SELECTIVE INHIBITION OF HEPATITIS C VIRUS REPLICATION BY ALPHA-ZAM, A NIGELLA SATIVA SEED FORMULATION

Campesterol and dithymoquinone as a potent inhibitors of SARS cov-2 main proteases-promising drug candidates for targeting its novel variants

The sudden outbreak of the COVID-19 pandemic has currently taken approximately 2.4 million lives, with no specific medication and fast-tracked tested vaccines for prevention. These vaccines have their own adverse effects, which have severely affected the global healthcare system. The discovery of the main protease structure of coronavirus (Mpro/Clpro) has resulted in the identification of compounds having antiviral potential, especially from the herbal system. In this study, the computer-associated drug design tools were utilised to analyze the reported phytoconstituents of Nigella sativa for their antiviral activity against the main protease. Fifty-eight compounds were subjected to pharmacological parameter analysis to determine their lead likeness in comparison to the standard drugs (chloroquine and nirmatrelvir) used in the treatment of SARS-CoV-2. Nearly 31 compounds were docked against five different SARS-CoV-2 main proteases, and all compounds showed better binding affinity and inhibition constant against the proteases. However, dithymoquinone and campesterol displayed the best binding scores and hence were further subjected to dynamics and MMPBSA study for 100 ns. The stability analysis shows that dithymoquinone and campesterol show less variation in fluctuation in residues compared to standard complexes. Moreover, dithymoquinone exhibited higher binding affinity and favorable interaction followed by campesterol as compared to the standard drug. The in silico computational analysis provides a promising hit for regulating the main proteases activity.

Potential Pharmacological Applications of Nigella Seeds with a Focus on Nigella sativa and Its Constituents against Chronic Inflammatory Diseases: Progress and Future Opportunities

The leading cause of death worldwide has been identified as chronic illnesses, according to the World Health Organization (WHO). Chronic inflammatory conditions such as asthma, cancer, diabetes, heart disease, and obesity account for three out of every five deaths. Although many people benefit from using nonsteroidal anti-inflammatory medicines (NSAIDs) for pain and inflammation relief, there are significant adverse effects to using these medications. Medicinal plants possess anti-inflammatory properties with minimal or no side effects. Nigella sativa (NS), also known as black cumin, is one of the plants used in traditional medicine the most. Many studies on the NS have shown that their therapeutic properties are attributed to the seed, oil, and secondary metabolites. This plant has been studied extensively and has many medical uses, such as anti-inflammatory. NS or its phytochemical compounds, such as thymoquinone, can cause cell apoptosis via oxidative stress, block efflux pumps, enhance membrane permeability, and exert potent biocidal effects. Notwithstanding the extensively documented anti-inflammatory effectiveness observed in the experimental model, the precise mechanisms underlying its anti-inflammatory effects in diverse chronic inflammatory diseases and its multi-targeting characteristics remain largely unexplored. This review examines NS or its secondary metabolites, a valuable source for the therapeutic development of chronic inflammatory diseases. Most clinical studies were done for diabetes and cardiovascular disease; therefore, more studies are required to examine the NS extracts and phytoconstituents to treat cancer, obesity, diabetes, asthma, neurological disorders, and COVID-19. This study will be a significant resource for clinicians and biologists seeking a pharmaceutical solution for inflammatory diseases.

Natural Products as a Potential Source of Promising Therapeutics for COVID-19 and Viral Diseases

Background

A global pandemic has recently been observed due to the new coronavirus disease, caused by SARS-CoV-2. Since there are currently no antiviral medicines to combat the highly contagious and lethal COVID-19 infection, identifying natural sources that can either be viricidal or boost the immune system and aid in the fight against the disease can be an essential therapeutic support.

Methods

This review was conducted based on published papers related to the herbal therapy of COVID-19 by search on databases including PubMed and Scopus with herbal, COVID-19, SARS-CoV-2, and therapy keywords.

Results

To combat this condition, people may benefit from the therapeutic properties of medicinal plants, such as increasing their immune system or providing an antiviral impact. As a result, SARS-CoV-2 infection death rates can be reduced. Various traditional medicinal plants and their bioactive components, such as COVID-19, are summarized in this article to assist in gathering and debating techniques for combating microbial diseases in general and boosting our immune system in particular.

Conclusion

The immune system benefits from natural products and many of these play a role in activating antibody creation, maturation of immune cells, and stimulation of innate and adaptive immune responses. The lack of particular antivirals for SARS-CoV-2 means that apitherapy might be a viable option for reducing the hazards associated with COVID-19 in the absence of specific antivirals.

COVID-19 and Thymoquinone: Clinical Benefits, Cure, and Challenges

In today’s world, the outbreak of the coronavirus disease 2019 (COVID-19) has spread throughout the world, causing severe acute respiratory syndrome (SARS) and several associated complications in various organs (heart, liver, kidney, and gastrointestinal tract), as well as significant multiple organ dysfunction, shock, and even death. In order to overcome the serious complications associated with this pandemic virus and to prevent SARS-CoV-2 entry into the host cell, it is necessary to repurpose currently available drugs with a broad medicinal application as soon as they become available. There are several therapeutics under investigation for improving the overall prognosis of COVID-19 patients, but none of them has demonstrated clinical efficacy to date, which is disappointing. It is in this pattern that Nigella sativa seeds manifest their extensive therapeutic effects, which have been reported to be particularly effective in the treatment of skin diseases, jaundice, and gastrointestinal problems. One important component of these seeds is thymoquinone (TQ), which has a wide range of beneficial properties, including antioxidant and anti-inflammatory properties, as well as antibacterial and parasitic properties, in addition to anticarcinogenic, antiallergic, and antiviral properties. This comprehensive review discussed the possibility of an emerging natural drug with a wide range of medical applications; the use of TQ to overcome the complications of COVID-19 infection; and the challenges that are impeding the commercialization of this promising phytochemical compound. TQ is recommended as a highly effective weapon in the fight against the novel coronavirus because of its dual antiviral action, in addition to its capacity to lessen the possibility of SARS-CoV-2 penetration into cells. However, future clinical trials are required to confirm the role of TQ in overcoming the complications of COVID-19 infection.

The Effect of Short Treatment with Nigella Sativa on Symptoms, the Cluster of Differentiation (CD) Profile, and Inflammatory Markers in Mild COVID-19 Patients: A Randomized, Double-Blind Controlled Trial

The current study investigated the impact of different doses of Nigella sativa seeds on the symptoms, the cluster of differentiation profile group, and inflammatory markers of mild COVID-19 cases.

METHODS

The study was a double-blind placebo-controlled clinical trial. Patients with mild and asymptomatic SARS-CoV-2 infection patients were randomly subdivided into seven subgroups: Group (GP) 1: received charcoal capsules as a control group, and GP 2: received three capsules of whole Nigella sativa seeds daily, two capsules in the morning and one in the evening; GP 3: received three capsules of whole Nigella sativa seeds every 12 h, GP 4: received five capsules in the morning and four capsules of whole Nigella sativa seeds in the evening, GP 5: received one capsule of Nigella sativa powder every 12 h; GP 6: received two capsules of Nigella sativa powder every 12 h; GP 7: received three capsules of Nigella sativa powder every 12 h; all treatment course was for ten days. Inflammatory parameters were assessed before and after interventions.

RESULTS

262 subjects were included in the final analysis. No significant difference was detected regarding age, gender, and nationality. No significant differences were detected between the inflammatory marker in all groups. The WBCs showed a significant difference between before and after the intervention. While for procalcitonin, a significant difference was demonstrated in groups 1,4, and 6.

CONCLUSIONS

The current randomized clinical trial did not reveal a significant effect of ten days of treatment with various doses of Nigella sativa on symptoms, differentiation profile, and inflammatory markers of patients with COVID-19. As a natural product, the effect of Nigella sativa on disease requires weeks to manifest itself.

Antiviral effects of black seeds: Effect on COVID-19

Due to the lack of prophylactic vaccines and effective treatment strategies against numerous public health conditions, viral infections remain a serious threat to global public health and socioeconomic development. The current ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, against which there is no prophylactic vaccine or licensed antiviral agents, underscores the need to continuously identify novel/effective treatment strategies against these infectious agents. Plants and plant-derived compounds have immensely contributed to the fight against numerous health conditions by providing bioactives that possess potent antimicrobial attributes, including antiviral activities. One such plant that has gathered much interest, due to its multiple medicinal properties, is the Nigella sativa plant, a flowering plant belonging to the family Ranunculacea, which is native to various regions of the world. In this chapter, we discuss the antiviral activities of N. sativa against critical viral pathogens, focusing more on the SARS-CoV-2 virus, the etiologic agent of the current unparalleled coronavirus disease (COVID-19) pandemic.

The Bioactivity and Phytochemicals of Pachyrhizus erosus (L.) Urb.: A Multifunctional Underutilized Crop Plant

Pachyrhizus erosus (L.) Urb. is an underutilized crop plant belonging to the Fabaceae family. In recent years, the plant received huge attention and was introduced in different countries owing to properties such as a high nutritional content, its nitrogen-fixing abilities, and different biological activities such as its antioxidant, immune modulation, anticancer, anti-diabetes, anti-osteoporosis, antiviral, and antiaging affects, among others. In this review, an attempt has been made to comprehensively compile the biological activities of the plant to provide a panoramic view of the current efforts and further directions, which may lead to the development of pharmacological applications. This information will be helpful in creating interest towards P. erosus and it may be useful in developing the plant for medical applications and/or as a functional food. More than 50 phytochemicals have been reported from the plant, which belong to different chemical classes such as triterpenoids, organic acid, flavonoids, and fatty acids. Numerous biological activities were reported from the plant through in vivo, in vitro, ex vivo, and human studies. However, well-defined clinical studies are still lacking for the establishment of any biological properties that could be further developed. Suggestions for the further development of P. erosus, according to current knowledge about the different biological properties, has also been provided.

Identifying the Most Potent Dual-Targeting Compound(s) against 3CLprotease and NSP15exonuclease of SARS-CoV-2 from Nigella sativa: Virtual Screening via Physicochemical Properties, Docking and Dynamic Simulation Analysis

Background: The outbreak of the coronavirus (SARS-CoV-2) has drastically affected the human population and caused enormous economic deprivation. It belongs to the β-coronavirus family and causes various problems such as acute respiratory distress syndrome and has resulted in a global pandemic. Though various medications have been under trial for combating COVID-19, specific medicine for treating COVID-19 is unavailable. Thus, the current situation urgently requires effective treatment modalities. Nigella sativa, a natural herb with reported antiviral activity and various pharmacological properties, has been selected in the present study to identify a therapeutic possibility for treating COVID-19. Methods: The present work aimed to virtually screen the bioactive compounds of N. sativa based on the physicochemical properties and docking approach against two SARS-CoV-2 enzymes responsible for crucial functions: 3CLpro (Main protease) and NSP15 (Nonstructural protein 15 or exonuclease). However, simulation trajectory analyses for 100 ns were accomplished by using the YASARA STRUCTURE tool based on the AMBER14 force field with 400 snapshots every 250 ps. RMSD and RMSF plots were successfully obtained for each target. Results: The results of molecular docking have shown higher binding energy of dithymoquinone (DTQ), a compound of N. sativa against 3CLpro and Nsp15, i.e., −8.56 kcal/mol and −8.31 kcal/mol, respectively. Further, the dynamic simulation has shown good stability of DTQ against both the targeted enzymes. In addition, physicochemical evaluation and toxicity assessment also revealed that DTQ obeyed the Lipinski rule and did not have any toxic side effects. Importantly, DTQ was much better in every aspect among the 13 N. sativa compounds and 2 control compounds tested. Conclusions: The results predicted that DTQ is a potent therapeutic molecule that could dual-target both 3CLpro and NSP15 for anti-COVID therapy.

Identification of SARS-CoV-2 RNA-dependent RNA polymerase inhibitors from the major phytochemicals of Nigella sativa: An in silico approach

The coronavirus disease 2019 (COVID-19), which emerged in December 2019, continues to be a serious health concern worldwide. There is an urgent need to develop effective drugs and vaccines to control the spread of this disease. In the current study, the main phytochemical compounds of Nigella sativa were screened for their binding affinity for the active site of the RNA-dependent RNA polymerase (RdRp) enzyme of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The binding affinity was investigated using molecular docking methods, and the interaction of phytochemicals with the RdRp active site was analyzed and visualized using suitable software. Out of the nine phytochemicals of N. sativa screened in this study, a significant docking score was observed for four compounds, namely α-hederin, dithymoquinone, nigellicine, and nigellidine. Based on the findings of our study, we report that α-hederin, which was found to possess the lowest binding energy (–8.6 kcal/mol) and hence the best binding affinity, is the best inhibitor of RdRp of SARS-CoV-2, among all the compounds screened here. Our results prove that the top four potential phytochemical molecules of N. sativa, especially α-hederin, could be considered for ongoing drug development strategies against SARS-CoV-2. However, further in vitro and in vivo testing are required to confirm the findings of this study.

Nigella sativa for the treatment of COVID-19: An open-label randomized controlled clinical trial

BACKGROUND

Effective treatment for Coronavirus Disease-2019 (COVID-19) is under intensive research. Nigella sativa oil (NSO) is a herbal medicine with antiviral and immunomodulatory activities, and has been recommended for the treatment of COVID-19. This study aimed to evaluate the efficacy of NSO treatment in patients with COVID-19.

METHODS

All adult patients with mild COVID-19 symptoms presented to King Abdulaziz University Hospital, Jeddah, Saudi Arabia, were recruited for an open label randomized clinical trial (RCT). They were randomly divided into control or treatment groups, with the latter receiving 500 mg NSO (MARNYS® Cuminmar) twice daily for 10 days. Symptoms were daily monitored via telecommunication. The primary outcome focused on the percentage of patients who recovered (symptom-free for 3 days) within 14-days. The trial was registered at clinicaltrials.gov (NCT04401202).

RESULTS

A total of 173 patients were enrolled for RCT. The average age was 36(±11) years, and 53 % of patients were males. The control and NSO groups included 87 and 86 patients respectively. The percentage of recovered patients in NSO group (54[62 %]) was significantly higher than that in the control group (31[36 %]; p = 0.001). The mean duration to recovery was also shorter for patients receiving NSO (10.7 ± 3.2 days) compared with the control group (12.3 ± 2.8 days); p = 0.001.

CONCLUSIONS

NSO supplementation was associated with faster recovery of symptoms than usual care alone for patients with mild COVID-19 infection. These potential therapeutic benefits require further exploration with placebo-controlled, double-blinded studies.

In Silico Investigation of the SARS CoV2 Protease with Thymoquinone, the Major Constituent of Nigella Sativa

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.

AIM

The aim of this study is to evaluate in silico the inhibition of the replication of SARS CoV2 by thymoquinone.

METHODS

This is a molecular simulation study using SARS CoV2 protease and thymoquinone structures provided by Protein Data Bank.

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.

Thymoquinone: A Promising Natural Compound with Potential Benefits for COVID-19 Prevention and Cure

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.

Combating COVID-19: The role of drug repurposing and medicinal plants

BACKGROUND

A novel corona virus-2 disease has spread to 213 countries and territories across the globe. The corona pandemic has claimed more than 548,934 deaths worldwide till the evening of 8th of July 2020 and the number of confirmed cases is increasing at an alarming rate. Therefore, there is an urgent need to find a treatment or a vaccine for COVID-19 at the earliest. The aim of this mini-review is to give an overview of identified repurposed anti-COVID-19 drugs which are currently under clinical trials.

METHODS

A thorough literature survey was done to retrieve relevant information using various web based search engines such as Google, Google scholar, and various other electronic research databases such as PubMed, Medline, MeSh etc. The findings of the recently published articles, clinical trials, COVID-19 update by World Health Organization etc., and the opinion of the authors is summarized in this brief review. The antiviral medicinal plants were identified based on their use in Chinese/Indian indigenous systems of medicine, traditional use, published scientific phytochemical studies and/or their effectiveness against upper respiratory infections, severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS).

RESULTS

The disease is just over six months old and effective prophylactic or therapeutic agents are yet to be developed for COVID-19. Thus, in the absence of an effective therapy, scientific community has rationally considered the drug repurposing approach for the development of anti COVID-19 drugs. Various studies and clinical trials involving antimalarial drugs, anti-HIV drugs, anti-hepatitis drugs, anti-parasitic drug, anti-inflammatory drugs, the combination of antimalarial and macrolide antibiotic and few other molecules identified through drug repurposing are currently underway to combat COVID-19. Due emphasis is also given to develop novel corona vaccines for the prophylaxis and to identify drugs for adjunct/supportive therapy. Several medicinal plants along with their major phytochemicals exhibiting antiviral activity are identified for further exploration. It is anticipated that these natural products might also play an important role in combating COVID-19.

CONCLUSIONS

Use of drug repurposing strategy to develop anti COVID-19 drugs and exploring antiviral medicinal plants as adjunct or supportive therapy appears to be a viable option. Therefore, it is the need of the hour to work in parallel on different strategies such as genetic engineering, in silico approach, herbal remedies and drug repositioning to achieve the common goal of finding a safe and effective treatment for COVID-19 at the earliest.

Positive Therapeutic Role of Selected Foods and Plant on Ailments with a Trend Towards COVID-19: A Review

Each day since December 2019, increasing numbers of cases of the novel coronavirus 2019 (COVID-19) infection are being detected as it spreads throughout all continents of the world except Antarctica. The virus is transmitted through contact with an infected environment or person, and the symptoms include fever, cough, and difficulty breathing. The healthcare systems of many countries are overwhelmed due to limited therapeutic options and the absence of an approved vaccine. Due to its poor healthcare systems, Africa may be the worst hit continent if other therapeutic alternatives are not explored. This review explores the source and origin of the COVID-19 infection, and alternative therapeutic options derived from available and cheap medicinal foods and plants that have been shown to alleviate similar infections. The results demonstrate the inhibitory activities of selected food crops and plants against human viruses similar to the novel COVID-19.

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

The currently available antiviral agents are associated with serious adverse effects, coupled with the increasing rate of viral resistance to the existing antiviral drugs. Hence, the search for alternative natural remedies is gaining momentum across the globe. Nigella sativa Linnen, also called Black seed, is a medicinal plant that is gaining worldwide recognition and has been extensively investigated. The present work is aimed to review the existing literature on the antiviral efficacy of Nigella sativa extracts (oil & bioactive compounds). The findings reveal that numerous articles have been published on Nigella sativa and its beneficial effects against different kinds of diseases. However, the antiviral efficacy of Nigella sativa is yet to be given the proper research attention it deserves.

Current approaches for target-specific drug discovery using natural compounds against SARS-CoV-2 infection

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The pandemic of COVID-19 remains to affect the whole world.

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Current remedies for COVID-19 is not satisfactory/available.

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The therapeutic efficacy of Natural Compounds is well explored in various viral infections.

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Natural Compounds could be explored as target specific therapeutic agents against COVID-19 infection.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) recently caused a pandemic outbreak called coronavirus disease 2019 (COVID-19). This disease has initially been reported in China and also now it is expeditiously spreading around the globe directly among individuals through coughing and sneezing. Since it is a newly emerging viral disease and obviously there is a lack of anti-SARS-CoV-2 therapeutic agents, it is urgently required to develop an effective anti-SARS-CoV-2-agent.Through recent advancements in computational biology and biological assays, several natural compounds and their derivatives have been reported to confirm their target specific antiviral potential against Middle East respiratory syndrome coronavirus (MERS-CoV) or Severe Acute Respiratory Syndrome(SARS-CoV).These targets including an important host cell receptor, i.e., angiotensin-converting enzyme ACE2 and several viral proteins e.g. spike glycoprotein (S) containing S1 and S2 domains, SARS CoV Chymotrypsin-like cysteine protease (3CL^pro), papain-like cysteine protease (PL^pro), helicases and RNA-dependent RNA polymerase (RdRp). Due to physical, chemical, and some genetic similarities of SARS CoV-2 with SARS−COV and MERS−COV, repurposing various anti-SARS−COV or anti-MERS−COV natural therapeutic agents could be helpful for the development of anti−COVID-19 herbal medicine. Here we have summarized various drug targets in SARS−COV and MERS−COV using several natural products and their derivatives, which could guide researchers to design and develop a safe and cost-effective anti-SARS−COV-2 drugs.

Ethanol extract of Nigella sativa has antioxidant and ameliorative effect against nickel chloride-induced hepato-renal injury in rats

Background

Nickel exposure causes hepato-renal toxicity via oxidative stress. Medicinal plants with antioxidants properties are being explored as treatment options. In this study, the effect of ethanol extract of Nigella sativa (ENS) on nickel chloride (NiCl2)-induced hepato-renal damage was evaluated by monitoring biochemical and oxidative stress markers. Additionally, the antioxidant capacity and phytochemical constituents of ENS were quantified using HPLC and GC-MS.

Result

NiCl2 significantly increased (p < 0.05) aspartate aminotransferase, creatinine, sodium ion, chloride ion and malondialdehyde levels, while antioxidant enzymes were decreased in the organs except for kidney glutathione-S-transferase when compared to the control. However, ENS exerted inhibitory effect against NiCl2 toxicity in both organs by reversing the biomarkers towards control levels. ENS has a high antioxidant capacity and is rich in antioxidants including gallic acid, quercetin, eucalyptol and levomenthol that may have accounted for the improvement of hepato-renal health in co-exposed rats.

Conclusion

Our result suggests that amelioration of nickel chloride-induced hepato-renal pathology by ethanol extract of Nigella sativa was related to its antioxidant properties. Therefore, Nigella sativa could be valuable in the management of nickel-induced toxicity.

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).

A narrative literature review on traditional medicine options for treatment of corona virus disease 2019 (COVID-19)

Coronavirus disease 2019 (COVID-19) as a life-threatening disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is accounted as global public health concern. Treatment of COVID-19 is primarily supportive and the role of antiviral agents is yet to be established. However, there are no specific anti-COVID-19 drugs and vaccine until now. This review focuses on traditional medicine such as medicinal plant extracts as promising approaches against COVID-19. Chinese, Indian and Iranian traditional medicine, suggests some herbs for prevention, treatment and rehabilitation of the diseases including COVID-19. Although, inhibition of viral replication is considered as general mechanism of herbal extracts, however some studies demonstrated that traditional herbal extracts can interact with key viral proteins which are associated with virus virulence. Chinese, Indian and Iranian traditional medicine, suggests some herbs for prevention, treatment and rehabilitation of the diseases including COVID-19. However the beneficial effects of these traditional medicines and their clinical trials remained to be known. Herein, we reviewed the latest updates on traditional medicines proposed for treatment of COVID-19.

Natural products for the management of the hepatitis C virus: a biochemical review

Chronic hepatitis C virus (HCV) infection is a significant public health problem, with a worldwide prevalence of approximately 170 million. Current therapy for HCV infection includes the prolonged administration of a combination of ribavirin and PEGylated interferon-α, for over a decade. This regimen is expensive and often associated with a poor antiviral response and unwanted side effects. A highly effective combination treatment is likely required for the future management of HCV infections and entry inhibitors could play an important role. Currently, no entry inhibitor has been licensed for the prophylactic treatment of hepatitis C. Therefore, additional agents that combat HCV infection are urgently needed and must be developed. Many phytochemical constituents have been identified that display considerable inhibition of HCV at some stage of the life cycle. This review will summarise the current state of knowledge on natural products and their possible activities in the context of HCV infection.