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 hetero-geneity sources. Meta-regression analysis was used to explore linear relationship between effect size and vari-ables. 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 mu mol/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-alpha (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-alpha and IL-6 using sensitivity analysis. NAC significantly decreased MDA, IL-8, and homocysteine levels. The effects of NAC on amending TNF-alpha and IL-6 levels were significant after sensitivity analysis. No significant change was observed on CRP levels.