J Herb Med. 2020 Oct;23:100382.
doi: 10.1016/j.hermed.2020.100382. Epub 2020 Jun 24.
An effective vaccine to prevent the SARS-CoV-2 causing COVID-19 is yet to be approved. Further there is no drug that is specific to treat COVID-19. A number of antiviral drugs such as Ribavirin, Remdesivir, Lopinavir/ritonavir, Azithromycin and Doxycycline have been recommended or are being used to treat COVID-19 patients. In addition to these drugs, rationale and evidence have been presented to use chloroquine to treat COVID-19, arguably with certain precautions and criticism. In line with the proposed use of chloroquine, Nigella sativa (black seed) could be considered as a natural substitute that contains a number of bioactive components such as thymoquinone, dithymoquinone, thymohydroquinone, and nigellimine. Further benefits to use N. sativa could be augmented by Zn supplement. Notably, Zn has been proven to improve innate and adaptive immunity in the course of any infection, be it by pathogenic virus or bacteria. The effectiveness of the Zn salt supplement could also be enhanced with N. sativa as its major bioactive component might work as ionophore to allow Zn2+ to enter pneumocytes – the target cell for SARSCoV-2. Given those benefits, this review paper describes how N. sativa in combination with Zn could be useful as a complement to COVID-19 treatment.
Phytother Res. 2020 Nov;34(11):2786-2789.
doi: 10.1002/ptr.6793. Epub 2020 Jul 10.
Phytother Res. 2021 Mar;35(3):1329-1344.
doi: 10.1002/ptr.6895. Epub 2020 Oct 12.
Nigella sativa seed and its active compounds have been historically recognized as an effective herbal panacea that can establish a balanced inflammatory response by suppressing chronic inflammation and promoting healthy immune response. The essential oil and other preparations of N. sativa seed have substantial therapeutic outcomes against immune disturbance, autophagy dysfunction, oxidative stress, ischemia, inflammation, in several COVID-19 comorbidities such as diabetes, cardiovascular disorders, Kawasaki-like diseases, and many bacterial and viral infections. Compelling evidence in the therapeutic efficiency of N. sativa along with the recent computational findings is strongly suggestive of combating emerged COVID-19 pandemic. Also, being an available candidate in nutraceuticals, N. sativa seed oil could be immensely potential and feasible to prevent and cure COVID-19. This review was aimed at revisiting the pharmacological benefits of N. sativa seed and its active metabolites that may constitute a potential basis for developing a novel preventive and therapeutic strategy against COVID-19. Bioactive compounds of N. sativa seed, especially thymiquinone, α-hederin, and nigellidine, could be alternative and promising herbal drugs to combat COVID-19. Preclinical and clinical trials are required to delineate detailed mechanism of N. sativa’s active components and to investigate their efficacy and potency under specific pathophysiological conditions of COVID-19.
Phytomedicine. 2021 May;85:153277.
doi: 10.1016/j.phymed.2020.153277. Epub 2020 Jul 10.
The world is witnessing a difficult time. The race of developing a new coronavirus (COVID-19) vaccine is becoming more urgent. Many preliminary studies on the pathophysiology of COVID-19 patients have provided some clues to treat this pandemic. However, no suitable treatment has found yet. Various symptoms of patients infected with COVID-19 indicated the importance of immune regulation in the human body. Severe cases admitted to the intensive care unit showed high level of pro-inflammatory cytokines which enhanced the disease severity. Acute Respiratory Distress Syndrome (ARDS) in COVID-19 patients is another critical factor of disease severity and mortality. So, Immune modulation is the only way of regulating immune system. Nigella sativa has been used for medicinal purposes for centuries. The components of this plant are known for its intense immune-regulatory, anti-inflammatory, and antioxidant benefits in obstructive respiratory disorders. A molecular docking study also gave evidences that N. sativa decelerates COVID-19 and might give the same or better results than the FDA approved drugs. The aim of this review was to investigate the possible immune-regulatory effects of N. sativa on COVID-19 pandemic. Our review found N. sativa’s Thymoquinone, Nigellidine, and α-hederin can be a potential influencer in reinforcing the immune response on molecular grounds.
J Biomol Struct Dyn. 2021 Jun;39(9):3194-3203.
doi: 10.1080/07391102.2020.1761881. Epub 2020 May 5.
SARS-CoV-2 has been emerged in December 2019 in China, causing deadly (5% mortality) pandemic pneumonia, termed COVID-19. More than one host-cell receptor is reported to be recognized by the viral spike protein, among them is the cell-surface Heat Shock Protein A5 (HSPA5), also termed GRP78 or BiP. Upon viral infection, HSPA5 is upregulated, then translocating to the cell membrane where it is subjected to be recognized by the SARS-CoV-2 spike. In this study, some natural product compounds are tested against the HSPA5 substrate-binding domain β (SBDβ), which reported to be the recognition site for the SARS-CoV-2 spike. Molecular docking and molecular dynamics simulations are used to test some natural compounds binding to HSPA5 SBDβ. The results show high to a moderate binding affinity for the phytoestrogens (Diadiazin, Genistein, Formontein, and Biochanin A), chlorogenic acid, linolenic acid, palmitic acid, caffeic acid, caffeic acid phenethyl ester, hydroxytyrosol, cis-p-Coumaric acid, cinnamaldehyde, thymoquinone, and some physiological hormones such as estrogens, progesterone, testosterone, and cholesterol to the HSPA5 SBDβ. Based on its binding affinities, the phytoestrogens and estrogens are the best in binding HSPA5, hence may interfere with SARS-CoV-2 attachment to the stressed cells. These compounds can be successful as anti-COVID-19 agents for people with a high risk of cell stress like elders, cancer patients, and front-line medical staff.Communicated by Ramaswamy H. Sarma.
Cells. 2021 Feb 2;10(2):302.
Since the beginning of the SARS-CoV-2(severe acute respiratory syndrome-coronavirus-2) pandemic, arace to develop a vaccine has been initiated, considering the massive and rather significant economic and healthcare hits that this virus has caused. The pathophysiology occurring following COVID-19(coronavirus disease-2019) infection has givenhints regarding the supportive and symptomatic treatments to establish for patients, as no specific anti-SARS-CoV-2 is available yet. Patient symptoms vary greatly and range from mild symptoms to severe fatal complications. Supportive treatments include antipyretics, antiviral therapies, different combinations of broad-spectrum antibiotics, hydroxychloroquine and plasma transfusion. Unfortunately, cancer patients are at higher risk of viral infection and more likely to develop serious complications due to their immunocompromised state, the fact that they are already administering multiple medications, as well as combined comorbidity compared to the general population. It may seem impossible to find a drug that possesses both potent antiviral and anticancer effects specifically against COVID-19 infection and its complications and the existing malignancy, respectively. Thymoquinone (TQ) is the most pharmacologically active ingredient in Nigella sativa seeds (black seeds); it is reported to have anticancer, anti-inflammatory and antioxidant effects in various settings. In this review, we will discuss the multiple effects of TQ specifically against COVID-19, its beneficial effects against COVID-19 pathophysiology and multiple-organ complications, its use as an adjuvant for supportive COVID-19 therapy and cancer therapy, and finally, its anticancer effects.
Curr Drug Discov Technol. 2021;18(4):570-573.
Introduction: The COVID-19 caused by a new type of coronavirus has emerged from China and led to thousands of deaths globally. Despite many groups engaged in studying the newly emerged virus and searching for the treatment, the understanding of the SARS-CoV2 target ligand interactions represents a key challenge. Several studies are being conducted to identify potential treatment. Alternatively, the results of numerous studies have shown that protease inhibitors can be a genuine leader in research. The antiviral activity and beneficial effect against respiratory disorders of thymoquinone have been largely demonstrated.
Results: The preliminary results have shown that thymoquinone may have inhibitory activities against SARS CoV2 protease.
Conclusion: Furthermore, given the demonstrated results of thymoquinone, we can conclude that it may be considered as an effective or adjuvant treatment for SARS CoV2 infection.
Drug Res (Stuttg). 2021 Jan;71(1):4-9.
doi: 10.1055/a-1274-1264. Epub 2020 Oct 30.
Drug repositioning is a strategy that identifies new uses of approved drugs to treat conditions different from their original purpose. Current efforts to treat Covid-19 are based on this strategy. The first drugs used in patients infected with SARS-CoV-2 were antimalarial drugs. It is their mechanism of action, i. e., rise in endosomal pH, which recommends them against the new coronavirus. Disregarding their side effects, the study of their antiviral activity provides valuable hints for the choice and design of drugs against SARS-CoV-2. One prominent drug candidate is thymoquinone, an antimalarial substance contained in Nigella sativa – most likely one of the first antimalarial drugs in human history. Since the outbreak of the pandemic, the number of articles relating thymoquinone to Covid-19 continuously increases. Here, we use it as an exemplary model drug, compare its antiviral mechanism with that of conventional antimalarial drugs and establish an irreducible parametric scheme for the identification of drugs with a potential in Covid-19.Translation into the laboratory is simple. Starting with the discovery of Nigella sativa seeds in the tomb of Pharaoh Tutankhamun, we establish a physicochemical model for the interaction of thymoquinone with both coronavirus and cells. Exploiting the predictive capability of the model, we provide a generalizable scheme for the systematic choice and design of drugs for Covid-19. An unexpected offshoot of our research is that Tutankhamun could not have died of malaria, a finding contrary to the mainstream theory.
J Biomol Struct Dyn. 2020 Oct 28;1-13.
doi: 10.1080/07391102.2020.1839560. Online ahead of print.
COVID-19, emerged at the end of 2019 have dramatically threatened the health, economy, and social mobility of people around the world and till date no medication is available for its treatment. An amazing herb, Nigella sativa, having antiviral, antihypertensive, anti- diarrhoeal, analgesics, and anti-bacterial properties, needs to be explored for its efficacy against SARS-CoV-2, the causative agent of COVID-19. In-silico studies were carried out to understand the role of its bioactive constituents in COVID-19 treatment and prevention. Firstly, the disease network was prepared by using ACE2 (Angiotensin-II receptor), as it is the entry site for virus. It was used to decipher the mechanism of SARS-COV-2 infection in humans. Second, the target receptors for N. sativa were predicted and protein interaction studies were conducted. Further, docking studies were also performed to analyse it for treatment purpose as well. This study concludes that pathways undertaken by N. sativa bioactive constituents were similar to the pathways followed in SARS-COV-2 pathology, like renin-angiotensin system, kidney functions, regulation of blood circulation, blood vessel diameter, etc. Also, in docking studies, the constituents of N. sativa, α-hederin, Thymohydroquinone and Thymoquinone were observed to be efficiently binding to ACE2. Also, the bioactive phytoconstituents are involved in molecular pathways like HIF1, VEGF, IL-17, AGE-RAGE, chemokine and calcium signaling pathways which can be majorly helpful in combating hypoxia and inflammation caused due to compromised immune system and oxidative stress. Therefore, N. sativa standardized extract having the above phytoconstituents could be useful in COVID-19 and hence opens a new treatment line.
Drug Des Devel Ther. 2021 May 3;15:1819-1833.
doi: 10.2147/DDDT.S308863. eCollection 2021.
COVID-19 has caused a major global health crisis, as excessive inflammation, oxidation, and exaggerated immune response in some sufferers can lead to a condition known as cytokine storm, which may progress to acute respiratory distress syndrome (ARDs), which can be fatal. So far, few effective drugs have emerged to assist in the treatment of patients with COVID-19, though some herbal medicine candidates may assist in the fight against COVID-19 deaths. Thymoquinone (TQ), the main active ingredient of black seed oil, possesses antioxidant, anti-inflammatory, antiviral, antimicrobial, immunomodulatory and anticoagulant activities. TQ also increases the activity and number of cytokine suppressors, lymphocytes, natural killer cells, and macrophages, and it has demonstrated antiviral potential against a number of viruses, including murine cytomegalovirus, Epstein-Barr virus, hepatitis C virus, human immunodeficiency virus, and other coronaviruses. Recently, TQ has demonstrated notable antiviral activity against a SARSCoV-2 strain isolated from Egyptian patients and, interestingly, molecular docking studies have also shown that TQ could potentially inhibit COVID-19 development through binding to the receptor-binding domain on the spike and envelope proteins of SARS-CoV-2, which may hinder virus entry into the host cell and inhibit its ion channel and pore forming activity. Other studies have shown that TQ may have an inhibitory effect on SARS CoV2 proteases, which could diminish viral replication, and it has also demonstrated good antagonism to angiotensin-converting enzyme 2 receptors, allowing it to interfere with virus uptake into the host cell. Several studies have also noted its potential protective capability against numerous chronic diseases and conditions, including diabetes, hypertension, dyslipidemia, asthma, renal dysfunction and malignancy. TQ has recently been tested in clinical trials for the treatment of several different diseases, and this review thus aims to highlight the potential therapeutic effects of TQ in the context of the COVID-19 pandemic.