Potential Implications of Black Seed and its Principal Constituent Thymoquinone in the Treatment of COVID-19 Patients

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of the current pandemic of Coronavirus Disease-2019 (COVID-19). The progression of COVID-19 is related to an excessive host inflammatory immune response to SARS-CoV-2 infection, which is considered a major cause of disease severity and death. Dysregulated immune response produces huge amounts of pro-inflammatory cytokines and chemokines called "cytokine storm". Moreover, the activation of microthrombi formation plays an important role in multiple organ failure. Methods: Keeping into consideration the potent anti-inflammatory activity of black seed and its major constituent Thymoquinone (TQ), we hypothesize their potential implication in the treatment of COVID-19 patients. A literature search was performed in PubMed, ScienceDirect, Google Scholar and Scopus electronic databases using the terms, including black seed, N. sativa, thymoquinone, SARSCoV- 2, COVID-19 and inflammatory immune response. Results: Various studies confirmed that Black seed and TQ reduced the thrombus formation, the expression of tissue factor and the immune activation. Furthermore, TQ demonstrated the broad-spectrum antimicrobial activity that may be effective in controlling the secondary infections in COVID-19 patients. Conclusion: Keeping into consideration the multi-targeting nature of the black seed and TQ, they may be used as a potential therapeutic formulation or as an adjunct therapy in the treatment of COVID-19 patients.