Effect of Nigella sativa Supplementation on Oxidative Stress and Antioxidant Parameters: A Meta-Analysis of Randomized Controlled Trials

Abstract

Introduction. Nigella sativa is a commonly used traditional medicine which has been shown to have antioxidant properties. However, its supplementation in patients of clinical trials showed conflicting results. Materials and Method. Relevant articles were searched through PubMed/Medline, SCOPUS, and Google Scholar databases using “Nigella sativa” or “black seed” or “black caraway” or “thymoquinone” and “oxidative stress” or “antioxidant” and “clinical trial” keywords. Randomized, placebo-controlled human interventions using Nigella sativa were included in this study. The methodological quality of studies was assessed using Jadad’s quality scales. Results. Five studies using 293 subjects met the inclusion criteria. The overall quality of all included trials was determined based on the low risk of bias and the high quality of reported information (Jadad score ≥ 3). Meta-analysis of 293 eligible subjects showed that treatment with Nigella sativa improved the superoxide dismutase (SOD) level (48.18; 95% CI 30.29 to 66.08; p<0.01), but there was no significant effect on the malondialdehyde (MDA) level (−5.32; 95% CI −1.19 to 0.128; p=0.114) and total antioxidant capacity (TAC) level (0.219; 95% CI −0.136 to 0.573; p = 0.227). Conclusion. This meta-analysis suggests that Nigella sativa supplementation in humans may benefit as an antioxidant by increasing SOD levels but has no significant effect on the MDA level and TAC level.

The effect of nigella sativa on biomarkers of inflammation and oxidative stress: A systematic review and meta‐analysis of randomized controlled trials

“…Our meta-analysis showed that the intake of NS seeds resulted in a significant increase in TAC and SOD levels, and also in a significant decrease of MDA levels (which is as an indicator of lipid peroxidation). Consistent with our results, a recent meta-analysis by Ardiana et al (2020) showed that NS supplementation was associated with improved SOD levels but had no significant effect on MDA and TAC levels. However, unlike in our paper, that study did not report data on subgroup analyses.…”

“…To the best of our knowledge, there are two recent metaanalyses which have reported the beneficial effects of NS on hs-CRP levels (Tavakoly et al, 2019) and oxidative stress parameters (Ardiana et al, 2020). However, none of these studies comprehensively examined the effects of black seed consumption on biomarkers of inflammation and oxidative stress.…”

Effects of Nigella sativa oil supplementation on selected metabolic parameters and anthropometric indices in patients with coronary artery disease: A randomized, double‐blind, placebo‐controlled clinical trial

“…Nigella sativa (NS) is a herbal medicine used in various studies as an alternative medication alongside their chemical counterparts. Several findings suggest that NS oil, obtained from its seeds, maybe a beneficial dietary supplement in preventing and managing various disorders by exerting antioxidative or anti‐inflammatory effects (Ardiana, Pikir, Santoso, Hermawan, & Al‐Farabi, 2020; Hallajzadeh et al, 2020; Tavakoly et al, 2019). It is also indicated that NS might be a suitable choice in managing most of the metabolic parameters, including glycemic homeostasis, lipid profile (Askari et al, 2019; Daryabeygi‐Khotbehsara, Golzarand, Ghaffari, & Djafarian, 2017; Sahebkar, Beccuti, Simental‐Mendía, Nobili, & Bo, 2016), and blood pressure (BP) (Sahebkar, Soranna, et al, 2016).…”

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

“…TQ treatment has also been shown to reduce oxidative stress markers (superoxide, hydrogen peroxide, and nitric oxide) and attenuate oxidative stress in lipopolysaccharide (LPS)/interferon-gamma (IFNγ) or H 2 O 2 -activated BV-2 microglia by promoting antioxidant enzymes (SOD and CAT), and GSH level, downregulating pro-oxidant genes and upregulating antioxidant genes [ 32 ]. A meta-analysis of five studies using 293 human subjects suggests that black cumin supplementation may have a beneficial role as an antioxidant by improving SOD levels without affecting MDA level and total antioxidant capacity [ 33 ]. With these recent data, it can be concluded that black cumin (in the form of NSO) and its main ingredient TQ have potential antioxidant values that underlie their protective actions against oxidative stress-induced cellular pathology.…”