The Effects of N-Acetylcysteine on Serum Level of Inflammatory Biomarkers in Adults. Findings From a Systematic Review and Meta-Analysis of Randomized Clinical Trials Publisher Pubmed



Askari M^{1, 2} ; Faryabi R³ ; Mozaffari H⁴ ; Darooghegi Mofrad M^{1, 2}
Source: Cytokine Published:2020

Abstract

Purpose: Randomized Clinical Trials (RCTs) have provided varied and conflicting findings regarding the effect of N-acetylcysteine (NAC) on inflammatory biomarkers. This study was conducted to review existing literature to determine whether NAC supplementation can affect inflammatory biomarkers in adults. Methods: Bibliographic databases of Scopus, and PubMed were used for relevant papers published until October 2019. Results were reported as weighted mean differences (WMD) with 95% confidence intervals (CI) using multi-level models. Cochrane's Q and I-squared (I2) tests were used to determine heterogeneity among studies. Results: Twenty-four RCTs which include 1057 sample size were entered to analysis. NAC doses and intervention duration ranged from 400 to 2000 mg/d, and 1 to 80 weeks, respectively. Oral supplementation of NAC reduced serum level of C-reactive protein (CRP) [WMD: −0.61 mg/L, 95% CI: −1.18 to −0.03, P = 0.039, I2 = 79.6%], and interleukin-6 (IL-6) [WMD: −0.43 pg/mL, 95% CI: −0.69 to −0.17, P = 0.001, I2 = 89.3%]. However, the effect of oral NAC supplementation on other inflammatory biomarkers was nonsignificant. Dose-response investigation showed a non-linear association between oral NAC supplementation with CRP. Conclusion: Oral NAC supplementation reduced serum level of CRP and IL-6, but did not affect other inflammatory biomarkers. Nevertheless, more RCTs seems to be required to explore how NAC in different dosage and different routes of administration can affect inflammatory biomarkers. © 2020 Elsevier Ltd