Licorice-saponin A3 is a broad-spectrum inhibitor for COVID-19 by targeting viral spike and anti-inflammation.

Currently, human health due to corona virus disease 2019 (COVID-19) pandemic has been seriously threatened. The coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein plays a crucial role in virus transmission and several S-based therapeutic approaches have been approved for the treatment of COVID-19. However, the efficacy is compromised by the SARS-CoV-2 evolvement and mutation. Here we report the SARS-CoV-2 S protein receptor-binding domain (RBD) inhibitor licorice-saponin A3 (A3) could widely inhibit RBD of SARS-CoV-2 variants, including Beta, Delta, and Omicron BA.1, XBB and BQ1.1. Furthermore, A3 could potently inhibit SARS-CoV-2 Omicron virus in Vero E6 cells, with EC50 of 1.016 µM. The mechanism was related with binding with Y453 of RBD determined by hydrogen-deuterium exchange mass spectrometry (HDX-MS) analysis combined with quantum mechanics/molecular mechanics (QM/MM) simulations. Interestingly, phosphoproteomics analysis and multi fluorescent immunohistochemistry (mIHC) respectively indicated that A3 also inhibits host inflammation by directly modulating the JNK and p38 MAPK pathways and rebalancing the corresponding immune dysregulation. This work supports A3 as a promising broad-spectrum small molecule drug candidate for COVID-19.

INVESTIGATING ANTIGENIC FEATURES OF THE SARS-CoV-2 ISOLATED IN RUSSIAN FEDERATION IN 2021-2022 BY HYPERIMMUNE MOUSE SERUM NEUTRALISATION.

Introduction. The rapid spread of a new coronavirus infection among populations in many countries worldwide has contributed to the genetic evolution of the virus, resulting in the emergence of multiple genetic variants of the SARSCoV-2 coronavirus. Mutations in the viral genome can affect the ability of the virus to bypass the immune system and complicate development of diagnostic and prophylactic drugs. Data on the neutralizing activity of the sera obtained against previously circulating genetic variants of the virus in relation to current SARS-CoV-2 strains may serve as a scientific basis for the selection of the antigens in vaccine development. The aim of this work was to study cross-reactivity of SARSCoV-2 coronavirus strains belonging to different genetic variants, which were isolated in the territory of the Russian Federation during 2020-2022 in the neutralization reaction using mouse hyperimmune sera. Materials and methods. Ten strains of SARS-CoV-2 coronavirus belonging to different genetic variants were used (three non-VOC strains, alpha, beta, gamma, delta, delta+AY, omicron 1 and omicron 2). The hCoV-19/Australia/VIC01/2020 strain (Wuhan) was included in the study as a prototypical variant. BALBc mice were immunized with inactivated concentrated antigen mixed with a 1:1 adjuvant, which was a virus-like immunostimulatory complex based on Quillaja saponaria (Quillaja saponaria). The antibody titer was determined in the neutralization reaction. Results. Essential decrease of neutralizing ability of antibodies specific to non-vOC genetic variants of SARS-CoV-2 coronavirus was revealed against beta VOC and to a lesser degree against alpha and gamma VOC variants. The differences in the neutralizing activity level of antibodies for alpha and beta VOC variants are not significant among themselves, and with gamma VOC variants - there are no significant differences. Neutralizing ability of antibodies specific to delta VOC against alpha and beta VOC variants decreased 4-fold. Neutralizing activity of sera obtained to omicron 1 and 2 variants in relation to the prototype coronavirus variant was reduced 18-fold, to the gamma variant - 12-fold, to delta variants - more than 30-fold;for other variants it was even lower. Conclusions. The results obtained testify to the presence of cross-reactivity between strains of coronavirus belonging to genetic lines Wuhan, alpha, beta, gamma;it is weaker for delta variants. Mutations in the genome of VOC omicron variants led to a significant decrease in antigenic cross-links with earlier genetic variants of the coronavirus. These findings explain the low efficacy of vaccines based on the Wuhan strain, synthetic immunogens, and recombinant proteins based on it against omicron VOC variants, which have caused a rise in morbidity since early 2022, as well as cases of re-infection of humans with new genetic variants of the coronavirus.Copyright © 2023 Saint Petersburg Pasteur Institute. All rights reserved.

The Matrix-M™ adjuvant: A critical component of vaccines for the 21st century.

Matrix-M™ adjuvant is a key component of several novel vaccine candidates. The Matrix-M adjuvant consists of two distinct fractions of saponins purified from the Quillaja saponaria Molina tree, combined with cholesterol and phospholipids to form 40-nm open cage-like nanoparticles, achieving potent adjuvanticity with a favorable safety profile. Matrix-M induces early activation of innate immune cells at the injection site and in the draining lymph nodes. This translates into improved magnitude and quality of the antibody response to the antigen, broadened epitope recognition, and the induction of a Th1-dominant immune response. Matrix-M-adjuvanted vaccines have a favorable safety profile and are well tolerated in clinical trials. In this review, we discuss the latest findings on the mechanisms of action, efficacy, and safety of Matrix-M adjuvant and other saponin-based adjuvants, with a focus on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine candidate NVX-CoV2373 developed to prevent coronavirus disease 2019 (COVID-19).

COVID-19 Vaccines: Fabrication Techniques and Current Status

The year 2020 was the most challenging period due to the havoc caused by the outbreak of novel coronavirus SARS-CoV-2. Scientists and researchers all around the world have endeav-ored every possible approach to find solutions in context to therapeutics and vaccines to control the spread of this life-threatening virus. The acceleration instigated by the outbreak of SARS-CoV-2 and its mutated strains has leveraged the use of numerous platform technologies for the development of vaccines against this unfathomable disease. Vaccines could play an important role in miti-gating the effects of COVID-19 and reducing the ongoing health crisis. Various innovative plat-forms like proteins, nucleic acids, viruses, and viral vectors have been exploited to fabricate vaccines depicting almost 90% of efficacy like BNT162b2, AZD1222, Ad5-nCoV, etc. Some of these vaccines are multipotent and have shown potent activity against newly emerged malicious strains of SARS-CoV-2 like B.1.351 and B.1.1.7. In this review article, we have gathered key findings from various sources of recently popularized vaccine candidates, which will provide an overview of potential vaccine candidates against this virus and will help the researchers to investi-gate possible ways to annihilate this menace and design new moieties.Copyright © 2022 Bentham Science Publishers.

Similarities and differences of chemical compositions and physical and functional properties of adjuvant system 01 and army liposome formulation with QS21.

A vaccine adjuvant known as Adjuvant System 01 (AS01) consists of liposomes containing a mixture of natural congeners of monophosphoryl lipid A (MPL®) obtained from bacterial lipopolysaccharide, and a tree saponin known as QS21. Two vaccines containing AS01 as the adjuvant have been licensed, including a malaria vaccine (Mosquirix®) approved by World Health. Organization and European Medicines Agency for use in sub-Saharan Africa, and a shingles vaccine (Shingrix®) approved by the U.S. Food and Drug Administration. The success of the AS01 vaccine adjuvant has led to the development of another liposomal vaccine adjuvant, referred to as Army Liposome Formulation with QS21 (ALFQ). Like AS01, ALFQ consists of liposomes containing monophosphoryl lipid A (as a synthetic molecule known as 3D-PHAD®) and QS21 as adjuvant constituents, and the polar headgroups of the liposomes of AS01 and ALFQ are similar. We compare here AS01 with ALFQ with respect to their similar and different liposomal chemical structures and physical characteristics with a goal of projecting some of the likely mechanisms of safety, side effects, and mechanisms of adjuvanticity. We hypothesize that some of the side effects exhibited in humans after injection of liposome-based vaccines might be caused by free fatty acid and lysophospholipid released by enzymatic attack of liposomal phospholipid by phospholipase A2 at the injection site or systemically after injection.

A Review of Phytochemistry and Pharmacology on Moringa Oleifera

Natural extracts have been of very interest since ancient times due to their enormous medicinal use and research attention. Moringa oleifera is well known as miracle tree as it consists of high nutritive values. Originally from India is widely distributed in many tropical regions, in the pacific region, west Africa as well as central America. India is the major supplier of Moringa worldwide, accounting for around 80% of global demand. It is a multipurpose plant cultivated for medicinal applications. It contains rich sources of Vit- A, B1, B2, B3 and C, It also has calcium, potassium, iron, magnesium, zinc and phospherus. Moringa species contain various phytoconstituents such as alkaloids, saponins,tannins, steroids.phenolic acids( gallic, vanillic and p-coumaric acids) and flavanoids(catechin), tocopherol ,glucosinolates and terpenes. Investigations of ethanol extract of the leaves gives lutein, B-carotene,phytyl fatty acids, esters, poly phenols, B- sitosterols,triglycerols,fatty acids and saturated hydrocarbons. Leaves were obtained by super critical extraction with CO2 using ethanol as a cosolvent, temperature 35-80 0C.The phenolic acids( gallic, vanillic and p- coumaric acids) and flavanoids(catechin) were identified in all extracts. Extracts obtained at 35 degrees shows the highest values of total phenolic compounds. The activities of plant include Anti-oxidants, anti-cancer, anti-microbial, anti-viral,anti- hyperglycemic,anti-hyperlipidemic,anti-inflammatory,anti-hypertension, anti-spasmodic and others. Due to covid-19 pandemic, the global Moringa products market size is estimated to be worth USD 5167.2 million in 2022. Leaf powder is expected to exceed USD 6 billion by 2025 on account of increasing demand in the dietary supplement and food applications.

Saponins: Research Progress and Their Potential Role in the Post-COVID-19 Pandemic Era.

In the post-COVID-19 pandemic era, the new global situation and the limited therapeutic management of the disease make it necessary to take urgent measures in more effective therapies and drug development in order to counteract the negative global impacts caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new infectious variants. In this context, plant-derived saponins-glycoside-type compounds constituted from a triterpene or steroidal aglycone and one or more sugar residues-may offer fewer side effects and promising beneficial pharmacological activities. This can then be used for the development of potential therapeutic agents against COVID-19, either as a therapy or as a complement to conventional pharmacological strategies for the treatment of the disease and its prevention. The main objective of this review was to examine the primary and current evidence in regard to the therapeutic potential of plant-derived saponins against the COVID-19 disease. Further, the aim was to also focus on those studies that highlight the potential use of saponins as a treatment against SARS-CoV-2. Saponins are antiviral agents that inhibit different pharmacological targets of the virus, as well as exhibit anti-inflammatory and antithrombotic activity in relieving symptoms and clinical complications related to the disease. In addition, saponins also possess immunostimulatory effects, which improve the efficacy and safety of vaccines for prolonging immunogenicity against SARS-CoV-2 and its infectious variants.

Lancemaside A from Codonopsis lanceolata: Studies on Antiviral Activity and Mechanism of Action against SARS-CoV-2 and Its Variants of Concern.

Several plant-derived natural products with anti-SARS-CoV-2 activity have been evaluated for the potential to serve as chemotherapeutic agents for the treatment of COVID-19. Codonopsis lanceolata (CL) has long been used as a medicinal herb in East Asian countries to treat inflammatory diseases of the respiratory system but its antiviral activity has not been investigated so far. Here, we showed that CL extract and its active compound lancemaside A (LA) displayed potent inhibitory activity against SARS-CoV-2 infection using a pseudotyped SARS-CoV-2 entry assay system. We demonstrated that this inhibitory effect of LA was due to the alteration of membrane cholesterol and blockade of the membrane fusion between SARS-CoV-2 and host cells by filipin staining and cell-based membrane fusion assays. Our findings also showed that LA, as a membrane fusion blocker, could impede the endosomal entry pathway of SARS-CoV-2 and its variants of concern (VOCs), including Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529), in Vero cells with similar of IC50 values ranging from 2.23 to 3.37 µM as well as the TMPRSS2-mediated viral entry pathway in A549 cells overexpressing ACE2 and TMPRSS2 with IC50 value of 3.92 µM. We further demonstrated that LA could prevent the formation of multinucleated syncytia arising from SARS-CoV-2 spike protein-mediated membrane fusion. Altogether, the findings reported here suggested that LA could be a broad-spectrum anti-SARS-CoV-2 therapeutic agent by targeting the fusion of viral envelope with the host cell membrane.

Development and laboratory production of virus-like immune-stimulating complexes based on saponins and evaluation of their adjuvant potential using mice immunisation with influenza antigens

The COVID-19 pandemic has exacerbated the public’s need for effective vaccines. Consequently, significant financial support has been provided to developers of a number of innovative vaccines, including the vaccines with saponin-based adjuvants. In 2021, the World Health Organisation recommended Mosquirix, the first malaria vaccine, which contains a saponin adjuvant. An anti-covid vaccine by Novavax is in the approval phase. A promising approach to vaccine development is presented by the use of virus-like immune-stimulating complexes (ISCOMs) containing saponins and by the creation of combinations of ISCOMs with antigens. The aim of the study was to develop, produce and characterise virus-like immune-stimulating complexes based on saponins of Quillaja saponaria, as well as similar saponins of Russian-sourced Polemonium caeruleum. Materials and methods: The ISCOM adjuvants, Matrix-BQ and Matrix-BP, were produced using liquid chromatography and examined using electron microscopy. Balb/c mice were immunised intraperitoneally and intramuscularly with ISCOM-antigen preparations. Afterwards, the immunised animals were challenged with the influenza virus strain, A/California/4/2009(H1N1)pdm09, adapted and lethal to mice. The serum samples were examined using haemagglutination inhibition (HI) tests. Results: The authors produced the ISCOMs containing saponins of Quillaja saponaria and Polemonium caeruleum. After one intramuscular injection of either of the ISCOM-antigen preparations with 1 µg of each of A/Brisbane/02/2018 (H1N1) pdm09, A/Kansas/14/2017 (H3N2), and B/Phuket/3073/2013 haemagglutinin antigens (HAs), HI tests detected serum antibody titres to the corresponding antigens of ≥1:40. Two intramuscular injections of the ISCOM-antigen preparation containing 50 ng of each of the HAs and Matrix-BQ resulted in a protective response. In some animals, two intraperitoneal injections of ISCOM-antigen preparations resulted in the maximum antibody titre to the A/Kansas/14/2017 (H3N2) vaccine strain of 1:20,480. Two intramuscular injections of a test preparation containing 5 µg, 1 µg, 200 ng, or 50 ng of each of the HAs and Matrix-BQ or a control preparation containing 5 µg, 1 µg, or 200 ng of each of the HAs (commercially available vaccines) to the mice that were afterwards infected with the lethal influenza strain protected the experimental animals from death. Conclusions: The ISCOM-based preparations had high immunostimulatory activity in the mouse-model study. The presented results indicate the potential of further studies of ISCOM-based preparations in terms of both vaccine and immunotherapeutic development.

Adjuvants to increase immunogenicity of SARS-CoV-2 RBD and support maternal-fetal transference of antibodies in mice.

Adjuvants are important components of vaccines, increasing immunogenicity and modulating the immune response. SARS-CoV-2 vaccines are still being developed in order to improve worldwide access to immunization. Specific populations should be addressed in these investigations, such as pregnant women-to protect both mothers and neonates. In this study, female adult mice were immunized with Receptor-binding domain (RBD) from SARS-CoV-2 adjuvanted by a mixture of DDA and Saponin and put to mating to verify the maternal transference of IgG. For comparison, other group received RBD adjuvanted by OMVs from Neisseria meningitidis and Alum. The adjuvants enhanced IgG production and neutralization. DDA/Sap contributed to increase IgG1, IgG2a, IgG2b, and IgG3 isotypes. Total IgG avidity was considered high, as well as IgG1, IgG2a, and IgG2b avidity. IgG antibodies were effectively transferred to the offspring, predominantly IgG2a, IgG2b, and IgG3. The passive transferred immunoglobulin maintained the neutralizing ability, although it lost avidity. ELISA data was confirmed in Dot-ELISA and immunoblotting assays. DDA and Saponin seem a promising adjuvant mixture to enhance the humoral response of SARS-CoV-2 antigens. Further studies considering the effects of maternal immunization in the protection of offspring are needed, regardless the platform used in COVID-19 vaccines.

Phytochemical Contents, Biological Activities and Therapeutic Applications of Hedera Helix (Ivy Leaf) Extracts: A Review

Background: Herbs have long been used as natural therapeutics, and recent controlled clinical studies have confirmed some of the presumed benefits. Hedera helix(ivy leaves) is a valuable common form related to the family Araliaceae. Many herbal preparations include extracts from their leaves as the principle active ingredient. Objective: The objective of this article is to summarize the pharmacological activities and phyto-chemical screening of H. helix. Methods: To prepare this article, the data was collected from different sources, including books, th-esis, research and etc. Results: The all-published studies depend on isolation, identification, and characterization of different active constituents of H. helix leaves, followed by the determination of biological activities in vivo and in vivo. Chemical screening has shown that H. helix leaves are a rich source of phytochem-icals demonstrating therapeutic activities, such as sterols, tannins, terpenoids, glycosides, phenols, emetine alkaloids, flavonoids, saponins, volatile and fixed oils, vitamins, carbohydrates, reducing sugars, and minerals. Further, studies of disease models and clinical trials have demonstrated an-ti-inflammatory, analgesic, cough suppressant, expectorant, anticancer, antimicrobial, anticoagu-lant, and smooth muscle relaxant activities. Conclusion: This review summarizes the bioactive constituents of H. helix leaves and their under-lying pharmacological mechanisms, clinical efficacies, and safety profiles. We also suggest potential therapeutic uses for COVID-19.

Saponin-based PAK-1 inhibitors as promising agents for struggle against SARS-CoV-2 infection

The serine/threonine p21-activating PAK kinases which act as important mediators of the Rho family of GTPases (Rho GTPases) Cdc42ĝ€¢GTP and Racĝ€¢GTP. PAK1 is one of the key molecules in the regulation of cytoskeletal actin assembly, phenotypic signaling, gene expression, and directly affects many cellular processes such as cell motility, invasion, metastasis, cell growth, angiogenesis, cell cycle progression. To date, several sulphated steroidal saponins have been reported to block the PAK1-dependent growth of A549 lung cancer. In this study, we investigated molecular interactions of N-triterpene saponins and PAK1 in silico molecular docking, and further evaluated the binding affinities. Molecular docking simulation was performed through AutoDock 4.2.2. an automated docking tool. We found that N-triterpene saponin 2 had the higher binding affinity towards PAK1 targeted protein. To the best of our knowledge, no report on N-triterpene saponins as a PAK1 inhibitor. © 2022 ACM.

Ayurvedic antiviral agents: Overview of medicinal plants perspective

In recent years, it has been reported that many herbal plants contain antiviral agents which combat a human disease that is caused by pathogenic viruses. The natural products which are obtained from plants as antiviral agents against viruses have gone through researches to check the efficacy and potentials of the herbal products in the prevention of viral disorders. On the basis of randomized controlled studies and in-vivo studies, and in-vitro studies, some agents are utilized all across the globe. Progressively numerous studies on therapy of antivirals have been increased. Though, efficacy remains disputable for antiviral drugs that are employed for viral disorders. The viral diseases are challenging for the health of people around the world cause significant increase in mortality and enhance crises. There are many synthetic antiviral drugs that have a large number of side effects and have narrow therapeutic window range, while in the other hand herbal formulations have minimized side effects. The advantages of herbal formulation over synthetic drugs encourage us to devise and expand new herbal moieties against the emerging viral infections. The medicinal plants contain phytochemicals that have antiviral properties. In this paper, the activity of antiviral agents from medicinal plants which have importance in Ayurveda, are discussed along with their source.

Therapeutic potential of plant secondary metabolites in treatment of respiratory viral diseases: A review

Respiratory viral infections are a major public health concern because of their global occurrence, ease of spread and considerable morbidity and mortality. Medical treatments for viral respiratory diseases primarily involve providing relief from symptoms like pain and discomfort rather than treating the infection. Very few antiviral medications have been approved with restrictive usage, high cost, unwanted side effects and limited availability. Plants with their unique metabolite composition and high remedial values offer unique preventive and therapeutic efficacy in treatment of viral infections. The present review is focused on the types and mode of action of plant secondary metabolites that have been used successfully ί in the treatment of infections caused by respiratory viruses like Influenza, SARS, MERS, RSV etc. Plant metabolites such as phenolics, alkaloids, terpenoids and oligosaccharides inhibit attachment and entry of the virus. Others such as flavonoids, viz quercetin and baicalein, alkaloids viz sanguinarine, berberine and emetine, specific lipids and fatty acids prevent viral replication and protein synthesis. These metabolites have the potential to be used as lead molecules that can be optimized to develop potent drugs for effectively combating pandemics caused by respiratory viruses.

Potential benefits of ginseng against COVID-19 by targeting inflammasomes.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogenic virus that causes coronavirus disease 2019 (COVID-19), with major symptoms including hyper-inflammation and cytokine storm, which consequently impairs the respiratory system and multiple organs, or even cause death. SARS-CoV-2 activates inflammasomes and inflammasome-mediated inflammatory signaling pathways, which are key determinants of hyperinflammation and cytokine storm in COVID-19 patients. Additionally, SARS-CoV-2 inhibits inflammasome activation to evade the host's antiviral immunity. Therefore, regulating inflammasome initiation has received increasing attention as a preventive measure in COVID-19 patients. Ginseng and its major active constituents, ginsenosides and saponins, improve the immune system and exert anti-inflammatory effects by targeting inflammasome stimulation. Therefore, this review discussed the potential preventive and therapeutic roles of ginseng in COVID-19 based on its regulatory role in inflammasome initiation and the host's antiviral immunity.

SARS-CoV-2 Ferritin Nanoparticle Vaccines Elicit Broad SARS Coronavirus Immunogenicity

Background. The zoonotic emergence of SARS-CoV-2 quickly developed into a global pandemic. Multiple vaccine platforms have been advanced to clinical trials and emergency use authorization. The recent emergence of SARS-CoV-2 virus variants with Spike receptor-binding domain (RBD) and N-terminal domain (NTD) mutations, highlights the need for next-generation vaccines that can elicit immune responses that are resilient against Spike mutations. Methods. Using a structure-based vaccine design approach, we developed multiple optimized SARS-CoV-2 nanoparticle immunogens that recapitulate the structural and antigenic profile of the SARS-CoV-2 prefusion spike. We assessed these immunogens in murine immunogenicity studies and in a K18-hACE2 transgenic mouse model with a SARS-CoV-2 challenge. Immune sera from vaccinated mice were assessed for SARS-CoV-2 binding, and neutralization against SARS-CoV-2, variants of concern, and the heterologous SARS-CoV-1 virus. Results. In combination with a liposomal-saponin based adjuvant (ALFQ), these immunogens induced robust binding, ACE2-inhibition, and authentic virus and pseudovirus neutralization. A Spike-Ferritin nanoparticle (SpFN) vaccine elicited neutralizing ID50 titers >10,000 after a single immunization, while RBD-Ferritin (RFN) nanoparticle immunogens elicited ID50 titer values >10,000 values after two immunizations. Purified antibody from SpFN- or RFN-immunized mice was transfused into K18-ACE2 transgenic mice and challenged with a high-dose SARS-CoV-2 virus stock. In order to understand the breadth of vaccine-elicited antibody responses, we analyzed SpFN- and RBD-FN-immunized animal sera against a set of heterologous SARSCoV-2 RBD variants and SARS-CoV RBD. High binding titers with ACE2-blocking activity were observed against SARS-CoV-2 variants and the heterologous SARSCoV-1 RBD. Furthermore, both SpFN- and RFN-immunized animal sera showed SARS-CoV-1 neutralizing ID50 titers of >2000. Conclusion. These observations highlight the importance of SARS-CoV-2 neutralizing antibody levels in providing protection against emerging SARS-like coronaviruses and provide a robust platform for pandemic preparedness. Structure-based design enables development of a SARS-CoV-2 nanoparticle immunogen.

Evaluation of Peronema canescens Leaves Extract: Fourier Transform Infrared Analysis, Total Phenolic and Flavonoid Content, Antioxidant Capacity, and Radical Scavenger Activity

BACKGROUND: Peronema canescens (Sungkai) leaves have been popular in Indonesia which contain various bioactive compounds with empirical therapeutic efficacy in dealing with COVID-19 and various other diseases. Total phenolic and flavonoid content and antioxidant activity using the DPPH method from P. canescens leaf extract have not been studied much. AIM: This research has several objectives. The first is to compare the results of qualitative phytochemical analysis of the ethanol extract of the leaves of P. canescens (EEPL). The second is to measure the total phenol and flavonoid content. The third is to test the FTIR and antioxidant activity of the ethanol extract of P. canescens leaves in vitro using the DPPH method. METHODS: Fresh plant material and simplicia, ethanol extract extracted by maceration method using 96% ethanol as solvent from P. canescens. The Dragendorff’s and Mayer test carried out the qualitative phytochemical analysis, FeCl3 test, Salkowski method, Liebermann–Burchard method, foam test, and NaOH reagent. The total phenolic and flavonoid levels were tested using the Folin–Ciocalteu method. In vitro antioxidant activity was carried out using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. RESULTS: The results of qualitative phytochemical screening showed that alkaloids, flavonoids, saponins, tannins, and steroids were detected in the extract of P. canescens. The spectra from the FTIR test results showed various absorbance peak values indicating the bonding of specific functional groups, namely: 418.12, 599.94, 666.67, 1036.39, 1159.52, 1224.16, 1348.95, 1454.19, 1600.87, 1732.00, 2923.13, and 3353.01 cm-1. In the test results, total phenolic content was as much as 5.64% (mgEAG/g) and total flavonoid content of 142,247 mgEQ/g in a sample of 1 mg extract, which was equivalent to 1 mg quercetin. EEPL has antioxidant activity with the DPPH IC50 method of 116.7865 ppm. CONCLUSION: The data obtained at this time can contribute to the exploitation of P. canescens leaves in the future as one of the nutraceutical products, supplements, and herbal medicines by specific industries related to improving the health status of the world community. The higher the bioactive substance in preparation, the more significant the effect of the pharmacological efficacy response. P. canescens ethanol extract has good total phenolic content, total flavonoid content, and antioxidant action.

Natural triterpenoids from licorice potently inhibit SARS-CoV-2 infection.

Introduction: The COVID-19 global epidemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) is a great public health emergency. Discovering antiviral drug candidates is urgent for the prevention and treatment of COVID-19. Objectives: This work aims to discover natural SARS-CoV-2 inhibitors from the traditional Chinese herbal medicine licorice. Methods: We screened 125 small molecules from Glycyrrhiza uralensis Fisch. (licorice, Gan-Cao) by virtual ligand screening targeting the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. Potential hit compounds were further evaluated by ELISA, SPR, luciferase assay, antiviral assay and pharmacokinetic study. Results: The triterpenoids licorice-saponin A3 (A3) and glycyrrhetinic acid (GA) could potently inhibit SARS-CoV-2 infection, with EC50 of 75 nM and 3.17 µM, respectively. Moreover, we reveal that A3 mainly targets the nsp7 protein, and GA binds to the spike protein RBD of SARS-CoV-2. Conclusion: In this work, we found GA and A3 from licorice potently inhibit SARS-CoV-2 infection by affecting entry and replication of the virus. Our findings indicate that these triterpenoids may contribute to the clinical efficacy of licorice for COVID-19 and could be promising candidates for antiviral drug development.

Exploring the possible use of saponin adjuvants in COVID-19 vaccine.

There is an urgent need for a safe, efficacious, and cost-effective vaccine for the coronavirus disease 2019 (COVID-19) pandemic caused by novel coronavirus strain, severe acute respiratory syndrome-2 (SARS-CoV-2). The protective immunity of certain types of vaccines can be enhanced by the addition of adjuvants. Many diverse classes of compounds have been identified as adjuvants, including mineral salts, microbial products, emulsions, saponins, cytokines, polymers, microparticles, and liposomes. Several saponins have been shown to stimulate both the Th1-type immune response and the production of cytotoxic T lymphocytes against endogenous antigens, making them very useful for subunit vaccines, especially those for intracellular pathogens. In this review, we discuss the structural characteristics, mechanisms of action, structure-activity relationship of saponins, biological activities, and use of saponins in various viral vaccines and their applicability to a SARS-CoV-2 vaccine.

Development and immunogenic potentials of chitosan-saponin encapsulated DNA vaccine against avian infectious bronchitis coronavirus.

Infectious Bronchitis (IB) is an economically important avian disease that considerably threatens the global poultry industry. This is partly, as a result of its negative consequences on egg production, weight gain as well as mortality rate.The disease is caused by a constantly evolving avian infectious bronchitis virus whose isolates are classified into several serotypes and genotypes that demonstrate little or no cross protection. In order to curb the menace of the disease therefore, broad based vaccines are urgently needed. The aim of this study was to develop a recombinant DNA vaccine candidate for improved protection of avian infectious bronchitis in poultry. Using bioinformatics and molecular cloning procedures, sets of monovalent and bivalent DNA vaccine constructs were developed based on the S1 glycoprotein from classical and variants IBV strains namely, M41 and CR88 respectively. The candidate vaccine was then encapsulated with a chitosan and saponin formulated nanoparticle for enhanced immunogenicity and protective capacity. RT-PCR assay and IFAT were used to confirm the transcriptional and translational expression of the encoded proteins respectively, while ELISA and Flow-cytometry were used to evaluate the immunogenicity of the candidate vaccine following immunization of various SPF chicken groups (A-F). Furthermore, histopathological changes and virus shedding were determined by quantitative realtime PCR assay and lesion scoring procedure respectively following challenge of various subgroups with respective wild-type IBV viruses. Results obtained from this study showed that, groups vaccinated with a bivalent DNA vaccine construct (pBudCR88-S1/M41-S1) had a significant increase in anti-IBV antibodies, CD3+ and CD8+ T-cells responses as compared to non-vaccinated groups. Likewise, the bivalent vaccine candidate significantly decreased the oropharyngeal and cloacal virus shedding (p < 0.05) compared to non-vaccinated control. Chickens immunized with the bivalent vaccine also exhibited milder clinical signs as well as low tracheal and kidney lesion scores following virus challenge when compared to control groups. Collectively, the present study demonstrated that bivalent DNA vaccine co-expressing dual S1 glycoprotein induced strong immune responses capable of protecting chickens against infection with both M41 and CR88 IBV strains. Moreso, it was evident that encapsulation of the vaccine with chitosan-saponin nanoparticle further enhanced immune responses and abrogates the need for multiple booster administration of vaccine. Therefore, the bivalent DNA vaccine could serve as efficient and effective alternative strategy for the control of IB in poultry.