Antiviral Effects of Compound Traditional Chinese Medicine on Newcastle Disease Virus

[Objective] To investigate the mechanism of compound traditional Chinese medicine （TCM） on Newcastle disease virus （NDV） and to provide a scientific basis for the reasonable usage of antiviral drugs in clinic. [Method] The compound TCM was composed of Hedyotis diffusa, Lonicera japonica Thunb, Radix astragali and Glycyrrhiza uralensis. Different dilutions of fluid extract were prepared. Its antiviral effects on NDV were observed through three inoculation ways, first, inoculation with the medicine and NDV mixture which had been incubated at 37 ℃; second, incubating chicken embryo fibroblasts （CEF） with the medicine followed by inoculation with NDV; third, inoculation with N DV followed by incubating CEF with the medicine. The A,= was determined by M]-r [ 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） ~ method. Therapeutic indexes were used to evaluate the antiviral effects. [ Result] The minimum effective concentration of the compound TCM which acted through the three ways was 1.0 × 2^-10 1.0 × 2^-8 and 1.0 × 2^-7 g/ml, respectively. The antiviral effects of the compound TCM were the best through inoculation with the incubated medicine and NDV mixture, followed by the second method and the third method. [ Conclusion] The compound TCM can not only kill NDV directly in vitro but also inhibit viral propagation.

Antiviral effects of natural small molecules on aquatic rhabdovirus by interfering with early viral replication

Spring viremia of carp virus(SVCV)is globally widespread and poses a serious threat to aquatic ecology and aquaculture due to its broad host range.To develop effective agents to control SVCV infection,we selected 16 naturally active small molecules to assess their anti-SVCV activity.Notably,dihydroartemisinin(DHA)(100μmol/L)and(S,S)-(+)-tetrandrine(TET)(16μmol/L)exhibited high antiviral effects in epithelioma papulosum cyprinid(EPC)cells,with inhibitory rates of 70.11%and 73.54%,respectively.The possible antiviral mechanisms were determined as follows:1.Preincubation with DHA and TET decreased viral particle infectivity in fish cells,suggesting that horizontal transmission of SVCV in the aquatic environment was disrupted;2.Although neither had an effect on viral adhesion,TET(but not DHA)interfered with SVCV entry into host cells(>80%),suggesting that TET may have an antiviral function in early viral replication.For in vivo study,both agents enhanced the survival rate of SVCV-infected zebrafish by 53.3%,significantly decreased viral load,and modulated the expression of antiviralrelated genes,indicating that DHA and TET may stimulate the host innate immune response to prevent viral infection.Overall,our findings indicated that DHA and TET had positive effects on suppressing SVCV infection by affecting early-stage viral replication,thus holding great potential as immunostimulants to reduce the risk of aquatic rhabdovirus disease outbreaks.

Antiviral Effects of Interferons and Their Therapeutic Potentials for SARS

Viruses are obligatory intracellular parasites. Most of the cells in animaland human body possess the innate ability to fight viruses. Innate immune function restrictsinfection at the early stage and delay spread of virus. The early stage of infection is the stage ofinteraction between the virus and the host's defence system. Once the latter is breached, the earlynon-specific or innate immune components such as interferon (IFN), natural killer (NK) cells andmacrophages become active. As the infection proceeds, the adaptive (specific) immune responsedevelops, with the appearance of cytotoxic T cells, helper T cells and antiviral antibodies.Antibodies provide a major barrier to virus spread between cells and cells and are particularlyimportant in restriction of virus spread in the blood stream. Virus infection directly activates thetranscription of type Ⅰ IFN (IFN-alfa/beta) genes in infected cells, while the type Ⅱ IFN(IFN-gamma) plays an essential role in the regulation of an adaptive immune response rather thaninnate immune response. Therefore, Type Ⅰ IFN is the first defence for host and neighbouring cellsto resist virus infection.

In Vivo and in Vitro Antiviral Effects of Berberine on Influenza Virus

Objective：To explore the potential effects of berberine on influenza virus infection both in vitro and in vivo.Methods：In vitro anti-influenza virus assays were performed by cytopathogenic effect and neuraminidase assays in Madin Darby canine kidney cells.In vivo anti-influenza virus assays were performed on the viral pneumonia model of mice.The numbers of mice that died within day 2 to day 14 postinfection were recorded to calculate the mortality.On days 2,4,and 6,the viral titers in the lungs were determined by hemagglutination assay;hematoxylin/eosin staining was used to assess the pathogenic changes of lung tissues; the concentrations of tumor necrosis factor-alpha（TNF-α） and monocyte specific chemoattractant molecule （MCP-1） were measured by radio immunoassay or enzyme-linked immunosorbent assay;the concentrations of nitric oxide（NO） and inducible nitric oxide synthetase（iNOS） were detected by colorimetric method;reverse transcription polymerase chain reaction was used to detect the mRNA level of TNF-αand MCP-1.Results： Berberine showed inhibitory effects on cytopathogenic effects and neuraminidase activity of virus,with the therapeutic index 9.69.In vivo,berberine decreased mice mortality from 90%to 55%,reduced virus titers in the lungs on day 2 postinfection（P0.05）.The lung histology scores were 1.50±0.67,4.50±1.00,and 5.50±1.00 in the berberine group on days 2,4,and 6,respectively,which were significantly reduced compared to 2.17±0.22,6.83±0.44,and 8.50±0.33 in the infected group（P0.05）.The productions of NO and iNOS were repressed by berberine compared with those in the infected group（P0.01）.The transcription and expression of TNF-αwere inhibited by berberine on day 4（P0.01） and day 6（P0.05）,and those of MCP-1 were inhibited on day 6（P0.01） compared with the infected group.Conclusions：Berberine exhibited antiviral effects on the influenza virus both in vitro and in vivo.The possible therapeutic mechanism of berberine on influenza-induced viral pneumonia might be inhibiting the virus infection,as well as improving the pathogenic changes by repressing inflammatory substances release

ANTIVIRAL EFFECTS ON MOUSE LEUKEMIA VIRUS REPLICATION BY OLIGODEOXYNUCLEOTIDES IN VITRO AND IN VIVO

Oligodeoxynucleotides (Oligomers) including modified and unmodified, homo-and heterooligomers were tested for their ability to inhibit mouse SRS leukemia virus (SRSV)-induced proliferation of cells, colony formation, syncytium formation and reverse transcriptase (RT) activity in vitro. Phosphorothioate analogs complementary to Mo-MuLV sequences, as well as noncomplementary homooligomers, were found to be active. Unmodified homooligomer (dC14) also showed inhibition of growth of ascitic lymphoma carrying SRS virus. Our study suggests that different classes of oligonucleotides may inhibit SRSV replication with different mechanisms.

Anti-viral and anti-inflammatory effects of kaempferol and quercetin and COVID-2019:A scoping review

Severe acute respiratory syndrome coronavirus type 2(SARS-CoV-2)is a novel coronavirus identified at the end of 2019.It is recognized as the causative agent of coronavirus disease 2019(COVID-19).Flavonoids have been shown to exhibit therapeutical effect on complications related to COVID-19.The present study reviews possible therapeutic benefits of flavonoids on SARS-CoV-2.The Web of Science,PubMed,Scopus,and Google Scholar were searched using keywords:“COVID-19”,“SARS-CoV-2”,“Kaempferol”and“Quercetin”in the Title/Abstract.Relevant published articles in the English language until August 2020 were considered.Kaempferol and quercetin showed antiviral properties such as inhibition of protein kinase B and phosphorylation of protein kinase and blocking effects on a selective channel(3a channel)expressed in SARS-CoV infected cells.They also reduced the level of reactive oxygen species,expression of inducible nitric oxide synthase,pro-inflammatory mediators including TNF-α,IL-1α,IL-1β,IL-6,IL-10,and IL-12 p70,and chemokines.Kaempferol and quercetin might exert beneficial effects in the control or treatment of COVID-19 because of their antiviral,antioxidant,anti-inflammatory,and immunomodulatory effects.

Antiviral Effect of Emodin from Rheum palmatum against Coxsakievirus B_5 and Human Respiratory Syncytial Virus In Vitro

Summary： Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus （CV） and respira- tory syncytial virus （RSV）. However, no antiviral agents with low toxicity and drug resistance are cur- rently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin （an ingredient of Rheum palmatum） against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum pal- matum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication in- hibition, virucidal and anti-absorption effects, by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tet- razolium bromide （MTT） assay and plaque reduction assay （PRA）. The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR （qPCR）. Cytokine （IFN-γ, TNF-α） mRNA expressions after emodin treatment （7.5, 15, 30 μmol/L） were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration （EC50） ranging from 13.06 to 14.27 μmol/L and selectivity index （SI） being 5.38-6.41 μmol/L. However, emodin couldn＇t directly inacti- vate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB4 and RSV in a concentration- and time-dependent manner, especially during the first 0-4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

Evaluation of the Antiviral Activity of Propolis from Native Bees (<i>Plebeia frontalis</i>) against Canine Distemper Virus

Propolis is a natural substance made from resins collected from trees and plants, and which bees combine with pollen, wax, and their own enzymes. It has a complex chemical composition that varies with the harvest season, vegetation type, bee species, and geographical region. Thanks to its components, it has valuable biological properties such as antifungal, antibacterial, anticancer, antiviral, and immunomodulatory activity. For this study, a sample of propolis harvested in April 2019 was used, which came from a bee native to Mexico (Plebeia frontalis) in whose geographical environment there are seven other native species. Canine distemper virus is an RNA virus that causes a systemic infection with high fatality rates in guests without protective immunity. In this work, the antiviral effect of Plebeia frontalis propolis on canine distemper virus was tested, administering it one hour before and simultaneously to infection. The antiviral effect was evaluated by determining cellular viability with the MTT assay. The results obtained show that this propolis has a statistically significant antiviral effect on both treatments, although it is slightly better when applied one hour before viral infection, so we can recommend it as an antiviral treatment in both domestic animals and human beings. There are currently few studies of the antiviral effect of propolis, this being the first study of a melliponium propolis in veterinary medicine.

In vitro study on the antiviral activity of 9 extracts of traditional Chinese herbal medicine against the human respiratory syncytial virus

Objective:To study the in vitro virucidal activity of 9 extracts of traditional Chinese herbal medicine(the water extracts of Evodia lepta,Clausena lansium,Clerodendrum cyrtophyllum,Callicarpa nudiflora,Nauclea officinalis and Elaeagnus gonyanthes,the alcohol extracts of Nauclea officinalis,Elaeagnus gonyanthes and Zanthoxylumarmatum)on human respiratory syncytial virus(HRSV).Methods:The cytotoxic effect of the extracts on cells was evaluated by a cell viability assay using the CCK-8 method,a concentration of the extracts with cell viability greater than 50%was selected for the follow-up anti-HRSV effect assay,the 50%effective concentration(EC50)was assessed by an in vitro cell infection model.Results:The EC50s of the water extract from Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes were 0.05 mg/mL,0.03 mg/mL and 0.05 mg/mL,and the therapeutic index(TI)of them were 18.60,21.67 and 56.80 respectively.Conclusion:The water extracts of Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes possess the activity of anti-HRSV virus.

Study of Guanhuang Ganmao Keli on the antiviral activity on human respiratory syncytial virus

Objective:To study the antiviral activity of Guanhuang Ganmao Keli on human respiratory syncytial virus(RSV)in vitro. Methods:The Guanhuang Ganmao Keli was dissolved in pure water and filtered by a 0.22 micron filter to get solution. Cyclopiazonic acid(CPA)was used as positive control. The toxicity of Guanhuang Ganmao Keli on Hep-2 cells was tested by cell counting kit 8(CCK-8). The protective effect of Guanhuang Ganmao Keli on RSV was evaluated under the highest toxic concentration. Results:The TC50 and EC50 of Guanhuang Ganmao Keli is 0.647 mg/mL and 0.014 mg/mL,respectively. Guanhuang Ganmao Keli showed significant antiviral effect when added 0、2、4、6 and 8 h post-infection. Conclusion:Guanhuang Ganmao Keli is an effective antiviral agent on RSV in vitro.

Preliminary Study on Effects of Anthraquinone Extract of Polygonum cuspidatum on KHV

[Objectives]To study the toxic effect and antiviral activity of anthraquinone extract of Polygonum cuspidatum on infection of Koi herpes virus(KHV).[Methods]The MTT method and CPE microscopy were used to detect the common carp brain(CCB)cytotoxicity of the P.cuspidatum anthraquinone extract in 48 h.Eight groups of different concentrations of the P.cuspidatum anthraquinone extract 1.96,3.91,7.28,15.63,31.25,62.5,125,250μg/mL experimental groups and a control group without drug effect were set up.After determining the maximum non-toxic range of the P.cuspidatum anthraquinone extract,the viral replication inhibition test was carried out.[Results]The concentration of the P.cuspidatum anthraquinone extract 31.25μg/mL was recognized as the maximum non-toxic concentration.The survival rate of CCB cells was higher than 80%,and the toxic dose(CC50)of the drug for 50%cell death was(72.67±2.12)μg/mL.The maximum inhibition rate of the P.cuspidatum anthraquinone extract was 78.63%±5.47%at a concentration of 31.25μg/mL,and the 50%effective drug dose(IC50)for inhibiting the virus was(13.67±0.47)μg/mL,and the therapeutic index(TI)was 5.48±0.49.In the direct virus killing test,the highest virus inhibition rate was 32.21%.[Conclusions]Under the experimental conditions,it can be concluded that the P.cuspidatum anthraquinone extract has high anti-KHV activity,and at the same time.It is expected to lay a theoretical foundation for the research of P.cuspidatum anthraquinone extract against KHV.

Turmeric (Curcuminoids): A Possible Effective Antiviral Herb

Turmeric is an herbal plant that is widely used as a traditional herbal medicine in many countries. Curcumin displays its anti-viral activities through several mechanisms of action. In this case report we present a 10-year-old child with herpetic vesiculo-ulcerative lesions who was treated with turmeric along with systemic acyclovir which resulted in complete healing by the third day of application.

Use of hydroxychloroquine and azithromycin combination to treat the COVID-19 infection

Coronavirus disease 2019(COVID-19)infection is unequivocally the worst crisis in recent decades,which is caused by a severe acute respiratory virus 2.Currently,there is no effective therapy for the COVID-19 infection.Different countries have different guidelines for treating COVID-19 in the absence of an approved therapy for COVID-19.Therefore,there is an imminent need to identify effective treatments,and several clinical trials have been conducted worldwide.Both hydroxychloroquine[HCQS],chloroquine,and azithromycin(AZ)have been widely used for management based on in vitro studies favoring antiviral effects against the COVID-19 virus.However,there is evidence both in favor and against the use of hydroxychloroquine and azithromycin(HCQS+AZ)combination therapy to manage the COVID-19 infection.The combination of hydroxychloroquine and azithromycin was significantly associated with increased adverse events.However,the inference of these findings was from observational studies.Therefore,large randomized trials are imperative to show the future path for the use of HCQS+AZ combination therapy.However,owing to the ban on HCQS use in COVID-19,this may no longer be essential.This review is on the pharmacology,trials,regimens,and side effects of hydroxychloroquine and azithromycin combination therapy.

Four FDA-approved drugs exhibited inhibition effect on severe fever with thrombocytopenia syndrome virus in vitro

Objective:To screen the anti-SFTSV drugs from 1430 FDA-approved drugs via mini-genome system,and to investigate which stage of the infection process could be suppressed by the identified drugs.Methods:The SFTSV mini-genome system was used to screen drugs with inhibitory effect on SFTSV replication and transcription,and the 50%inhibitory concentration(IC_(50))of each drug was calculated by drug concentration gradient inhibition experiment.Drugs were used to pre-incubate with virus and then incubate with cells,to incubate with virus and cells simultaneously,to incubate with cells after virus invading into cells,or to incubate during the whole infection process,and then qRT-PCR was used to measure the viral RNA copies in the culture supernatant.These experiments were performed to quantitatively determine the inhibition effects of drugs on SFTSV indifferent stages of the whole process including virion stability,entry and post-entry stages,so as to clarify the inhibition mechanism of these drugs.Results:Four drugs including Mycophenolate mofetil,Mycophenolic acid,Nitazoxanide,and Vidofludimus were identified having efficient inhibitory effects on SFTSV RNA replication via minigenome system,with the IC_(50) of 0.014μmol/L,0.627μmol/L,1.283μmol/L,and 0.059μmol/L,respectively.All four drugs showed effective inhibition when adding during the whole SFTSV infection process as well as the post-entry stage.Conclusion:Mycophenolate mofetil,Mycophenolic acid,Nitazoxanide and Vidofludimus show efficient anti-viral effects on SFTSV infection.

Self-assemblies of plasmonic gold/layered double hydroxides with highly efficient antiviral effect against the hepatitis B virus

Engineering complex nanocomposites that specifically target the hepatitis B virus （HBV） and overcome the limitations of current therapies such as limited efficacy and serious side effects is very challenging. Here, for the first time, the antiviral effect of engineered plasmonic gold and layered double hydroxide self-assemblies （AuNPs/LDHs） is demonstrated, using HBV as a model virus and hepatoma-derived HepG2.2.215 ceils for viral replication, assembly, and secretion of infectious virions and subviral particles. AuNPs/LDHs were obtained by a simple, cost-effective procedure in which small AuNPs （-3.5 nm） were directly obtained and organized on the surface of larger LDH nanoparticles （-150 nm） by exploiting the capability of MgLDH, ZnLDH, and MgFeLDH to manifest their ＂structural memory＂ in the aqueous solution of Au（O2CCH3）3. The self-assembly approach of AuNPs and LDHs was assessed by transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, powder X-ray diffraction （PXRD）, and UV-Vis analysis （UV-Vis）. All AuNPs/LDHs tested reduced the amount of viral and subviral particles released from treated cells by up to 80% and exhibited good cytocompatibility. AuNPs/MgFeLDH showed the highest antiviral HBV response with more than 90% inhibition of HBV secretion for the whole concentration range. Preliminary studies on the mechanism of HBV inhibition reveals that in the presence of AuNPs/LDHs, HBV particles are sequestered within the treated cells. The antiviral and low cytotoxic plasmonic properties of these Au/LDH nanocomposites indicate that they hold significant potential to be tailored as novel efficient therapeutics for the treatment of hepatitis B.

OGG1 inhibition suppresses African swine fever virus replication

African swine fever virus(ASFV)is an important pathogen that causes a highly contagious and lethal disease in swine,for which neither a vaccine nor treatment is available.The DNA repair enzyme 8-oxoguanine DNA glycosylase 1(OGG1),which excises the oxidative base lesion 8-oxo-7,8-dihydroguanine(8-oxoG),has been linked to the pathogenesis of different diseases associated with viral infections.However,the role of OGG1-base excision repair(BER)in ASFV infection has been poorly investigated.Our study aimed to characterize the alteration of host reactive oxygen species(ROS)and OGG1 and to analyse the role of OGG1 in ASFV infection.We found that ASFV infection induced high levels and dynamic changes in ROS and 8-oxoG and consistently increased the expression of OGG1.Viral yield,transcription level,and protein synthesis were reduced in ASFV-infected primary alveolar macrophages(PAMs)treated by TH5487 or SU0268 inhibiting OGG1.The expression of BER pathway associated proteins of ASFV was also suppressed in OGG1-inhibited PAMs.Furthermore,OGG1 was found to negatively regulate interferonβ(IFN-β)production during ASFV infection and IFN-βcould be activated by OGG1 inhibition with TH5487 and SU0268,which blocked OGG1 binding to 8-oxoG.Additionally,the interaction of OGG1 with viral MGF360-14-L protein could disturb IFN-βproduction to further affect ASFV replication.These results suggest that OGG1 plays the crucial role in successful viral infection and OGG1 inhibitors SU0268 or TH5487 could be used as antiviral agents for ASFV infection.

Oral administration of Allium sativum extract protects against infectious bursal disease in chickens

Garlic(Allium sativum,Liliaceae)has been safely used for more than 5000 years,and research on garlic extract is rapidly increasing because of its multiple biological functions.The in vivo effects of oral administration of garlic mixture(GM,water-soluble extract)on infectious bursal disease virus(IBDV)-infected specific pathogen free male white leghorn chicken were examined through histopathological,immunohistochemical,and Western blot analyses,and enzyme-linked immunosorbent assay.The results confirmed the protective effects of oral administration of 5 mg·kg^(–1) BW GM(Group GM1)on bursal lesions after IBDV infection.In particular,protein expression of IBDV in the bursa decreased in Group GM1,indicating that GM administration decreased IBDV replication in the bursa.Furthermore,immunoglobulin M-and A-bearing B lymphocytes significantly increased 7 days post infection in bursae in Group GM1(P<0.01),suggesting that the oral administration of 5 mg·kg^(–1) GM offers moderate protection against B cell destruction after IBDV infection.During infection,the concentration of bursal interferon gamma(IFN-g)increased and peaked in Group GM1 earlier than in Group T(IBDV-exposed),demonstrating that GM administration prompted the production of IFN-g to protect against IBDV infection.

Sorafenib suppresses hepatitis B virus gene expression viainhibiting JNK pathway

Aim:Hepatitis B virus(HBV)infection is a major cause of chronic liver diseases.Sorafenib is a multikinase inhibitor and an approved anti-liver cancer drug.Here we demonstrated the antiviral effect of sorafenib on HBV gene expression.Methods:To investigate the effect of sorafenib on HBV gene expression,a luciferase assay was performed with×1.3 Cp-luciferase HBV construct and reverse transcriptase polymerase chain reaction(PCR),real-time PCR,and Western blotting analyses were performed using HepG2 cells derived from hepatocellular carcinoma and Chang liver cells derived from a normal liver tissue.Results:Sorafenib suppressed HBV gene expression via inhibiting the JNK pathway.In this process,the farnesoid X receptor(FXR),a transcription factor that has been reported to increase HBV replication and gene expression,was under control of the JNK pathway.Notably,JNK activation increased FXR protein levels,not mRNA levels.Conclusion:Sorafenib suppressed HBV gene expression via inhibiting the JNK pathway,which regulates FXR activity.