METHODS
We followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses and used the PubMed, LILACS, and Cochrane databases, Google Scholar, and article references, irrespective of publication time.
RESULTS
Ten articles involving 485 rats were selected, and the effects of melatonin on antioxidant markers were investigated. Melatonin increased superoxide dismutase in nine studies, glutathione peroxidase in seven studies, and catalase in five studies. In contrast, melatonin reduced glutathione in three studies and malonaldehyde in seven of eight studies.
CONCLUSION
Our findings suggest that melatonin effectively reduces oxidative stress.
PubMed: 38671887
DOI: 10.3390/antiox13040439