The effects of Nigella sativa on respiratory, allergic and immunologic disorders, evidence from experimental and clinical studies, a comprehensive and updated review.

Nigella sativa (N. sativa) seed had been used traditionally due to several pharmacological effects. The updated experimental and clinical effects of N. sativa and its constituents on respiratory, allergic and immunologic disorders are provided in this comprehensive review article. Various databases including PubMed, Science Direct and Scopus were used. The preventive effects of N. sativa on pulmonary diseases were mainly due to its constituents such as thymoquinone, thymol, carvacrol and alpha-hederin. Extracts and constituents of N. sativa showed the relaxant effect, with possible mechanisms indicating its bronchodilatory effect in obstructive pulmonary diseases. In experimental animal models of different respiratory diseases, the preventive effect of various extracts and constituents of N. sativa was demonstrated by mechanisms such as antioxidant, immunomodulatory and antiinflammatory effects. Bronchodilatory and preventive effects of the plant and its components on asthma, COPD and lung disorders due to exposure to noxious agents as well as on allergic and immunologic disorders were also shown in the clinical studies. Various extracts and constituents of N. sativa showed pharmacological and therapeutic effects on respiratory, allergic and immunologic disorders indicating possible remedy effect of that the plant and its effective substances in treating respiratory, allergic and immunologic diseases.