Nigella sativa L as a potential phytotherapy for coronavirus disease 2019: A mini review of in silico studies

BACKGROUND: Coronaviruses are responsible for several human diseases, such as the infectious novel coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nigella sativa is a natural food supplement with a known safety profile that may provide a wealth of documented antiviral compounds. OBJECTIVE: To explore the studies supporting the N sativa potential for hitting SARS-CoV-2 targets. METHODS: A literature search for published or preprint in silico studies between 1990 and 2020 in electronic databases (PubMed, Science Direct, Scopus, and Google Scholar) was performed for the terms Nigella sativa, black seed, coronavirus, SARS-CoV-2, and COVID-19. RESULTS: At least 8 in silico studies have shown that some compounds of N sativa, including nigelledine, α-hederin, hederagenin, thymohydroquinone, and thymoquinone, had high to moderate affinity with SARS-CoV-2 enzymes and proteins. These compounds may potentially inhibit SARS-CoV-2 replication and attachment to host cell receptors. CONCLUSIONS: These preliminary data of in silico studies propose N sativa as a potential phytotherapy candidate for COVID-19. Further preclinical experimental evidence is required followed by a Phase I clinical trial. (Curr Ther Res Clin Exp. 2020; 81:XXX–XXX)