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

Abstract

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 α (TNF‐α), 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.

Nigella sativa and health outcomes: An overview of systematic reviews and meta-analyses

“…Subsequently, 210 records were excluded after screening titles and abstracts. The full texts of 34 records were further evaluated, and 20 records (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) were eventually included in the analysis (Figure 1 shows the flow chart of study selection).…”

“…All meta-analyses were published in peer-reviewed journals between 2016 and 2022. These studies were conducted in seven regions: 13 from Iran ( 28 , 30 , 33 , 34 , 37 – 45 ), two from China ( 32 , 35 ), and one each from Australia ( 26 ), India ( 27 ), United Kingdom ( 29 ), the USA ( 31 ), and Indonesia ( 36 ). The number of RCTs ranged from three to 50, with 187–3,679 subjects.…”

“…Nineteen studies reported doses of N. sativa , ranging from 0.5 to 6 g or 2.5 to 5 ml daily ( 26 – 30 , 32 – 45 ). Five studies reported the frequency of N. sativa administration, which varied between once, twice, and thrice a day ( 29 , 32 – 35 ). The treatment duration ranged from 2 weeks to 1 year.…”

“…Four studies registered protocols on the PROSER platform ( 27 – 29 , 39 ) and one in the Cochrane library ( 31 ). In terms of the risk of bias tools, 10 studies used the Cochrane risk of bias tool ( 26 – 28 , 30 , 31 , 33 , 35 , 39 , 44 , 45 ), nine studies used the Jadad scale ( 32 , 34 , 36 – 38 , 40 – 43 ), and one used the standardized JBI critical appraisal checklist ( 29 ). Table 1 summarizes the basic characteristics of the included meta-analyses.…”

“…Most studies have reported forms of N. sativa, including capsules, oils, and powders. Nineteen studies reported doses of N. sativa, ranging from 0.5 to 6 g or 2.5 to 5 ml daily (26)(27)(28)(29)(30)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45). Five studies reported the frequency of N. sativa administration, which varied between once, twice, and thrice a day (29, [32][33][34][35].…”