Glycyrrhizin Effectively Inhibits SARS-CoV-2 Replication by Inhibiting the Viral Main Protease

Ursane hybrids with 5-amino-1,2,3,4-thiatriazole, 1-tetrazole-5-thione, and 1-tetrazole-5-amines and study of their inhibition of main SARS-CoV-2 protease

A series of new heterocyclic ursane and 28-norursane hybrids - derivatives of 5-amino-1,2,3,4-thiatriazole, 1-tetrazole-5-thione, and 1-tetrazole-5-amines were prepared. Reacting triterpenoids holding NCS groups at different distances from the pentacyclic backbone with hydrazine hydrate resulted in ursane-derived hydrazinecarbothioamides. Subsequent nitrosation afforded terpenoid derivatives of 5-amino-1,2,3,4-thiatriazole. Heterocyclization of amino-thioureas with 3β-acetoxyurs-12-en-28-yl substituent under the action of Hg(OAc)2-NaN3 led to hybrids of 1-tetrazole-5-amines. 1-Tetrazole-5-thiones with different positions of heterocycle relative to the triterpene skeleton were prepared by coupling sodium azide with triterpene isothiocyanates. The activity of the new heterocyclic derivatives as inhibitors of 3CLpro of SARS-CoV-2 was investigated. Remarkable inhibition was observed for the 1-tetrazole-5-thione hybrids of triterpenoids. The highest activity among the studied compounds was provided by the combination of a 1-tetrazole-5-thione moiety at the C(28)H2 group of the ursane frame having a free OH group at the 3-position. Molecular docking assumed the covalent binding of 3CLpro via the formation of a disulfide bond between the thiol groups of the catalytic Cys145 and the tetrazole heterocycle of the new hybrid compounds. The triterpenoid backbone provided multiple external hydrophobic contacts essential for the stability of the complex. The results demonstrate the potential of heterocyclic thione hybrids as non-peptidomimetic covalent inhibitors targeting 3CLpro protease (3-Chymotrypsin-like Protease).

Berbamine inhibits Pseudorabies virus in vitro and in vivo

Pseudorabies virus (PRV) is a significant pathogen that causes acute infectious diseases in pigs, resulting in considerable economic losses for the global pig industry. The lack of effective control measures and vaccines against the circulating variants of PRV highlights the pressing need for novel treatment strategies. In this study, a screening of a natural product library identified Berbamine as a promising compound that inhibits PRV replication, with a selectivity index of 17. Preliminary investigations demonstrated that Berbamine impedes viral proliferation by targeting the replication and release stages of the PRV life cycle. In experiments with mice artificially infected with PRV, Berbamine significantly alleviated clinical symptoms and histopathological changes in brain tissue caused by PRV infection. Furthermore, molecular docking studies indicated that Berbamine targets the UL50 protein, not only of PRV but also of HSV-1, FHV-1, and BoHV-1. Given that the UL50 protein is a promising target for antiviral drug development, Berbamine holds considerable potential for broad application in antiviral therapies.

The mutual lipid-mediated effect of the transmembrane domain of SARS-CoV-2 E-protein and glycyrrhizin nicotinate derivatives on the localization in the lipid bilayer

Glycyrrhizinic acid (GA) is one of the active substances in licorice root. It exhibits antiviral activity against various enveloped viruses, for example, SARS-CoV-2. GA derivatives are promising biologically active compounds from perspective of developing broad-spectrum antiviral agents. Given that GA nicotinate derivatives (Glycyvir) demonstrate activity against various DNA- and RNA-viruses, a search for a possible mechanism of action of these compounds is required. In the present paper, the interaction of Glycyvir with the transmembrane domain of the SARS-CoV-2 E-protein (ETM) in a model lipid membrane was investigated by NMR spectroscopy and molecular dynamics simulation. The lipid-mediated influence on localization of the SARS-CoV-2 E-protein by Glycyvir was observed. The presence of Glycyvir leads to deeper immersion of the ETM in lipid bilayer. Taking into account that E-protein plays a significant role in virus production and takes part in virion assembly and budding, the data on the effect of potential antiviral agents on ETM localization and structure in the lipid environment may provide a basis for further studies of potential coronavirus E-protein inhibitors.

Glycyrrhizic acid conjugates with amino acid methyl esters target the main protease, exhibiting antiviral activity against wild-type and nirmatrelvir-resistant SARS-CoV-2 variants

COVID-19 pandemic is predominantly caused by SARS-CoV-2, with its main protease, Mpro, playing a pivotal role in viral replication and serving as a potential target for inhibiting different variants. In this study, potent Mpro inhibitors were identified from glycyrrhizic acid (GL) derivatives with amino acid methyl/ethyl esters. Out of the 17 derivatives semisynthesized, Compounds 2, 6, 9, and 15, with methionine methyl esters, D-tyrosine methyl esters, glutamic acid methyl esters, and methionines in the carbohydrate moiety, respectively, significantly inhibited wild-type SARS-CoV-2 Mpro-mediated proteolysis, with IC50 values ranging from 0.06 μM to 0.84 μM. They also demonstrated efficacy in inhibiting trans-cleavage by mutant Mpro variants (Mpro_P132H, Mpro_E166V, Mpro_P168A, Mpro_Q189I), with IC50 values ranging from 0.05 to 0.92 μM, surpassing nirmatrelvir (IC50: 1.17-152.9 μM). Molecular modeling revealed stronger interactions with Valine166 in the structural complex of Mpro_E166V with the compounds compared to nirmatrelvir. Moreover, these compounds efficiently inhibited the post-entry viral processes of wild-type SARS-CoV-2 single-round infectious particles (SRIPs), mitigating viral cytopathic effects and reducing replicon-driven GFP reporter signals, as well as in vitro infectivity of wild-type, Mpro_E166V, and Mpro_Q189I SRIPs, with EC50 values ranging from 0.02 to 0.53 μM. However, nirmatrelvir showed a significant decrease in inhibiting the replication of mutant SARS-CoV-2 SRIPs carrying Mpro_E166V (EC50: >20 μM) and Mpro_Q189I (EC50: 13.2 μM) compared to wild-type SRIPs (EC50: 0.06 μM). Overall, this study identifies four GL derivatives as promising lead compounds for developing treatments against various SARS-CoV-2 strains, including Omicron, and nirmatrelvir-resistant variants.

Anatolian medicinal plants as potential antiviral agents: bridging traditional knowledge and modern science in the fight against COVID-19 and related viral infections

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the cause of the coronavirus 2019 (COVID-19), commonly known as the coronavirus pandemic. Since December 2020, COVID-19 vaccines have been extensively administered in numerous countries. In addition to new antiviral medications, the treatment regimen encompasses symptom management. Despite sustained research efforts, the outbreak remains uncontrolled, with affected patients still lacking proper treatment. This review is a valuable asset for researchers and practitioners aiming to delve into the yet unexplored potential of Anatolian flora in the fight against COVID-19 and other viral infections. Numerous medicinal plants in Anatolia, such as thyme, sage, cannabis, oregano, licorice root, and Origanum sp., contain bioactive compounds with proven antiviral properties that have been used in the region for centuries. The rich legacy of traditional Anatolian medicine (TAM), has significantly influenced modern medicine; thus, the profusion of medicinal plants native to Anatolia holds promise for antiviral drug development, making this review essential for researchers and practitioners.

The efficacy of herbal medicines on the length of stay and negative conversion time/rate outcomes in patients with COVID-19: a systematic review

Introduction

In recent years, diverse initiatives have been carried out to control the COVID-19 pandemic, ranging from measures restricting social activities to analyzing drugs and vaccines. Studies on herbal medicines are also increasingly conducted in various countries as an adjuvant therapy or supplement. Therefore, this systematic review aimed to investigate the efficacy of herbal medicines analyzed from various countries through clinical trials with the randomized controlled trial method. The outcomes of Length of Stay (LOS), Negative Conversion Time (NCT), and Negative Conversion Rate (NCR) were the main focus.

Methods

An extensive review of literature spanning from 2019 to 2023 was carried out using well-known databases including PubMed, Scopus, and Cochrane. The search included relevant keywords such as "randomized controlled trial," "COVID-19," and "herbal medicine."

Results

A total of 8 articles were part of the inclusion criteria with outcomes of LOS, NCT, and NCR. In terms of LOS outcomes, all types of herbal medicines showed significant results, such as Persian Medicine Herbal (PM Herbal), Persian Barley Water (PBW), Jingyin Granules (JY granules), Reduning Injection, and Phyllanthus emblica (Amla). However, only JY granules showed significant results in NCR outcome, while JY granules and Reduning Injection showed significant results in reducing NCT.

Conclusion

These findings enrich our understanding of the potential benefits of herbal medicines in influencing LOS, NCR and NCT parameters in COVID-19 patients. Herbal medicines worked to treat COVID-19 through antiviral, anti-inflammatory, and immunomodulatory mechanisms.

Glycyrrhizin alleviates varicellovirus bovinealpha 1-induced oxidative stress, inflammation, and apoptosis in MDBK cells by inhibiting NF-κB/NLRP3 axis through the Nrf2 signalling pathway

Varicellovirus bovinealpha 1 (BoAHV-1) is one of the crucial pathogens of bovine respiratory diseases, and its pathogenic mechanism involves oxidative stress, inflammation response, and apoptosis. Glycyrrhizin (GLY) possesses powerful antiviral, antioxidant, anti-inflammatory, and anti-apoptotic bioactivities. However, the anti-BoAHV-1 activity of GLY and its role in BoAHV-1-induced oxidative stress, inflammation, and apoptosis remain unclear. Therefore, the current study investigated the anti-BoAHV-1 effect of GLY and its ability to alleviate BoAHV-1-induced oxidative stress, inflammation, and apoptosis using an in vitro model (MDBK cells). Our results showed that BoAHV-1 titers significantly increased in MDBK cells after infection, and GLY reduced the BoAHV-1 titers in MDBK cells exposed to it. Furthermore, Interleukin (IL)-1β, IL-8, tumor necrosis factor (TNF)-α, phosphorylated NF-κB p65 (p-NF-κB p65), the NLR pyrin domain containing 3 (NLRP3), Caspase-1, and Cleaved Caspase-3 levels were significantly upregulated when MDBK cells were challenged with BoAHV-1. In BAY 11-7085 (a specific NF-κB inhibitor) treated MDBK cells, IL-1β, IL-8, TNF-α, p-NF-κB p65, NLRP3, Caspase-1, and Cleaved Caspase-3 levels were downregulated. Notably, GLY treatment had the same trend as the BAY 11-7085 treatment. Thus, these results suggested that GLY exerted anti-inflammatory and anti-apoptotic activities by blocking NF-κB/NLRP3 axis. In addition, after BoAHV-1 infection, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and p-NF-κB p65 and apoptosis rate were increased, and catalase (CAT) and glutathione peroxidase (GSH-Px) enzyme activities, as well as NF-E2-related nuclear factor erythroid-2 (Nrf2) protein expression were repressed. Compared with BoAHV-1-infected MDBK cells, GLY treatment significantly downregulated intracellular ROS, MDA, and p-NF-κB p65 levels and apoptotic rates and significantly increased intracellular CAT and GSH-Px enzyme activities and Nrf2 expression. Additionally, ML385 (a specific Nrf2 inhibitor) abolished the enhancing effect of GLY on Nrf2 and the attenuating effect on ROS, p-NF-κB p65, and apoptosis. These results suggested that GLY had an anti-BoAHV-1 effect and could mitigate BoAHV-1-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2 signalling and restraining NF-κB/NLRP3 axis.

Plant-derived compounds as potential leads for new drug development targeting COVID-19

COVID-19, which was first identified in 2019 in Wuhan, China, is a respiratory illness caused by a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although some patients infected with COVID-19 can remain asymptomatic, most experience a range of symptoms that can be mild to severe. Common symptoms include fever, cough, shortness of breath, fatigue, loss of taste or smell and muscle aches. In severe cases, complications can arise including pneumonia, acute respiratory distress syndrome, organ failure and even death, particularly in older adults or individuals with underlying health conditions. Treatments for COVID-19 include remdesivir, which has been authorised for emergency use in some countries, and dexamethasone, a corticosteroid used to reduce inflammation in severe cases. Biological drugs including monoclonal antibodies, such as casirivimab and imdevimab, have also been authorised for emergency use in certain situations. While these treatments have improved the outcome for many patients, there is still an urgent need for new treatments. Medicinal plants have long served as a valuable source of new drug leads and may serve as a valuable resource in the development of COVID-19 treatments due to their broad-spectrum antiviral activity. To date, various medicinal plant extracts have been studied for their cellular and molecular interactions, with some demonstrating anti-SARS-CoV-2 activity in vitro. This review explores the evaluation and potential therapeutic applications of these plants against SARS-CoV-2. This review summarises the latest evidence on the activity of different plant extracts and their isolated bioactive compounds against SARS-CoV-2, with a focus on the application of plant-derived compounds in animal models and in human studies.

The Potential of Anti-coronavirus Plant Secondary Metabolites in COVID-19 Drug Discovery as an Alternative to Repurposed Drugs: A Review

In early 2020, a global pandemic was announced due to the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), known to cause COVID-19. Despite worldwide efforts, there are only limited options regarding antiviral drug treatments for COVID-19. Although vaccines are now available, issues such as declining efficacy against different SARS-CoV-2 variants and the aging of vaccine-induced immunity highlight the importance of finding more antiviral drugs as a second line of defense against the disease. Drug repurposing has been used to rapidly find COVID-19 therapeutic options. Due to the lack of clinical evidence for the therapeutic benefits and certain serious side effects of repurposed antivirals, the search for an antiviral drug against SARS-CoV-2 with fewer side effects continues. In recent years, numerous studies have included antiviral chemicals from a variety of plant species. A better knowledge of the possible antiviral natural products and their mechanism against SARS-CoV-2 will help to develop stronger and more targeted direct-acting antiviral agents. The aim of the present study was to compile the current data on potential plant metabolites that can be investigated in COVID-19 drug discovery and development. This review represents a collection of plant secondary metabolites and their mode of action against SARS-CoV and SARS-CoV-2.

Metabolite profiling, enzyme inhibitory activity and antioxidant potential of different extracts from Glycyrrhiza foetida Desf. (Fabaceae, Galegeae, Glycyrrhizinae)

Obesity, a risk factor for the development of type 2 diabetes, represents a socio-economic burden for healthcare systems. Consequently multiple studies aiming to facilitate early diagnostic and prevent complications have demonstrated the promising role of phenolic derivatives on diabetes management. In this frame, the present study aimed to establish for the first time the chemical ingredients and to appraise the antioxidant and the enzyme inhibitory properties of Glycyrrhiza foetida aerial parts and roots extracts using methanol, ethyl acetate and chloroform solvents. The phytochemicals were analyzed via (HPLC-MS/MS). In addition, the extracts were tested for inhibitory activities against α-amylase, α-glucosidase, acetylcholinesterase, butyrylcholinesterase, and tyrosinase. The antioxidant capabilities were evaluated using various methods (phospho‑molybdenum, DPPH, ABTS, FRAP, CUPRAC, and metal chelating assays). Notably, twenty-nine secondary metabolites, namely eleven phenolic acids, seventeen flavonoids and a non-phenolic acid have been identified. Delphinidin 3,5-diglucoside, rutin, isoquercitrin, hyperoside, catechin, phloridzin and hesperidin were the major compounds in the aerial parts extracts while trans-cinnamic acid was the dominant compound in roots. Among phenolic acids, vanillic acid was found to be the main constituent in all extracts. The tested extracts were found to yield TPC in amounts ranging from 34.08 to 49.36 mg GAE/g and TFC ranging from 7.01 to 45.74 mg RE/g. G. foetida extracts showed interesting in vitro antioxidant properties. Additionally, all extracts showed a significant anti-tyrosinase activity, with inhibition values ranging between 52.84 and 80.34 mg KAE/g. Thus, G. foetida remains an exceptional matrix for further investigations and application in cosmetics and food additives.

Identification of SARS-CoV-2 Main Protease Inhibitors Using Chemical Similarity Analysis Combined with Machine Learning

SARS-CoV-2 Main Protease (Mpro) is an enzyme that cleaves viral polyproteins translated from the viral genome, which is critical for viral replication. Mpro is a target for anti-SARS-CoV-2 drug development. Herein, we performed a large-scale virtual screening by comparing multiple structural descriptors of reference molecules with reported anti-coronavirus activity against a library with >17 million compounds. Further filtering, performed by applying two machine learning algorithms, identified eighteen computational hits as anti-SARS-CoV-2 compounds with high structural diversity and drug-like properties. The activities of twelve compounds on Mpro's enzymatic activity were evaluated by fluorescence resonance energy transfer (FRET) assays. Compound 13 (ZINC13878776) significantly inhibited SARS-CoV-2 Mpro activity and was employed as a reference for an experimentally hit expansion. The structural analogues 13a (ZINC4248385), 13b (ZNC13523222), and 13c (ZINC4248365) were tested as Mpro inhibitors, reducing the enzymatic activity of recombinant Mpro with potency as follows: 13c > 13 > 13b > 13a. Then, their anti-SARS-CoV-2 activities were evaluated in plaque reduction assays using Vero CCL81 cells. Subtoxic concentrations of compounds 13a, 13c, and 13b displayed in vitro antiviral activity with IC50 in the mid micromolar range. Compounds 13a-c could become lead compounds for the development of new Mpro inhibitors with improved activity against anti-SARS-CoV-2.

Formulation and in vitro characterization of nanoemulsions containing remdesivir or licorice extract: A potential subcutaneous injection for coronavirus treatment

The management of coronavirus necessitates that medicines are available, reasonably priced, and easy to administer. The work aimed at formulating and characterizing remdesivir and licorice extract nanoemulsions and comparing their efficacy against coronavirus for further subcutaneous injection. First, the solubility of remdesivir was determined in different oils, surfactants, and co-surfactants to choose the optimal nanoemulsion components. Nanoemulsions were optimized concerning surfactant: co-surfactant ratio (5:1, 4:1, 3:1, 2:1, and 1:1) and oil to surfactant: co-surfactant ratio (1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, and 1:1). The formulations were evaluated concerning % transmittance, emulsification time, pH, viscosity, droplet size, polydispersity index, zeta potential, drug content, transmission electron microscopy, in-vitro drug release, stability (of the optimal formulas), and antiviral effect against coronavirus. The optimal nanoemulsion formula was F7, exhibiting an acceptable pH level, a rapid emulsification rate, a viscosity of 20 cP, and 100% drug content. The formulation droplet size was 16 and 17 nm, the polydispersity index was 0.18 and 0.26, and the zeta potential was - 6.29 and - 10.34 mV for licorice extract and remdesivir nanoemulsions, respectively. However, licorice extract nanoemulsion exhibited better release and physical stability. Licorice extract nanoemulsion may be a potential subcutaneous injection for combating mild to moderate coronavirus.

Plant-derived strategies to fight against severe acute respiratory syndrome coronavirus 2

The coronavirus disease 2019 (COVID-19) pandemic has caused an unprecedented crisis, which has been exacerbated because specific drugs and treatments have not yet been developed. In the post-pandemic era, humans and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will remain in equilibrium for a long time. Therefore, we still need to be vigilant against mutated SARS-CoV-2 variants and other emerging human viruses. Plant-derived products are increasingly important in the fight against the pandemic, but a comprehensive review is lacking. This review describes plant-based strategies centered on key biological processes, such as SARS-CoV-2 transmission, entry, replication, and immune interference. We highlight the mechanisms and effects of these plant-derived products and their feasibility and limitations for the treatment and prevention of COVID-19. The development of emerging technologies is driving plants to become production platforms for various antiviral products, improving their medicinal potential. We believe that plant-based strategies will be an important part of the solutions for future pandemics.

Nebulized glycyrrhizin/enoxolone drug modulates IL-17A in COVID-19 patients: a randomized clinical trial

Introduction

Glycyrrhizin (GA) and its derivative Enoxolone (18β), isolated from the Glycyrrhiza glabra plant, are two potential molecules for treating viral diseases. Both demonstrate to regulate immune system with antiviral and anti-inflammatory activities, with the latter mainly due to modulation of inflammatory cytokines. The aim of this clinical trial was to evaluate the safety and efficacy of a nebulized GA/18β drug for treating COVID-19 patients.

Methods

An open label, randomized, placebo-controlled clinical trial was conducted in Mexico City from January-August 2022 (Registration No. PROTAP-CLI-00). Clinical and biochemical parameters were recorded. Blood samples from patients were regularly collected to evaluate interleukins IL-4, IL-2, IL-1b, TNF-α, IL-17A, IL-6, IL-10,IFN-γ, IL-12, IL-8 and TGF-β1, as well as IgM and IgG against SARS-CoV-2. Two doses of the drug were used - 30/2 mg (dose A) and 90/4 mg (dose B).

Results and discussion

Both GA/18β doses modulated inflammatory response by reducing mainly IL-17A expression, which in turn kept IL-1β, IL-6, IL-8 and TNF-α interleukins unchanged, indicating significant modulation of key interleukin levels to prevent exacerbation of the immune response in COVID-19 patients. Early on, dose A increased IgM, while dose B induced expression of the antiviral IFN-γ. No severe side effects were seen with either dose, indicating nebulized GA/18β is a safe treatment that could be used for COVID-19 and potentially other viral infections involving inflammatory response.

COVID-19-associated liver injury: Adding fuel to the flame

COVID-19 is mainly characterized by respiratory disorders and progresses to multiple organ involvement in severe cases. With expansion of COVID-19 and SARS-CoV-2 research, correlative liver injury has been revealed. It is speculated that COVID-19 patients exhibited abnormal liver function, as previously observed in the SARS and MERS pandemics. Furthermore, patients with underlying diseases such as chronic liver disease are more susceptible to SARS-CoV-2 and indicate a poor prognosis accompanied by respiratory symptoms, systemic inflammation, or metabolic diseases. Therefore, COVID-19 has the potential to impair liver function, while individuals with preexisting liver disease suffer from much worse infected conditions. COVID-19 related liver injury may be owing to direct cytopathic effect, immune dysfunction, gut-liver axis interaction, and inappropriate medication use. However, discussions on these issues are infancy. Expanding research have revealed that angiotensin converting enzyme 2 (ACE2) expression mediated the combination of virus and target cells, iron metabolism participated in the virus life cycle and the fate of target cells, and amino acid metabolism regulated immune response in the host cells, which are all closely related to liver health. Further exploration holds great significance in elucidating the pathogenesis, facilitating drug development, and advancing clinical treatment of COVID-19-related liver injury. This article provides a review of the clinical and laboratory hepatic characteristics in COVID-19 patients, describes the etiology and impact of liver injury, and discusses potential pathophysiological mechanisms.

Structure and function of SARS-CoV and SARS-CoV-2 main proteases and their inhibition: A comprehensive review

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) identified in 2003 infected ∼8000 people in 26 countries with 800 deaths, which was soon contained and eradicated by syndromic surveillance and enhanced quarantine. A closely related coronavirus SARS-CoV-2, the causative agent of COVID-19 identified in 2019, has been dramatically more contagious and catastrophic. It has infected and caused various flu-like symptoms of billions of people in >200 countries, including >6 million people died of or with the virus. Despite the availability of several vaccines and antiviral drugs against SARS-CoV-2, finding new therapeutics is needed because of viral evolution and a possible emerging coronavirus in the future. The main protease (Mpro) of these coronaviruses plays important roles in their life cycle and is essential for the viral replication. This article represents a comprehensive review of the function, structure and inhibition of SARS-CoV and -CoV-2 Mpro, including structure-activity relationships, protein-inhibitor interactions and clinical trial status.

Activation of PXR causes drug interactions with Paxlovid in transgenic mice

Paxlovid is a nirmatrelvir (NMV) and ritonavir (RTV) co-packaged medication used for the treatment of coronavirus disease 2019 (COVID-19). The active component of Paxlovid is NMV and RTV is a pharmacokinetic booster. Our work aimed to investigate the drug/herb-drug interactions associated with Paxlovid and provide mechanism-based guidance for the clinical use of Paxlovid. By using recombinant human cytochrome P450s (CYPs), we confirmed that CYP3A4 and 3A5 are the major enzymes responsible for NMV metabolism. The role of CYP3A in Paxlovid metabolism were further verified in Cyp3a-null mice, which showed that the deficiency of CYP3A significantly suppressed the metabolism of NMV and RTV. Pregnane X receptor (PXR) is a ligand-dependent transcription factor that upregulates CYP3A4/5 expression. We next explored the impact of drug- and herb-mediated PXR activation on Paxlovid metabolism in a transgenic mouse model expressing human PXR and CYP3A4/5. We found that PXR activation increased CYP3A4/5 expression, accelerated NMV metabolism, and reduced the systemic exposure of NMV. In summary, our work demonstrated that PXR activation can cause drug interactions with Paxlovid, suggesting that PXR-activating drugs and herbs should be used cautiously in COVID-19 patients receiving Paxlovid.

Culinary spices and herbs in managing early and long-COVID-19 complications: A comprehensive review

Human race is preparing for the upsurge and aftermath of COVID-19 pandemic complicated by novel variants, new waves, variable mortality rate, and post-COVID complications. Despite use of repurposed drugs, symptomatic treatments and licensing of multiple vaccines, the daily number of cases and rate of transmission are significant. Culinary spices and herbs have been historically used in pandemic and non-pandemic times to reduce respiratory viral burden. Specific food items and culinary spices can boost the levels of protective immunity and also offer therapeutic benefits against impervious bugs via well-known as well as less-known but scientifically testable mechanisms. Here, we analyzed the phytochemicals profile of Ayurvedic herbs and inferred from the clinical trials/observational studies to provide a focused and succinct perspective on the relevance of "food-based" traditional decoction to moderate COVID-19 disease and long-COVID via modulation of immunity and reinstatement of homeostasis. We also underscore the druggable targets in pathogenesis of COVID-19 which are relevant to the ongoing clinical trials using spices and herbs. This information will provide a strong scientific rationale for standardization of the traditional herbs-based therapies and adopting the use of herbs, spices, and their formulations for reducing SARS-CoV-2 transmission, long-COVID symptoms, and COVID-19 disease progression.

Contribution of traditional Japanese Kampo medicines, kakkonto with shosaikotokakikyosekko, in treating patients with mild-to-moderate coronavirus disease 2019: Further analysis of a multicenter, randomized controlled trial

We previously reported the finding of symptom relief in a randomized controlled trial with the combined use of kakkonto and shosaikotokakikyosekko added to conventional treatment in patients with coronavirus disease 2019 (COVID-19). For further evaluation, we performed post hoc analysis focused on symptom disappearance without recurrence, to determine a clearer effect of Kampo medicine. Patients with mild and moderate COVID-19 were randomly allocated to a control group receiving symptomatic therapy or a Kampo group receiving kakkonto (2.5 g) with shosaikotokakikyosekko (2.5 g) three times daily in addition to symptomatic therapy. The data of 161 patients (Kampo group, n = 81; control group, n = 80) were analyzed post hoc for the time to symptom disappearance. Kaplan-Meier and Cox proportional hazard estimates of disappearance of symptoms showed that all and each symptom targeted in this study disappeared faster in the Kampo group than in the control group, although not statistically significant (all symptomatic cases; hazard ratio [HR] 3.73, 95% confidence interval [CI] 0.46-29.98, log-rank p = 0.1763). In a supplemental assessment using covariate adjustment and competing risk analysis, fever disappeared faster in the Kampo group than in the control group (all symptomatic cases, HR 1.62, 95% CI 0.99-2.64, p = 0.0557; unvaccinated cases, HR 1.68, 95% CI 1.00-2.83, p = 0.0498) and shortness of breath disappeared significantly faster in Kampo group than in control group (all symptomatic cases, HR 1.92, 95% CI 1.07-3.42, p = 0.0278; unvaccinated cases, HR 2.15, 95% CI 1.17-3.96, p = 0.0141). These results demonstrate the advantages of Kampo treatment for acute COVID-19.

Neuroprotective Agents with Therapeutic Potential for COVID-19

COVID-19 patients can exhibit a wide range of clinical manifestations affecting various organs and systems. Neurological symptoms have been reported in COVID-19 patients, both during the acute phase of the illness and in cases of long-term COVID. Moderate symptoms include ageusia, anosmia, altered mental status, and cognitive impairment, and in more severe cases can manifest as ischemic cerebrovascular disease and encephalitis. In this narrative review, we delve into the reported neurological symptoms associated with COVID-19, as well as the underlying mechanisms contributing to them. These mechanisms include direct damage to neurons, inflammation, oxidative stress, and protein misfolding. We further investigate the potential of small molecules from natural products to offer neuroprotection in models of neurodegenerative diseases. Through our analysis, we discovered that flavonoids, alkaloids, terpenoids, and other natural compounds exhibit neuroprotective effects by modulating signaling pathways known to be impacted by COVID-19. Some of these compounds also directly target SARS-CoV-2 viral replication. Therefore, molecules of natural origin show promise as potential agents to prevent or mitigate nervous system damage in COVID-19 patients. Further research and the evaluation of different stages of the disease are warranted to explore their potential benefits.

A combination of structure-based virtual screening and experimental strategies to identify the potency of caffeic acid ester derivatives as SARS-CoV-2 3CLpro inhibitor from an in-house database

Drug development requires significant time and resources, and computer-aided drug discovery techniques that integrate chemical and biological spaces offer valuable tools for the process. This study focused on the field of COVID-19 therapeutics and aimed to identify new active non-covalent inhibitors for 3CLpro, a key protein target. By combining in silico and in vitro approaches, an in-house database was utilized to identify potential inhibitors. The drug-likeness criteria were considered to pre-filter 553 compounds from 12 groups of natural products. Using structure-based virtual screening, 296 compounds were identified that matched the chemical features of SARS-CoV-2 3CLpro peptidomimetic inhibitor pharmacophore models. Subsequent molecular docking resulted in 43 hits with high binding affinities. Among the hits, caffeic acid analogs showed significant interactions with the 3CLpro active site, indicating their potential as promising candidates. To further evaluate their efficacy, enzyme-based assays were conducted, revealing that two ester derivatives of caffeic acid (4k and 4l) exhibited more than a 30% reduction in 3CLpro activity. Overall, these findings suggest that the screening approach employed in this study holds promise for the discovery of novel anti-SARS-CoV-2 therapeutics. Furthermore, the methodology could be extended for optimization or retrospective evaluation to enhance molecular targeting and antiviral efficacy of potential drug candidates.

Exploring the binding effect and mechanism of glycyrrhizin to ovomucin by combining spectroscopic analysis and molecular docking

Ovomucin (OVM) is an ideal natural macromolecular glycoprotein extracted from eggs with good adhesion. Based on the defect that glycyrrhizin (GL) has good antiviral activity but fast metabolism, this study aimed to explore the binding effect and mechanism of GL to OVM, using multi-spectroscopic techniques, isothermal titration calorimetry (ITC), and molecular docking. The adhesion ability of OVM to the hydrophilic interface and GL was first demonstrated by dual polarization interferometry (DPI) analysis and binding capacity assay, and the OVM-GL complex exhibited a similar affinity for the spike protein of COVID-19. The spectroscopic results show that GL can quench the inherent fluorescence and change the glycosidic bond and secondary structure of OVM. The ITC measurements suggested that the binding was exothermic, the hydrogen bond was the dominant binding force for forming OVM-GL. Finally, molecular docking results indicated that GL has hydrogen bond interaction with several amino acid residues located in α-OVM and β-OVM while embedding into the hydrophobic pocket of OVM via hydrophobic interactions. In conclusion, OVM can adhere to the hydrophilic interface and bind to GL through hydrogen bonding and hydrophobic interactions to form a stable complex, that is expected to be helpful in virus prophylaxis.

Plausibility of natural immunomodulators in the treatment of COVID-19-A comprehensive analysis and future recommendations

The COVID-19 pandemic has inflicted millions of deaths worldwide. Despite the availability of several vaccines and some special drugs approved for emergency use to prevent or treat this disease still, there is a huge concern regarding their effectiveness, adverse effects, and most importantly, their efficacy against the new variants. A cascade of immune-inflammatory responses is involved with the pathogenesis and severe complications with COVID-19. People with dysfunctional and compromised immune systems display severe complications, including acute respiratory distress syndrome, sepsis, multiple organ failure etc., when they get infected with the SARS-CoV-2 virus. Plant-derived natural immune-suppressant compounds, such as resveratrol, quercetin, curcumin, berberine, luteolin, etc., have been reported to inhibit pro-inflammatory cytokines and chemokines. Therefore, natural products with immunomodulatory and anti-inflammatory potential could be plausible targets to treat this contagious disease. This review aims to delineate the clinical trials status and outcomes of natural compounds with immunomodulatory potential in COVID-19 patients along with the outcomes of their in-vivo studies. In clinical trials several natural immunomodulators resulted in significant improvement of COVID-19 patients by diminishing COVID-19 symptoms such as fever, cough, sore throat, and breathlessness. Most importantly, they reduced the duration of hospitalization and the need for supplemental oxygen therapy, improved clinical outcomes in patients with COVID-19, especially weakness, and eliminated acute lung injury and acute respiratory distress syndrome. This paper also discusses many potent natural immunomodulators yet to undergo clinical trials. In-vivo studies with natural immunomodulators demonstrated reduction of a wide range of proinflammatory cytokines. Natural immunomodulators that were found effective, safe, and well tolerated in small-scale clinical trials are warranted to undergo large-scale trials to be used as drugs to treat COVID-19 infections. Alongside, compounds yet to test clinically must undergo clinical trials to find their effectiveness and safety in the treatment of COVID-19 patients.

The role of HMGB1 in COVID-19-induced cytokine storm and its potential therapeutic targets: A review

Hyperinflammation characterized by elevated proinflammatory cytokines known as 'cytokine storms' is the major cause of high severity and mortality seen in COVID-19 patients. The pathology behind the cytokine storms is currently unknown. Increased HMGB1 levels in serum/plasma of COVID-19 patients were reported by many studies, which positively correlated with the level of proinflammatory cytokines. Dead cells following SARS-CoV-2 infection might release a large amount of HMGB1 and RNA of SARS-CoV-2 into extracellular space. HMGB1 is a well-known inflammatory mediator. Additionally, extracellular HMGB1 might interact with SARS-CoV-2 RNA because of its high capability to bind with a wide variety of molecules including nucleic acids and could trigger massive proinflammatory immune responses. This review aimed to critically explore the many possible pathways by which HMGB1-SARS-CoV-2 RNA complexes mediate proinflammatory responses in COVID-19. The contribution of these pathways to impair host immune responses against SARS-CoV-2 infection leading to a cytokine storm was also evaluated. Moreover, since blocking the HMGB1-SARS-CoV-2 RNA interaction might have therapeutic value, some of the HMGB1 antagonists have been reviewed. The HMGB1- SARS-CoV-2 RNA complexes might trigger endocytosis via RAGE which is linked to lysosomal rupture, PRRs activation, and pyroptotic death. High levels of the proinflammatory cytokines produced might suppress many immune cells leading to uncontrolled viral infection and cell damage with more HMGB1 released. Altogether these mechanisms might initiate a proinflammatory cycle leading to a cytokine storm. HMGB1 antagonists could be considered to give benefit in alleviating cytokine storms and serve as a potential candidate for COVID-19 therapy.

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.

Fighting cytokine storm and immunomodulatory deficiency: By using natural products therapy up to now

A novel coronavirus strain (COVID-19) caused severe illness and mortality worldwide from 31 December 2019 to 21 March 2023. As of this writing, 761,071,826 million cases have been diagnosed worldwide, with 6,879,677 million deaths accorded by WHO organization and has spread to 228 countries. The number of deaths is closely connected to the growth of innate immune cells in the lungs, mainly macrophages, which generate inflammatory cytokines (especially IL-6 and IL-1β) that induce "cytokine storm syndrome" (CSS), multi-organ failure, and death. We focus on promising natural products and their biologically active chemical constituents as potential phytopharmaceuticals that target virus-induced pro-inflammatory cytokines. Successful therapy for this condition is currently rare, and the introduction of an effective vaccine might take months. Blocking viral entrance and replication and regulating humoral and cellular immunity in the uninfected population are the most often employed treatment approaches for viral infections. Unfortunately, no presently FDA-approved medicine can prevent or reduce SARS-CoV-2 access and reproduction. Until now, the most important element in disease severity has been the host's immune response activation or suppression. Several medicines have been adapted for COVID-19 patients, including arbidol, favipiravir, ribavirin, lopinavir, ritonavir, hydroxychloroquine, chloroquine, dexamethasone, and anti-inflammatory pharmaceutical drugs, such as tocilizumab, glucocorticoids, anakinra (IL-1β cytokine inhibition), and siltuximab (IL-6 cytokine inhibition). However, these synthetic medications and therapies have several side effects, including heart failure, permanent retinal damage in the case of hydroxyl-chloroquine, and liver destruction in the case of remdesivir. This review summarizes four strategies for fighting cytokine storms and immunomodulatory deficiency induced by COVID-19 using natural product therapy as a potential therapeutic measure to control cytokine storms.

New insights for infection mechanism and potential targets of COVID-19: Three Chinese patent medicines and three Chinese medicine formulas as promising therapeutic approaches

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high pathogenicity and infectiousness has become a sudden and lethal pandemic worldwide. Currently, there is no accepted specific drug for COVID-19 treatment. Therefore, it is extremely urgent to clarify the pathogenic mechanism and develop effective therapies for patients with COVID-19. According to several reliable reports from China, traditional Chinese medicine (TCM), especially for three Chinese patent medicines and three Chinese medicine formulas, has been demonstrated to effectively alleviate the symptoms of COVID-19 either used alone or in combination with Western medicines. In this review, we systematically summarized and analyzed the pathogenesis of COVID-19, the detailed clinical practice, active ingredients investigation, network pharmacology prediction and underlying mechanism verification of three Chinese patent medicines and three Chinese medicine formulas in the COVID-19 combat. Additionally, we summarized some promising and high-frequency drugs of these prescriptions and discussed their regulatory mechanism, which provides guidance for the development of new drugs against COVID-19. Collectively, by addressing critical challenges, for example, unclear targets and complicated active ingredients of these medicines and formulas, we believe that TCM will represent promising and efficient strategies for curing COVID-19 and related pandemics.

Antiviral effects of phytochemicals against severe acute respiratory syndrome coronavirus 2 and their mechanisms of action: A review

The worldwide spreading of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to health, economic, environmental, and social aspects of human lives. Currently, there are no approved treatments that can effectively block the virus although several existing antimalarial and antiviral agents have been repurposed and allowed use during the pandemic under the emergency use authorization (EUA) status. This review gives an updated overview of the antiviral effects of phytochemicals including alkaloids, flavonoids, and terpenoids against the COVID-19 virus and their mechanisms of action. Search for natural lead molecules against SARS-CoV-2 has been focusing on virtual screening and in vitro studies on phytochemicals that have shown great promise against other coronaviruses such as SARS-CoV. Until now, there is limited data on in vivo investigations to examine the antiviral activity of plants in SARS-CoV-2-infected animal models and the studies were performed using crude extracts. Further experimental and preclinical investigations on the in vivo effects of phytochemicals have to be performed to provide sufficient efficacy and safety data before clinical studies can be performed to develop them into COVID-19 drugs. Phytochemicals are potential sources of new chemical leads for the development of safe and potent anti-SARS-CoV-2 agents.

Molecular docking, molecular dynamics simulation and MM-GBSA studies of the activity of glycyrrhizin relevant substructures on SARS-CoV-2 RNA-dependent-RNA polymerase

SARS-CoV-2 is the causative agent of Coronavirus Disease (COVID-19), which is a life-threatening disease. The World Health Organization has classified COVID-19 as a severe worldwide public health pandemic due to its high death rate, quick transmission, and lack of medicines. To counteract the recurrence of the severe acute respiratory syndrome, active antiviral medications are urgently required. Glycyrrhizin was documented with activity on different viral proteins, including SARS-CoV-2; in this study, the activity of glycyrrhizin and its substructures (604 molecules) were screened on SARS-CoV-2 RNA-dependent-RNA polymerase using molecular docking, molecular dynamic (MD) simulation, and MM/GBSA. Sixteen molecules exhibited docking energy higher than -7 kcal/mol; four compounds (10772603, 101088272, 154730753 and glycyrrhizin) showed the highest binding energy, and good stability during MD simulation. The glycyrrhizin compound exhibited favorable docking energy (-7.9 kcal/mol), and it was the most stable complex during MD simulation. The predicted binding free energy of the glycyrrhizin complex was -57 ± 8 kcal/mol. These findings suggest that this molecule, after more validation, could become a good candidate for developing and manufacturing an anti-SARS-CoV-2 medication.Communicated by Ramaswamy H. Sarma.

Dengue virus induced autophagy is mediated by HMGB1 and promotes viral propagation

Dengue virus (DENV) exploits various cellular pathways including autophagy to assure enhanced virus propagation. The mechanisms of DENV mediated control of autophagy pathway are largely unknown. Our investigations have revealed a novel role for high-mobility group box1 protein (HMGB1) in regulation of cellular autophagy process in DENV-2 infected A549 cell line. While induction of autophagy by rapamycin treatment resulted in enhanced DENV-2 propagation, the blockade of autophagy flux with bafilomycin A1 suppressed viral replication. Furthermore, siRNA-mediated silencing of HMGB1 significantly abrogated dengue induced autophagy, while LPS induced HMGB1 expression counteracted these effects. Interestingly, silencing of HMGB1 showed reduction of BECN1 and stabilization of BCL-2 protein. On the contrary, LPS induction of HMGB1 resulted in enhanced BECN1 and reduction in BCL-2 levels. This study shows that the modulation of autophagy by DENV-2 is HMGB1/BECN1 dependent. In addition, glycyrrhizic acid (GA), a potent HMGB1 inhibitor suppressed autophagy as well as DENV-2 replication. Altogether, our data suggests that HMGB1 induces BECN1 dependent autophagy to promote DENV-2 replication.

Molecular Screening of Bioactive Compounds of Garlic for Therapeutic Effects against COVID-19

An outbreak of pneumonia occurred on December 2019 in Wuhan, China, which caused a serious public health emergency by spreading around the globe. Globally, natural products are being focused on more than synthetic ones. So, keeping that in view, the current study was conducted to discover potential antiviral compounds from Allium sativum. Twenty-five phytocompounds of this plant were selected from the literature and databases including 3-(Allylsulphinyl)-L-alanine, Allicin, Diallyl sulfide, Diallyl disulfide, Diallyl trisulfide, Glutathione, L-Cysteine, S-allyl-mercapto-glutathione, Quercetin, Myricetin, Thiocysteine, Gamma-glutamyl-Lcysteine, Gamma-glutamylallyl-cysteine, Fructan, Lauricacid, Linoleicacid, Allixin, Ajoene, Diazinon Kaempferol, Levamisole, Caffeicacid, Ethyl linoleate, Scutellarein, and S-allylcysteine methyl-ester. Virtual screening of these selected ligands was carried out against drug target 3CL protease by CB-dock. Pharmacokinetic and pharmacodynamic properties defined the final destiny of compounds as drug or non-drug molecules. The best five compounds screened were Allicin, Diallyl Sulfide, Diallyl Disulfide, Diallyl Trisulfide, Ajoene, and Levamisole, which showed themselves as hit compounds. Further refining by screening filters represented Levamisole as a lead compound. All the interaction visualization analysis studies were performed using the PyMol molecular visualization tool and LigPlot+. Conclusively, Levamisole was screened as a likely antiviral compound which might be a drug candidate to treat SARS-CoV-2 in the future. Nevertheless, further research needs to be carried out to study their potential medicinal use.

Chemical composition, antifungal and antibiofilm activities of essential oils from Glycyrrhiza foetida (Desf.) growing in Tunisia

This study was designated to investigate the chemical composition, the antifungal activity and antibiofilm properties of Glycyrrhiza foetida (Desf.) growing in Tunisia and recognized for its pharmacological and therapeutic effects. The chemical analysis of essential oil samples prepared via hydrodistillation of the aerial parts was performed by gas chromatography-mass spectrometry (GC-MS). Moreover, the antifungal activity of G. foetida essential oil was developed against three dermatophyte strains, two molds and Candida spp. yeasts using the broth microdilution assay. According to the percentages, the main constituents are δ-cadinene (13.9%), (E)-caryophyllene (13.2%) and γ-cadinene (8.3%). The efficiency of the essential oil in inhibiting Candida albicans biofilms formation was also evaluated in terms of inhibitory percentages. The results showed that C. albicans and Microsporum canis were the most sensitive to G. foetida essential oil with a complete inhibition at 0.4 and 0.2 mg ml^-1 , respectively. Candida albicans biofilm development was reduced by 80% by the volatile oil at a concentration of 0.8 mg ml^-1 . The essential oil of G. foetida has a promising role in the control of fungal agents with medical interest and in inhibition of Candida biofilm development.

Inhibitory Activity of Saussurea costus Extract against Bacteria, Candida, Herpes, and SARS-CoV-2

Medicinal herbs have long been utilized to treat various diseases or to relieve the symptoms of some ailments for extended periods. The present investigation demonstrates the phytochemical profile, molecular docking, anti-Candida activity, and anti-viral activity of the Saussurea costus acetic acid extract. GC-MS analysis of the extract revealed the presence of 69 chemical compounds. The chemical compounds were alkaloids (4%), terpenoids (79%), phenolic compounds (4%), hydrocarbons (7%), and sterols (6%). Molecular docking was used to study the inhibitory activity of 69 identified compounds against SARS-CoV-2. In total, 12 out of 69 compounds were found to have active properties exhibiting SARS-CoV-2 inhibition. The binding scores of these molecules were significantly low, ranging from -7.8 to -5.6 kcal/mol. The interaction of oxatricyclo [20.8.0.0(7,16)] triaconta-1(22),7(16),9,13,23,29-hexaene with the active site is more efficient. Furthermore, the extract exhibited significant antimicrobial activity (in vitro) against Candida albicans, which was the most susceptible microorganism, followed by Bacillus cereus, Salmonella enterica, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, respectively. On the other hand, its antiviral activity was evaluated against HSV-1 and SARS-CoV-2, and the results showed a significant positive influence against HSV-1 (EC₅₀ = 82.6 g/mL; CC₅₀ = 162.9 g/mL; selectivity index = 1.9). In spite of this, no impact could be observed in terms of inhibiting the entry of SARS-CoV-2 in vitro.

Discovery of Natural Bisbenzylisoquinoline Analogs from the Library of Thai Traditional Plants as SARS-CoV-2 3CLPro Inhibitors: In Silico Molecular Docking, Molecular Dynamics, and In Vitro Enzymatic Activity

The emergence of SARS-CoV-2 in December 2019 has become a global issue due to the continuous upsurge in patients and the lack of drug efficacy for treatment. SARS-CoV-2 3CL^Pro is one of the most intriguing biomolecular targets among scientists worldwide for developing antiviral drugs due to its relevance in viral replication and transcription. Herein, we utilized computer-assisted drug screening to investigate 326 natural products from Thai traditional plants using structure-based virtual screening against SARS-CoV-2 3CL^Pro. Following the virtual screening, the top 15 compounds based on binding energy and their interactions with key amino acid Cys145 were obtained. Subsequently, they were further evaluated for protein-ligand complex stability via molecular dynamics simulation and binding free energy calculation using molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approaches. Following drug-likeness and ADME/Tox assessments, seven bisbenzylisoquinolines were obtained, including neferine (3), liensinine (4), isoliensinine (5), dinklacorine (8), tiliacorinine (13), 2'-nortiliacorinine (14), and yanangcorinine (15). These compounds computationally showed a higher binding affinity than native N3 and GC-373 inhibitors and attained stable interactions on the active site of 3CL^pro during 100 ns in molecular dynamics (MD) simulation. Moreover, the in vitro enzymatic assay showed that most bisbenzylisoquinolines could experimentally inhibit SARS-CoV-2 3CL^Pro. To our delight, isoliensinine (5) isolated from Nelumbo nucifera demonstrated the highest inhibition of protease activity with the IC₅₀ value of 29.93 μM with low toxicity on Vero cells. Our findings suggested that bisbenzylisoquinoline scaffolds could be potentially used as an in vivo model for the development of effective anti-SARS-CoV-2 drugs.

Traditional Tibetan medicine to fight against COVID-19: Basic theory and therapeutic drugs

The Coronavirus Diseases 2019 (COVID-19) has been rapidly spreading globally and has caused severe harm to the health of people and a substantial social burden. In response to this situation, experts around the world have considered various treatments, including the use of traditional medicine. Traditional Tibetan medicine (TTM), one of the traditional medicines in China, has played an important role in the treatment of infectious diseases in history. It has formed a solid theoretical foundation and accumulated rich experience in the treatment of infectious diseases. In this review, we provide a comprehensive introduction to the basic theory, treatment strategies, and commonly used drugs of TTM for the treatment of COVID-19. In addition, the efficacies and potential mechanisms of these TTM drugs against COVID-19 are discussed based on available experimental data. This review may provide important information for the basic research, clinical application and drug development of traditional medicines for the treatment of COVID-19 or other infectious diseases. More pharmacological studies are needed to reveal the therapeutic mechanisms and active ingredients of TTM drugs in the treatment of COVID-19.

Towards a transactional medicine approach to combating global emerging pathogens: the case of COVID-19

When the COVID-19 pandemic struck and China reported the first case to the World Health Organization in December 2019, there was no evidence-based treatment to combat it. With the catastrophic situation that followed, materialised by a considerable number of deaths, researchers, doctors, traditional healers, and governments of all nations committed themselves to find therapeutic solutions, including preventive and curative. There are effective treatments offered both by modern medicine and traditional medicine for COVID-19 today. However, other therapeutic proposals have not been approved due to the lack of effectiveness and scientific rigour during their development process. Proponents of modern medicine prefer biomedical therapies while in some countries, traditional treatments are used regularly because of their availability, affordability and satisfaction they bring to the population. In this paper, we propose a transactional medicine approach where the interaction between traditional and modern medicine produces a change. With this approach, the promoters of traditional medicine and those of modern medicine will be able to acquire knowledge through the experience produced by their encounters. Transactional medicine aims to be a model for decolonising medicine and recognising the value of both traditional and modern medicine in the fight against COVID-19 and other global emerging pathogens.

Long-Term Vaccination and Treatment Strategies for COVID-19 Disease and Future Coronavirus Pandemics

The appearance of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with increased infectivity and immune escape capabilities has allowed continuation of the COVID-19 pandemic for the foreseeable future. This review describes the worldwide efforts aimed at developing new vaccination and treatment strategies to keep pace with these variants as they emerge. In the case of vaccines and monoclonal antibody-based therapeutics, we describe the development of variant-specific, multivalent, and universal coronavirus directed approaches. Existing treatment approaches consist of repurposed medicines, such as antiviral compounds and anti-inflammatory agents, although efforts are underway to develop new ways of preventing or minimizing the effects of infection with the use of small molecules that disrupt binding the SARS-CoV-2 virus to host cells. Finally, we discuss the preclinical and clinical testing of natural products from medicinal herbs and spices, which have demonstrated anti-inflammatory and antiviral properties and therefore show potential as novel and safe COVID-19 treatment approaches.

Evaluation of noscapine-licorice combination effects on cough relieving in COVID-19 outpatients: A randomized controlled trial

Background: As February 2023, SARS-CoV-2 is still infecting people and children worldwide. Cough and dyspnea are annoying symptoms almost present in a large proportion of COVID-19 outpatients, and the duration of these symptoms might be long enough to affect the patients' quality of life. Studies have shown positive effects for noscapine plus licorice in the previous COVID-19 trials. This study aimed to assess the effects of the combination of noscapine and licorice-for relieving cough in outpatients with COVID-19. Methods: This randomized controlled trial was conducted on 124 patients at the Dr. Masih Daneshvari Hospital. Participants over 18 years of age with confirmed COVID-19 and cough were allowed to enter the study if the onset of symptoms was less than 5 days. The primary outcome was to assess the response to treatment over 5 days using the visual analogue scale. Secondary outcomes included the assessment of cough severity after 5 days using Cough Symptom Score, as well as the cough-related quality of life and dyspnea relieving. Patients in the noscapine plus licorice group received Noscough^® syrup 20 mL every 6 h for 5 days. The control group received diphenhydramine elixir 7 mL every 8 h. Results: By day five, 53 (85.48%) patients in the Noscough^® group and 49 (79.03%) patients in the diphenhydramine group had response to treatment. This difference was not statistically significant (p-value = 0.34). The presence of dyspnea was significantly lower in the Noscough^® group versus diphenhydramine at day five (1.61% in the Noscough^® group vs. 12.9% in the diphenhydramine group; p-value = 0.03). The cough-related quality of life and severity also significantly favored Noscough^® syrup (p-values <0.001). Conclusion: Noscapine plus licorice syrup was slightly superior to diphenhydramine in relieving cough symptoms and dyspnea in the COVID-19 outpatients. The severity of cough and cough-related quality of life were also significantly better in the noscapine plus licorice syrup. Noscapine plus licorice may be a valuable treatment in relieving cough in COVID-19 outpatients.

Assessment of the potential value of combining western medicine therapies with traditional chinese medicine in the treatment of COVID-19: Mechanistic perspectives

BACKGROUND

The pandemic caused by the novel coronavirus disease (COVID-19) since early 2020 is one of the most significant global health issues in history. Although there is currently no specific treatment for COVID-19, researchers have provided a whole array of potential treatments, both from the Western medicine approach, which is molecular target and pathogenesis based, and from the traditional Chinese medicine (TCM) approach, which is based on the exposure to toxins/pathogens and the balance of the body to combat them for recovery.

OBJECTIVE

The aim of this research is to find combinations of Western medicine and TCM that may offer better therapeutic efficacy synergystically with a better adverse events profile. The findings of the research may provide a new insight in the development of the treatment of COVID-19.

METHODS

From the Western medicine perspective, drugs target the mechanisms of viral infection, including the stages of viral entry (Arbidol, Camostat Mesylate, Convalescent Plasma therapy) and viral replication (Lopinavir/Ritonavir, Redemsivir, Ribavirin). Additional therapies target host defenses, preventing cytokine storms (Tocilizumab) and stimulating the immune system (Interferons). On the other hand, TCM also proposed a number of treatment methods for COVID-19 with new scientific approaches identifying their antiviral and immunomodulatory activities. The novel combination of Western medicine and TCM can be proposed by analyzing their respective molecular targets.

RESULTS

Although TCM is not generally accepted in the Western community because of the general lack of knowledge on their detailed mechanisms, studies and clinical trials suggest that TCM could be beneficial in combating COVID-19.

CONCLUSION

Based on the principle of combining TCM and Western medicine, two combinations are tested effective in clinical trials, and three possible combinations that might be effective are proposed in the paper.

Clinical efficacy of Jingyin granules, a Chinese patent medicine, in treating patients infected with coronavirus disease 2019

BACKGROUND

Jingyin granules (JY), one patented Chinese herbal formula, have been advised for treating coronavirus disease 2019 (COVID-19) in China. As of now, the safety and effectiveness of JY in treating COVID-19 patients were still to be evaluated.

PURPOSE

To investigate the safety and clinical effectiveness of JY in treating mild COVID-19 patients.

STUDY DESIGN

We carried out a prospective cohort study, as the highly infectious COVID-19 omicron variant ranged in Shanghai (ClinicalTrial.gov registration number: ChiCTR2200058692).

METHODS

Participants infected with COVID-19, who were diagnosed as mild cases, were assigned to receive either JY (JY group) or traditional Chinese medicine placebo (placebo group) orally for 7 days. The primary clinical indicators were the RNA negative conversion rate (NCR) and the incidence of severe cases. The secondary clinical indicators were the negative conversion time (NCT), inpatient length of stay (ILOS), and the disappearance rates of clinical symptoms.

RESULTS

Nine hundred participants were recruited in this clinical trial study, and 830 patients met the eligibility criteria. Seven hundred and ninety-one patients, accomplished the following-up assessment, including 423 cases of JY group and 368 cases of placebo group. NCR in JY group at 7-day posttreatment was considerably greater compared with placebo group (89.8% [380/423] vs 82.6% [304/368], P = 0.003). None of the patients with mild COVID-19 developed into severe cases. The median NCT of SARS-CoV-2 and ILOS in JY group were lesser than that in placebo group (4.0 [3.0,6.0]vs 5.0 [4.0,7.0] days, P < 0.001; 6.0 [4.0, 8.0] vs 7.0 [5.0, 9.0] days, P < 0.001). In both groups, the obvious improvement in clinical symptoms was observed, but the difference was not significant. In the subgroup of age ≤ 60 years, JY promoted SARS-CoV-2 RNA negative conversion (HR=1.242; 95% CI: 1.069-1.444, P < 0.001). No patients in both groups were reported as the case of serious adverse event.

CONCLUSION

JY maybe the potential medicine for treating mild COVID-19 patients, which had beneficial effects on increasing NCR, and shortening NCT and ILOS.

In Silico Identification of Anti-SARS-CoV-2 Medicinal Plants Using Cheminformatics and Machine Learning

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of COVID-19, is spreading rapidly and has caused hundreds of millions of infections and millions of deaths worldwide. Due to the lack of specific vaccines and effective treatments for COVID-19, there is an urgent need to identify effective drugs. Traditional Chinese medicine (TCM) is a valuable resource for identifying novel anti-SARS-CoV-2 drugs based on the important contribution of TCM and its potential benefits in COVID-19 treatment. Herein, we aimed to discover novel anti-SARS-CoV-2 compounds and medicinal plants from TCM by establishing a prediction method of anti-SARS-CoV-2 activity using machine learning methods. We first constructed a benchmark dataset from anti-SARS-CoV-2 bioactivity data collected from the ChEMBL database. Then, we established random forest (RF) and support vector machine (SVM) models that both achieved satisfactory predictive performance with AUC values of 0.90. By using this method, a total of 1011 active anti-SARS-CoV-2 compounds were predicted from the TCMSP database. Among these compounds, six compounds with highly potent activity were confirmed in the anti-SARS-CoV-2 experiments. The molecular fingerprint similarity analysis revealed that only 24 of the 1011 compounds have high similarity to the FDA-approved antiviral drugs, indicating that most of the compounds were structurally novel. Based on the predicted anti-SARS-CoV-2 compounds, we identified 74 anti-SARS-CoV-2 medicinal plants through enrichment analysis. The 74 plants are widely distributed in 68 genera and 43 families, 14 of which belong to antipyretic detoxicate plants. In summary, this study provided several medicinal plants with potential anti-SARS-CoV-2 activity, which offer an attractive starting point and a broader scope to mine for potentially novel anti-SARS-CoV-2 drugs.

Arjunetin as a promising drug candidate against SARS-CoV-2: molecular dynamics simulation studies

Stem and bark of the tree Terminalia arjuna Wight & Arn. (Combretaceae) has been documented to exhibit therapeutic properties like cardiotonic, anticancer, antiviral, antibacterial, antifungal, hypercholesterolemia, hypolipidemic, and anti-coagulant. Our previous studies have shown that, ethanolic extract of T. arjuna bark exhibits radical scavenging anti-oxidant activity and also effectively inhibited catalase activity. In this study, oleanane triterpenoids type compounds viz., oleanolic acid, arjunolic acid, arjunolitin, arjunetin were isolated from ethanolic bark extract as bio-active compound and their structures were elucidated using ¹H, ¹³C NMR, HR-ESIMS, IR. Of the various compounds, Arjunetin showed significant inhibition of catalase activity as compared to the other compounds. Based on the structural similarity between arjunetin and current antiviral drugs, we propose that arjunetin might exhibit antiviral activity. Molecular docking and molecular dynamics studies showed that arjunetin binds to the binds to key targets of SARS-CoV-2 namely, 3CLpro, PLpro, and RdRp) with a higher binding energy values (3CLpro, -8.4 kcal/mol; PLpro, -7.6 kcal/mol and RdRp, -8.1 kcal/mol) as compared with FDA approved protease inhibitor drugs to Lopinavir (3CLpro, -7.2 kcal/mole and PLpro -7.7 kcal/mole) and Remdesivir (RdRp -7.6 kcal/mole). To further investigate this, we performed 200-500 ns molecular dynamics simulation studies. The results transpired that the binding affinity of Arjunetin is higher than Remdesivir in the RNA binding cavity of RdRp. Based on structural similarity between arjunetin and Saikosaponin (a known antiviral agents) and based on our molecular docking and molecular dynamic simulation studies, we propose that arjunetin can be a promising drug candidate against Covid-19.Communicated by Ramaswamy H. Sarma.

Glycyrrhizin and boswellic acids, the golden nutraceuticals: multitargeting for treatment of mild-moderate COVID-19 and prevention of post-COVID cognitive impairment

Breakthrough infections have been reported in fully vaccinated persons. Furthermore, rebound symptoms have been reported following the new FDA granted emergency use to combat SARS-CoV-2. Glycyrrhizin (GR) and boswellic acids (BAs) combination has been shown to have highly successful actions against COVID-19 in our recent clinical trial. However, the study is limited by the small sample size, and therefore, the aim of this article is to comprehensively evaluate recent evidence on the efficacy of GR and BAs in preventing the development of COVID-19 in patients with mild and moderate infections and in preventing post-COVID-19 cognitive impairment, which is the most important symptom after recovery from Covid-19 disease. We have reviewed and discussed information published since the outbreak of the COVID-19 pandemic until July 2022 on preclinical (in vivo, in vivo and bioinformatics) and clinical studies related to the antiviral, anti-inflammatory and immunomodulatory activity of Gr and BAs. Sixteen studies were performed to determine the efficacy of GR against SARS-CoV-2. Ten studies were used primarily for in vitro and in vivo assays and six used molecular docking studies. However, the antiviral activity of BAs against SARS-CoV-2 was determined in only five studies using molecular modeling and bioinformatics. All these studies confirmed that GR n and BAs have strong antiviral activity and can be used as a therapeutic agent for COVID-19 and as a protective agent against SARS-CoV-2. They may act by inhibiting the main protease SARS-CoV-2 (Mpro) responsible for replication and blocking spike protein-mediated cell entry. Only seven rigorously designed clinical trials regarding the usefulness of GR, BAs or their combinations in the treatment of COVID-19 have been published as of July 2022. Although there is no clinical study regarding the treatment of cognitive impairment after COVID-19 that has been published so far, several preclinical and clinical studies have demonstrated the potential effect of GR and BAs in the prevention and treatment of cognitive impairment by inhibiting the activity of several molecules that activate inflammatory signaling pathway. In conclusion, the findings of our study documented the beneficial use of GR and BAs to treat SARS-CoV-2 and its variants and prevent post-COVID cognitive impairment. However, it warrants further studies with a larger randomized sample size to ensure that the studies have sufficient evidence of benefits against COVID-19 and post-COVID-19 symptoms.

Broad Antiviral Spectrum of Glycyrrhizic Acid for Human and Veterinary Medicine: Reality or Fiction?

BACKGROUND

Emerging virus infections provoke health problems in people and animals, which generate social and economic issues worldwide. This has spurred the search for new pharmacological strategies to confront them.

SUMMARY

The purpose of this review is to draw the reader's attention to pharmacological evaluations of glycyrrhizic acid (GA) and its analogs on the broad range of viruses known in human and veterinary medicine. GA is the main water-soluble constituent extracted from the roots of plants from the genus Glycyrrhiza, commonly known as licorice root. It has long been used due to its broad spectrum of bioactivities, including anti-inflammatory, antiulcer, and antitumor properties. It has also been proposed as an antiviral agent. Medicines derived from GA are currently being used to combat acute and chronic hepatitis and herpes viruses.

KEY MESSAGES

This review suggests that GA could be a new broad-spectrum antiviral due to its ability to inhibit DNA or RNA viruses both in vitro and in vivo. GA could be a potential drug for preventing and/or treating various viral diseases.

Identification of potential anti-pneumonia pharmacological components of Glycyrrhizae Radix et Rhizoma after the treatment with Gan An He Ji oral liquid

Glycyrrhizae Radix et Rhizoma, a traditional Chinese medicine also known as Gan Cao (GC), is frequently included in clinical prescriptions for the treatment of pneumonia. However, the pharmacological components of GC for pneumonia treatment are rarely explored. Gan An He Ji oral liquid (GAHJ) has a simple composition and contains GC liquid extracts and paregoric, and has been used clinically for many years. Therefore, GAHJ was selected as a compound preparation for the study of GC in the treatment of pneumonia. We conducted an in vivo study of patients with pneumonia undergoing GAHJ treatments for three days. Using the intelligent mass spectrometry data-processing technologies to analyze the metabolism of GC in vivo, we obtained 168 related components of GC in humans, consisting of 24 prototype components and 144 metabolites, with 135 compounds screened in plasma and 82 in urine. After analysis of the metabolic transformation relationship and relative exposure, six components (liquiritin, liquiritigenin, glycyrrhizin, glycyrrhetinic acid, daidzin, and formononetin) were selected as potential effective components. The experimental results based on two animal pneumonia models and the inflammatory cell model showed that the mixture of these six components was effective in the treatment of pneumonia and lung injury and could effectively downregulate the level of inducible nitric oxide synthase (iNOS). Interestingly, glycyrrhetinic acid exhibited the strongest inhibition on iNOS and the highest exposure in vivo. The following molecular dynamic simulations indicated a strong bond between glycyrrhetinic acid and iNOS. Thus, the current study provides a pharmaceutical basis for GC and reveals the possible corresponding mechanisms in pneumonia treatment.

Role of ethno-phytomedicine knowledge in healthcare of COVID-19: advances in traditional phytomedicine perspective

Background

Since the outbreak of the COVID-19 virus, ethnomedicinal plants have been used in diverse geographical locations for their purported prophylactic and pharmacological effects. Medicinal plants have been relied on by people around the globe for centuries, as 80% of the world’s population rely on herbal medicines for some aspect of their primary health care needs, according to the World Health Organization.

Main body

This review portrays advances in traditional phytomedicine by bridging the knowledge of ethno-phytomedicine and COVID-19 healthcare. Ethnomedicinal plants have been used for symptoms related to COVID-19 as antiviral, anti-infective, anti-inflammatory, anti-oxidant, antipyretic, and lung–gut immune boosters. Traditionally used medicinal plants have the ability to inhibit virus entry and viral assembly, bind to spike proteins, membrane proteins, and block viral replications and enzymes. The efficacy of traditional medicinal plants in the terms of COVID-19 management can be evaluated by in vitro, in vivo as well as different in silico techniques (molecular docking, molecular dynamics simulations, machine learning, etc.) which have been applied extensively to the quest and design of effective biotherapeutics rapidly. Other advances in traditional phytomedicines against COVID-19 are controlled clinical trials, and notably the roles in the gut microbiome. Targeting the gut microbiome via medicinal plants as prebiotics is also found to be an alternative and potential strategy in the search for a COVID-19 combat strategy.

Conclusions

Since medicinal plants are the sources of modern biotherapeutics development, it is essential to build collaborations among ethnobotanists, scientists, and technologists toward developing the most efficient and the safest adjuvant therapeutics against the pandemic of the twenty-first century, COVID-19.

Multicenter, randomized controlled trial of traditional Japanese medicine, kakkonto with shosaikotokakikyosekko, for mild and moderate coronavirus disease patients

The traditional Japanese (Kampo) medicine, kakkonto with shosaikotokakikyosekko, has antiviral and anti-inflammatory effects. In this randomized trial, patients with mild and moderate coronavirus disease (COVID-19) were randomly allocated to the control group receiving conventional treatment for symptom relief such as antipyretics and antitussives or the Kampo group receiving mixed extract granules of kakkonto (2.5 g) and shosaikotokakikyosekko (2.5 g) three times a day for 14 days in addition to conventional treatment. The main outcome was the number of days until total symptom relief. The secondary outcome was the number of days until each symptom's relief and whether the disease progressed to respiratory failure. We enrolled a total of 161 patients (Kampo group, n = 81; control group, n = 80). The results from Kaplan-Meier estimates of symptom relief showed that there are no significant differences between the groups. However, covariate-adjusted cumulative incidence of fever relief considering competitive risk showed that the recovery was significantly faster in the Kampo group than in the control group (HR 1.76, 95% CI 1.03-3.01). Additionally, the risk of disease progression to moderate COVID-19 requiring oxygen inhalation was lower in the Kampo group than in the control group (Risk Difference -0.13, 95% CI -0.27-0.01). No significant drug-related side effects were observed. Kakkonto with shosaikotokakikyosekko is effective for fever relief with suppression of disease progression in COVID-19 patients. Clinical Trial Registration: https://jrct.niph.go.jp/en-latest-detail/jRCTs021200020, identifier [jRCTs021200020].

Efficacy and safety of glycyrrhizic acid preparation treating comorbid liver injury in COVID-19: A systematic review

Background: No specific drug for COVID-19 has been found, and many studies have found that different degrees of liver injury often occurred after infection with COVID-19. Glycyrrhizic acid preparation (GAP) has been frequently used clinically, often combined with conventional treatments such as antiviral therapy, to improve the prognosis of COVID-19 and patients' liver function. Aims: To critically review and analyze clinical evidence on the efficacy and safety of GAP in the treatment of COVID-19 alone and COVID-19 with comorbid liver injury. Methods: A systematic literature review was performed following a sensitive searching strategy that examines all articles published in "WHO COVID-19 Research Database," "Cochrane Library," "VIP," "CNKI," "Wanfang," and "CBM" from 2020 to July 2022. Articles were evaluated by peer reviewers and used Joanna Briggs Institute (JBI) critical appraisal tools to complete the assessment of the risk of bias. Results: Ten clinical studies were finally included, involving 598 patients with COVID-19, of whom 189 were confirmed to be with comorbid liver injury. The main GAPs used are diammonium glycyrrhizinate and magnesium isoglycyrrhizinate, which have shown efficacy in improving liver function, inhibiting inflammation, and enhancing immunity. We are still seeking more related research. Conclusion: Glycyrrhizic acid preparations (mainly diammonium glycyrrhizinate and magnesium isoglycyrrhizinate) have a considerable clinical effect on improving liver function in patients with COVID-19 alone or with comorbid liver injury. Further studies on the use of GAP in the treatment of COVID-19 with comorbid liver injury and its mechanism are still needed. Systematic Review Registration: [www.crd.york.ac.uk/prospero], identifier [CRD42021234647].