Nigella sativa (Black Seed) as a Natural Remedy against Viruses

Unlocking the therapeutic potential of Nigella sativa extract: phytochemical analysis and revealing antimicrobial and antioxidant marvels

The growing global threat of antimicrobial resistance endangers both human and animal life, necessitating the urgent discovery of novel antimicrobial solutions. Medicinal plants hold promise as sources of potential antimicrobial compounds. In this study, we investigated the phytochemical constituents and microbicidal capabilities of the ethanolic extract from Nigella sativa (black seed). Gas chromatography analysis (GC) identified 11 compounds, among them thymoquinone, and thymol, contributing to antimicrobial and antioxidant properties. Antimicrobial assays demonstrated notable inhibition zones against broad spectra of bacteria, including Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Enterobacter, and Bacillus subtilis, along with potent antifungal activity against Aspergillus niger, Penicillium, and Candida albicans. Notably, when combined with antibiotics, the extract displayed exceptional synergistic antimicrobial efficacy. The black seed extract demonstrated membrane-damaging activity and disrupted virulence factors that protect microbes from antimicrobial agents, including the formation of bacterial biofilm and protease secretion. Thymoquinone, the primary active constituent of the extract, exhibited similar antimicrobial and ant virulence properties. In silico analysis targeting key regulators of quorum sensing and biofilm formation in P. aeruginosa, such as RhlG, LasR, and PqsR, showed a remarkable affinity of thymol and thymoquinone for these targets. Moreover, the N. sativa extract exhibited dose-dependent cytotoxicity against both the promastigote and amastigote forms of Leishmania tropica parasites, hinting at potential antiparasitic activity. In addition to its antimicrobial properties, the extract displayed potential antioxidant activity at a concentration of 400 μg/mL.

Exploring the inhibitory potential of Nigella sativa against dengue virus NS2B/NS3 protease and NS5 polymerase using computational approaches

Dengue fever, a highly infectious and rapidly spreading vector borne illness, is classified as a Neglected Tropical Disease (NTD) by WHO because they generally afflict the world's poor and historically have not received as much attention as other diseases. DENV NS2B/NS3 protease and NS5 polymerase are regarded as significant prospective therapeutic targets because of their critical involvement in the viral replication cycle. To date, no specific antiviral agents exist for dengue. The commonly used herbal plant Nigella sativa is known for its antibacterial, antiviral, anti-inflammatory, wound-healing, and dermatological properties. Nevertheless, not enough studies on the antiviral effects of Nigella sativa against DENV are reported. The current study used several prediction techniques to anticipate the oral bioavailability of substances, druglikeness, and non-toxic and non-mutagenic effects which could lead to the development of novel, safer medications. Therefore, the current study was conducted to explore the inhibitory potential of 18 phytochemicals from Nigella sativa against two important enzymes of dengue virus i.e., NS2B/NS3 and NS5. Promising results have been observed for NS2B/NS3 with Taraxerol (-9.1 kcal mol^-1), isoquercetin (8.4 kcal mol^-1), apigenin, and stigmasterol (-8.3 kcal mol^-1). Similarly, NS5 has shown favorable outcomes with apigenin (-9.9 kcal mol^-1), rutin (-9.3 kcal mol^-1), nigellicine (-9.1 kcal mol^-1), and stigmasterol (-8.8 kcal mol^-1). MD simulations validated the structural flexibility of the NS2B/NS3-taraxerol and NS5-apigenin docking complexes based on an RMSF value below 5 Å. The study concluded that among the understudied phytocomponents of N. sativa, apigenin, nigellicine, nigellidine, dithymoquinone, taraxerol, campesterol, cycloeucalenol, stigmasterol and beta-sitosterol have been revealed as potential drug candidates, expected to show antiviral activity and promising drug likeliness. Phytochemicals on the short list may serve as inspiration for the creation of new drugs in the future. Further in vitro examination will assist in elucidating the molecular complexity of therapeutic and antiviral capabilities, opening several opportunities for researchers to identify novel medications throughout the drug development process.

Effects of Active Compounds of Nigella sativa in COVID-19: A Narrative Review

BACKGROUND

SARS-CoV-2 infection that led to the COVID-19 pandemic has changed human health and the economy globally. SARS CoV-2 is a type of Coronaviruses that has caused pneumonia and its complications with many deaths over the past two years. The use of hydroxychloroquine and chloroquine, accepted as generally safe for patients with autoimmune diseases or malaria, was attempted in many trials for COVID-19 treatment. Nigella sativa (NS) (black caraway, also known as black cumin, nigella or Kalonji) is an annual flowering plant of the Ranunculaceae family, chemically composed of the main constituent natural Thymoquinone (TQ) (30%- 48%) in forms of thymohydroquinone, dithymoquinone (Nigellone) is a native to wider regions, including parts of eastern Europe, west Asia, North of Africa and east of Myanmar. In this review, we explored the Randomized Controlled Trial, Controlled Trial, and Systematic review studies that support Nigella sativa Thymoquinone-targeted SARS-CoV-2 targeting. Therefore, A literature search was performed for publications published on the electronic databases (PubMed, Embase, Scopus, CNKI, and Google Scholar) for Nigella sativa, black seeds, Kalonji, coronavirus, SARS-CoV -2 and COVID-19. This review aimed to find relevant evidence of Nigella sativa preferences as a natural feasible remedy with no side effects in COVID-19. Studies reported the benefits of NS as beneficial, another appropriate remedy for patients with COVID-19. However, all studies have shown limitations, such as limiting clinical symptom outcomes due to regulations imposed by isolation policies and lack of adequate funding. Therefore, the evidence suggests that the chemical contents of NS are a safe and possible treatment for COVID-19 patients that helps to improve COVID-19 infection in patients with no side effects.

CONCLUSION

Nigella sativa seeds were one of the well-documented herbal products. Three reviewed randomized controlled trials reported that NS reduced covid-19 risk and could improve immune function. It was also helpful in upper respiratory infections such as asthma and bronchitis, with one RCT showing that honey and NS significantly improved symptoms, viral clearance, and mortality of COVID-19 patients. This review concludes that NS has a positive barrier effect on people at risk of acquiring a COVID-19 infection.

Therapeutic role of traditionally used Indian medicinal plants and spices in combating COVID-19 pandemic situation

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is a big challenge and burning issue to the scientific community and doctors worldwide. Globally, COVID-19 has created a health disaster and adversely affects the economic growth. Although some vaccines have already emerged, no therapeutic medication has yet been approved by FDA for the treatment of COVID-19 patients. Traditionally, we have been using different medicinal plants like neem, tulsi, tea, and many spices like garlic, ginger, turmeric, black seed, onion, etc. for the treatment of flu-like diseases. In this paper, we are highlighting the recent research progress in the identification of natural products from the Indian medicinal plants and spices that have potential inhibition properties against SARS-CoV-2. This study will provide an initiative to stimulate further research by providing useful guidance to the medicinal chemists for designing new protease inhibitors effective against SARS-CoV-2 in future.