The effects of N-acetylcysteine on inflammatory and oxidative stress biomarkers: A systematic review and meta-analysis of controlled clinical trials.

Prolonged inflammation could be considered as the leading cause of chronic diseases such as cardiovascular disorders, type two diabetes, and obesity. N-acetylcysteine (NAC) is considered an antioxidant. The present meta-analysis aims to determine the efficacy of NAC in alleviating inflammation and oxidative stress. PubMed-Medline, SCOPUS, Web of Science and Embase databases and Google Scholar were searched up to Nov 2019. Random effect analysis was used to perform meta-analysis. Subgroup analyses were carried out to find heterogeneity sources. Meta-regression analysis was used to explore linear relationship between effect size and variables. Trim and fill analysis were performed in case of the presence of publication bias. Quality assessment was performed using Cochrane Collaboration's tool. A total of 28 studies were included in meta-analysis. NAC significantly decreased malondialdehyde (MDA) (SMD = -1.44 μmol/L; 95% CI: -2.05, -0.84; P < 0.001), IL-8 (WMD = -2.56 pg/ml; 95% CI: -3.89, -1.23; P < 0.001) and homocysteine (WMD = -1.45 pg/ml; 95% CI: -2.74, -0.17; P = 0.027) levels. There were no significant effects of NAC supplementation on CRP (SMD = -0.1 g/L; 95% CI: -0.52, 0.32; P = 0.647), TNF- α (WMD = -0.2 pg/ml; 95% CI: -0.65, 0.25; P = 0.378) and IL-6 (WMD = -0.41 pg/ml; 95% CI: -1.15, 0.32; P = 0.270) levels. However, NAC effects were significant in ameliorating TNF-α and IL-6 using sensitivity analysis. NAC significantly decreased MDA, IL-8, and homocysteine levels. The effects of NAC on amending TNF-α and IL-6 levels were significant after sensitivity analysis. No significant change was observed on CRP levels.

Faghfouri AH ，Zarezadeh M ，Tavakoli-Rouzbehani OM ，Radkhah N ，Faghfuri E ，Kord-Varkaneh H ，Tan SC ，Ostadrahimi A ... -  《-》

Impact of Cinnamon Supplementation on cardiometabolic Biomarkers of Inflammation and Oxidative Stress: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

To date, cinnamon supplementation has been investigated due to its antioxidant and anti-inflammatory properties. Several studies have confirmed the effects of cinnamon supplementation on several markers of cardiometabolic health. However, the effects of cinnamon supplementation on inflammation and oxidative stress levels warrant further investigation. Hence, the current meta-analysis was conducted to elucidate the impact of cinnamon supplementation on biomarkers of inflammation and oxidative stress. To perform this systematic review and meta-analysis, we employed the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The systematic search of available clinical trials was performed using the following databases: PubMed/MEDLINE, Scopus, Cochrane Library, Web of Science, Embase, and Google Scholar, up to January 2020. After removing the duplicates, 1145 studies were eligible for analysis and 12 of them were included in the meta-analysis. The dose of cinnamon powder investigated in the included trials ranged from 1.5 to 4 g/day. Cinnamon supplementation resulted in a significant reduction of C-reactive protein (CRP) (weight mean difference (WMD): -2.22 mg/L, 95 % CI: -3.74, -0.69, P = 0.004) and malondialdehyde (MDA) (WMD: -0.79 mmol/L, 95 % CI: -1.28, -0.29, P = 0.002), and marginally statistical significant decrease in interleukin-6 (IL-6) (WMD: -1.48 pg/mL, 95 % CI: -2.96, -0.01, P = 0.049). Moreover, it was associated with an increase in the total antioxidant capacity (TAC) (WMD: 0.34 mmol/L, 95 % CI: 0.04, 0.64, P = 0.026). However, the levels of intercellular adhesion molecule-1 (ICAM-1) (WMD: 1.53 ng/mL, 95 % CI: -12.03, 15.10, P = 0.82) did not change significantly following cinnamon supplementation. Cinnamon supplementation may be an adjuvant for reducing inflammation and oxidative stress levels in humans.

Zhu C ，Yan H ，Zheng Y ，Santos HO ，Macit MS ，Zhao K ... -  《-》

Spirulina supplementation and oxidative stress and pro-inflammatory biomarkers: A systematic review and meta-analysis of controlled clinical trials.

Studies investigating the effects of spirulina on inflammation and oxidative stress status are controversial. Therefore, the current systematic review and meta-analysis aimed to evaluate the impacts of spirulina supplementation on oxidative stress indicators and inflammatory markers. PubMed-Medline, SCOPUS, Web of Science, Embase databases and Google Scholar were searched up to 1 October 2020. Random-effect analysis was applied to perform meta-analysis. Subgroup analyses and multivariate meta-regression were performed to find heterogeneity sources. Quality assessment was conducted using Cochrane Collaboration's tool. A total of 11 studies that enrolled 465 subjects were included in our meta-analysis. Pooled results demonstrated a significant increase in interleukin-2 (IL-2) concentrations [Standardized mean difference (SMD = 2.69 pg/mL; 95% CI: 0.26, 5.11; P = .03)]; however this result changed to insignificant (SMD = 0.54 pg/mL; 95% CI: -1.29, 2.27; P > .05) when sensitivity analysis performed. A marginal decreasing effect were also found on interleukin-6 (IL-6) (SMD = -0.72 mg/dL; 95% CI: -1.50, 0.07; P = .073) and thiobarbituric acid reactive substances (TBARS) levels (SMD = -0.65; 95% CI: -1.37, 0.08; P = .08). In addition, results of subgroup analysis revealed a significant reduction in IL-6 and TBARS concentrations when the baseline body mass index (BMI) of participants was lower than 25 kg/m2 . Moreover, spirulina had no significant effect on tumour necrosis factor-α (TNF-α) (SMD = -0.07 mg/dL; 95% CI: -0.33, 0.18; P = .56) and malondialdehyde (MDA) concentrations (SMD = -0.42; 95% CI: -0.98, 0.14; P = .14). Spirulina consumption contributed to a significant increase in IL-2 concentrations changing to insignificant after sensitivity analysis and marginal decreasing effects on IL-6 and TBARS levels. No considerable impacts were observed on TNF-α and MDA concentrations.

Mohiti S ，Zarezadeh M ，Naeini F ，Tutunchi H ，Ostadrahimi A ，Ghoreishi Z ，Ebrahimi Mamaghani M ... -  《-》

Antioxidant and anti-inflammatory effects of curcumin/turmeric supplementation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Turmeric and its prominent bioactive compound, curcumin, have been the subject of many investigations with regard to their impact on inflammatory and oxidative balance in the body. In this systematic review and meta-analysis, we summarized the existing literature on randomized controlled trials (RCTs) which examined this hypothesis. Major databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were searched from inception up to October 2022. Relevant studies meeting our eligibility criteria were obtained. Main outcomes included inflammatory markers (i.e. C-reactive protein(CRP), tumour necrosis factorα(TNF-α), interleukin-6(IL-6), and interleukin 1 beta(IL-1β)) and markers of oxidative stress (i.e. total antioxidant capacity (TAC), malondialdehyde(MDA), and superoxide dismutase (SOD) activity). Weighted mean differences (WMDs) were reported. P-values < 0.05 were considered significant. Sixty-six RCTs were included in the final analysis. We observed that turmeric/curcumin supplementation significantly reduces levels of inflammatory markers, including CRP (WMD: -0.58 mg/l, 95 % CI: -0.74, -0.41), TNF-α (WMD: -3.48 pg/ml, 95 % CI: -4.38, -2.58), and IL-6 (WMD: -1.31 pg/ml, 95 % CI: -1.58, -0.67); except for IL-1β (WMD: -0.46 pg/ml, 95 % CI: -1.18, 0.27) for which no significant change was found. Also, turmeric/curcumin supplementation significantly improved anti-oxidant activity through enhancing TAC (WMD = 0.21 mmol/l; 95 % CI: 0.08, 0.33), reducing MDA levels (WMD = -0.33 µmol /l; 95 % CI: -0.53, -0.12), and SOD activity (WMD = 20.51 u/l; 95 % CI: 7.35, 33.67). It seems that turmeric/curcumin supplementation might be used as a viable intervention for improving inflammatory/oxidative status of individuals.

Dehzad MJ ，Ghalandari H ，Nouri M ，Askarpour M ... -  《-》

Effects of dairy products consumption on inflammatory biomarkers among adults: A systematic review and meta-analysis of randomized controlled trials.

This study aimed to summarize earlier studies on the effects of dairy consumption on inflammatory biomarkers in adults and to quantify these effects through meta-analysis. A comprehensive search of all relevant articles, published up to December 2019 indexed in PubMed, ISI (Institute for Scientific Information), EmBase, Scopus, and Google Scholar was done using relevant keywords. Randomized controlled trials (RCTs) that examined the effect of dairy products consumption, compared with low or no dairy intake, on inflammatory biomarkers in adults were included. Overall, 11 RCTs with 663 participants were included in this meta-analysis. We found that high consumption of dairy products, compared with low or no dairy intake, might significantly reduce CRP [weighed mean difference (WMD): -0.24 mg/L; 95% CI, -0.35, -0.14], TNF-α (WMD:- 0.66 pg/mL; 95% CI, -1.23, -0.09), IL-6 (WMD: -0.74 pg/mL; 95% CI, -1.36, -0.12), and MCP concentrations (WMD: -25.58 pg/mL; 95% CI, -50.31, -0.86). However, when the analyses were confined to cross-over trials, no such beneficial effects of dairy intake on inflammation were observed. In addition, high dairy intake might result in increased adiponectin levels (WMD: 2.42 μg/mL; 95% CI, 0.17, 4.66). No significant effect of dairy consumption on serum leptin (WMD: -0.32 ng/mL; 95% CI, -3.30, 2.65), ICAM-1 (WMD: -3.38 ng/ml; 95% CI, -15.57, 8.96) and VCAM-1 (WMD: 3.1 ng/mL; 95% CI, -21.38, 27.58) levels was observed. In summary, the current meta-analysis indicated that dairy intake might improve several inflammatory biomarkers in adults. In most subgroups without heterogeneity, effects tended to be null. Study design and participants' age were the main sources of heterogeneity. More research, with a particular focus on fat content of dairy foods, is recommended.

Moosavian SP ，Rahimlou M ，Saneei P ，Esmaillzadeh A ... -  《-》