Abstract
Considering the different untoward effects of the drugs prescribed for the treatment
of rheumatoid arthritis (RA), there has been an increasing interest in adjuvant therapies
devoid of such unfavorable reactions. Although the beneficial effects of Nigella sativa (N. sativa) on RA have been established, it seems that its mechanisms of action have not still
been reviewed. The present review is designed to evaluate the effects of N. sativa on RA systematically. We searched these electronic databases until April 2019: PubMed,
Scopus, ISI Web of Science, Cochrane Library, Embase, Ovid, ProQuest, and Google scholar.
No restriction was conducted based on language or publication date. We selected all
of the related clinical, animal, and in vitro studies. Review papers, abstracts in conferences, book chapters, and papers regarding
the effects of N. sativa combined with other herbs, as well as articles regarding the effects of N. sativa on other diseases, were excluded. Each article was assessed critically for the possible
risk of bias. Nineteen articles were reviewed. Animal and in vitro investigations supported the favorable effects of N. sativa on clinical, inflammatory, oxidative, and immunologic parameters on RA, whereas results
of limited clinical studies did not illustrate any change or improvement of inflammatory
and oxidative biomarkers in RA. N. sativa could control RA via multiple ways such as decreasing inflammation, inhibiting oxidative
stress, and modulating the immune system. This paper provides persuasive clues to
defend the efficacy of N. sativa in RA and justifies the significance of subsequent clinical trials.
Key words
Nigella sativa
- Ranunculaceae - thymoquinone - rheumatoid arthritis