Eugenol, a Component of Holy Basil (Tulsi) and Common Spice Clove, Inhibits the Interaction Between SARS-CoV-2 Spike S1 and ACE2 to Induce Therapeutic Responses

Eugenol's electrochemical behavior, complexation interaction with copper chloride, antioxidant activity, and potential drug molecular docking application for Covid-19

Electrochemical studies were conducted to analyze the behavior of eugenol, CuCl2, and their complex using cyclic voltammetry. The oxidation mechanisms of eugenol and the redox behavior of copper ions were elucidated, showing differences in reversibility and charge transfer coefficients. Various kinetic and solvation parameters were determined. The redox behavior of CuCl2 was found to be more reversible compared to the copper-eugenol complex. The copper-eugenol complex exhibited enhanced antioxidant activity compared to eugenol and standard ascorbic acid. The eugenol was oxidized to form eugenol quinone methide through two postulated irreversible mechanisms. Molecular docking studies suggested higher potential bioactivity of the copper-eugenol complex towards the target protein of COVID-19 than the eugenol ligand.

Sulfoquinovosyl diacylglycerol, a component of Holy Basil Ocimum tenuiflorum, inhibits the activity of the SARS-CoV-2 main protease and viral replication in vitro

The persistence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the emergence of new mutant strains continue to present a substantial threat with potential for future pandemics. Safe, effective, and readily available COVID-19 therapeutics are urgently needed to prepare for future coronavirus pandemics. To help identify new antiviral agents, the present study focused on natural products in the extracts of Holy Basil, Ocimum tenuiflorum L., which show potential inhibitory effects against the SARS-CoV-2 main protease (Mpro). Bioassay-guided isolation of the MeOH extracts of O. tenuiflorum led to the identification of a sulfur-containing glyceroglycolipid, sulfoquinovosyl diacylglycerol (SQDG: 1), as a potent Mpro inhibitor that effectively inhibited Mpro activity (IC50: 0.42 µM). SQDG (1) also markedly suppressed SARS-CoV-2 replication (EC50, 51.2 µM) in vitro while displaying no cytotoxicity (CC50 > 100 µM). Further inhibition kinetic studies and docking simulations clearly demonstrated that SQDG strongly inhibited SARS-CoV-2 Mpro in a competitive and mixed-inhibition manner. These findings highlight SQDG as a promising lead compound for COVID-19 therapy and emphasize the need to explore new drugs from natural sources.

Anti-Inflammatory and Antioxidant Activities of Eugenol: An Update

Medicinal plants are a rich source of bioactive compounds that possess pharmacological properties for preventing and treating inflammation-related diseases. Essential oils is a chemical class that contains many bioactive compounds, such as eugenol, which is capable of inhibiting or modulating the inflammatory response. This natural product emerges as a compound that promotes various biological activities, including antioxidant activity, which makes it useful in the food industry. Recently, its pharmacological applications have also been highlighted. So, this review aims to update and discuss the most recent findings on the anti-inflammatory and antioxidant activities of eugenol, along with its mechanisms of action and therapeutic potential for treating inflammation and oxidative imbalance conditions.

Eucalyptus Essential Oil Inhibits Cell Infection by SARS-CoV-2 Spike Pseudotyped Lentivirus

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a public health concern due to infections with new SARS-CoV-2 variants. Therefore, finding effective preventive and therapeutic treatments against all SARS-CoV-2 variants is of great interest. In this study, we examined the capacity of eucalyptus essential oil (EEO) and eucalyptol (EOL) to prevent SARS-CoV-2 infection, using as a model SARS-CoV-2 Spike pseudotyped lentivirus (SARS-CoV-2 pseudovirus) and 293T cells transfected with human angiotensin-converting enzyme 2 (hACE2-293T cells). First, we determined the cytotoxicity of EEO and EOL using the MTT colorimetric assay, selecting non-cytotoxic concentrations ≤ 0.1% (v/v) for further analysis. Subsequently, we evaluated the capacity of EEO and EOL in cell cultures to preclude infection of hACE2-293T cells by SARS-CoV-2 pseudovirus, using a luciferase-based assay. We found that EEO and EOL significantly reduced SARS-CoV-2 pseudovirus infection, obtaining IC50 values of 0.00895% and 0.0042% (v/v), respectively. Likewise, EEO and EOL also reduced infection by vesicular stomatitis virus (VSV) pseudovirus, although higher concentrations were required. Hence, EEO and EOL may be able to inhibit SARS-CoV-2 infection, at least partially, through a Spike-independent pathway, supporting the implementation of aromatherapy with these agents as a cost-effective antiviral measure.

In Silico Approaches to Polyherbal Synergy: Protocol for a Scoping Review

BACKGROUND

According to the World Health Organization, more than 80% of the world's population relies on traditional medicine. Traditional medicine is typically based on the use of single herbal drugs or polyherbal formulations (PHFs) to manage diseases. However, the probable mode of action of these formulations is not well studied or documented. Over the past few decades, computational methods have been used to study the molecular mechanism of phytochemicals in single herbal drugs. However, the in silico methods applied to study PHFs remain unclear.

OBJECTIVE

The aim of this protocol is to develop a search strategy for a scoping review to map the in silico approaches applied in understanding the activity of PHFs used as traditional medicines worldwide.

METHODS

The scoping review will be conducted based on the methodology developed by Arksey and O'Malley and the recommendations of the Joanna Briggs Institute (JBI). A set of predetermined keywords will be used to identify the relevant studies from five databases: PubMed, Embase, Science Direct, Web of Science, and Google Scholar. Two independent reviewers will conduct the search to yield a list of relevant studies based on the inclusion and exclusion criteria. Mendeley version 1.19.8 will be used to remove duplicate citations, and title and abstract screening will be performed with Rayyan software. The JBI System for the Unified Management, Assessment, and Review of Information tool will be used for data extraction. The scoping review will be reported based on the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines.

RESULTS

Based on the core areas of the scoping review, a 3-step search strategy was developed. The initial search produced 3865 studies. After applying filters, 875 studies were short-listed for further review. Keywords were further refined to yield more relevant studies on the topic.

CONCLUSIONS

The findings are expected to determine the extent of the knowledge gap in the applications of computational methods in PHFs for any traditional medicine across the world. The study can provide answers to open research questions related to the phytochemical identification of PHFs, criteria for target identification, strategies applied for in silico studies, software used, and challenges in adopting in silico methods for understanding the mechanisms of action of PHFs. This study can thus provide a better understanding of the application and types of in silico methods for investigating PHFs.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/56646.

Cu-catalyzed click reaction in synthesis of eugenol derivatives as potent antimalarial agents

Eugenol(1), a terpenoid found in Ocimum, has various biological activities. The present study aims at extraction, isolation of the plant secondary metabolite eugenol (1), it's derivatisation and structure identification as bioactive molecules. Synthesis and antiplasmodial activity (in-vitro and in-vivo), of a series of fourteen novel eugenol-based 1,2,3-triazole derivatives was done in the present study. Derivatives 5a-5n showed good antimalarial activity against the strain Plasmodium falciparum NF54. Derivative 5 m, IC50 at 2.85 µM was found to be several times better than its precursor 1 (106.82 µM) whereas the derivative 5n showed three fold better activity than compound 1, in vitro. The structure-activity relationship of the synthesised compounds indicated that the presence of triazole ring in eugenol analogues is responsible for their good activity. Compound 5m, was further evaluated for in-vivo antimalarial activity which showed about 79% parasitemia suppression. It is the first report on antimalarial activity of triazole eugenol derivatives.

Nanostructured lipid carriers loaded with essential oils: a strategy against SARS-CoV-2

This work aimed to investigate the effectiveness of Lippia sidoides and Syzygium aromaticum essential oils (EOs) encapsulated in nanostructured lipid carriers (NLCs) as SARS-CoV-2 inhibitors through virucidal activity assessment. We developed anionic and cationic NLCs loaded with the EOs and assessed their physicochemical properties and SARS-CoV-2 virucidal activity, focusing on the effects of EO type and the NLCs composition. The NLCs exhibited particle sizes of 141.30 to 160.53 nm for anionic and 109.30 to 138.60 nm for cationic types, with PDIs between 0.16 and 0.25. High zeta potentials (>29.0 in modulus) indicated stable formulations. The NLCs effectively encapsulated the EOs, achieving encapsulation efficiencies between 84.6 to 100% w/w of marker compound. The EOs-loaded NLCs reduced the SARS-CoV-2 virion count, exceeding 2 logs over the control. NLCs loaded with Lippia sidoides and Syzygium aromaticum EOs represent an innovative strategy for combating SARS-CoV-2.

Identification of Cinnamein, a Component of Balsam of Tolu/Peru, as a New Ligand of PPARα for Plaque Reduction and Memory Protection in a Mouse Model of Alzheimer's Disease

Background

Despite intense investigations, no effective treatment is yet available to reduce plaques and protect memory and learning in patients with Alzheimer's disease (AD), the most common neurodegenerative disorder. Therefore, it is important to identify a non-toxic, but effective, treatment option for AD.

Objective

Cinnamein, a nontoxic compound, is naturally available in Balsam of Peru and Tolu Balsam. We examined whether cinnamein treatment could decrease plaques and improve cognitive functions in 5XFAD mouse model of AD.

Methods

We employed in silico analysis, time-resolved fluorescence energy transfer assay, thermal shift assay, primary neuron isolation, western blot, immunostaining, immunohistochemistry, Barnes maze, T maze, and open field behavior.

Results

Oral administration of cinnamein led to significant reduction in amyloid-β plaque deposits in the brain and protection of spatial learning and memory in 5XFAD mice. Peroxisome proliferator-activated receptor alpha (PPARα), a nuclear hormone receptor, is involved in plaque lowering and increase in hippocampal plasticity. While investigating underlying mechanisms, we found that cinnamein served as a ligand of PPARα. Accordingly, oral cinnamein upregulated the level of PPARα, but not PPARβ, in the hippocampus, and remained unable to decrease plaques from the hippocampus and improve memory and learning in 5XFAD mice lacking PPARα. While A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is one of the drivers of nonamyloidogenic pathway, transcription factor EB (TFEB) is considered as the master regulator of autophagy. Cinnamein treatment was found to upregulate both ADAM10 and TFEB in the brain of 5XFAD mice via PPARα.

Conclusions

Our results suggest that this balsam component may have therapeutic importance in AD.

Cinnamic acid, a natural plant compound, exhibits neuroprotection in a mouse model of Sandhoff disease via PPARα

Tay-Sachs disease (TSD) and its severe form Sandhoff disease (SD) are autosomal recessive lysosomal storage metabolic disorders, which often result into excessive GM2 ganglioside accumulation predominantly in lysosomes of nerve cells. Although patients with these diseases appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to early death accompanied by manifestation of motor difficulties and gradual loss of behavioral skills. Unfortunately, there is still no effective treatment available for TSD/SD. The present study highlights the importance of cinnamic acid (CA), a naturally occurring aromatic fatty acid present in a number of plants, in inhibiting the disease process in a transgenic mouse model of SD. Oral administration of CA significantly attenuated glial activation and inflammation and reduced the accumulation of GM2 gangliosides/glycoconjugates in the cerebral cortex of Sandhoff mice. Besides, oral CA also improved behavioral performance and increased the survival of Sandhoff mice. While assessing the mechanism, we found that oral administration of CA increased the level of peroxisome proliferator-activated receptor α (PPARα) in the brain of Sandhoff mice and that oral CA remained unable to reduce glycoconjugates, improve behavior and increase survival in Sandhoff mice lacking PPARα. Our results indicate a beneficial function of CA that utilizes a PPARα-dependent mechanism to halt the progression of SD and thereby increase the longevity of Sandhoff mice.

In vitro Genotoxicity and In silico Docking Analyses of the Essential Oils of Thuja orientalis

Two main objectives were pursued to assess the reliability of Thuja orientalis essential oils (TOEO). The first objective was to extract TOEO, analyze them by GC-MS, and determine their in vitro genotoxicity against selected plants using the RAPD-PCR method. The second objective was to evaluate the in-silico toxicity of TOEO. The binding sites and energies of each content was calculated against B-DNA. In-silico analyses were performed using a simulation program, AutoDock Vina, and Toxicity Estimation Software Tools. 3-carene, cedrol, and 2-pinene were identified as the predominant components. In vitro studies showed that the TOEO had a more significant impact on reducing genomic stability in wheat compared to the amaranth. The lowest stability was determined as 39.78 % in wheat and 53.58 % in amaranth. Cedrol (-5,7 kcal/mol) and selinene (-5,6 kcal/mol) exhibited the highest binding affinity. The toxicity test indicated that components other than cyclohexene may have toxic effects, none of them were predicted to be mutagenic, and LD50 (mol/kg) values could vary between 1.33 and 1.55.

Development of a functional cake with probiotics and micro-encapsulated essential oils: Evaluation of nutritional properties, liver protection, and immune boosting

This study used probiotics and micro-encapsulated clove and cinnamon oils to develop a functional cream-stuffed cake based on sweet potatoes flour and rice flour instead of wheat flour. The cake was evaluated for its physical, chemical, and sensory properties and its antioxidant capacity. The protective effect of the cake against liver injury and immunosuppression induced by thioacetamide injection in male rats was also evaluated. The study found that eugenol and cinnamaldehyde were the majority of volatile compounds in the essential oils used in the cake, with values of 78.73 % and 81.57 %, respectively, as determined by GC-MS analysis. The viable counts of added probiotics in the cake ranged from 13.15 to 11.21 log CFU/g and were still above the threshold for health benefits. The cake had an increased dietary fiber and protein content while containing a low-fat percentage compared to a commercial cake sample. The innovative cake also contained higher levels of water-soluble and fat-soluble vitamins and minerals such as iron, calcium, potassium, and zinc. The antioxidant capacity of the cake was evaluated, and it was found to contain 1827.23 mg GAE/100 g of total phenols and 97.13 mg QE/100 g of flavonoids. The cake was also found to have antioxidant activity and was effective in protecting the liver from oxidative stress and inflammation and reducing immunodeficiency associated with liver damage.

COVID-19 in Dental Practice Is Prevented by Eugenol Responsible for the Ambient Odor Specific to Dental Offices: Possibility and Speculation

Dental professionals routinely work in proximity to patients even when either or both of them have suspected or confirmed COVID-19. The oral cavity also serves as a reservoir for SARS-CoV-2 because the virus is present in and replicates in oral secretions (saliva and gingival crevicular fluid), oral tissues (salivary gland and periodontal tissue), and oral microenvironments (gingival sulcus and periodontal pocket). Despite a high risk of SARS-CoV-2 infection, the prevalence of COVID-19 in dentists, dental hygienists, dental assistants, and their patients was similar to that in the general population even during the pandemic. We propose that eugenol, which is responsible for the ambient odor specific to dental offices, could contribute to prevention of COVID-19 in dental settings. Eugenol is not only released from dental materials (filling, cement, and sealer) but is also aerosolized by dental procedures (grinding, polishing, and restoration). Such eugenol has been suggested to possess the potential to inhibit the infectivity and replication of SARS-CoV-2, the entry of SARS-CoV-2 into human cells by binding specifically to the viral spike protein, and the protease indispensable for SARS-CoV-2 replication. It has been shown that aerosolized eugenol acts on airborne viruses to reduce their loads. This review highlights a hypothesis that the environment of dental offices impregnated with eugenol suppresses SARS-CoV-2 airborne transmission and SARS-CoV-2 contagion between dental professionals and patients, preventing COVID-19 in dental practice. Anti-COVID-19 eugenol might give insights into the safe delivery of dental treatment and oral care in the COVID-19 era.

Ayurveda-based phytochemical composition attenuates lung inflammation and precipitates pharmacokinetic interaction with favipiravir: an in vivo investigation using disease-state of acute lung injury

Acute respiratory distress syndrome (ARDS) is a critical form of acute lung injury (ALI). Here, we investigated the effect of a defined combination of ten pure phytochemicals in equal proportions of weight (NPM) from plants, recommended by Ayurveda for any protective action against lipopolysaccharide (LPS)-induced ALI. Results indicate that NPM markedly improved protein and neutrophil contents, myeloperoxidase and hydroxyproline levels, oxidative stress markers (glutathione and malonaldehyde), inflammatory cytokines, and genes (IL-6, TNF-α, TGF-β, and NF-κB/IκBα) in BALF/lung tissue. The histopathological examination of the lung revealed the shielding effect of NPM against ALI. NPM exhibited a protective effect on the lung by reducing oxidative stress and inhibiting inflammation. A substantial drop in favipiravir's oral exposure was observed in ALI-state compared to normal-state, but oral exposure upon NPM treatment in ALI-state followed similar behaviour of favipiravir alike normal-state without NPM treatment. Overall, results offer potential insight into Ayurvedic recommendations for immunity boosting during ALI situations.

Muscle-building supplement β-hydroxy β-methylbutyrate binds to PPARα to improve hippocampal functions in mice

This study underlines the importance of β-hydroxy β-methylbutyrate (HMB), a muscle-building supplement in human, in increasing mouse hippocampal plasticity. Detailed proteomic analyses reveal that HMB serves as a ligand of peroxisome proliferator-activated receptor α (PPARα), a nuclear hormone receptor involved in fat metabolism, via interaction with the Y314 residue. Accordingly, HMB is ineffective in increasing plasticity of PPARα-/- hippocampal neurons. While lentiviral establishment of full-length PPARα restores the plasticity-promoting effect of HMB in PPARα-/- hippocampal neurons, lentiviral transduction of Y314D-PPARα remains unable to do that, highlighting the importance of HMB's interaction with the Y314 residue. Additionally, oral HMB improves spatial learning and memory and reduces plaque load in 5X familial Alzheimer's disease (5XFAD) mice, but not in 5XFADΔPPARα mice (5XFAD lacking PPARα), indicating the involvement of PPARα in HMB-mediated neuroprotection in 5XFAD mice. These results delineate neuroprotective functions of HMB and suggest that this widely used supplement may be repurposed for AD.

Prenol, but Not Vitamin C, of Fruit Binds to SARS-CoV-2 Spike S1 to Inhibit Viral Entry: Implications for COVID-19

Fruit consumption may be beneficial for fighting infection. Although vitamin C is the celebrity component of fruit, its role in COVID-19 is unclear. Because spike S1 of SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE2) on host cells to enter the cell and initiate COVID-19, using an α-screen-based assay, we screened vitamin C and other components of fruit for inhibiting the interaction between spike S1 and ACE2. We found that prenol, but neither vitamin C nor other major components of fruit (e.g., cyanidin and rutin), reduced the interaction between spike S1 and ACE2. Thermal shift assays indicated that prenol associated with spike S1, but not ACE2, and that vitamin C remained unable to do so. Although prenol inhibited the entry of pseudotyped SARS-CoV-2, but not vesicular stomatitis virus, into human ACE2-expressing HEK293 cells, vitamin C blocked the entry of pseudotyped vesicular stomatitis virus, not SARS-CoV-2, indicating the specificity of the effect. Prenol, but not vitamin C, decreased SARS-CoV-2 spike S1-induced activation of NF-κB and the expression of proinflammatory cytokines in human A549 lung cells. Moreover, prenol also decreased the expression of proinflammatory cytokines induced by spike S1 of N501Y, E484K, Omicron, and Delta variants of SARS-CoV-2. Finally, oral treatment with prenol reduced fever, decreased lung inflammation, enhanced heart function, and improved locomotor activities in SARS-CoV-2 spike S1-intoxicated mice. These results suggest that prenol and prenol-containing fruits, but not vitamin C, may be more beneficial for fighting against COVID-19.

Strategies for the Management of Spike Protein-Related Pathology

In the wake of the COVID-19 crisis, a need has arisen to prevent and treat two related conditions, COVID-19 vaccine injury and long COVID-19, both of which can trace at least part of their aetiology to the spike protein, which can cause harm through several mechanisms. One significant mechanism of harm is vascular, and it is mediated by the spike protein, a common element of the COVID-19 illness, and it is related to receiving a COVID-19 vaccine. Given the significant number of people experiencing these two related conditions, it is imperative to develop treatment protocols, as well as to consider the diversity of people experiencing long COVID-19 and vaccine injury. This review summarizes the known treatment options for long COVID-19 and vaccine injury, their mechanisms, and their evidentiary basis.

Food Plant Secondary Metabolites Antiviral Activity and Their Possible Roles in SARS-CoV-2 Treatment: An Overview

Natural products and plant extracts exhibit many biological activities, including that related to the defense mechanisms against parasites. Many studies have investigated the biological functions of secondary metabolites and reported evidence of antiviral activities. The pandemic emergencies have further increased the interest in finding antiviral agents, and efforts are oriented to investigate possible activities of secondary plant metabolites against human viruses and their potential application in treating or preventing SARS-CoV-2 infection. In this review, we performed a comprehensive analysis of studies through in silico and in vitro investigations, also including in vivo applications and clinical trials, to evaluate the state of knowledge on the antiviral activities of secondary metabolites against human viruses and their potential application in treating or preventing SARS-CoV-2 infection, with a particular focus on natural compounds present in food plants. Although some of the food plant secondary metabolites seem to be useful in the prevention and as a possible therapeutic management against SARS-CoV-2, up to now, no molecules can be used as a potential treatment for COVID-19; however, more research is needed.

Integrative network pharmacology and in silico analyses identify the anti-omicron SARS-CoV-2 potential of eugenol

Eugenol as a natural product is the source of isoniazid, and purified eugenol is extensively used in the cosmetics industry and the productive processes of edible spices. Accumulating evidence suggested that eugenol exerted potent anti-microorganism and anti-inflammation effects. Application of eugenol effectively reduced the risk of atherosclerosis, arterial embolism, and Type 2 diabetes. A previous study confirmed that treatment with eugenol attenuated lung inflammation and improved heart functions in SARS-CoV-2 spike S1-intoxicated mice. In addition to the study, based on a series of public datasets, computational analyses were conducted to characterize the acting targets of eugenol and the functional roles of these targets in COVID-19. The binding capacities of eugenol to conservative sites of SARS-CoV-2 like RNA-dependent RNA polymerase (RdRp) and mutable site as spike (S) protein, were calculated by using molecular docking following the molecular dynamics simulation with RMSD, RMSF, and MM-GBSA methods. The results of network pharmacology indicated that six targets, including PLAT, HMOX1, NUP88, CTSL, ITGB1 andTMPRSS2 were eugenol-SARS-CoV-2 interacting proteins. The omics results of in-silico study further implicated that eugenol increased the expression of SCARB1, HMOX1 and GDF15, especially HMOX1, which were confirmed the potential interacting targets between eugenol and SARS-CoV-2 antigens. Enrichment analyses indicated that eugenol exerted extensive biological effects such as regulating immune infiltration of macrophage, lipid localization, monooxyenase activity, iron ion binding and PPAR signaling. The results of the integrated analysis of eugenol targets and immunotranscription profile of COVID-19 cases shows that eugenol also plays an important role in strengthen of immunologic functions and regulating cytokine signaling. As a complement to the integrated analysis, the results of molecular docking indicated the potential binding interactions between eugenol and four proteins relating to cytokine production/release and the function of T type lymphocytes, including human TLR-4, TCR, NF-κB, JNK and AP-1. Furthermore, results of molecular docking and molecular dynamics (100ns) simulations implicated that stimulated modification of eugenol to the SARS-CoV-2 Omicron Spike-ACE2 complex, especially for human ACE2, and the molecular interaction of eugenol to SARS-CoV-2 RdRp, were no less favorable than two positive controls, molnupiravir and nilotinib. Dynamics (200ns) simulations indicated that the binding capacities and stabilities of eugenol to finger subdomain of RdRp is no less than molnupiravir. However, the simulated binding capacity of eugenol to SARS-CoV-2 wild type RBD and Omicron mutant RBD were less than nilotinib. Eugenol was predicted to have more favor LD50 value and lower cytotoxicity than two positive controls, and eugenol can pass through the blood-brain barrier (BBB). In a brief, eugenol is helpful for attenuating systemic inflammation induced by SARS-CoV-2 infection, due to the direct interaction of eugenol to SARS-CoV-2 proteins and extensive bio-manipulation of pro-inflammatory factors. This study carefully suggests eugenol is a candidate compound of developing drugs and supplement agents against SARS-CoV-2 and its Omicron variants.

Bio-guided chemical characterization and nano-formulation studies of selected edible volatile oils with potentials antibacterial and anti-SARS-CoV-2 activities

The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has opened the door to potential threats of the respiratory system. The discovery of drugs from natural sources is one of the most important strategies for treating the upper respiratory tract. In this study, we investigated the selected formulated EOs activities against Gram-negative (E. coli, K. pneumonia, and P. aeruginosa) and Gram-positive (S. aureus, E. fecalis) bacteria and against the SARS-CoV-2 virus, with the mode of action investigated as anti-SARS-CoV-2. Cinnamomum zeylanicum and Syzygium aromaticum EOs were the most promising antibacterial oils. C. zeylanicum EO showed MIC values of 1, 1, 2, ≤0.5, and 8 µg/mL against E. coli, K. pneumoniae, P. aeruginosa, S. aureus, and E. fecalis, respectively, while S. aromaticum EO showed MIC values of 8, 4, 32, 8, 32 µg/mL against the same organisms. The cytotoxic activity of the oil samples was tested in VERO-E6 cells using (MTT) assay and showed that the safest oil was F. vulgare, then L. nobilis, C. carvi, S. aromaticum, and E. globulus. The most potent antiviral EOs were C. zeylanicum oil and S. aromaticum, with IC₅₀ value of 15.16 and 96.5 µg/mL, respectively. Moreover, the safety index of S. aromaticum EO (26.3) was greater than the oil of C. zeylanicum (7.25). The mechanism by which C. zeylanicum oil exerts its antiviral activity may involve both the virucidal effect and its impact on viral reproduction. The nano-emulsion dosage form of the potent EOs was prepared and re-examined against the same bacterial and viral strains. Finally, the chemical characterization of these promising essential oils was analyzed and identified using the GC-MS approach. To the best of our knowledge, this is the first report concerning the in vitro investigation of anti-SARS-CoV-2 activity of these selected essential oils, along with a proposed mechanism for the potent oil's activity.

Investigation on the Essential Oils of the Achillea Species: From Chemical Analysis to the In Silico Uptake against SARS-CoV-2 Main Protease

In this study, phytochemicals extracted from three different Achillea genera were identified and analyzed to be screened for their interactions with the SARS-CoV-2 main protease. In particular, the antiviral potential of these natural products against the SARS-CoV-2 main protease was investigated, as was their effectiveness against the SARS-CoV-1 main protease as a standard (due to its high similarity with SARS-CoV-2). These enzymes play key roles in the proliferation of viral strains in the human cytological domain. GC-MS analysis was used to identify the essential oils of the Achillea species. Chemi-informatics tools, such as AutoDock 4.2.6, SwissADME, ProTox-II, and LigPlot, were used to investigate the action of the pharmacoactive compounds against the main proteases of SARS-CoV-1 and SARS-CoV-2. Based on the binding energies of kessanyl acetate, chavibetol (m-eugenol), farnesol, and 7-epi-β-eudesmol were localized at the active site of the coronaviruses. Furthermore, these molecules, through hydrogen bonding with the amino acid residues of the active sites of viral proteins, were found to block the progression of SARS-CoV-2. Screening and computer analysis provided us with the opportunity to consider these molecules for further preclinical studies. Furthermore, considering their low toxicity, the data may pave the way for new in vitro and in vivo research on these natural inhibitors of the main SARS-CoV-2 protease.

Selected Phytochemicals to Combat Lungs Injury: Natural Care

The human has two lungs responsible for respiration and drug metabolism. Severe lung infection caused by bacteria, mycobacteria, viruses, fungi, and parasites may lead to lungs injury. Smoking and tobacco consumption may also produce lungs injury. Inflammatory and pain mediators are secreted by alveolar macrophages. The inflammatory mediators, such as cytokines, interleukin (IL)-1, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α, neutrophils, and fibroblasts are accumulated in the alveoli sac, which becomes infected. It may lead to hypoxia followed by severe pulmonary congestion and the death of the patient. There is an urgent need for the treatment of artificial respiration and ventilation. However, the situation may be the worst for patients suffering from lung cancer, pulmonary tuberculosis, and acute pneumonia caused by acute respiratory distress syndrome (ARDS). Re-urgency has been happening in the case of coronavirus disease of 2019 (COVID-19) patients. Therefore, it is needed to protect the lungs with the intake of natural phytomedicines. In the present review, several selected phyto components having the potential role in lung injury therapy have been discussed. Regular intake of natural vegetables and fruits bearing these constituents may save the lungs even in the dangerous attack of SARS-CoV-2 in lung cancer, pulmonary TB, and pneumatic patients.

Regression of Lung Cancer in Mice by Intranasal Administration of SARS-CoV-2 Spike S1

This study underlines the importance of SARS-CoV-2 spike S1 in prompting death in cultured non-small cell lung cancer (NSCLC) cells and in vivo in lung tumors in mice. Interestingly, we found that recombinant spike S1 treatment at very low doses led to death of human A549 NSCLC cells. On the other hand, boiled recombinant SARS-CoV-2 spike S1 remained unable to induce death, suggesting that the induction of cell death in A549 cells was due to native SARS-CoV-2 spike S1 protein. SARS-CoV-2 spike S1-induced A549 cell death was also inhibited by neutralizing antibodies against spike S1 and ACE2. Moreover, our newly designed wild type ACE2-interacting domain of SARS-CoV-2 (wtAIDS), but not mAIDS, peptide also attenuated SARS-CoV-2 spike S1-induced cell death, suggesting that SARS-CoV-2 spike S1-induced death in A549 NSCLC cells depends on its interaction with ACE2 receptor. Similarly, recombinant spike S1 treatment also led to death of human H1299 and H358 NSCLC cells. Finally, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) intoxication led to the formation tumors in lungs of A/J mice and alternate day intranasal treatment with low dose of recombinant SARS-CoV-2 spike S1 from 22-weeks of NNK insult (late stage) induced apoptosis and tumor regression in the lungs. These studies indicate that SARS-CoV-2 spike S1 may have implications for lung cancer treatment.

Chemical Compositions of Clove (Syzygium aromaticum (L.) Merr. & L.) Extracts and Their Potentials in Suppressing SARS-CoV-2 Spike Protein-ACE2 Binding, Inhibiting ACE2, and Scavenging Free Radicals

COVID-19 is initiated by binding the SARS-CoV-2 spike protein to angiotensin-converting enzyme 2 (ACE2) on host cells. Food factors capable of suppressing the binding between the SARS-CoV-2 spike protein and ACE2 or reducing the ACE2 availability through ACE2 inhibitions may potentially reduce the risk of SARS-CoV-2 infection and COVID-19. In this study, the chemical compositions of clove water and ethanol extracts were investigated, along with their potentials in suppressing SARS-CoV-2 spike protein-ACE2 binding, reducing ACE2 availability, and scavenging free radicals. Thirty-four compounds were tentatively identified in the clove water and ethanol extracts, with six reported in clove for the first time. Clove water and ethanol extracts dose-dependently suppressed SARS-CoV-2 spike protein binding to ACE2 and inhibited ACE2 activity. The water extract had stronger inhibitory effects than the ethanol extract on a dry weight basis. The clove water extract also had more potent free radical scavenging activities against DPPH^• and ABTS^•+ (536.9 and 3525.06 μmol TE/g, respectively) than the ethanol extract (58.44 and 2298.01 μmol TE/g, respectively). In contrast, the ethanol extract had greater total phenolic content (TPC) and relative HO^• scavenging capacity (HOSC) values (180.03 mg GAE/g and 2181.08 μmol TE/g, respectively) than the water extract (120.12 mg GAE/g and 1483.02 μmol TE/g, respectively). The present study demonstrated the potential of clove in reducing the risk of SARS-CoV-2 infection and COVID-19 development.

Herbo-mineral formulation, Divya-Swasari-Vati averts SARS-CoV-2 pseudovirus entry into human alveolar epithelial cells by interfering with spike protein-ACE 2 interaction and IL-6/TNF-α /NF-κB signaling

The herbo-mineral formulation, Divya-Swasari-Vati (DSV), is a well-known Ayurvedic medication for respiratory ailments. In a recent pre-clinical study, DSV rescued humanized zebrafish from SARS-CoV-2 S-protein-induced pathologies. This merited for an independent evaluation of DSV as a SARS-CoV-2 entry inhibitor in the human host cell and its effectiveness in ameliorating associated cytokine production. The ELISA-based protein-protein interaction study showed that DSV inhibited the interactions of recombinant human ACE 2 with three different variants of S proteins, namely, Smut 1 (the first reported variant), Smut 2 (W436R variant) and Smut 3 (D614G variant). Entry of recombinant vesicular stomatitis SARS-CoV-2 (VSVppSARS-2S) pseudovirus, having firefly luciferase and EGFP reporters, was assessed through luciferase assay and fluorescent microscopy. DSV exhibited dose-dependent inhibition of VSVppSARS-2S pseudovirus entry into human lung epithelial A549 cells and also suppressed elevated levels of secreted pro-inflammatory cytokines such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) induced by viral infection mimicking Poly I:C-, S-protein- and VSVppSARS-2S pseudovirus. In human immune cells, DSV also moderated TNF-α-mediated NF-κB induction, in a dose-dependent manner. The observed anti-viral effect of DSV against SARS-CoV-2 is attributable to the presence of different metabolites Summarily, the observations from this study biochemically demonstrated that DSV interfered with the interaction between SARS-CoV-2 S-protein and human ACE 2 receptor which consequently, inhibited viral entry into the host cells and concomitant induction of inflammatory response.

Physiological responses and variation in secondary metabolite content among Thai holy basil cultivars (Ocimum tenuiflorum L.) grown under controlled environmental conditions in a plant factory

Holy basil (Ocimum Tenuiflorum L.) is a widely used herb containing several bioactive compounds of interest for the food and pharmaceutical industries. Plant factories using artificial lighting (PFAL) is a modern agricultural system that offers opportunity to improve crop production and stabilizes productivity in many herbal plants. However, little is known about the variation among holy basil varieties that can be cultivated and provide reasonable biomass and bioactive compounds in PFAL. We therefore evaluated 10 Thai accessions and two commercial cultivars in a PFAL (with hydroponic cultivation) to categorize cultivar characteristics by investigating physiological responses and secondary metabolite variation at plant flowering stage. Among Thai varieties, net photosynthetic rate (Pn) was significantly highest in varieties OC059 and OC081. The greatest growth and biomass measures were observed in OC064. Antioxidant capacity also varied, with the greatest accumulation of total phenolic compounds (TPC), flavonoids, and antioxidant activity by DPPH assay in OC064, and highest terpenoid content in OC194. The accumulation of major compounds confirmed by showing the highest levels of eugenol in OC057, OC063, OC194, and OC195 and methyl eugenol in OC072 and OC081. The highest α-humulene content was found in OC059. PCA based on physiological responses and secondary metabolites indicate that OC064 was clearly distinguished from other cultivars/accessions. These findings demonstrate variation across holy basil accessions for physiologic responses, antioxidant capacity, and secondary compounds in PFAL. These insights lead to identification of suitable varieties which is the most important step of developing an efficient method for producing high quality raw materials of Thai holy basil for supplying the foods and pharmaceutical industries.

The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the “Cytokine Storm”, which is a dramatic increase in inflammatory cytokines in the blood. In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or “Long COVID”. Therefore, there is an urgent need to better understand the mechanisms of the virus. The spike protein on the surface of the virus is composed of joined S1–S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm. In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.

An exhaustive comprehension of the role of herbal medicines in Pre- and Post-COVID manifestations

ETHNOPHARMACOLOGICAL RELEVANCE

The coronavirus disease (COVID-19) has relentlessly spread all over the world even after the advent of vaccines. It demands management, treatment, and prevention as well with utmost safety and effectiveness. It is well researched that herbal medicines or natural products have shown promising outcomes to strengthen immunity with antiviral potential against SARS-COV-2.

AIM OF THE REVIEW

Our objective is to provide a comprehensive insight into the preventive and therapeutic effects of herbal medicines and products (Ayurvedic) for pre-and post-COVID manifestations.

MATERIAL AND METHOD

The database used in the text is collected and compiled from Scopus, PubMed, Nature, Elsevier, Web of Science, bioRxiv, medRxiv, American Chemical Society, and clinicaltrials.gov up to January 2022. Articles from non-academic sources such as websites and news were also retrieved. Exploration of the studies was executed to recognize supplementary publications of research studies and systematic reviews. The keywords, such as "SARS-COV-2, coronavirus, COVID-19, herbal drugs, immunity, herbal immunomodulators, infection, herbal antiviral drugs, and WHO recommendation" were thoroughly searched. Chemical structures were drawn using the software Chemdraw Professional 15.0.0.160 (PerkinElmer Informatics, Inc.).

RESULT

A plethora of literature supports that the use of herbal regimens not only strengthen immunity but can also treat SARS-COV-2 infection with minimal side effects. This review summarizes the mechanistic insights into herbal therapy engaging interferons and antibodies to boost the response against SARS-COV-2 infection, several clinical trials, and in silico studies (computational approaches) on selected natural products including, Ashwagandha, Guduchi, Yashtimadhu, Tulsi, etc. as preventive and therapeutic measures against COVID. We have also emphasized the exploitation of herbal medicine-based pharmaceutical products along with perspectives for unseen upcoming alike diseases.

CONCLUSION

According to the current state of art and cutting-edge research on herbal medicines have showed a significant promise as modern COVID tools. Since vaccination cannot be purported as a long-term cure for viral infections, herbal/natural medicines can only be considered a viable alternative to current remedies, as conceived from our collected data to unroot recurring viral infections.

Targeting autophagy regulation in NLRP3 inflammasome-mediated lung inflammation in COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Emerging evidence indicates that the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is activated, which results in a cytokine storm at the late stage of COVID-19. Autophagy regulation is involved in the infection and replication of SARS-CoV-2 at the early stage and the inhibition of NLRP3 inflammasome-mediated lung inflammation at the late stage of COVID-19. Here, we discuss the autophagy regulation at different stages of COVID-19. Specifically, we highlight the therapeutic potential of autophagy activators in COVID-19 by inhibiting the NLRP3 inflammasome, thereby avoiding the cytokine storm. We hope this review provides enlightenment for the use of autophagy activators targeting the inhibition of the NLRP3 inflammasome, specifically the combinational therapy of autophagy modulators with the inhibitors of the NLRP3 inflammasome, antiviral drugs, or anti-inflammatory drugs in the fight against COVID-19.

Effect of natural products use prior to infection with COVID-19 on disease severity and hospitalization: A self-reported cross-sectional survey study

Background: Managing coronavirus disease 2019 (COVID-19) using available resources is essential to reduce the health burden of disease. The severity of COVID-19 is affected by nutritional status. In this study the effect of natural product use prior to infection with COVID-19 on disease severity and hospitalization was explored.

Methods: This was a cross-sectional study. Between March and July 2021, a self-administered survey was conducted in Jordan. Individuals who recovered from COVID-19 and were ≥18 years old were the study population. Study measures included the use of natural products, COVID-19 severity, and hospitalization status. A multivariate regression model was used for statistical analysis.

Results: The mean age (mean ± SD) of the study sample (n=2,148) was 40.25 ± 15.58 years old. Multivariate logistic regression showed that the regular intake of carnation (OR [0.56], CI [0.37–0.85]), onion (OR [0.69], CI [0.52–0.92]), lemon (OR [0.68], CI [0.51–0.90]), and citrus fruits (OR [0.66], CI [0.50–0.89]) before infection were associated with a substantial reduction in COVID-19 severity (P<0.01). Also, the consumption of carnation (OR [0.55], CI [0.34–0.88]), lemon (OR [0.57], CI [0.42–0.78]), and citrus fruits (OR [0.61], CI [0.44–0.84]) were associated with a significant decrease in the frequency of COVID-19-induced hospitalization (P<0.01).

Conclusions: Regular consumption of carnation, lemon, and citrus fruits before infection was associated with better outcomes for COVID-19. Studies on other populations are required to confirm these findings.

Medha Plus - A novel polyherbal formulation ameliorates cognitive behaviors and disease pathology in models of Alzheimer's disease

Alzheimer's disease (AD) is a multi-faceted neurodegenerative disorder that leads to drastic cognitive impairments culminating in death. Pathologically, it is characterized by amyloid-β (Aβ) plaques, neurofibrillary tangles and neurodegeneration in brain. Complete cure of AD remains elusive to date. Available synthetic drugs only provide symptomatic reliefs targeting single molecule, hence, are unable to address the multi-factorial aspects in AD pathogenesis. It is imperative to develop combinatorial drugs that address the multiple molecular targets in AD. We show a unique polyherbal formulation of Brahmi, Mandukaparni, Shankhpushpi, Yastimadhu, Kokilaksha and Shunthi called 'Medha Plus' (MP), conventionally used for improving memory and reducing anxiety, was able to ameliorate cognitive deficits and associated pathological hallmarks of AD. Viability assays revealed that MP prevented Aβ-induced loss of neurites as well as neuronal apoptosis in cellular models. An array of behavioral studies showed that MP was able to recover AD-associated memory deficits in both Aβ-injected rats and 5XFAD mice. Immunohistochemical studies further revealed that MP treatment reduced Aβ depositshpi and decreased apoptotic cell death in the hippocampus. Enzymatic assays demonstrated anti-oxidative and anti-acetyl cholinesterase properties of MP especially in hippocampus of Aβ-injected rats. An underlying improvement in synaptic plasticity was observed with MP treatment in 5XFAD mice along with an increased expression of phospho-Akt at serine 473 indicating a role of PI3K/Akt signaling in correcting these synaptic deficits. Thus, our strong experiment-driven approach shows that MP is an incredible combinatorial drug that targets multiple molecular targets with exemplary neuroprotective properties and is proposed for clinical trial.

The Neuroimmune Pharmacology of SARS-CoV-2

This guest commentary introduces “The Neuroimmune Pharmacology of SARS-CoV-2,” a special theme issue for The Journal of Neuroimmune Pharmacology led by the Society on NeuroImmune Pharmacology. The issue builds on the Society’s Virtual Workshop on COVID-19 held April 9, 2021.