Revisiting pharmacological potentials of Nigella sativa seed: A promising option for COVID-19 prevention and cure

Phytochemical Analysis and Anti-Biofilm Potential That Cause Dental Caries from Black Cumin Seeds (Nigella sativa Linn.)

The oral cavity is an excellent place for various microorganisms to grow. Spectrococcus mutans and Spectrococcus sanguinis are Gram-negative bacteria found in the oral cavity as pioneer biofilm formers on the tooth surface that cause caries. Caries treatment has been done with antibiotics and therapeutics, but the resistance level of S. mutans and S. sanguinis bacteria necessitates the exploration of new drug compounds. Black cumin (Nigella sativa Linn.) is known to contain secondary metabolites that have antioxidant, antibacterial, anti-biofilm, anti-inflammatory and antifungal activities. The purpose of this review article is to present data on the potential of Nigella sativa Linn seeds as anti-biofilm. This article will discuss biofilm-forming bacteria, the resistance mechanism of antibiotics, the bioactivity of N. sativa extracts and seed isolates together with the Structure Activity Relationship (SAR) review of N. sativa compound isolates. We collected data from reliable references that will illustrate the potential of N. sativa seeds as anti-biofilm drug.

Immune stimulatory effect of Nigella sativa in healthy animal models: A systematic review and meta-analysis

The immune-modulatory effects of black seeds (Nigella sativa seeds, NSS) are well documented, but the overall in vivo impact of this important natural medicinal product on immune system function has yet to be established. Here we systematically reviewed and meta-analyzed the effects of NSS on humoral [serum titers of immunoglobulins including IgG, IgM, anti-Newcastle virus disease (anti-NDV), and sheep red blood cell antigen (anti-SRBC)] and cellular immunity [total white blood cell (WBC) count and percentages of monocytes, lymphocytes, basophils, neutrophils, and eosinophils] in healthy animals. The PubMed, ScienceDirect, Web of Science, and Scopus databases were searched according to predefined eligibility criteria. Meta-analyses were performed to estimate the final effect size using RevMan software. Seventeen animal studies were eligible for analysis. For humoral immunity, the overall pooled effect size (ES) of NSS on serum titers of IgM and anti-NVD antibodies was not significantly different [mean difference (MD) 75.27, 95% CI: -44.76 to 195.30, p = 0.22 (I2 = 89%, p = 0.003), and -0.01, 95% CI: -0.27 to 0.25, p = 0.94 (I2 = 74%, p = 0.02), respectively]. However, NSS significantly increased serum titers of IgG and anti-SRBC antibodies [MD 3.30, 95% CI: 2.27 to 4.32, p = 0.00001 (I2 = 0%, p = 0.97), and 1.15, 95% CI: 0.74 to 1.56, p = 0.00001 (I2 = 0%, p = 0.43), respectively]. For cellular immunity, the ES of NSS on WBCs, monocytes, and lymphocytes were not significantly different [MD 0.29, 95% CI: -0.55 to 1.13, p = 0.50, (I2 = 14%, p = 0.32), - 0.01, 95% CI: -0.45 to 0.44, p = 0.97 (I2 = 0%, p = 0.77), and 4.73, 95% CI: -7.13 to 16.59, p = 0.43, (I2 = 99%, p = 0.00001), respectively]. In conclusion, black seeds enhance humoral immunity in healthy animals but do not affect cellular immunity.

Nigella sativa for the treatment of COVID-19 patients: A rapid systematic review and meta-analysis of randomized controlled trials

Nigella sativa is an herbal therapy for various afflictions. It has some potential to be a promising option as an efficacious treatment for COVID-19 patients that can contribute to global healthcare as a relatively cheap therapy but evidence of its use from randomized controlled trials (RCTs) is limited. Therefore, to explore the effect of N. sativa in combating COVID-19, we undertook this meta-analysis. We searched several databases to retrieve all RCTs investigating N. sativa for the treatment of COVID-19 as compared to placebo or standard care. We used RevMan 5.4 for all analyses with risk ratio (RR) or odds ratio (OR) as the effect measures. We included a total of seven RCTs in this review. N. sativa significantly reduced the risk of all-cause mortality in patients with COVID-19 compared to the control group (RR 0.27, 95% CI: 0.10 to 0.72; I 2 = 0%). N. sativa significantly reduced the rate of viral PCR positivity (RR 0.62, 95% CI: 0.39 to 0.97; I 2 = 0%). We did not find any significant difference in the risk of hospitalization (RR 0.26, 95% CI: 0.04 to 1.54; I 2 = 0%) and the rate of no recovery (OR 0.48, 95% CI: 0.20 to 1.15; I 2 = 84%) between the two groups. N. sativa is an easily available herbal medicine that may decrease the risk of mortality and improve virological clearance in COVID-19 patients. However, our results are limited by the small number of RCTs available. Further large-scale RCTs are needed to better understand the anti-inflammatory and antiviral effects of N. sativa in COVID-19 patients.

Nigella sativa and its chemical constituents: pre-clinical and clinical evidence for their potential anti-SARS-CoV-2 effects

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over 500 million reported cases of COVID-19 worldwide with relatively high morbidity and mortality. Although global vaccination drive has helped control the pandemic, the newer variant of the virus still holds the world in ransom. Several medicinal herbs with antiviral properties have been reported, and one such promising herb is Nigella sativa (NS). Recent molecular docking, pre-clinical, and clinical studies have shown that NS extracts may have the potential to prevent the entry of coronaviruses into the host cell as well as to treat and manage COVID-19 symptoms. Several active compounds from NS, such as nigelledine, α-hederin, dithymoquinone (DTQ), and thymoquinone (TQ), have been proposed as excellent ligands to target angiotensin-converting enzyme 2 (ACE2 receptors) and other targets on host cells as well as the spike protein (S protein) on SARS-CoV-2. By binding to these target proteins, these ligands could potentially prevent the binding between ACE2 and S protein. Though several articles have been published on the promising therapeutic role of NS and its constituents against SARS-CoV-2 infection, in this review, we consolidate the published information on NS and SARS-CoV-2, focusing on pre-clinical in silico studies as well as clinical trials reported between 2012 and 2023.

Effect of thymoquinone on transient receptor potential melastatin (TRPM) channels in rats with liver ischemia reperfusion model in rats

Objectives

We aimed to investigate the levels of transient receptor potential melastatin (TRPM) gene expression, and the antioxidant and histopathologic effect of thymoquinone (Tmq) in the hepatic I/R rat model.

Materials and Methods

Fifty Wistar rats were divided into 5 groups. Group 1: Control; Group 2: Sham; Group 3: Hepatic I/R (45 min/45 min); Group 4: Tmq (50 mg/kg); Group 5: Tmq+I/R (ten days before I/R at the dose of 50 mg/kg of Tmq). The hepatic I/R (45min/45min) model was performed at the portal vein and the hepatic artery with atraumatic vascular clamp in the ischemia groups. The liver tissues and blood samples that were taken at the end of the study were evaluated for histopathologic and biochemical analysis. Besides TRPM gene expression levels were determined in liver tissues. It was seen that cellular swelling, congestion, PNL, and apoptosis parameters statistically decreased in Tmq and Tmq+I/R groups in comparison with the I/R group in histopathological evaluation.

Results

It was observed that biochemical parameters, AST, ALT, GGT, LDH, creatinine, and urea levels significantly increased in the I/R group as compared with, sham, Tmq, and Tmq+I/R groups. It was found that TRPM2,6,7,8 gene expression decreased significantly in Tmq+I/R groups as compared to the I/R group.

Conclusion

We showed that thymoquinone can inhibit the entry of Ca+2 into the cell by decreasing TRPM2,6,7,8 gene expression. Based on our findings, we think that Tmq application in the treatment of liver diseases due to I/R damage may be important in terms of both ischemia and apoptosis and can also be used in the treatment of liver-related diseases.

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.

How to Naturally Support the Immune System in Inflammation-Essential Oils as Immune Boosters

Efficient functionality of the immune system is needed to fight against the development of infectious diseases, including, among others, serious recurrent chronic infections. Research has shown that many modern common diseases, such as inflammatory bowel diseases and cardiovascular diseases, e.g., thromboembolism, cancer, obesity, or depression, are connected with inflammatory processes. Therefore, new, good stimulators of the immune system's response are sought. They include synthetic compounds as well as biological preparations such as lipopolysaccharides, enzymes, bacterial metabolites, and secondary metabolites of plants, demonstrating a multidirectional effect. Essential oils are characterized by many invaluable activities, including antimicrobial, antioxidant, anti-inflammatory, and immunostimulating. Essential oils may stimulate the immune system via the utilization of their constituents, such as antibodies, cytokines, and dendritic cells. Some essential oils may stimulate the proliferation of immune-competent cells, including polymorphonuclear leukocytes, macrophages, dendritic cells, natural killer cells, and B and T lymphocytes. This review is focused on the ability of essential oils to affect the immune system. It is also possible that essential oil components positively interact with recommended anti-inflammatory and antimicrobial drugs. Thus, there is a need to explore possible synergies between essential oils and their active ingredients for medical use.

Cellular, Molecular, Pharmacological, and Nano-Formulation Aspects of Thymoquinone-A Potent Natural Antiviral Agent

The goal of an antiviral agent research is to find an antiviral drug that reduces viral growth without harming healthy cells. Transformations of the virus, new viral strain developments, the resistance of viral pathogens, and side effects are the current challenges in terms of discovering antiviral drugs. The time has come and it is now essential to discover a natural antiviral agent that has the potential to destroy viruses without causing resistance or other unintended side effects. The pharmacological potency of thymoquinone (TQ) against different communicable and non-communicable diseases has been proven by various studies, and TQ is considered to be a safe antiviral substitute. Adjunctive immunomodulatory effects in addition to the antiviral potency of TQ makes it a major compound against viral infection through modulating the production of nitric oxide and reactive oxygen species, decreasing the cytokine storm, and inhibiting endothelial dysfunction. Nevertheless, TQ's low oral bioavailability, short half-life, poor water solubility, and conventional formulation are barriers to achieving its optimal pharmacologic benefits. Nano-formulation proposes numerous ways to overcome these obstacles through a small particle size, a big surface area, and a variety of surface modifications. Nano-based pharmaceutical innovations to combat viral infections using TQ are a promising approach to treating surmounting viral infections.

Potentials of curcumin against polycystic ovary syndrome: Pharmacological insights and therapeutic promises

Polycystic ovary syndrome (PCOS) is a common hormonal disorder among women (4%-20%) when the ovaries create abnormally high levels of androgens, the male sex hormones that are typically present in women in trace amounts. The primary characteristics of PCOS include oxidative stress, inflammation, hyperglycemia, hyperlipidemia, hyperandrogenism, and insulin resistance. Generally, metformin, spironolactone, eflornithine and oral contraceptives are used to treat PCOS, despite their several side effects. Therefore, finding a potential candidate for treating PCOS is necessary. Curcumin is a major active natural polyphenolic compound derived from turmeric (Curcuma longa). A substantial number of studies have shown that curcumin has anti-inflammatory, anti-oxidative stress, antibacterial, and anti-apoptotic activities. In addition, curcumin reduces hyperglycemia, hyperlipidemia, hyperandrogenism, and insulin resistance in various conditions, including PCOS. The review highlighted the therapeutic aspects of curcumin against the pathophysiology of PCOS. We also offer a hypothesis to improve the development of medicines based on curcumin against PCOS.

Plant Spices as a Source of Antimicrobial Synergic Molecules to Treat Bacterial and Viral Co-Infections

The COVID-19 pandemic exposed the lack of antiviral agents available for human use, while the complexity of the physiological changes caused by coronavirus (SARS-CoV-2) imposed the prescription of multidrug pharmacotherapy to treat infected patients. In a significant number of cases, it was necessary to add antibiotics to the prescription to decrease the risk of co-infections, preventing the worsening of the patient's condition. However, the precautionary use of antibiotics corroborated to increase bacterial resistance. Since the development of vaccines for COVID-19, the pandemic scenario has changed, but the development of new antiviral drugs is still a major challenge. Research for new drugs with synergistic activity against virus and resistant bacteria can produce drug leads to be used in the treatment of mild cases of COVID-19 and to fight other viruses and new viral diseases. Following the repurposing approach, plant spices have been searched for antiviral lead compounds, since the toxic effects of plants that are traditionally consumed are already known, speeding up the drug discovery process. The need for effective drugs in the context of viral diseases is discussed in this review, with special focus on plant-based spices with antiviral and antibiotic activity. The activity of plants against resistant bacteria, the diversity of the components present in plant extracts and the synergistic interaction of these metabolites and industrialized antibiotics are discussed, with the aim of contributing to the development of antiviral and antibiotic drugs. A literature search was performed in electronic databases such as Science Direct; SciELO (Scientific Electronic Library Online); LILACS (Latin American and Caribbean Literature on Health Sciences); Elsevier, SpringerLink; and Google Scholar, using the descriptors: antiviral plants, antibacterial plants, coronavirus treatment, morbidities and COVID-19, bacterial resistance, resistant antibiotics, hospital-acquired infections, spices of plant origin, coronaviruses and foods, spices with antiviral effect, drug prescriptions and COVID-19, and plant synergism. Articles published in English in the period from 2020 to 2022 and relevant to the topic were used as the main inclusion criteria.

Utilization of Nanotechnology to Improve Bone Health in Osteoporosis Exploiting Nigella sativa and Its Active Constituent Thymoquinone

Osteoporosis, a chronic bone disorder, is one of the leading causes of fracture and morbidity risk. Numerous medicinally important herbs have been evaluated for their efficacy in improving bone mass density in exhaustive preclinical and limited clinical studies. Nigella sativa L. has been used as local folk medicine, and traditional healers have used it to manage various ailments. Its reported beneficial effects include controlling bone and joint diseases. The present manuscript aimed to provide a sound discussion on the pharmacological evidence of N. sativa and its active constituent, thymoquinone, for its utility in the effective management of osteoporosis. N. sativa is reported to possess anti-IL-1 and anti-TNF-α-mediated anti-inflammatory effects, leading to positive effects on bone turnover markers, such as alkaline phosphatase and tartrate-resistant acid phosphatase. It is reported to stimulate bone regeneration by prompting osteoblast proliferation, ossification, and decreasing osteoclast cells. Thymoquinone from N. sativa has exhibited an antioxidant effect on bone tissue by reducing the FeNTA-induced oxidative stress. The present manuscript highlights phytochemistry, pharmacological effect, and the important mechanistic perspective of N. sativa and its active constituents for the management of osteoporosis. Further, it also provides sound discussion on the utilization of a nanotechnology-mediated drug delivery approach as a promising strategy to improve the therapeutic performance of N. sativa and its active constituent, thymoquinone, in the effective management of osteoporosis.

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.

Effects of two triterpenoids from Nigella sativa seeds on insulin resistance of 3T3-L1 adipocytes

Insulin resistance (IR) is a physiological abnormality that occurs when insulin fails to activate the signal transduction pathway in target organs. It was found that supplementation of Nigella sativa seeds with oral antidiabetic medicines helps improve blood glucose control by enhanced β cells activity and alleviation of IR. However, the activities and related mechanisms of phytochemicals from N. sativa seeds have not been thoroughly explored. In this study, the effects of two triterpenoids, 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1→4)-β-D-glucopyranose-L-(1→6)-β-D-glucopyranose]-hederagenin (Hxrarg) and 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-hederagenin (Hxra), on IR were studied by 3T3-L1 adipocytes model. The results demonstrated that Hxrarg and Hxra inhibited maturation of 3T3-L1 preadipocytes, dramatically stimulated glucose uptake of IR-3T3-L1 adipocytes, promoted transcription of IRS, AKT, PI-3K, and GLUT4 mRNA. Western Blot results suggested that Hxrarg and Hxra were able to markedly up-regulate expression of p-IRS, p-AKT, PI-3K, and GLUT4 proteins. These findings could provide a basic foundation for the continued development and application of N. sativa in medicine and functional foods.

Black Seed (Nigella sativa): A Favourable Alternative Therapy for Inflammatory and Immune System Disorders

In the recent years, various food additives, medicinal plants, and their bioactive components have been utilized in anti-inflammatory and immunomodulatory therapy. Nigella sativa is a key dietary supplement and food additive which has a strong traditional background. It is also one of the most broadly studied seeds in the global pharmaceutical and nutraceutical sector. N. sativa seeds are potential sources of natural metabolite such as phenolic compounds and alkaloids. The anti-inflammatory and immunomodulatory abilities of these seeds, most peculiarly with reference to some inflammatory and immune mediators, are reviewed. N. sativa and its bioactive compounds modulate inflammatory and immunomodulatory mediators including tumor necrosis factor-alpha (TNF-α), interferon gamma (IFN-γ), nuclear factor kappa B (NF-kB) cyclooxygenase (COX), lipoxygenase (LOX), transforming growth factor beta (TGF-β), interleukins, and immunoglobulin levels. This paper comprehensively describes the biomarkers and signaling pathways underlying the anti-inflammatory and immunomodulatory potential of N. sativa. This review also explains the scientific basis and the pharmacological properties of core bioactive ingredients of N. sativa responsible for these biological activities which indicates that their bioactive components could be possibly regarded as favorable therapy for disorders linked to inflammation and immune-dysregulation.

In Silico Studies on Zinc Oxide Based Nanostructured Oil Carriers with Seed Extracts of Nigella sativa and Pimpinella anisum as Potential Inhibitors of 3CL Protease of SARS-CoV-2

Coming into the second year of the pandemic, the acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants continue to be a serious health hazard globally. A surge in the omicron wave, despite the discovery of the vaccines, has shifted the attention of research towards the discovery and use of bioactive compounds, being potential inhibitors of the viral structural proteins. The present study aimed at the green synthesis of zinc oxide (ZnO) nanoparticles with seed extracts of Nigella sativa and Pimpinella anisum—loaded nanostructured oil carriers (NLC)—using a mixture of olive and black seed essential oils. The synthesized ZnO NLC were extensively characterized. In addition, the constituent compounds in ZnO NLC were investigated as a potential inhibitor for the SARS-CoV-2 main protease (3CLpro or Mpro) where 27 bioactive constituents, along with ZnO in the nanostructure, were subjected to molecular docking studies. The resultant high-score compounds were further validated by molecular dynamics simulation. The study optimized the compounds dithymoquinone, δ-hederin, oleuropein, and zinc oxide with high docking energy scores (ranging from −7.9 to −9.9 kcal/mol). The RMSD and RMSF data that ensued also mirrored these results for the stability of proteins and ligands. RMSD and RMSF data showed no conformational change in the protein during the MD simulation. Histograms of every simulation trajectory explained the ligand properties and ligand–protein contacts. Nevertheless, further experimental investigations and validation of the selected candidates are imperative to take forward the applicability of the nanostructure as a potent inhibitor of COVID-19 (Coronavirus Disease 2019) for clinical trials.

Assessment of commitment to healthy daily habits and diets, preventive measures, and beliefs about natural products utilization during COVID-19 pandemic in certain population in Egypt and Saudi Arabia

Objective

The purpose of this research is to assess the commitment of participants in Saudi Arabia and Egypt towards healthy daily habits, preventive measures, healthy food habits, and beliefs about natural products as an immunostimulants during COVID-19 pandemic.

Method

A cross-sectional questionnaire-based study was conducted in Saudi Arabia (mainly Riyadh and Jeddah) and Egypt (mainly Cairo). The questionnaire instrument was created based on an extensive literature review on the COVID-19 pandemic, including its spreading and transmission methods, preventive measures, healthy lifestyle, and diets that increase human immunity against viral infections and the use of natural products and drinks. The questionnaire was created by Microsoft 365® office forms, participants were invited through emails and other social media. The questionnaire includes a demographic section (gender, nationality, residency country, city, age, marital status, educational level, employment status, chronic disease history, under anxiety or stress, have a temper or irritable person, were infected/currently infected and in contact to COVID-19 patient) and (23) questions arranged under five domains; Domain I daily habits (4), Domain II keeping preventive measures (4), Domain III healthy eating habits (9), Domain IV for participants currently or previously infected, or in contact with a patient (4) Domain V for assessment of participants' beliefs towards the use of natural products to elevate immunity during COVID-19 pandemic (2), beside 4 choice questions (stimulant drinks, natural drinks, natural products, and zinc-rich food). SPSS® was used to analyze the results using Student' t-test, ANOVA, and Tukey's HSD tests.

Result

510 individuals with various demographic characteristics participated in the study. This study revealed that the participants belief in healthy foods, natural drinks (mainly ginger, lemon, and cinnamon), natural products (mainly honey, olive oil, and black seed), healthy habits, and preventive measures as sanitizers, social distance, and exercise. Only 13% of all participants were infected with COVID-19, although 31% of them were in contact with COVID -19 patients, about 93% were under stress, and 22% were with chronic diseases. Participants who are married, not in contact with patients and not previously infected by COVID-19 are more adhered to preventive measures while those previously or currently infected are more committed to healthy lifestyle and diet habits. Qualification level seems to make no significant difference in any domain. 78.6% of the participants beliefs in the benefits of utilizing natural products in preventing infection with corona virus or reducing the period of treatment in case of infection. About 95.7% of the infected persons had no need of hospitalization and about 50% are cured within two weeks of infection. The questionnaire revealed that Nescafe and black tea were the most used stimulant drinks among the participants, particularly the students and who were always under stress. Most of the participants agreed with the utilization of Zn-rich food, particularly Egyptians, which may help in boosting their immunity.

Conclusion

Natural products selected in the present study can be used in combination with the existing clinical standards of care that have the potential to serve as prophylactic agents in populations that are at risk to develop COVID-19 infection.

The Immunomodulatory Effects of Active Ingredients From Nigella sativa in RAW264.7 Cells Through NF-κB/MAPK Signaling Pathways

Nigella sativa is a valuable herb for its functional compositions in both food and medication. N. sativa seeds can enhance immunity, anti-inflammation and analgesia and hypoglycemia, but most of the related researches are related to volatile oil and extracts, and the activity and mechanism of compounds is not clear. In this study, Ethyl-α-D-galactopyranoside (EG), Methyl-α-D-glucoside (MG), 3-O-[β-D-xylopyranose-(1 → 3)-α-L-rhamnose-(1 → 2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1 → 4)-β-D-glucopyranose-L-(1 → 6)-β-D-glucopyranose]-hederagenin (HXRARG) and 3-O-[β-D-xylopyranose-(1 → 3)-α-L-rhamnose-(1 → 2)-α-L-arabinose]-hederagenin (HXRA) were isolated and identified from N. sativa seeds. In addition, four compounds could activate NF-κB pathway by promoting the expression of phosphorylation of P65 and IκBα, promoting the phosphorylation of JNK, Erk and P38 to activate MAPK signaling pathway, enhancing the proliferation and phagocytic activity of RAW264.7 cells, and promoting the release of NO, TNF-α and IL-6 on RAW264.7 cell in vitro. The results showed that N. sativa can be used as dietary supplement to enhance immune.

Human Cell Organelles in SARS-CoV-2 Infection: An Up-to-Date Overview

Since the end of 2019, the whole world has been struggling with the life-threatening pandemic amongst all age groups and geographic areas caused by Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). The Coronavirus Disease 2019 (COVID-19) pandemic, which has led to more than 468 million cases and over 6 million deaths reported worldwide (as of 20 March 2022), is one of the greatest threats to human health in history. Meanwhile, the lack of specific and irresistible treatment modalities provoked concentrated efforts in scientists around the world. Various mechanisms of cell entry and cellular dysfunction were initially proclaimed. Especially, mitochondria and cell membrane are crucial for the course of infection. The SARS-CoV-2 invasion depends on angiotensin converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), and cluster of differentiation 147 (CD147), expressed on host cells. Moreover, in this narrative review, we aim to discuss other cell organelles targeted by SARS-CoV-2. Lastly, we briefly summarize the studies on various drugs.

Nigella sativa L. and COVID-19: A Glance at The Anti-COVID-19 Chemical Constituents, Clinical Trials, Inventions, and Patent Literature

COVID-19 has had an impact on human quality of life and economics. Scientists have been identifying remedies for its prevention and treatment from all possible sources, including plants. Nigella sativa L. (NS) is an important medicinal plant of Islamic value. This review highlights the anti-COVID-19 potential, clinical trials, inventions, and patent literature related to NS and its major chemical constituents, like thymoquinone. The literature was collected from different databases, including Pubmed, Espacenet, and Patentscope. The literature supports the efficacy of NS, NS oil (NSO), and its chemical constituents against COVID-19. The clinical data imply that NS and NSO can prevent and treat COVID-19 patients with a faster recovery rate. Several inventions comprising NS and NSO have been claimed in patent applications to prevent/treat COVID-19. The patent literature cites NS as an immunomodulator, antioxidant, anti-inflammatory, a source of anti-SARS-CoV-2 compounds, and a plant having protective effects on the lungs. The available facts indicate that NS, NSO, and its various compositions have all the attributes to be used as a promising remedy to prevent, manage, and treat COVID-19 among high-risk people as well as for the therapy of COVID-19 patients of all age groups as a monotherapy or a combination therapy. Many compositions of NS in combination with countless medicinal herbs and medicines are still unexplored. Accordingly, the authors foresee a bright scope in developing NS-based anti-COVID-19 composition for clinical use in the future.

Natural products can be used in therapeutic management of COVID-19: Probable mechanistic insights

The unexpected emergence of the new Coronavirus disease (COVID-19) has affected more than three hundred million individuals and resulted in more than five million deaths worldwide. The ongoing pandemic has underscored the urgent need for effective preventive and therapeutic measures to develop anti-viral therapy. The natural compounds possess various pharmaceutical properties and are reported as effective anti-virals. The interest to develop an anti-viral drug against the novel severe acute respiratory syndrome Coronavirus (SARS-CoV-2) from natural compounds has increased globally. Here, we investigated the anti-viral potential of selected promising natural products. Sources of data for this paper are current literature published in the context of therapeutic uses of phytoconstituents and their mechanism of action published in various reputed peer-reviewed journals. An extensive literature survey was done and data were critically analyzed to get deeper insights into the mechanism of action of a few important phytoconstituents. The consumption of natural products such as thymoquinone, quercetin, caffeic acid, ursolic acid, ellagic acid, vanillin, thymol, and rosmarinic acid could improve our immune response and thus possesses excellent therapeutic potential. This review focuses on the anti-viral functions of various phytoconstituent and alkaloids and their potential therapeutic implications against SARS-CoV-2. Our comprehensive analysis provides mechanistic insights into phytoconstituents to restrain viral infection and provide a better solution through natural, therapeutically active agents.

Pharmacogenetics and Precision Medicine Approaches for the Improvement of COVID-19 Therapies

Many drugs are being administered to tackle coronavirus disease 2019 (COVID-19) pandemic situations without establishing clinical effectiveness or tailoring safety. A repurposing strategy might be more effective and successful if pharmacogenetic interventions are being considered in future clinical studies/trials. Although it is very unlikely that there are almost no pharmacogenetic data for COVID-19 drugs, however, from inferring the pharmacokinetic (PK)/pharmacodynamic(PD) properties and some pharmacogenetic evidence in other diseases/clinical conditions, it is highly likely that pharmacogenetic associations are also feasible in at least some COVID-19 drugs. We strongly mandate to undertake a pharmacogenetic assessment for at least these drug–gene pairs (atazanavir–UGT1A1, ABCB1, SLCO1B1, APOA5; efavirenz–CYP2B6; nevirapine–HLA, CYP2B6, ABCB1; lopinavir–SLCO1B3, ABCC2; ribavirin–SLC28A2; tocilizumab–FCGR3A; ivermectin–ABCB1; oseltamivir–CES1, ABCB1; clopidogrel–CYP2C19, ABCB1, warfarin–CYP2C9, VKORC1; non-steroidal anti-inflammatory drugs (NSAIDs)–CYP2C9) in COVID-19 patients for advancing precision medicine. Molecular docking and computational studies are promising to achieve new therapeutics against SARS-CoV-2 infection. The current situation in the discovery of anti-SARS-CoV-2 agents at four important targets from in silico studies has been described and summarized in this review. Although natural occurring compounds from different herbs against SARS-CoV-2 infection are favorable, however, accurate experimental investigation of these compounds is warranted to provide insightful information. Moreover, clinical considerations of drug–drug interactions (DDIs) and drug–herb interactions (DHIs) of the existing repurposed drugs along with pharmacogenetic (e.g., efavirenz and CYP2B6) and herbogenetic (e.g., andrographolide and CYP2C9) interventions, collectively called multifactorial drug–gene interactions (DGIs), may further accelerate the development of precision COVID-19 therapies in the real-world clinical settings.

Natural Products and Nanotechnology Against Coronavirus Disease 2019

Coronavirus disease 2019 (COVID-19) is a new and severe infectious disease and new global disaster and is spreading rapidly worldwide. Natural products have a long history and have been widely used to treat various acute, chronic, and even life-threatening diseases worldwide. However, the natural products have reduced bioavailability and availability as they have poor kinetic properties, such as large molecular weight, inability to cross lipid membranes, and weak absorption ability. With the rapid development of nanotechnology, using novel nanotechnology in conjunction with natural products can effectively eliminate the molecular restriction of the entry of nanoproducts into the body and can be used to diagnose and treat various diseases, including COVID-19, bringing new strategies and directions for medicine. This article reviews the role and implementation of natural products against COVID-19 based on nanotechnology.

Artemisinins in Combating Viral Infections Like SARS-CoV-2, Inflammation and Cancers and Options to Meet Increased Global Demand

Artemisinin is a natural bioactive sesquiterpene lactone containing an unusual endoperoxide 1, 2, 4-trioxane ring. It is derived from the herbal medicinal plant Artemisia annua and is best known for its use in treatment of malaria. However, recent studies also indicate the potential for artemisinin and related compounds, commonly referred to as artemisinins, in combating viral infections, inflammation and certain cancers. Moreover, the different potential modes of action of artemisinins make these compounds also potentially relevant to the challenges the world faces in the COVID-19 pandemic. Initial studies indicate positive effects of artemisinin or Artemisia spp. extracts to combat SARS-CoV-2 infection or COVID-19 related symptoms and WHO-supervised clinical studies on the potential of artemisinins to combat COVID-19 are now in progress. However, implementing multiple potential new uses of artemisinins will require effective solutions to boost production, either by enhancing synthesis in A. annua itself or through biotechnological engineering in alternative biosynthesis platforms. Because of this renewed interest in artemisinin and its derivatives, here we review its modes of action, its potential application in different diseases including COVID-19, its biosynthesis and future options to boost production.

Possible therapeutic effects of Nigella sativa and its thymoquinone on COVID-19

CONTEXT

COVID-19 is a novel coronavirus that causes a severe infection in the respiratory system. Nigella sativa L. (Ranunculaceae) is an annual flowering plant used traditionally as a natural food supplement and multipurpose medicinal agent.

OBJECTIVE

The possible beneficial effects of N. sativa, and its constituent, thymoquinone (TQ) on COVID-19 were reviewed.

METHODS

The key words including, COVID-19, N. sativa, thymoquinone, antiviral effects, anti-inflammatory and immunomodulatory effects in different databases such as Web of Science (ISI), PubMed, Scopus, and Google Scholar were searched from 1990 up to February 2021.

RESULTS

The current literature review showed that N. sativa and TQ reduced the level of pro-inflammatory mediators including, IL-2, IL-4, IL-6, and IL-12, while enhancing IFN-γ. Nigella sativa and TQ increased the serum levels of IgG1 and IgG2a, and improved pulmonary function tests in restrictive respiratory disorders.

DISCUSSION AND CONCLUSIONS

These preliminary data of molecular docking, animal, and clinical studies propose N. sativa and TQ might have beneficial effects on the treatment or control of COVID-19 due to antiviral, anti-inflammatory and immunomodulatory properties as well as bronchodilatory effects. The efficacy of N. sativa and TQ on infected patients with COVID-19 in randomize clinical trials will be suggested.

Forecasting of Oxidant/Antioxidant levels of COVID-19 patients by using Expert models with biomarkers used in the Diagnosis/Prognosis of COVID-19

Background

Early detection of oxidant-antioxidant levels and special care in severe patients are important in combating the COVID-19 epidemic. However, this process is costly and time consuming. Therefore, there is a need for faster, reliable and economical methods.

Methods

In this study, antioxidant/oxidant levels of patients were estimated by Expert-models using biomarkers, which are effective in the diagnosis/prognosis of COVID-19 disease. For this purpose, Expert-models were trained and created between the white-blood-cell-count (WBC), lymphocyte-count (LYM), C-reactive-protein (CRP), D-dimer, ferritin values of 35 patients with COVID-19 and antioxidant/oxidant parameter values of the same patients. Error criteria and R² ratio were taken into account for the performance of the models. The validity of the all models was checked by the Box-Jenkis-method.

Results

Antioxidant/Oxidant levels were estimated with 95% confidence-coefficient using the values of WBC, LYM, CRP, D-dimer, ferritin of different 500 patients diagnosed with COVID-19 with the trained models. The error rate of all models was low and the coefficients of determination were sufficient. In the first data set, there was no significant difference between measured antioxidant/oxidant levels and predicted antioxidant/oxidant levels. This result showed that the models are accurate and reliable. In determining antioxidant/oxidant levels, LYM and ferritin biomarkers had the most effect on models, while WBC and CRP biomarkers had the least effect. The antioxidant/oxidant parameter estimated with the highest accuracy was Native-Thiol divided by Total-Thiol.

Conclusions

The results showed that the antioxidant/oxidant levels of infected patients can be estimated accurately and reliably with LYM, ferritin, D-dimer, WBC, CRP biomarkers in the COVID-19 outbreak.

Protective Effects of Black Cumin (Nigella sativa) and Its Bioactive Constituent, Thymoquinone against Kidney Injury: An Aspect on Pharmacological Insights

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and a close association between acute kidney injury (AKI) and CKD has recently been identified. Black cumin (Nigella sativa) has been shown to be effective in treating various kidney diseases. Accumulating evidence shows that black cumin and its vital compound, thymoquinone (TQ), can protect against kidney injury caused by various xenobiotics, namely chemotherapeutic agents, heavy metals, pesticides, and other environmental chemicals. Black cumin can also protect the kidneys from ischemic shock. The mechanisms underlying the kidney protective potential of black cumin and TQ include antioxidation, anti-inflammation, anti-apoptosis, and antifibrosis which are manifested in their regulatory role in the antioxidant defense system, NF-κB signaling, caspase pathways, and TGF-β signaling. In clinical trials, black seed oil was shown to normalize blood and urine parameters and improve disease outcomes in advanced CKD patients. While black cumin and its products have shown promising kidney protective effects, information on nanoparticle-guided targeted delivery into kidney is still lacking. Moreover, the clinical evidence on this natural product is not sufficient to recommend it to CKD patients. This review provides insightful information on the pharmacological benefits of black cumin and TQ against kidney damage.

A Systematic Review on Traditional Medicinal Plants Used for the Treatment of Viral and Fungal Infections in Ethiopia

BACKGROUND

Traditional medicine is still playing an important role in meeting the basic health care requirement of the peoples in different parts of Ethiopia. There is no published review that clearly indicates documented medicinal plants available in different parts of the country used for treating viral and fungal infections. Currently, viral epidemics with high mortality and morbidity like SARS COV-2 are emerging. Screening of promising drug from plant source is vital to control such viral and fungal infections. In addition, indicating the most commonly used parts of the plant and their route of administration will help for further drug formulation studies. This review aimed to present an indication of the ethnomedicinal plants used for the treatment of fungal and viral infections.

METHODS

The databases (Google Scholar, pub med, hinari, and research gate) were searched for published articles on the ethnobotany of medicinal plants used to treat viral and fungal infection in Ethiopia without restriction in the methodology and year of publication. Viral infections, fungal infections, anti-fungal and anti-viral activity, ethnobotany, Ethiopia, and medicinal plants were the key search terms. Studies that did not have complete ethnobotanical data and did not address viral and fungal infection as a disease treated traditionally by the practitioners were excluded.

RESULTS

A total of 249 articles were produced by database search. After amendment for exclusion criteria and duplicates, 15 articles were found appropriate for the review. The majority of the studies were qualitative and others were mixed type in nature. All of the medicinal plants traditionally used to treat viral and fungal infections in Ethiopia were not scientifically confirmed. Out of the 95 identified plants, 40.8% were herbs and from the plant parts used and 43.9% and 21.1% were leaves and roots, respectively. The majority, (48.8%), of the plant remedies were given orally. Rabies and Tinea capitis constitute the highest percentage of viral and fungal infections treated by traditional medicinal plants followed by hepatitis and Tinea corporis, respectively.

CONCLUSION

Various plants have been used to treat viral and fungal infections. Information obtained from this review serves as a guide to discover novel antiviral and antifungal agents from plants. Therefore, it is advisable for field researchers to properly identify, document, conserve and conduct efficacy and safety studies on such medicinal plants in animal models.

Thymoquinone against infectious diseases: Perspectives in recent pandemics and future therapeutics

The recent pandemics caused by coronavirus infections have become major challenges in 21st century human health. Scientists are struggling hard to develop a complete cure for infectious diseases, for example, drugs or vaccines against these deadly infectious diseases. We have searched papers on thymoquinone (TQ) and its effects on different infectious diseases in databases like Pubmed, Web of Science, Scopus, and Google Scholar, and reviewed them in this study. To date research suggests that natural products may become a potential therapeutic option for their prodigious anti-viral or anti-microbial effects on infectious diseases. TQ, a natural phytochemical from black seeds, is known for its health-beneficial activities against several diseases, including infections. It is evident from different in vitro and in vivo studies that TQ is effective against tuberculosis, influenza, dengue, Ebola, Zika, hepatitis, malaria, HIV, and even recent pandemics caused by severe acute respiratory syndrome of coronaviruses (SARS-CoV and SARS-CoV-2). In these cases, the molecular mechanism of TQ is partly clear but mostly obscure. In this review article, we have discussed the role of TQ against different infectious diseases, including COVID-19, and also critically reviewed the future use of TQ use to fight against infectious diseases.

Effects of Nigella sativa on Performance, Blood Profiles, and Antibody Titer against Newcastle Disease in Broilers

Recent anxiety about resistance to chemical drugs has elevated the position of phytogenic feed additives including Nigella sativa in preventive strategy in the poultry industry. During this study, a completely randomized experiment was designed to investigate the efficacy of different levels (0 to 16%) of N. sativa seeds supplemented in the diet of broilers on performance, immune responses, and hematological and biochemical parameters. The results indicated the following: (a) Supplementation of 1% N. sativa seeds in diet had the highest positive effects and 16% N. sativa had the highest significant (p=0.03) adverse effects on weight gain, while up to 2% N. sativa seeds in the diet reduced feed conversion ratio (FCR) whereas 4% and over that increased the FCR. (b) Chickens fed with a diet containing 1% N. sativa seeds had the highest antibody titers, but those fed with 16% N. sativa seeds had the lowest antibody titers at end of the experiment. (c) Dietary inclusion of N. sativa seeds increased hemogram parameters and the group fed with 16% N. sativa seeds had the highest values on day 21 until the end of the experiment. (d) Supplementation of N. sativa seeds decreased in WBC and lymphocytes but increased heterophils, H/L, monocytes, eosinophils, and basophils percentages. Supplementation of up to 2% of N. sativa seeds in broiler's diets elaborated serum level of those parameters, while supplementation of ≥ 4% N. sativa seeds decreased their serum levels. In conclusion, supplementation of N. sativa seed (1-2%) in broiler diets, as a multipurpose natural growth promoter, improves performance, elevates humoral immune responses, affects serum biochemical profiles of broiler chickens, and induces changes in their hemogram and leukogram, while there are no side, residual, and hazardous effects.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

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.

Prospects of honey in fighting against COVID-19: pharmacological insights and therapeutic promises

Honey and its compounds are drawing attention as an effective natural therapy because of its ability to attenuate acute inflammation through enhancing immune response. Several studies have proved its potential healing capability against numerous chronic diseases/conditions, including pulmonary disorders, cardiac disorders, diabetes, hypertension, autophagy dysfunction, bacterial, and fungal infections. More importantly, honey has proved its virucidal effect on several enveloped viruses such as HIV, influenza virus, herpes simplex, and varicella-zoster virus. Honey may be beneficial for patients with COVID-19 which is caused by an enveloped virus SARS-CoV-2 by boosting the host immune system, improving comorbid conditions, and antiviral activities. Moreover, a clinical trial of honey on COVID-19 patients is currently undergoing. In this review, we have tried to summarize the potential benefits of honey and its ingredients in the context of antimicrobial activities, some chronic diseases, and the host immune system. Thus, we have attempted to establish a relationship with honey for the treatment of COVID-19. This review will be helpful to reconsider the insights into the possible potential therapeutic effects of honey in the context of the COVID-19 pandemic. However, the effects of honey on SARS-CoV-2 replication and/or host immune system need to be further investigated by in vitro and in vivo studies.