Endothelial Function Responses to Nigella sativa (Black Seed) Supplementation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

(NS), commonly known as black cumin or black seed, is a medicinal plant with a rich history of traditional use in various cultures. Recent research has shed light on its potential therapeutic properties, particularly its effects on endothelial markers involved in inflammatory processes. This systematic review and meta-analysis evaluated the endothelial function responses, including intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), to NS supplementation. We systematically searched Medline via PubMed, Scopus, Web of Science, and Embase databases from inception until August 5, 2023. Comparative randomized controlled trials (RCTs) were included. Pairwise meta-analysis was conducted using RevMan version 5.4 for Windows. Pooled data were reported as mean difference (MD), with their 95% confidence interval (CI). The present meta-analysis included three RCTs, which included 146 patients. The pooled random-effect size showed no difference between the NS group and the control group in terms of ICAM (MD = -59.32, 95% CI: -137.18 to 18.54; p = 0.14) and VCAM (MD = -200.1, 95% CI: -429.9 to 29.69; p = 0.09). The pooled data were severely heterogeneous. In conclusion, NS supplementation does not have a significant impact on the endothelial function of patients with CVD or the risks of CVD. Further comparative RCTs with larger sample sizes and more diverse populations are needed to establish the efficacy and safety of NS in different clinical settings.