Effect of Nigella sativa in the treatment of nonalcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials

The effectiveness of Nigella sativa (NS) treatment for nonalcoholic fatty liver disease (NAFLD) remains controversial. This systematic review, and meta-analysis, was conducted to evaluate potential benefits of NS for NAFLD. Up to June 11, 2020, randomized controlled trials (RCTs) evaluating NS for the treatment of NAFLD were searched and included from PubMed, Embase, Cochrane Library, and Web of science. Mean differences (MD) or risk ratio (RR) and 95% confidence intervals (CI) were calculated. Six articles from five trails with a total of 358 participants were included. Although NS has no beneficial effect on the levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL), triglyceride (TG), insulin, and tumor necrosis factor alpha (TNF-alpha), its supplementation did improve the levels of alanine transaminase (ALT), aspartate transaminase (AST), fasting blood sugar (FBS), high-density lipoprotein cholesterol (HDL), high-sensitivity C reactive protein (hs-CRP), and grade of fatty liver compared with placebo. In summary, this study showed that NS supplementation was effective in the treatment of NAFLD and could improve the levels of ALT, AST, FBS, HDL, and hs-CRP in patients with NAFLD, as well as the severity of NAFLD. High-quality large sample RCTs are necessary to confirm the benefit of NS supplementation for NAFLD.