Therapeutic effects of Nigella sativa on asthma: a systematic review of clinical trial

Introduction: Nigella sativa (N. sativa) in the family of Ranunculaceae, has been traditionally used as food additive and spice. N. sativa showed protective effects on respiratory system including trachea responsiveness and lung inflammation in various animals’ models studies. The possible therapeutic effects of N. sativa on asthma were investigated in this systematic review study.. Methods: The published studies were searched in the different databases including; PubMed, Web of Science (ISI), Scopus and Cochrane, until September 2020, by: (asthma) AND (“Nigella sativa”) OR (“Nigella sativa oil”) OR (Black seed). All unrelated articles such as duplicates, animal and review studies as well as clinical studies without control group were excluded from obtained studied. Then 9 articles were considered for further evaluation. Results: After analyzing 9 articles including 434 participants, these following results were achieved: N. sativa improved the asthma control test and pulmonary function tests values, while reduced respiratory symptoms including, cough and wheeze. Furthermore, N. sativa, reduced eosinophils count and serum levels of pro-inflammatory mediators such as interleukin-4 and immunoglobulin E, while increased production of anti-inflammatory mediator such as interferon-γ in the serum. Conclusion: The results of this systematic review article revealed that supplementation of N. sativa might be effective in the control or treatment of asthma.