Probing the effect of quercetin 3-glucoside from Dianthus superbus L against influenza virus infection- In vitro and in silico biochemical and toxicological screening

Exploring Bioactive Phytomedicines for Advancing Pulmonary Infection Management: Insights and Future Prospects

Pulmonary infections have a profound influence on global mortality rates. Medicinal plants offer a promising approach to address this challenge, providing nontoxic alternatives with higher levels of public acceptance and compliance, particularly in regions where access to conventional medications or diagnostic resources may be limited. Understanding the pathophysiology of viruses and bacteria enables researchers to identify biomarkers essential for triggering diseases. This knowledge allows the discovery of biological molecules capable of either preventing or alleviating symptoms associated with these infections. In this review, medicinal plants that have an effect on COVID-19, influenza A, bacterial and viral pneumonia, and tuberculosis are discussed. Drug delivery has been briefly discussed as well. It examines the effect of bioactive constituents of these plants and synthesizes findings from in vitro, in vivo, and clinical studies conducted over the past decade. In conclusion, many medicinal plants can be used to treat pulmonary infections, but further in-depth studies are needed as most of the current studies are only at preliminary stages. Extensive investigation and clinical studies are warranted to fully elucidate their mechanisms of action and optimize their use in clinical practice.

Phytochemical analysis and biological evaluation of Ferulago setifolia K. Koch

BACKGROUND

Ferulago setifolia K. Koch (Apiaceae) has been the subject of this study, aiming to comprehensively determine its phenolic fingerprint and evaluate its various biological activities. The liquid chromatography-tandem mass spectrometry analysis of the 70% methanol extract of F. setifolia (FS) revealed the presence of 23 phytochemicals, among which chlorogenic acid, quinic acid, kaempferol-3-O-glucoside, and quercetin-3-O-glucoside were identified as the major phenolics in the extract.

RESULTS

The biological screening included examinations of antioxidant, antibacterial, antiproliferative, and cytotoxic activities. The FS extract displayed moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging and ferric-reducing capacity, indicating moderate antioxidant activity. Furthermore, FS exhibited significant antiproliferative effects on cancer cells while showing low cytotoxicity on normal cells. The antibacterial activity findings revealed that FS demonstrated potent activity against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus, and Escherichia coli.

CONCLUSION

The findings of this study suggest that the methanolic extract of FS holds promise as a potential source of biologically active compounds. It can be utilized for the development of pharmaceutical formulations, thanks to its significant antiproliferative and antibacterial activities. Additionally, FS can serve as a valuable source of chlorogenic acid for industrial applications. © 2023 Society of Chemical Industry.

A potential Chinese medicine monomer against influenza A virus and influenza B virus: isoquercitrin

BACKGROUND

Influenza viruses, especially Influenza A virus and Influenza B virus, are respiratory pathogens and can cause seasonal epidemics and pandemics. Severe influenza viruses infection induces strong host-defense response and excessive inflammatory response, resulting in acute lung damage, multiple organ failure and high mortality. Isoquercitrin is a Chinese medicine monomer, which was reported to have multiple biological activities, including antiviral activity against HSV, IAV, SARS-CoV-2 and so on. Aims of this study were to assess the in vitro anti-IAV and anti-IBV activity, evaluate the in vivo protective efficacy against lethal infection of the influenza virus and searched for the more optimal method of drug administration of isoquercitrin.

METHODS

In vitro infection model (MDCK and A549 cells) and mouse lethal infection model of Influenza A virus and Influenza B virus were used to evaluate the antiviral activity of isoquercitrin.

RESULTS

Isoquercitrin could significantly suppress the replication in vitro and in vivo and reduced the mortality of mouse lethal infection models. Compared with virus infection group, isoquercitrin mitigated lung and multiple organ damage. Moreover, isoquercitrin blocked hyperproduction of cytokines induced by virus infection via inactivating NF-κB signaling. Among these routes of isoquercitrin administration, intramuscular injection is a better drug delivery method.

CONCLUSION

Isoquercitrin is a potential Chinese medicine monomer Against Influenza A Virus and Influenza B Virus infection.

Phenolic Compounds in Salicornia spp. and Their Potential Therapeutic Effects on H1N1, HBV, HCV, and HIV: A Review

Despite public health risk mitigation measures and regulation efforts by many countries, regions, and sectors, viral outbreaks remind the world of our vulnerability to biological hazards and the importance of mitigation actions. The saltwater-tolerant plants in the Salicornia genus belonging to the Amaranthaceae family are widely recognized and researched as producers of clinically applicable phytochemicals. The plants in the Salicornia genus contain flavonoids, flavonoid glycosides, and hydroxycinnamic acids, including caffeic acid, ferulic acid, chlorogenic acid, apigenin, kaempferol, quercetin, isorhamnetin, myricetin, isoquercitrin, and myricitrin, which have all been shown to support the antiviral, virucidal, and symptom-suppressing activities. Their potential pharmacological usefulness as therapeutic medicine against viral infections has been suggested in many studies, where recent studies suggest these phenolic compounds may have pharmacological potential as therapeutic medicine against viral infections. This study reviews the antiviral effects, the mechanisms of action, and the potential as antiviral agents of the aforementioned phenolic compounds found in Salicornia spp. against an influenza A strain (H1N1), hepatitis B and C (HBV/HCV), and human immunodeficiency virus 1 (HIV-1), as no other literature has described these effects from the Salicornia genus at the time of publication. This review has the potential to have a significant societal impact by proposing the development of new antiviral nutraceuticals and pharmaceuticals derived from phenolic-rich formulations found in the edible Salicornia spp. These formulations could be utilized as a novel strategy by which to combat viral pandemics caused by H1N1, HBV, HCV, and HIV-1. The findings of this review indicate that isoquercitrin, myricetin, and myricitrin from Salicornia spp. have the potential to exhibit high efficiency in inhibiting viral infections. Myricetin exhibits inhibition of H1N1 plaque formation and reverse transcriptase, as well as integrase integration and cleavage. Isoquercitrin shows excellent neuraminidase inhibition. Myricitrin inhibits HIV-1 in infected cells. Extracts of biomass in the Salicornia genus could contribute to the development of more effective and efficient measures against viral infections and, ultimately, improve public health.

Green synthesis of silver nanoparticles mediated Diospyros kaki L. (Persimmon): determination of chemical composition and evaluation of their antimicrobials and anticancer activities

The eco-friendly synthesis of metallic nanoparticles (MNPs) using biological materials is an encouraging and innovativeness approach to nanotechnology. Among other synthesizing methods, biological methods are chosen because of their high efficiency and purity in many aspects. In this work, using the aqueous extract obtained from the green leaves of the D. kaki L. (DK); silver nanoparticles were synthesized in a short time and simply with an eco-friendly approach. The properties of the synthesized silver nanoparticles (AgNPs) were characterized using various techniques and measurements. In the characterization data of AgNPs, Maximum absorbance at 453.34 nm wavelengths, the average size distribution of 27.12 nm, the surface charge of -22.4 mV, and spherical appearance were observed. LC-ESI-MS/MS analysis was used to assess the compound composition of D. kaki leaf extract. The chemical profiling of the crude extract of D. kaki leaves revealed the presence of a variety of phytochemicals, predominantly phenolics, resulting in the identification of five major high-feature compounds: two major phenolic acids (Chlorogenic acid and Cynarin), and tree flavonol glucosides (hyperoside, quercetin-3-glucoside, and quercetin-3- D-xyloside). The components with the highest concentrations were cynarin, chlorogenic acid, quercetin-3- D-xyloside, hyperoside, and quercetin-3-glucoside, respectively. Antimicrobial results were determined by a MIC assay. The biosynthesized AgNPs exhibited strong antibacterial activity against the human and food pathogen Gram (+ and -) bacteria and good antifungal activity against pathogenic yeast. It was determined that 0.03-0.050 μg/mL concentrations ranges of DK-AgNPs were growth suppressive concentrations on all pathogen microorganisms. The MTT technique was used to study the cytotoxic effects of produced AgNPs on cancer cell lines (Glioblastoma (U118), Human Colorectal Adenocarcinoma (Caco-2), Human Ovarian Sarcoma (Skov-3) cancer cell lines, and Human Dermal Fibroblast (HDF) healthy cell line). It has been observed that they have a suppressive effect on the proliferation of cancerous cell lines. After 48 h of treatment with Ag-NPs, the DK-AgNPs were found to be extremely cytotoxic to the CaCo-2 cell line, inhibiting cell viability by up to 59.49% at a concentration of 50 g mL^-1. It was found that the viability was inversely related to the DK-AgNP concentration. The biosynthesized AgNPs had dose-dependent anticancer efficacy. Because of the high concentration of bioactive chemicals in Diospyros kaki, it may be employed as a biological resource in medicinal applications. DK-AgNPs were shown to be an effective antibacterial agent as well as a prospective anticancer agent. The results provide a potential approach for the biogenic production of DK-AgNPs utilizing D. kaki aqueous leaf extract.

Plant Extracts and SARS-CoV-2: Research and Applications

The recent pandemic of COVID-19 caused by the SARS-CoV-2 virus has brought upon the world an unprecedented challenge. During its acute dissemination, a rush for vaccines started, making the scientific community come together and contribute to the development of efficient therapeutic agents and vaccines. Natural products have been used as sources of individual molecules and extracts capable of inhibiting/neutralizing several microorganisms, including viruses. Natural extracts have shown effective results against the coronavirus family, when first tested in the outbreak of SARS-CoV-1, back in 2002. In this review, the relationship between natural extracts and SARS-CoV is discussed, while also providing insight into misinformation regarding the use of plants as possible therapeutic agents. Studies with plant extracts on coronaviruses are presented, as well as the main inhibition assays and trends for the future regarding the yet unknown long-lasting effects post-infection with SARS-CoV-2.

Quercetin: A Functional Food-Flavonoid Incredibly Attenuates Emerging and Re-Emerging Viral Infections through Immunomodulatory Actions

Many of the medicinally active molecules in the flavonoid class of phytochemicals are being researched for their potential antiviral activity against various DNA and RNA viruses. Quercetin is a flavonoid that can be found in a variety of foods, including fruits and vegetables. It has been reported to be effective against a variety of viruses. This review, therefore, deciphered the mechanistic of how Quercetin works against some of the deadliest viruses, such as influenza A, Hepatitis C, Dengue type 2 and Ebola virus, which cause frequent outbreaks worldwide and result in significant morbidity and mortality in humans through epidemics or pandemics. All those have an alarming impact on both human health and the global and national economies. The review extended computing the Quercetin-contained natural recourse and its modes of action in different experimental approaches leading to antiviral actions. The gap in effective treatment emphasizes the necessity of a search for new effective antiviral compounds. Quercetin shows potential antiviral activity and inhibits it by targeting viral infections at multiple stages. The suppression of viral neuraminidase, proteases and DNA/RNA polymerases and the alteration of many viral proteins as well as their immunomodulation are the main molecular mechanisms of Quercetin's antiviral activities. Nonetheless, the huge potential of Quercetin and its extensive use is inadequately approached as a therapeutic for emerging and re-emerging viral infections. Therefore, this review enumerated the food-functioned Quercetin source, the modes of action of Quercetin for antiviral effects and made insights on the mechanism-based antiviral action of Quercetin.

Antiviral Effect of Isoquercitrin against Influenza A Viral Infection via Modulating Hemagglutinin and Neuraminidase

Isoquercitrin (IQC) is a component abundantly present in many plants and is known to have an anti-viral effect against various viruses. In this study, we demonstrate that IQC exhibits strong anti-influenza A virus infection, and its effect is closely related to the suppression of hemagglutinin (HA) and neuraminidase (NA) activities. We used green fluorescent protein-tagged Influenza A/PR/8/34 (H1N1), A/PR/8/34 (H1N1), and HBPV-VR-32 (H3N2) to evaluate the anti-IAV effect of IQC. The fluorescence microscopy and fluorescence-activated cell sorting analysis showed that IQC significantly decreases the levels of GFP expressed by IAV infection, dose-dependently. Consistent with that, IQC inhibited cytopathic effects by H1N1 or H3N2 IAV infection. Immunofluorescence analysis confirmed that IQC represses the IAV protein expression. Time-of-addition assay showed that IQC inhibits viral attachment and entry and exerts a strong virucidal effect during IAV infection. Hemagglutination assay confirmed that IQC affects IAV HA. Further, IQC potently reduced the NA activities of H1N1 and H3N2 IAV. Collectively, IQC prevents IAV infection at multi-stages via virucidal effects, inhibiting attachment, entry and viral release. Our results indicate that IQC could be developed as a potent antiviral drug to protect against influenza viral infection.

Comprehensive Comparative Analysis and Development of Molecular Markers for Dianthus Species Based on Complete Chloroplast Genome Sequences

Dianthus spp. is a genus with high economic and ornamental value in the Caryophyllaceae, which include the famous fresh-cut carnation and the traditional Chinese herbal medicine, D. superbus. Despite the Dianthus species being seen everywhere in our daily lives, its genome information and phylogenetic relationships remain elusive. Thus, we performed the assembly and annotation of chloroplast genomes for 12 individuals from seven Dianthus species. On this basis, we carried out the first comprehensive and systematic analysis of the chloroplast genome sequence characteristics and the phylogenetic evolution of Dianthus. The chloroplast genome of 12 Dianthus individuals ranged from 149,192 bp to 149,800 bp, containing 124 to 126 functional genes. Sequence repetition analysis showed the number of simple sequence repeats (SSRs) ranged from 75 to 80, tandem repeats ranged from 23 to 41, and pair-dispersed repeats ranged from 28 to 43. Next, we calculated the synonymous nucleotide substitution rates (Ks) of all 76 protein coding genes to obtain the evolution rate of these coding genes in Dianthus species; rpl22 showed the highest Ks (0.0471), which suggested that it evolved the swiftest. By reconstructing the phylogenetic relationships within Dianthus and other species of Caryophyllales, 16 Dianthus individuals (12 individuals reported in this study and four individuals downloaded from NCBI) were divided into two strongly supported sister clades (Clade A and Clade B). The Clade A contained five species, namely D. caryophyllus, D. barbatus, D. gratianopolitanus, and two cultivars (‘HY’ and ‘WC’). The Clade B included four species, in which D. superbus was a sister branch with D. chinensis, D. longicalyx, and F1 ‘87M’ (the hybrid offspring F1 from D. chinensis and ‘HY’). Further, based on sequence divergence analysis and hypervariable region analysis, we selected several regions that had more divergent sequences, to develop DNA markers. Additionally, we found that one DNA marker can be used to differentiate Clade A and Clade B in Dianthus. Taken together, our results provide useful information for our understanding of Dianthus classification and chloroplast genome evolution.

Modern aspects of the use of natural polyphenols in tumor prevention and therapy

Polyphenols are secondary plant metabolites or organic compounds synthesized by them. In other words, these are molecules that are found in plants. Due to the wide variety of polyphenols and the plants in which they are found, these compounds are divided according to the source of origin, the function of the polyphenols, and their chemical structure; where the main ones are flavonoids. All the beneficial properties of polyphenols have not yet been studied, since this group of substances is very extensive and diverse. However, most polyphenols are known to be powerful antioxidants and have anti-inflammatory effects. Polyphenols help fight cell damage caused by free radicals and immune system components. In particular, polyphenols are credited with a preventive effect that helps protect the body from certain forms of cancer. The onset and progression of tumors may be related directly to oxidative stress, or inflammation. These processes can increase the amount of DNA damage and lead to loss of control over cell division. A number of studies have shown that oxidative stress uncontrolled by antioxidants or an uncontrolled and prolonged inflammatory process increases the risk of developing sarcoma, melanoma, and breast, lung, liver, and prostate cancer. Therefore, a more in-depth study of the effect of polyphenolic compounds on certain signaling pathways that determine the complex cascade of oncogenesis is a promising direction in the search for new methods for the prevention and treatment of tumors.

Isoquercetin as an Anti-Covid-19 Medication: A Potential to Realize

Isoquercetin and quercetin are secondary metabolites found in a variety of plants, including edible ones. Isoquercetin is a monoglycosylated derivative of quercetin. When ingested, isoquercetin accumulates more than quercetin in the intestinal mucosa where it is converted to quercetin; the latter is absorbed into enterocytes, transported to the liver, released in circulation, and distributed to tissues, mostly as metabolic conjugates. Physiologically, isoquercetin and quercetin exhibit antioxidant, anti-inflammatory, immuno-modulatory, and anticoagulant activities. Generally isoquercetin is less active than quercetin in vitro and ex vivo, whereas it is equally or more active in vivo, suggesting that it is primarily a more absorbable precursor to quercetin, providing more favorable pharmacokinetics to the latter. Isoquercetin, like quercetin, has shown broad-spectrum antiviral activities, significantly reducing cell infection by influenza, Zika, Ebola, dengue viruses among others. This ability, together with their other physiological properties and their safety profile, has led to the proposition that administration of these flavonols could prevent infection by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), or arrest the progression to severity and lethality of resulting coronavirus disease of 2019 (Covid-19). In silico screening of small molecules for binding affinity to proteins involved SARS-CoV-2 life cycle has repeatedly situated quercetin and isoquercetin near to top of the list of likely effectors. If experiments in cells and animals confirm these predictions, this will provide additional justifications for the conduct of clinical trials to evaluate the prophylactic and therapeutic efficacy of these flavonols in Covid-19.

Preparative isolation of maltol glycoside from Dianthus superbus and its anti-inflammatory activity in vitro

Dianthus superbus is a traditional Chinese medicine that is commonly utilized as a treatment for inflammation, pain, and immunological conditions. In this study, an anti-inflammatory maltol glycoside derived from Dianthus superbus was isolated for the first time via medium and high-pressure liquid chromatography, and at the same time, the in vitro anti-inflammatory activity of this maltol glycoside was preliminarily explored. Initially, crude samples of Dianthus superbus were preprocessed via MCI GEL® CHP20P and Spherical C18 medium-pressure chromatography, under the guidance of evaluation of in vitro anti-inflammatory activity. Fr44 was found to be the target fraction, and it was further isolated via two-dimensional reversed-phase/hydrophilic interaction liquid chromatography, yielding > 95% pure and was identified as tunicoside B. MTT assay, nitric oxide and nitric oxide synthase were used to evaluate the effects of tunicoside B on murine macrophage Raw264.7 by nitric oxide synthase assay kit, molecular docking, and western blotting. The results showed that tunicoside B did not affect the viability of cells and exhibited significant anti-inflammatory activity. As far as we know, this is the first report of tunicoside B from Dianthus superbus and the first study on the anti-inflammatory activity of tunicoside B. More importantly, the approach established in this study is expected to provide a theoretical basis for the separation and pharmacological activity study of maltol glycosides from other natural products.

Focus on the high therapeutic potentials of quercetin and its derivatives

BACKGROUND

Polyphenols and particularly flavonoids are of constant interest to the scientific community. Flavonoids are investigated for their biological and pharmacological purposes, notably as antioxidant, anticancer, antiviral and for their anti-inflammatory activities. Certainly, one of the best-known flavonols recognized for its therapeutic and preventive properties, is quercetin. Despite its biological interest, quercetin suffer from some drawbacks, mainly related to its bioavailability. Hence, its synthetic or biosynthetic derivatives have been the subject of intensive research. The health-promoting biological activities of flavonols and derivatives mainly arise from their capacity to disrupt the host-pathogen interactions and/or to regulate host cellular functions including oxidative processes and immunological responses. In the age of coronavirus pandemic, the anti-inflammatory and antiviral potential of flavonols should be put forward to explore these substances for decreasing the viral load and inflammatory storm caused by the infection.

PURPOSE OF STUDY

The present review will decipher and discuss the antioxidant, anti-inflammatory and antiviral capacities of major flavonol with a focus on the molecular basis and structure-activity relationships.

STUDY DESIGN

Current study used a combination of quercetin derivatives, pathway, antioxidant, anti-inflammatory, antiviral activities as keywords to retrieve the literature. This study critically reviewed the current literature and presented the ability of natural analogs of quercetin having superior antioxidant, anti-inflammatory and antiviral effects than the original molecule.

RESULTS

This review allowed the identification of relevant key structure-activity relationship elements and highlight approaches on the mechanisms governing the antioxidant, antiviral and anti-inflammatory activities.

CONCLUSION

Through a critical analysis of the literature, flavonols and more precisely quercetin derivatives reviewed and found to act simultaneously on inflammation, virus and oxidative stress, three key factors that may lead to life threatening diseases.

O-Glycoside quercetin derivatives: Biological activities, mechanisms of action, and structure-activity relationship for drug design, a review

Quercetin as a valuable natural flavonoid has shown extensive biological activities, including anticancer, antioxidant, antibacterial, antiinflammatory, anti-Alzheimer, antifungal, antiviral, antithalassemia, iron chelation, antiobesity, antidiabetic, antihypertension, and antiphospholipase A2 (PLA2) activities, by the modulation of various targets and signaling pathways that have attracted much attention. However, the low solubility and poor bioavailability of quercetin have limited its applications; therefore, the researchers have tried to design and synthesize many new derivatives of quercetin through different strategies to modify quercetin restrictions and improve its biological activities. This review categorized the O-glycoside derivatives of Quercetin into two main classes, 3-O-glycoside and other O-glycoside derivatives. Also, it studied biological activities, structure-activity relationship (SAR), and the action mechanism of O-glycoside quercetin derivatives. Overall, we summarized past and present research for discovering new potent lead compounds.

Modulating Neurological Complications of Emerging Infectious Diseases: Mechanistic Approaches to Candidate Phytochemicals

Growing studies are revealing the critical manifestations of influenza, dengue virus (DENV) infection, Zika virus (ZIKV) disease, and Ebola virus disease (EVD) as emerging infectious diseases. However, their corresponding mechanisms of major complications headed for neuronal dysfunction are not entirely understood. From the mechanistic point of view, inflammatory/oxidative mediators are activated during emerging infectious diseases towards less cell migration, neurogenesis impairment, and neuronal death. Accordingly, the virus life cycle and associated enzymes, as well as host receptors, cytokine storm, and multiple signaling mediators, are the leading players of emerging infectious diseases. Consequently, chemokines, interleukins, interferons, carbohydrate molecules, toll-like receptors (TLRs), and tyrosine kinases are leading orchestrates of peripheral and central complications which are in near interconnections. Some of the resulting neuronal manifestations have attracted much attention, including inflammatory polyneuropathy, encephalopathy, meningitis, myelitis, stroke, Guillain-Barré syndrome (GBS), radiculomyelitis, meningoencephalitis, memory loss, headaches, cranial nerve abnormalities, tremor, and seizure. The complex pathophysiological mechanism behind the aforementioned complications urges the need for finding multi-target agents with higher efficacy and lower side effects. In recent decades, the natural kingdom has been highlighted as promising neuroprotective natural products in modulating several dysregulated signaling pathways/mediators. The present study provides neuronal manifestations of some emerging infectious diseases and underlying pathophysiological mechanisms. Besides, a mechanistic-based strategy is developed to introduce candidate natural products as promising multi-target agents in combating major dysregulated pathways towards neuroprotection in influenza, DENV infection, ZIKV disease, and EVD.

In silico targeting SARS-CoV-2 spike protein and main protease by biochemical compounds

Since there is no general agreement on drug treatment of SARS-CoV-2, the search for a new drug capable of treating COVID-19 is of utmost priority. This study aims to dereplicate the chemical compounds of the methanol extract of Salvia officinalis and Artemisia dracunculus, and assay the inhibitory effect of these compounds as well as the previously dereplicated components of Zingiber officinale against SARS-CoV-2 in an in-silico study. A molecular networking (MN) technique was applied to find the chemical constituents of the extracts. Docking analysis was also used to find the binding affinity of dereplicated components from S. officinalis, A. dracunculus, and Z. officinale to COV-2-SP and M^pro. 57 compounds were dereplicated from the MeOH extracts of S. officinalis and A. dracunculus which include the class of polyphenols, flavonoids, coumarins, phenylpropanoids, anthocyanins, and dihydrochalcones. Molecular docking analysis indicated a high affinity of about 27 compounds from three mentioned plants against studied targets. kaempferol 3-O-rutinoside, neodiosmin, and querciturone with docking score values of -10.575, -10.208, and - 9.904 Kcal/mol and k_i values of 0.016606, 0.030921, and 0.051749, respectively were found to have the highest affinities against COV-2-SP. 2-phenylethyl beta-primeveroside, curcumin PE, and kaempferol 3-O-rutinoside also indicated the highest affinity against M^pro with docking scores of -10.34, -10.126 and - 9.705 and k_i values of 0.024726, 0.035529, and 0.072494, respectively. MN can be successfully used for the dereplication of metabolites from plant extracts. In addition, the in-silico binding energies introduced several inhibitors from Z. officinale, S. officinalis, and A. dracunculus for the treatment of SARS-CoV-2 disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11756-021-00881-z.

Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused a devastating health crisis worldwide. In this review, we have discussed that prophylactic phytochemical quercetin supplementation in the form of foods or nutraceuticals may help manage the COVID-19 pandemic. The following evidence supports our argument. First, nuclear factor erythroid-derived 2-like 2 (NRF2) agonists abrogate replication of SARS-CoV-2 in lung cells, and quercetin is a potent NRF2 agonist. Second, quercetin exerts antiviral activity against several zoonotic coronaviruses, including SARS-CoV-2, mainly by inhibiting the entry of virions into host cells. Third, inflammatory pathways activated by nuclear factor kappa B, inflammasome, and interleukin-6 signals elicit cytokine release syndrome that promotes acute respiratory distress syndrome in patients with COVID-19, and quercetin inhibits these pro-inflammatory signals. Fourth, patients with COVID-19 develop thrombosis, and quercetin mitigates coagulation abnormalities by inhibiting plasma protein disulfide isomerase. This review provides a strong rationale for testing quercetin for the management of COVID-19.

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Quercetin may inhibit SARS-CoV-2 entry into cells by altering viral envelope proteins.

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Quercetin may inhibit SARS-CoV-2 replication by activating the NRF2 pathway.

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Quercetin attenuates proinflammatory signals and cytokine release syndrome.

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Quercetin may reduce coagulopathy by inhibiting protein disulphide isomerase.

Comparative analysis of metabolic variations, antioxidant potential and cytotoxic effects in different parts of Chelidonium majus L

Metabolic variations, antioxidant potential and cytotoxic effects were investigated in the different plant parts like the leaf, stem, flower, pod, and root of C. majus L. using spectroscopic and chromatographic methods. Total phenolics and flavonoids were studied in the different parts of C. majus L., leaf showed higher flavonoid content (137.43 mg/g), while the pod showed the highest phenolic (23.67 mg/g) content, when compared with the stem, flower and root. In the ABTS antioxidant assay, the flower extract showed 57.94% effect, while the leaf, pod and root extract exhibited 39.10%, 36.08% and 28.88% activity, respectively. The pod and leaf extracts demonstrated the potential effect, exhibiting 45.46 and 41.61% activity, respectively, for the DPPH assay. Similar to the phosphomolybdenum assay, the flower revealed higher antioxidant activity (46.82%) than the other plant parts. The in vitro SRB assay facilitated evaluation of the cytotoxic effect against the HeLa and CaSki human cervical cancerous cells. The extract displayed dose-dependent inhibitory effect on both the cell lines. The highest cytotoxic effect was observed in the pod and flower extracts post 48 h of exposure at 1000 μg/mL. The results of C. majus L. offered new insights in the preliminary steps regarding the development of a high value product for phytomedicine applications though promising metabolic variations with antioxidant and anticancer potentials.

The traditional herbal formulation, Jianpiyifei II, reduces pulmonary inflammation induced by influenza A virus and cigarette smoke in mice

Chronic obstructive pulmonary disease (COPD) is a worldwide chronic inflammatory lung disease, and influenza A virus (IAV) infection is a common cause of acute exacerbations of COPD (AECOPD). Therefore, targeting viral infections represents a promising strategy to prevent the occurrence and development of inflammatory flare ups in AECOPD. Jianpiyifei II (JPYFII) is a traditional herbal medicine used in China to treat patients with COPD, and its clinical indications are not well understood. However, investigation of the anti-inflammatory effects and underlying mechanism using an animal model of smoking have been reported in a previous study by our group. In addition, some included herbs, such as Radix astragali and Radix aupleuri, were reported to exhibit antiviral effects. Therefore, the aim of the present study was to investigate whether JPYFII formulation relieved acute inflammation by clearing the IAV in a mouse model that was exposed to cigarette smoke experimentally. JPYFII formulation treatment during smoke exposure and IAV infection significantly reduced the number of cells observed in bronchoalveolar lavage fluid (BALF), expression of proinflammatory cytokines, chemokines, superoxide production, and viral load in IAV-infected and smoke-exposed mice. However, JPYFII formulation treatment during smoke exposure alone did not reduce the number of cells in BALF or the expression of Il-6, Tnf-a, and Il-1β. The results demonstrated that JPYFII formulation exerted an antiviral effect and reduced the exacerbation of lung inflammation in cigarette smoke (CS)-exposed mice infected with IAV. Our results suggested that JPYFII formulation could potentially be used to treat patients with AECOPD associated with IAV infection.

Overview of Viral Pneumonia Associated With Influenza Virus, Respiratory Syncytial Virus, and Coronavirus, and Therapeutics Based on Natural Products of Medicinal Plants

Viral pneumonia has been a serious threat to global health, especially now we have dramatic challenges such as the COVID-19 pandemic. Approximately six million cases of community-acquired pneumonia occur every year, and over 20% of which need hospital admission. Influenza virus, respiratory virus, and coronavirus are the noteworthy causative agents to be investigated based on recent clinical research. Currently, anaphylactic reaction and inflammation induced by antiviral immunity can be incriminated as causative factors for clinicopathological symptoms of viral pneumonia. In this article, we illustrate the structure and related infection mechanisms of these viruses and the current status of antiviral therapies. Owing to a set of antiviral regiments with unsatisfactory clinical effects resulting from side effects, genetic mutation, and growing incidence of resistance, much attention has been paid on medicinal plants as a natural source of antiviral agents. Previous research mainly referred to herbal medicines and plant extracts with curative effects on viral infection models of influenza virus, respiratory virus, and coronavirus. This review summarizes the results of antiviral activities of various medicinal plants and their isolated substances, exclusively focusing on natural products for the treatment of the three types of pathogens that elicit pneumonia. Furthermore, we have introduced several useful screening tools to develop antiviral lead compounds.

Construction of a red emission fluorescent protein chromophore-based probe for detection of carboxylesterase 1 and carbamate pesticide in culture cells

Designing fluorescent probe for detecting carboxylesterase 1 is remains challenging. Herein, a red emission human carboxylesterase 1 (CES1) probe (CAE-FP) was synthesized based on fluorescent protein chromophore. Probe CAE-FP can specific detect human CES1 with high selectively. The fluorescence quantum yield was calucated as 0.19. The carboxylic acid ester in CAE-FP could be easily hydrolyzed by CES1 under physiological conditions, and this process could induce the obvious fluorescence signal in red emission region. The detection limit of CES1 was calculated as 84.5 ng/mL. Due to the biological detoxification mechanism of carboxylesterase and the obvious inhibitory effect of pesticides on its activity, CAE-FP was applied to detect carbamate pesticide and have achieved good application results. Since fluorescent protein chromophore has excellent biocompatibility, probe CAE-FP with good cell membrane permeable and was successfully applied to monitor the real activities of CES1 in living cells. In summary, this is one of the few reported fluorescent probes that can specific detect the real-time activity of CES1 in biological samples. Besides, we first applied the fluorescent protein chromophore to construct the specific target enzyme probe. This work would contribute to further investigate CES1-associated physiological and pathological processe.

Potential anti-influenza effective plants used in Turkish folk medicine: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Due to the outbreaks such as SARS, bird flu and swine flu, which we frequently encounter in our century, we need fast solutions with no side effects today more than ever. Due to having vast ethnomedical experience and the richest flora (34% endemic) of Europe and the Middle East, Turkey has a high potential for research on this topic. Plants that locals have been using for centuries for the prevention and treatment of influenza can offer effective alternatives to combat this problem. In this context, 224 herbal taxa belonging to 45 families were identified among the selected 81 studies conducted in the seven regions of Turkey. However, only 35 (15.6%) of them were found to be subjected to worldwide in vitro and in vivo research conducted on anti-influenza activity. Quercetin and chlorogenic acid, the effectiveness of which has been proven many times in this context, have been recorded as the most common (7.1%) active ingredients among the other 56 active substances identified.

AIM OF THE STUDY

This study has been carried out to reveal the inventory of plant species that have been used in flu treatment for centuries in Turkish folk medicine, which could be used in the treatment of flu or flu-like pandemics, such as COVID 19, that humanity has been suffering with, and also compare them with experimental studies in the literature.

MATERIALS AND METHODS

The investigation was conducted in two stages on the subject above by using electronic databases, such as Web of Science, Scopus, ScienceDirect, ProQuest, Medline, Cochrane Library, EBSCO, HighWire Press, PubMed and Google Scholar. The results of both scans are presented in separate tables, together with their regional comparative analysis.

RESULTS

Data obtained on taxa are presented in a table, including anti-influenza mechanism of actions and the active substances. Rosa canina (58.7%) and Mentha x piperita (22.2%) were identified as the most common plants used in Turkey. Also, Sambucus nigra (11.6%), Olea europaea (9.3%), Eucalyptus spp., Melissa officinalis, and Origanum vulgare (7.0%) emerged as the most investigated taxa.

CONCLUSION

This is the first nationwide ethnomedical screening work conducted on flu treatment with plants in Turkey. Thirty-nine plants have been confirmed in the recent experimental anti-influenza research, which strongly shows that these plants are a rich pharmacological source. Also, with 189 (84.4%) taxa, detections that have not been investigated yet, they are an essential resource for both national and international pharmacological researchers in terms of new natural medicine searches. Considering that the production of antimalarial drugs and their successful use against COVID-19 has begun, this correlation was actually a positive and remarkable piece of data, since there are 15 plants, including Centaurea drabifolia subsp. Phlocosa (an endemic taxon), that were found to be used in the treatment of both flu and malaria.

Quercetin as a Natural Therapeutic Candidate for the Treatment of Influenza Virus

The medical burden caused by respiratory manifestations of influenza virus (IV) outbreak as an infectious respiratory disease is so great that governments in both developed and developing countries have allocated significant national budget toward the development of strategies for prevention, control, and treatment of this infection, which is seemingly common and treatable, but can be deadly. Frequent mutations in its genome structure often result in resistance to standard medications. Thus, new generations of treatments are critical to combat this ever-evolving infection. Plant materials and active compounds have been tested for many years, including, more recently, active compounds like flavonoids. Quercetin is a compound belonging to the flavonols class and has shown therapeutic effects against influenza virus. The focus of this review includes viral pathogenesis as well as the application of quercetin and its derivatives as a complementary therapy in controlling influenza and its related symptoms based on the targets. We also touch on the potential of this class of compounds for treatment of SARS-COV-2, the cause of new pandemic.

Network pharmacology and molecular docking analyses on Lianhua Qingwen capsule indicate Akt1 is a potential target to treat and prevent COVID-19

Objectives

Coronavirus disease 2019 (COVID‐19) is rapidly spreading worldwide. Lianhua Qingwen capsule (LQC) has shown therapeutic effects in patients with COVID‐19. This study is aimed to discover its molecular mechanism and provide potential drug targets.

Materials and Methods

An LQC target and COVID‐19–related gene set was established using the Traditional Chinese Medicine Systems Pharmacology database and seven disease‐gene databases. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and protein‐protein interaction (PPI) network were performed to discover the potential mechanism. Molecular docking was performed to visualize the patterns of interactions between the effective molecule and targeted protein.

Results

A gene set of 65 genes was generated. We then constructed a compound‐target network that contained 234 nodes of active compounds and 916 edges of compound‐target pairs. The GO and KEGG indicated that LQC can act by regulating immune response, apoptosis and virus infection. PPI network and subnetworks identified nine hub genes. The molecular docking was conducted on the most significant gene Akt1, which is involved in lung injury, lung fibrogenesis and virus infection. Six active compounds of LQC can enter the active pocket of Akt1, namely beta‐carotene, kaempferol, luteolin, naringenin, quercetin and wogonin, thereby exerting potential therapeutic effects in COVID‐19.

Conclusions

The network pharmacological strategy integrates molecular docking to unravel the molecular mechanism of LQC. Akt1 is a promising drug target to reduce tissue damage and help eliminate virus infection.

Redox control in the pathophysiology of influenza virus infection

Triggered in response to external and internal ligands in cells and animals, redox homeostasis is transmitted via signal molecules involved in defense redox mechanisms through networks of cell proliferation, differentiation, intracellular detoxification, bacterial infection, and immune reactions. Cellular oxidation is not necessarily harmful per se, but its effects depend on the balance between the peroxidation and antioxidation cascades, which can vary according to the stimulus and serve to maintain oxygen homeostasis. The reactive oxygen species (ROS) that are generated during influenza virus (IV) infection have critical effects on both the virus and host cells. In this review, we outline the link between viral infection and redox control using IV infection as an example. We discuss the current state of knowledge on the molecular relationship between cellular oxidation mediated by ROS accumulation and the diversity of IV infection. We also summarize the potential anti-IV agents available currently that act by targeting redox biology/pathophysiology.