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Statins have been widely used for their cholesterol-lowering properties. Recent studies have shown that they increase survival in human infectious diseases by promoting host defense and inhibiting pathological inflammation. Infectious diseases caused by viruses have been a major challenge to public health. This review discusses potential use of statins to treat viral infection. [ABSTRACT FROM AUTHOR]

The effectiveness of acyclovir, a selective anti-herpesvirus agent, was tested both in silico and in vitro against two ranaviruses, namely the European catfish virus (ECV) and Frog virus 3 (FV3). ECV can cause significant losses in catfish aquaculture, while FV3 poses a risk to vulnerable amphibian populations. The genome of ranaviruses encodes thymidine kinases (TKs) similar to those of herpesviruses. Molecular docking simulations demonstrated that the acyclovir molecule can bind to the active sites of both investigated viral TKs in an orientation conducive to phosphorylation. Subsequently, the antiviral effect of acyclovir was tested in vitro in Epithelioma Papulosum Cyprini (EPC) cells with endpoint titration and qPCR. Acyclovir was used at a concentration of 800 µM, which significantly reduced the viral loads and titers of the ranaviruses. A similar reduction rate was observed with Ictalurid herpesvirus 2, which was used as a positive control virus. These promising results indicate that acyclovir might have a wider range of uses; besides its effectiveness against herpesviruses, it could also be used against ranavirus infections. [ABSTRACT FROM AUTHOR]

Abstract Background Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe diarrhea and death in neonatal piglets, which has brought huge economic losses to the pork industry worldwide since its first discovery in the early 1970s in Europe. Passive immunization with neutralizing antibodies against PEDV is an effective prevention measure. To date, there are no effective therapeutic drugs to treat the PEDV infection. Results We conducted a screening of specific nanobodies against the S1 protein from a phage display library obtained from immunized alpacas. Through competitive binding to antigenic epitopes, we selected instead of chose nanobodies with high affinity and constructed a multivalent tandem. These nanobodies were shown to inhibit PEDV infectivity by the neutralization assay. The antiviral capacity of nanobody was found to display a dose-dependent pattern, as demonstrated by IFA, TCID50, and qRT-PCR analyses. Notably, biparatopic nanobody SF-B exhibited superior antiviral activity. Nanobodies exhibited low cytotoxicity and high stability even under harsh temperature and pH conditions, demonstrating their potential practical applicability to animals. Conclusions Nanobodies exhibit remarkable biological properties and antiviral effects, rendering them a promising candidate for the development of anti-PEDV drugs.

Background: Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe diarrhea and death in neonatal piglets, which has brought huge economic losses to the pork industry worldwide since its first discovery in the early 1970s in Europe. Passive immunization with neutralizing antibodies against PEDV is an effective prevention measure. To date, there are no effective therapeutic drugs to treat the PEDV infection. Results: We conducted a screening of specific nanobodies against the S1 protein from a phage display library obtained from immunized alpacas. Through competitive binding to antigenic epitopes, we selected instead of chose nanobodies with high affinity and constructed a multivalent tandem. These nanobodies were shown to inhibit PEDV infectivity by the neutralization assay. The antiviral capacity of nanobody was found to display a dose-dependent pattern, as demonstrated by IFA, TCID50, and qRT-PCR analyses. Notably, biparatopic nanobody SF-B exhibited superior antiviral activity. Nanobodies exhibited low cytotoxicity and high stability even under harsh temperature and pH conditions, demonstrating their potential practical applicability to animals. Conclusions: Nanobodies exhibit remarkable biological properties and antiviral effects, rendering them a promising candidate for the development of anti-PEDV drugs. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs), of diverse origin and content, are membranous structures secreted by a broad range of cell types. Recent advances in molecular biology have highlighted the pivotal role of EVs in mediating intercellular communication, facilitated by their ability to transport a diverse range of biomolecules, including proteins, lipids, DNA, RNA and metabolites. A striking feature of EVs is their ability to exert dual effects during viral infections, involving both proviral and antiviral effects. This review explores the dual roles of EVs, particularly in the context of pandemic viruses such as HIV-1 and SARS-CoV-2. On the one hand, EVs can enhance viral replication and exacerbate pathogenesis by transferring viral components to susceptible cells. On the other hand, they have intrinsic antiviral properties, including activation of immune responses and direct inhibition of viral infection. By exploring these contrasting functions, our review emphasizes the complexity of EV-mediated interactions in viral pathogenesis and highlights their potential as targets for therapeutic intervention. The insights obtained from investigating EVs in the context of HIV-1 and SARS-CoV-2 provide a deeper understanding of viral mechanisms and pathologies, and offer a new perspective on managing and mitigating the impact of these global health challenges. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Influenza A viruses (IAV) are a high threat to humanity because of a lack of proper effective antiviral drugs and resistance of viruses to existing vaccines. We describe the sufficient anti-IAV effect of Ans/PL-Dz nanocomposites that contain deoxyribozymes (Dz) immobilized on anatase TiO 2 nanoparticles (Ans) through polylysine linker (PL). The Dz-containing nanocomposites appear to be more efficient than the Ans/PL-ODN nanocomposites that contain common oligodeoxyribonucleotides (ODN) targeted to the same RNA regions of the viral genome. The simultaneous use of nanocomposites that contain Dz and ODN, which are targeted to different sites of viral RNA provides a higher overall effect than the independent action of each of them (synergism). The inhibition of IAV with the proposed nanocomposites was shown to be effective, sequence-specific, and dose-dependent. The most efficient Ans/PL-Dz nanocomposite exhibited a high antiviral effect in vivo on mice models. The efficiency of IAV inhibition with this nanocomposite in vitro and in vivo is higher than that for the approved antiflu drug oseltamivir. The results open the prospect of creating a unique antiviral agent suitable for IAV suppression. [Display omitted] • DNAzymes in the anatase-based nanocomposites are highly active against IAV. • The selectivity index of the most active nanocomposite in vitro is about 9000. • This nanocomposite is highly efficient on a mouse model. • This nanocomposite is more active than oseltamivir in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Copyright of Mersin University School of Medicine Lokman Hekim Journal of History of Medicine & Folk Medicine is the property of Mersin University School of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bovine viral diarrhoea virus (BVDV) can cause diarrhoea (BVD) in an animal herd, leading to heavy economic losses. There are limited drugs available for treating and controlling BVD. This research aims to investigate the antiviral and immunoregulatory effects of two traditional Chinese herb extracts against BVDV infection. The extracts are matrine and icariin, which have been proved to have immunostimulant and antiviral effects.

Introduction. Due to the ability of the influenza virus to mutate, it is necessary to constantly search for new drugs with preventive and direct antiviral effects.The aim of the study is to investigate the protective antiviral properties of the drug Thymogen®, a dosed nasal spray, on a model of lethal influenza pneumonia in laboratory animals.Material and methods. White mature mice were selected for the experiment on the antiviral activity of the tested drug samples against H1N1 influenza virus; the mice were divided into the following groups (30 animals each): two negative control groups; two groups receiving Thymogen®, a dosed nasal spray (before and after infection); one group of animals received Tamiflu®, and one received Hexoral®. The mortality of animals with influenza pneumonia was assessed; histological and morphometric analyses were also carried out.Results and discussion. The morphological picture of the lungs of animals correlated with their protective activity when analyzing the survival of animals. The normalization of tissue structure was pronounced the most in the group of animals infected with the virus, pre-incubated with Thymogen®, a dosed nasal spray, and in the group receiving Tamiflu®. Moreover, the viral load in the lungs was lower by 1.5 and 1.2 orders of magnitude in the group receiving Thymogen®, dosed nasal spray, compared to the negative control group (the 3rd and the 6th days of the experiment, respectively), which corresponds to a decrease in the intensity of viral reproduction by 31.6 and 15.8 times

Metformin, known in the medical community as the drug of first choice for type 2 diabetes mellitus, belongs to the group of biguanides and has proven to be an effective treatment in clinical practice. Our knowledge of the pharmacodynamic properties of metformin has long been limited to the following well-known mechanisms: a decrease in hyperglycemia due to an increase in peripheral insulin sensitivity, glucose utilization by cells, inhibition of hepatic gluconeogenesis, an increase in the capacity of all types of membrane glucose transporters, activation of fibrinolysis, and a decrease in the levels of atherogenic lipoproteins. Recent studies show that the range of positive pleiotropic effects of metformin is not limited to the above, and that the molecular mechanisms of its action are more complex than previously thought. This article presents a less known, but equally important action of metformin, in particular, its anti-oncogenic, antiviral, and anti-aging effects. In our study, we highlight that the activation of 5’-adenosine monophosphate-activated protein kinase (AMPK) should be considered as the primary mechanism of action through which almost all beneficial effects are achieved. In the light of recent scientific advances in metformin pharmacology, together with the pathogenetic uncertainty of the term «biguanide», it seems fair and reasonable to apply a more relevant definition to the drugn, namely «AMPK activator».

The effectiveness of acyclovir, a selective anti-herpesvirus agent, was tested both in silico and in vitro against two ranaviruses, namely the European catfish virus (ECV) and Frog virus 3 (FV3). ECV can cause significant losses in catfish aquaculture, while FV3 poses a risk to vulnerable amphibian populations. The genome of ranaviruses encodes thymidine kinases (TKs) similar to those of herpesviruses. Molecular docking simulations demonstrated that the acyclovir molecule can bind to the active sites of both investigated viral TKs in an orientation conducive to phosphorylation. Subsequently, the antiviral effect of acyclovir was tested in vitro in Epithelioma Papulosum Cyprini (EPC) cells with endpoint titration and qPCR. Acyclovir was used at a concentration of 800 µM, which significantly reduced the viral loads and titers of the ranaviruses. A similar reduction rate was observed with Ictalurid herpesvirus 2, which was used as a positive control virus. These promising results indicate that acyclovir might have a wider range of uses; besides its effectiveness against herpesviruses, it could also be used against ranavirus infections.

Background: The production of interferons (IFNs) is essential for the control of viral infections, and interferon regulatory factor 7 (IRF7) is considered as a vital regulator for the transcription of type I IFNs. Amphibians appear to possess a highly expanded type I IFN repertoire, consisting of intron-containing genes as observed in fish, and intronless genes as in other higher vertebrates. However, the knowledge on transcriptional regulatory mechanism of these two types of type I IFN genes is rather scarce in amphibians. Methods and results: A IRF7 gene named as Np-IRF7 was identified in Tibetan frog (Nanorana parkeri), and bioinformatic analysis revealed that the predicted protein of Np-IRF7 contains several important structural features known in IRF7. Expression analysis showed that Np-IRF7 gene was widely expressed and rapidly induced by poly(I:C) in different organs/tissues. Interestingly, luciferase reporter assay revealed that intronless IFN promoters were more effectively activated than intron-containing IFN promoter in Np-IRF7-transfected cells. Moreover, the overexpression of Np-IRF7 could induce the expression of ISGs and suppress the replication of FV3 in A6 cells. Conclusion: Np-IRF7 is indeed the ortholog of known IRF7, and IRF7 is structurally conserved in different lineages of vertebrates. Np-IRF7 played distinct roles in the activation of intron-containing and intronless type I IFN promoters, thus inducing the expression of interferon-stimulated antiviral effectors and providing a protection against ranavirus infection. The present research thus contributes to a better understanding of regulatory function of IRF7 in the IFN-mediated antiviral response of anuran amphibians. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Veterinary Journal is the property of Sivas Cumhuriyet University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Singapore grouper iridovirus (SGIV) is a virus with high fatality rate in the grouper culture industry. The outbreak of SGIV is often accompanied by a large number of grouper deaths, which has a great impact on the economy. Therefore, it is of great significance to find effective drugs against SGIV. It has been reported that edaravone is a broad-spectrum antiviral drug, most widely used clinically in recent years, but no report has been found exploring the effect of edaravone on SGIV infections. In this study, we evaluated the antiviral effect of edaravone against SGIV, and the anti-SGIV mechanism of edaravone was also explored. It was found that the safe concentration of edaravone on grouper spleen (GS) cells was 50 µg/mL, and it possessed antiviral activity against SGIV infection in a dose-dependent manner. Furthermore, edaravone could significantly disrupt SGIV particles and interference with SGIV binding to host cells, as well as SGIV replication in host cells. However, edaravone was not effective during the SGIV invasion into host cells. This study was the first time that it was determined that edaravone could exert antiviral effects in response to SGIV infection by directly interfering with the processes of SGIV infecting cells, aiming to provide a theoretical basis for the control of grouper virus disease. [ABSTRACT FROM AUTHOR]

Both Manganese (Mn2+) and MSA-2 can activate the downstream signal pathway through stimulator of interferon genes (STING) and induce the expression of type I interferon, which is important for hosts to protect against DNA viruses. However, its effect on RNA viruses remains unknown. In this study, we used Seneca Valley virus (SVV) as a model RNA virus to investigate the inhibitory effects of Mn2+ and MSA-2 on the virus replication in the porcine cells (PK-15 cells). The results showed that both MSA-2 and Mn2+ were able to inhibit the SVV replication in PK-15 cells. The combination of MAS-2 and Mn2+ could confer better protection against SVV. Further studies showed that MSA-2 and Mn2+ could activate TBK1, IRF3 and NFκB through STING and induce the expression of IFN-β, IL-6 and TNF-α. The present study confirmed that MSA-2 synergized with Mn2+ in STING activation to generate a better antiviral effect in vitro, which would be helpful for the further development of effective antiviral drugs in the future. [ABSTRACT FROM AUTHOR]

Introduction. The requirements of modern clinical guidelines for the treatment of respiratory viral infections suggest the possibility of identifying a specific viral pathogen. In this regard, the search for drugs with selective activity against respiratory syncytial virus and parainfluenza virus is relevant. The purpose of the work is to study the antiviral activity of the drug Cytovir®-3 in vitro in relation to the cytopathogenic effect of respiratory viruses (parainfluenza virus and respiratory syncytial virus). Material and methods. The antiviral effect of Cytovir®-3 in comparison with Umifenovir against parainfluenza virus and respiratory syncytial virus was studied on Vero cell culture. Drugs were administered 1 hour before (prophylactic regimen) and 1 hour after (treatment regimen) infection of the cell culture with respiratory viruses. The working range of concentrations of the studied drugs was calculated based on the values of 50% cytotoxic concentration calculated based on the results of a quantitative microtetrazole test. Results and discussion. The drug Cytovir®-3 in two schemes of application (therapeutic or prophylactic) showed its antiviral efficacy in vitro against respiratory syncytial virus and parainfluenza virus due in the non-toxic range (0–794 µg/ml). At the same time, the suppressive effect of the drug Cytovir®-3 against the parainfluenza virus begins at lower concentrations of the drug with its early (preventive) introduction into cell culture (250 mcg/ml). Conclusion. Antiviral activity of Cytovir®-3 has been proven in vitro against parainfluenza virus and respiratory syncytial virus. At the same time, in all series of experiments, Cytovir®-3 had a higher index of selectivity of antiviral action than that of the comparison drug Umifenovir.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens in the global swine industry over the past three decades. There is no licensed antiviral medication that can effectively control this infection. In the present study, the structure of SP-1 isolated and purified from Sargassum weizhouense was analyzed, and its antioxidant capacity and antiviral effect in MARC-145 cells against PRRSV were investigated. The results showed that SP-1 is a novel polysaccharide which mainly is composed of →4)-β-D-ManpA-(1→, →4)-α-L-GulpA-(1→ and a small amount of →4)-β-D-GalpA-(1→. PRRSV adsorption, replication, and release were all suppressed by SP-1. SP-1 therapy down-regulated mRNA expression of the CD163 receptor while increasing the antioxidant gene expression of Nrf2, TXNIP, and HO-1; increasing the protein expression of NQO1 and HO-1; and drastically reducing the protein expression of p-p65. The findings indicated that SP-1 reduces PRRSV adsorption, replication, and release through blocking the expression of the crucial CD163 receptor during infection. Meanwhile, SP-1 exerts antioxidant effects in PRRSV-infected cells through the activation of the Nrf2-HO1 signaling pathway. [ABSTRACT FROM AUTHOR]

Cholesterol, as an important component in mammalian cells, is efficient for viral entry, replication, and assembly. Oxysterols especially hydroxylated cholesterols are recognized as novel regulators of the innate immune response. The antiviral ability of 25HC (25-Hydroxycholesterol) is uncovered due to its role as a metabolic product of the interferon-stimulated gene CH25H (cholesterol-25-hydroxylase). With the advancement of research, the biological functions of 25HC and its structural functions have been interpreted gradually. Furthermore, the underlying mechanisms of antiviral effect of 25HC are not only limited to interferon regulation. Taken up by the special biosynthetic ways and structure, 25HC contributes to modulate not only the cholesterol metabolism but also autophagy and inflammation by regulating signaling pathways. The outcome of modulation by 25HC seems to be largely dependent on the cell types, viruses and context of cell microenvironments. In this paper, we review the recent proceedings on the regulatory effect of 25HC on interferon-independent signaling pathways related to its antiviral capacity and its putative underlying mechanisms. [ABSTRACT FROM AUTHOR]

Chitosan, poly[β-(1–4)-linked-2-amino-2-deoxy-d-glucose], is a polysaccharide with broad applications in various biomaterial and biomedical fields, primarily because of its nontoxicity. Because the biodegradable biopolymer chitosan can be catalyzed by the alkaline partial deacetylation of chitin in shrimp and crab shells, its degree of deacetylation is crucial for proper application. However, the antiviral properties of deacetylated chitosan in combination with other compounds remain unclear. We used a plaque assay to examine the antiviral activity of deacetylated chitosan against human influenza A virus (H1N1) and parainfluenza virus type 3 (HPIV3) when supplemented with grapefruit seed extract (GSE). We demonstrated that deacetylated chitosan reduced H1N1- and HPIV3-induced plaque formation in Madin–Darby canine kidney (MDCK) cells. Chitosan also decreased viral RNA expression in H1N1- and HPIV3-infected A549 cells. Furthermore, antiviral activity analysis in human A549 cells revealed that deacetylated chitosan prevented virus-induced p38 MAPK activation and mitochondrial fragmentation. These findings indicate that deacetylated chitosan with GSE may be a promising antiviral biomaterial against influenza and parainfluenza viruses. [ABSTRACT FROM AUTHOR]

The efficacy of silver nanoparticles (AgNPs) was tested in vitro against three different fish viruses, causing significant economic damage in aquaculture. These viruses were the spring viraemia of carp virus (SVCV), European catfish virus (ECV), and Ictalurid herpesvirus 2 (IcHV-2). The safe concentration of AgNPs that did not cause cytotoxic effects in EPC cells proved to be 25 ng/mL. This dose of AgNPs decreased significantly (5–330×) the viral load of all three viruses in three different types of treatments (virus pre-treatment, cell pre-treatment, and cell post-treatment with the AgNPs). In a higher concentration, the AgNPs proved to be efficient against ECV and IcHV-2 even in a delayed post-cell-treatment experiment (AgNP treatment was applied 24 h after the virus inoculation). These first in vitro results against three devastating fish viruses are encouraging to continue the study of the applicability of AgNPs in aquaculture in the future. [ABSTRACT FROM AUTHOR]

Background. The rapidly developing resistance of viruses to synthetic antiviral drugs indicates the need to use substances with multitarget action (to avoid polypharmacy and to improve the safety of treatment).Objective: systematic analysis of the scientific literature on the pharmacology of bioflavonoids with an emphasis on their antiviral action.Material and methods. More than 150,000 references of primary sources were found in the PubMed/MEDLINE database of biomedical publications, including 3282 references on the antiviral effects of bioflavonoids. A systematic computerized analysis of this array of publications was carried out in order to identify the main directions in the pharmacology of bioflavonoids with an emphasis on their antiviral, antibacterial and immunomodulatory effects. The literature analysis was carried out using modern methods of topological and metric analysis of big data.Results. The molecular mechanisms of action of baicalin, hesperidin, rutin, quercetin, leukodelphinidin bioflavonoids and epigallocatechin-3-gallate, curcumin polyphenols, their anti-inflammatory, antioxidant, antiviral, bactericidal, angioprotective, regenerative effects, and their prospects in therapy, prevention and rehabilitation of patients with COVID-19 and other respiratory viral infections were described in detail.Conclusion. Bioflavonoids and synergistic polyphenols exhibit not only multitarget antiviral effects by inhibiting the main protease, spike proteins, and other target proteins, but also pronounced anti-inflammatory, hepatoprotective, and immunomodulatory effects.

Woo-Jin Jeon,1,* Hong-Ki Lee,2,3,* Young-Guk Na,1 Minwoo Jung,1 Su-Cheol Han,2 Jeong Ho Hwang,2 Eunhye Jung,4 Dasom Hwang,4 Jin Soo Shin,4 Cheong-Weon Cho1 1College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon, 34134, Republic of Korea; 2Center for Companion Animal New Drug Development, Jeonbuk Branch, Korea Institute of Toxicology (KIT), Jeongeup, Jeollabuk-do, 53212, Republic of Korea; 3Human Health Risk Assessment Center, Jeonbuk Branch, Korea Institute of Toxicology (KIT), Jeongeup, Jeollabuk-do, 53212, Republic of Korea; 4Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea*These authors contributed equally to this workCorrespondence: Jin Soo Shin, Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea, Email jsshin@krict.re.kr Cheong-Weon Cho, College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea, Email chocw@cnu.ac.krIntroduction: The ongoing SARS-CoV-2 pandemic has affected public health, the economy, and society. This study reported a nanotechnology-based strategy to enhance the antiviral efficacy of the antiviral agent remdesivir (RDS).Results: We developed a nanosized spherical RDS-NLC in which the RDS was encapsulated in an amorphous form. The RDS-NLC significantly potentiated the antiviral efficacy of RDS against SARS-CoV-2 and its variants (alpha, beta, and delta). Our study revealed that NLC technology improved the antiviral effect of RDS against SARS-CoV-2 by enhancing the cellular uptake of RDS and reducing SARS-CoV-2 entry in cells. These improvements resulted in a 211% increase in the bioavailability of RDS.Conclusion: Thus, the application of NLC against SARS-CoV-2 may be a beneficial strategy to improve the antiviral effects of antiviral agents.Keywords: remdesivir, nanostructured lipid carrier, antiviral effect, SARS-CoV-2, virus entry

Fibroblast growth factor 11 (FGF11) is a member of the intracellular FGF family, which shows different signal transmission compared with other FGF superfamily members. The molecular function of FGF11 is not clearly understood. In this study, we identified the inhibitory effect of FGF11 on hepatitis B virus (HBV) gene expression through transcriptional suppression. FGF11 decreased the mRNA and protein expression of HBV genes in liver cells. While the nuclear receptor FXRα1 increased HBV promoter transactivation, FGF11 decreased the FXRα-mediated gene induction of the HBV promoter by the FXRα agonist. Reduced endogenous levels of FXRα by siRNA and the dominant negative mutant protein (aa 1–187 without ligand binding domain) of FXRα expression indicated that HBV gene suppression by FGF11 is dependent on FXRα inhibition. In addition, FGF11 interacts with FXRα protein and reduces FXRα protein stability. These results indicate that FGF11 inhibits HBV replicative expression through the liver cell-specific transcription factor, FXRα, and suppresses HBV promoter activity. Our findings may contribute to the establishment of better regimens for the treatment of chronic HBV infections by including FGF11 to alter the bile acid mediated FXR pathway. [ABSTRACT FROM AUTHOR]

This study investigated the antiviral activity of aqueous leaf extract of Costus speciosus (TB100) against influenza A. Pretreatment of TB100 in RAW264.7 cells enhanced antiviral activity in an assay using the green fluorescence-expressing influenza A/Puerto Rico/8/1934 (H1N1) virus. The fifty percent effective concentration (EC50) and fifty percent cytotoxic concentration (CC50) were determined to be 15.19 ± 0.61 and 117.12 ± 18.31 µg/mL, respectively, for RAW264.7 cells. Based on fluorescent microscopy, green fluorescence protein (GFP) expression and viral copy number reduction confirmed that TB100 inhibited viral replication in murine RAW264.7 and human A549 and HEp2 cells. In vitro pretreatment with TB100 induced the phosphorylation of transcriptional activators TBK1, IRF3, STAT1, IKB-α, and p65 associated with interferon pathways, indicating the activation of antiviral defenses. The safety and protective efficacy of TB100 were assessed in BALB/c mice as an oral treatment and the results confirmed that it was safe and effective against influenza A/Puerto Rico/8/1934 (H1N1), A/Philippines/2/2008 (H3N2), and A/Chicken/Korea/116/2004 (H9N2). High-performance liquid chromatography of aqueous extracts led to the identification of cinnamic, caffeic, and chlorogenic acids as potential chemicals for antiviral responses. Further confirmatory studies using these acids revealed that each of them confers significant antiviral effects against influenza when used as pretreatment and enhances the antiviral response in a time-dependent manner. These findings suggest that TB100 has the potential to be developed into an antiviral agent that is effective against seasonal influenza. [ABSTRACT FROM AUTHOR]

The cucumber green mottle mosaic virus (CGMMV) and tobacco vein banding mosaic virus (TVBMV) (Tobamovirus and Potyvirus genera, respectively) are responsible for significant economic damage to cucurbitaceous and tobacco crops worldwide. In this research, we show that the Nicotiana benthamiana protease inhibitor (NbPI) interacts with the coat proteins (CP) of these two viruses. When the NbPI gene was silenced by virus-induced gene silencing (VIGS), inoculation of CGMMV or TVBMV into plants resulted in more severe symptoms and a higher viral RNA replication level compared to plants without gene silencing. These results indicate the antiviral role of host factor NbPI against CGMMV and TVBMV in N. benthamiana. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease (FMD) is an acute contagious infectious disease that affects cloven-hoofed animals. Although current emergency FMD vaccines only take effect 7 days after vaccination, antiviral agents, such as quercetin, which is a common flavonoid, could reduce the spread of FMD virus (FMDV) during outbreaks. We investigated the in vitro and in vivo antiviral effects of quercetin against FMDV. Analysis of viral copy numbers showed that quercetin had a dose-dependent inhibitory effect on FMDV at concentrations between 19.5 and 1,250 μM in porcine cells. In addition, we observed a quercetin-induced interferon (IFN)-α protein and interferon-stimulated gene (ISG) upregulation in swine cells. Enzyme-linked immunosorbent assay of sera revealed that quercetin induces the production of IFN-α, IFN-β, IFN-γ, interleukin (IL)-12, and IL-15 in mice. Inoculation of mice with quercetin or a combination of quercetin with an inactivated FMD vaccine enhanced both the survival rate and neutralizing antibody titer. Therefore, we suggest the use of quercetin as a novel and effective antiviral agent for controlling FMDV infection; however, further investigation of its application in livestock is required. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) infection causes lethal watery diarrhea and high mortality in neonatal piglets, leading to huge economic losses in the global swine industry. Currently, the existing commercial vaccines cannot fully control PEDV, so it is urgent to develop effective antiviral agents to complement vaccine therapy. In the present study, we investigated the antiviral effect of Hypericum japonicum extract (HJ) against PEDV in vivo and in vitro. In in vitro assays, HJ could directly inactivate PEDV strains; moreover, it inhibited the proliferation of PEDV strains in Vero or IPI-FX cells at its non-cytotoxic concentrations. Time of addition assays revealed that HJ mainly inhibited PEDV at the later stages of the viral life cycle. In in vivo, compared with the model group, HJ could reduce the viral titers in the intestines of infected piglets, and improve their intestinal pathological, indicating that HJ could protect the newborn piglets from highly pathogenic PEDV variant infection. Furthermore, this effect may be related to the fact that HJ can not only directly inhibit viruses, but also regulate the structure of intestinal microbiota. In conclusion, our results indicate that Hypericum japonicum could inhibit PEDV replication in vitro and in vivo and might possess the potential to develop as the anti-PEDV drug. [ABSTRACT FROM AUTHOR]

ABSTRACTCoxsackievirus B3 (CVB3) is a single-stranded RNA virus that belongs to the Enterovirus genus. CVB3 is a human pathogen associated with serious conditions such as myocarditis, dilated cardiomyopathy, and pancreatitis. However, there are no therapeutic interventions to treat CVB3 infections. In this study, we found that CVB3 induced metabolic alteration in host cells through increasing glycolysis level, as indicated by an increase in the extracellular acidification rate (ECAR). CVB3-mediated metabolic alteration was confirmed by metabolite change analysis using gas chromatography-mass spectrometry (GC-MS). Based on findings, a strategy to inhibit glycolysis has been proposed to treat CVB3 infection. Indeed, glycolysis inhibitors (2-Deoxy-D-glucose, sodium oxide) significantly reduced CVB3 titers after CVB3 infection, indicating that glycolysis inhibitors can be used as effective antiviral agents. Taken together, our results reveal a novel mechanism by which CVB3 infection is controlled by regulation of host cell metabolism.

Background and aims: The lack of effective antiviral drugs for adenoviruses is one of the most important problems in this area. The aim of this study was to investigate the phytochemical properties and antiviral effect of the green tea extract (GTE) on adenovirus in HEp2 cells in vitro. Methods: In this experimental study, dried leaves of green tea were extracted by maceration. Total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity of the extract were measured by Folin-Ciocalteu, aluminum chloride, and 2,2-diphenyl-1- picrylhydrazyl (DPPH) colorimetric methods, respectively. The amounts of some phenolic compounds in the extract were also determined using high-performance liquid chromatography. The toxicity of the extract on Hep2 cells and antiviral activity of the extract on adenovirus were assessed by the MTT colorimetric method. The half-maximum cytotoxicity concentration (CC50) and the 50% inhibitory concentration (IC50) of the extract were calculated as well. Results: Phytochemical investigations showed that the IC50 of DPPH radical was 42.1 ± 3.2 μg/mL compared with butylated hydroxytoluene (IC50 of 33.5 ± 3.67 μg/mL). The TPC and TFC of the extract were 74.2 mg GAE/g and 16.3 mg RE/g of the dry extract, respectively. The extract demonstrated the highest amounts of syringic acid, gallic acid, 3,4-dihydroxybenzoic acid, and rutin levels (67.27, 20.12, 7.39, and 2.97 mg/g DW, respectively). Based on the results of cell culture, the CC50 and IC50 of GTE were 103.3 μg/mL and 25.16 μg/mL, respectively. Conclusion: GTE with phenolic and flavonoid compounds can exert dose-dependent inhibitory effects on adenoviruses.

Interferon (IFN) helps cells fight viral infections by further inducing the expression of many downstream IFN-stimulated genes (ISGs). Human interferon-inducible transmembrane proteins (IFITM) are one of these ISGs. The antiviral function of human IFITM1, IFITM2, and IFITM3 are well known. In this study, we report that IFITM can significantly inhibit EMCV infectivity in HEK293 cells. Overexpression of IFITM proteins could promote IFN-β production. Meanwhile, IFITMs facilitated type I IFN signaling pathway adaptor MDA5 expression. We detected the binding of IFITM2 to MDA5 in a co-immunoprecipitation assay. It was also found that the ability of IFITM2 to activate IFN-β was significantly inhibited after interfering with MDA5 expression, suggesting that MDA5 may play an important role in the activation of the IFN-β signaling pathway by IFITM2. Moreover, the N-terminal domain plays an active role in the antiviral activity and the activation of IFN-β by IFITM2. These findings suggest that IFITM2 plays a vital role in antiviral signaling transduction. In addition, a positive feed-forward loop between IFITM2 and type I IFN establishes a key role for IFITM2 in enforcing innate immune responses. [ABSTRACT FROM AUTHOR]

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Background: Influenza virus causes significant morbidity and mortality with pandemic threat. Oleaceae Fructus Forsythiae is a medicinal herb. This study aimed to investigate antiviral effect of Phillyrin, a purified bioactive compound from this herb, and its reformulated preparation FS21 against influenza and its mechanism. Methods: Madin–Darby Canine Kidney (MDCK) cells were infected by one of six influenza viruses: five influenza A viruses (IAVs: three H1N1 and two H3N2) and one influenza B virus (IBV). Virus‐induced cytopathic effects were observed and recorded under microscope. Viral replication and mRNA transcription were evaluated by quantitative polymerase chain reaction (qPCR) and protein expression by Western blot. Infectious virus production was assessed using TCID50 assay, and IC50 was calculated accordingly. Pretreatment and time‐of‐addition experiments with Phillyrin or FS21 added 1 h before or in early (0–3 h), mid (3–6 h), or late (6–9 h) stages of viral infection were performed to assess their antiviral effects. Mechanistic studies included hemagglutination and neuraminidase inhibition, viral binding and entry, endosomal acidification, and plasmid‐based influenza RNA polymerase activity. Results: Phillyrin and FS21 had potent antiviral effects against all six IAV and IBV in a dose‐dependent manner. Mechanistic studies showed that both suppressed influenza viral RNA polymerase with no effect on virus‐mediated hemagglutination inhibition, viral binding or entry, endosomal acidification, or neuraminidase activity. Conclusions: Phillyrin and FS21 have broad and potent antiviral effects against influenza viruses with inhibition of viral RNA polymerase as the distinct antiviral mechanism. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease (FMD) is an acute contagious disease of cloven-hoofed animals such as cattle, pigs, and sheep. Current emergency FMD vaccines are of limited use for early protection because their protective effect starts 7 days after vaccination. Therefore, antiviral drugs or additives are used to rapidly stop the spread of the virus during FMD outbreaks. Manganese (Mn2+) was recently found to be an important substance necessary for the host to protect against DNA viruses. However, its antiviral effect against RNA viruses remains unknown. In this study, we found that Mn2+ has antiviral effects on the FMD virus (FMDV) both in PK15 cells and mice. The inhibitory effect of Mn2+ on FMDV involves NF-κB activation and up-regulation of interferon-stimulated genes. Animal experiments showed that Mn2+ can be highly effective in protecting C57BL/6N mice from being infected with FMDV. Overall, we suggest Mn2+ as an effective antiviral additive for controlling FMDV infection. [ABSTRACT FROM AUTHOR]

Tannins derived from natural plant sources are known to provide many health benefits to humans and animals. Among the various tannins, those derived from persimmon (Diospyros kaki) have exhibited strong inactivating effects against pathogens that induce diseases in humans. However, few studies have focused on the antiviral effects of persimmon tannin against pathogen-induced diseases in animals. In this study, we investigated the antiviral effects of persimmon tannin against various avian influenza viruses revealing that tannin at a concentration of 1.0 mg ml−1 reduced viral infectivity in >6.0-log scale against all tested avian influenza viruses. In addition, this persimmon tannin concentration effectively inhibited the receptor binding and membrane fusion abilities of viral hemagglutinin (HA), which play important roles in avian influenza virus infection. These results suggest that persimmon tannin inactivates the HA of avian influenza viruses and reduces their infectivity. Persimmon tannin is a safer natural substance than the currently used chemical compound related to antiviral substance. When inactivation of the viruses which are present in environmental water such as roosting water of wild birds will be needed, persimmon tannin is expected to become an antiviral resource that may prevent the spread of several avian influenza virus subtypes. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS) is caused by the PRRS virus (PRRSV), which has brought huge economic losses to the pork industry worldwide since its first discovery in the late 1980s in North America. To date, there are no effective commercial vaccines or therapeutic drugs available for controlling the spread of PRRSV. Due to their unique advantages of high affinity and high specificity, nanobodies (Nbs) have received increasing attention in the process of disease diagnosis and treatment. Trans-activator transcription (TAT) can serve as a vector to carry specific proteins into cells by passing through cell membranes. In our previous study, a specific Nb against the PRRSV nucleocapsid (N) protein was screened using phage display technology. For this study, we developed a novel recombinant protein constituting a TAT-conjugated Nb, which we call TAT-Nb1. The target cell entry efficiency of TAT-Nb1 and its effect on PRRSV infection and replication were then investigated. Our results indicate that TAT delivered Nb1 into Marc-145 cells and porcine alveolar macrophages (PAMs) in a dose- and time-dependent manner. Furthermore, TAT-Nb1 dose-dependently suppressed PRRSV infection and replication, where this antiviral effect was independent of PRRSV strain. Co-immunoprecipitation results revealed that Nb1 efficiently interacted with the N protein of PRRSV. Taken together, the presented results suggest that TAT-Nb1 can effectively suppress PRRSV replication, and it may be considered as a new anti-PRRSV candidate drug. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) is a destructive pathogen that continues to adversely affect the swine industry worldwide due to a current lack of vaccines and drugs capable of effective disease control. In the present study, the neolignan-like drug, magnolol (MAG), was tested for its ability to inhibit a Vero-cell adapted PEDV strain DR13att. Our data revealed that MAG exhibited anti-PEDV activity in vitro, with IC50 and CC50 values of 28.21 μM and 57.28 μM, respectively. MAG was an efficient inhibitor of viral replication, and repression of viral proliferation was strongest when the host cells were exposed to MAG and the virus at the same time. Although our data indicate that MAG has the potential to be a useful PEDV control agent, in vivo testing of the drug, using animal hosts, is required. [ABSTRACT FROM AUTHOR]

Singapore grouper iridovirus (SGIV) is a virus with high fatality rate in the grouper culture industry. The outbreak of SGIV is often accompanied by a large number of grouper deaths, which has a great impact on the economy. Therefore, it is of great significance to find effective drugs against SGIV. It has been reported that edaravone is a broad-spectrum antiviral drug, most widely used clinically in recent years, but no report has been found exploring the effect of edaravone on SGIV infections. In this study, we evaluated the antiviral effect of edaravone against SGIV, and the anti-SGIV mechanism of edaravone was also explored. It was found that the safe concentration of edaravone on grouper spleen (GS) cells was 50 µg/mL, and it possessed antiviral activity against SGIV infection in a dose-dependent manner. Furthermore, edaravone could significantly disrupt SGIV particles and interference with SGIV binding to host cells, as well as SGIV replication in host cells. However, edaravone was not effective during the SGIV invasion into host cells. This study was the first time that it was determined that edaravone could exert antiviral effects in response to SGIV infection by directly interfering with the processes of SGIV infecting cells, aiming to provide a theoretical basis for the control of grouper virus disease.

New precautions have become part of our daily life since COVID-19 pandemic such as wearing masks, maintaining distance and disinfecting products bought from markets before using them which is exhausting. We aimed to test the inhibitory effect of Camellia sinensis (black tea) water extracts on respiratory viruses and the inhibition of viruses accumulated over different surface types after being soaked in water supplemented with the extracts. Two water extraction methods (extract A: maceration at 80 °C for 30 min and extract B: boiling for 40 min) were applied; extracts were analyzed by high-performance liquid chromatography to detect polyphenolic compounds. Results showed that 200 μg/ml of extract A and 50 μg/ml of extract B in water caused 100% inhibition of influenza A (enveloped virus) virus after 1.5 h and similar results were obtained for adenovirus (non-enveloped virus) but at the same concentration of extract A and at 100 μg/ml of extract B. Different surfaces (aluminum, glass, plastic or carton, vegetables of smooth (tomato) or rough (lemon) surfaces and green leaves) were inoculated with both viruses for 20 min and then soaked in the water supplemented with 200 μg/ml of extract A or 100 μg/ml of extract B for 1.5 h, and this resulted in complete inhibition of both viruses. HIGHLIGHTS Extracts of natural product represent a treasure of compounds that can work synergistically together better and cheaper than being isolated.; Water extracts of Camellia sinenses plant have a lot of polyphenolic compounds beside tannins that have direct inhibitory effect on tested viral particles.; Soaking substances of different surface natures in water containing that extract cause inhibition to accumulated viral particles on those surfaces within 1.5 hours.; This can be of great benefit during COVID-19 pandemic where accumulated viruses on surfaces bought from markets represent source of infection.;

The article discusses the current problems of the treatment of acute respiratory infections, excessive use of antibiotics and the growth of resistance to them, which is ahead of the development of effective antimicrobial drugs. The results of the research of a new drug (Rafamin) are presented. Rafamin is combining antiviral and antibacterial effects, and may be in demand both for the treatment of acute respiratory viral infections and for the prevention of bacterial complications. The mechanism of action of the drug is associated with the activation of immune mechanisms involved in the recognition of pathogens of both viral and bacterial nature and the launch of a subsequent humoral and cellular response that ensures the elimination of the pathogen. The effects of Rafamin are realized due to targeted effects on the system of the major histocompatibility complex, interferon gamma and CD4-receptor of T-lymphocytes.

Rotavirus is one of the main pathogens that cause diarrhoea in young animals, and countless animals have died of rotavirus infection worldwide. Three strains of lactic acid bacteria isolated from Tibetan mushrooms were used to study the inhibition of rotavirus in vitro and in vivo. One part was to identify and study the biochemical and probiotic characteristics of three isolated lactic acid bacteria, and the other part was to evaluate the inhibitory effect on rotavirus via in vivo and in vitro experiments. The whole genome of the lactic acid bacteria with the best antiviral effect was sequenced, and the differences between them and the standard strains were analyzed by comparative genomic analysis, so as to provide a theoretical basis for exploring the antiviral effect of lactic acid bacteria.The three strains were identified as Pediococcus acidilactici, Lactobacillus casei and Lactobacillus paracasei. Pediococcus acidilactici showed good acid tolerance, bile salt tolerance, survival in artificial intestinal fluid, survival in gastric fluid and bacteriostasis. In in vitro experiments, pig intestinal epithelial cells cocultured with Pediococcus acidilactici exhibited reduced viral infection. In the in vivo experiment, the duodenum of mice fed Pediococcus acidilactici had extremely low numbers of virus particles. The total genome size was 2,026,809 bp, the total number of genes was 1988, and the total length of genes was 1,767,273 bp. The proportion of glycoside hydrolases and glycoside transferases in CAZy was 50.6 and 29.6%, respectively. The Metabolism function in KEEG had the highest number of Global and overview maps. Among the comparative genomes, Pediococcus acidilactici had the highest homology with GCF 000146325.1, and had a good collinearity with GCF 013127755.1, without numerous gene rearrangement events such as insertion, deletion, inversion and translocation. In conclusion, Pediococcus acidilactici was a good candidate strain for antiviral probiotics. [ABSTRACT FROM AUTHOR]

Curcumae Rhizoma is the dry rhizome coming from Curcuma longa L. which grow widely in tropical south and southwest Asia. It has been used to treat conditions such as dermatoses, infections, stress, and depression. Moreover, in China, Curcumae Rhizoma and its active constituents have been made into different pharmaceutical preparations. Growing evidence suggests that these preparations can exert antioxidant, anti-inflammatory, and anti-cancer effects, which may play crucial roles in the treatment of various diseases, including cancer, infectious-, autoimmune-, neurological-, and cardiovascular diseases, as well as diabetes. The anti-infective effect of Curcumae Rhizoma has become a popular field of research around the world, including for the treatment of COVID-19, influenza virus, hepatitis B virus, human immunodeficiency virus, and human papilloma virus, among others. In this paper, the basic characteristics of Curcumae Rhizoma and its active constituents are briefly introduced, and we also give an overview on their applications and mechanisms in infectious diseases. [ABSTRACT FROM AUTHOR]

Retrospective data showed that when we administered ledipasvir/sofosbuvir (LDV/SOF) to patients with hepatitis B and C coinfection, there was a modest reduction in hepatitis B surface antigen (HBsAg). Therefore, we hypothesize that similar HBsAg reduction can be seen in hepatitis B virus (HBV) monoinfected subjects. Primary and secondary efficacy endpoints are the decline in HBsAg and HBV DNA at Week 12 from baseline, respectively. We conducted an open‐label Phase 2 pilot study to evaluate the safety, tolerability, and antiviral activity of LDV and/or SOF for HBV. Eligible subjects were either suppressed on antivirals (Group B) or inactive chronic HBV (Group A, C, D). Group A and B received LDV/SOF. Group C and D received SOF 400 mg and LDV 90 mg, respectively. All subjects completed the study, and all related adverse events (AEs) were mild. No discontinuations due to AEs or hepatitis flare occurred. At Week 12, HBsAg decline (log10 IU/ml) was similar between Group A (0.399) and B (0.400), less in Group C (0.207), and none in Group D, and there was HBV DNA decline in the inactive chronic HBV groups. LDV and SOF are safe and well tolerated when given to chronic hepatitis B subjects and have modest antiviral activity, particularly when given in combination. [ABSTRACT FROM AUTHOR]

Objective: To screen the anti-SFTSV drugs from 1 430 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 (IC50) 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 IC50 of 0.014 μmol/L, 0.627 μmol/L, 1.283 μmol/L, and 0.059 μmol/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. [ABSTRACT FROM AUTHOR]

Coxsackievirus B3 (CVB3) is a single-stranded RNA virus that belongs to the Enterovirus genus. CVB3 is a human pathogen associated with serious conditions such as myocarditis, dilated cardiomyopathy, and pancreatitis. However, there are no therapeutic interventions to treat CVB3 infections. In this study, we found that CVB3 induced metabolic alteration in host cells through increasing glycolysis level, as indicated by an increase in the extracellular acidification rate (ECAR). CVB3-mediated metabolic alteration was confirmed by metabolite change analysis using gas chromatography-mass spectrometry (GC-MS). Based on findings, a strategy to inhibit glycolysis has been proposed to treat CVB3 infection. Indeed, glycolysis inhibitors (2-Deoxy-D-glucose, sodium oxide) significantly reduced CVB3 titers after CVB3 infection, indicating that glycolysis inhibitors can be used as effective antiviral agents. Taken together, our results reveal a novel mechanism by which CVB3 infection is controlled by regulation of host cell metabolism. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Nervous necrosis virus (NNV) is one of the most destructive pathogens in marine fish aquaculture and is capable of infecting more than 50 fish species worldwide, which resulted in great economic losses. Effective drugs for managing NNV infection are urgently required. Medicinal plants have been known for thousands of years and benefit of medicinal plants against pathogens in aquaculture have emerged. Nowadays, the most commonly used method for detecting virus infection and assessing antiviral drugs efficacy is reverse transcription‐quantitative real‐time PCR. However, the application is limited on account of high reagent costs, complex time‐consuming operations and long detection time. Aptamers have been widely applied in application of pathogens or diseases diagnosis and treatments because of high specificity, strong affinity, good stability, easy synthesized and low costs. This study aimed to establish an aptamer (GBN34)‐based high‐throughput screening (GBN34‐AHTS) model for efficient selection and evaluation of natural ingredients against NNV infection. GBN34‐AHTS is an expeditious rapid method for selecting natural ingredients against NNV, which is characterized with high‐speed, dram, sensitive and accurate. AHTS strategy could reduce work intensity and experimental costs and shorten the whole screening cycle of effective ingredients. AHTS should be suitable for rapid selection of effective ingredients against other viruses, which is important for improving the prevention and controlling of aquatic diseases. [ABSTRACT FROM AUTHOR]

The problem of prevention and treatment of acute respiratory infections of the upper respiratory tract remains extremely at the top. Although viruses are the etiological factor in more than 90% of acute respiratory infections, the fact of the active use of antibiotics in the treatment of patients with this patology, along with the lack of effective antiviral agents can cause increasing concern, since this is assocatied with an increase in bacterial resistance, sensitization and inflammatory diseases and therefore requires the development of completely different alternative methods of treatment. Since the discovery of the human microbiome over the past two decades, not only the microbiota as a participant in the infectious process, but also probiotics as a factor in managing the immune responses of the macroorganism in viral infections have been actively studied. In addition, the antiviral activity of different probiotic strains has been demonstrated in the scientific literature, which explains the interest of the scientific community in the use of probiotics in acute respiratory infections, especially since probiotics have shown not only efficacy, but aalso high safety in patients of different age groups, including infants. Thus, the literature review showed that the currently available data both from clinical studies and experimental work on the use of probiotics in acute respiratory infections indicate the potential of such an innovative strategy not only for the prevention but also for the treatment of the acute period of the disease, which should be the basis for its wider use in real practice.

ABSTRACT: Multidrug-resistant (MDR) Staphylococcus aureus and its biofilm formation have been challenging to control in milk and dairy industries. Biofilms formed by Staph. aureus may result in the failure of antibacterial agents and disinfectants to penetrate the biofilm in an attempt to control contamination. Novel natural antibacterial agents are required to combat MDR bacteria and biofilms. In this study, we evaluated the bactericidal, antibiofilm, and antimotility effects of Rumex japonicus Houtt. (RJH) extract on MDR Staph. aureus isolated from milk. The RJH extract exhibited good antibacterial activity against MDR strains with minimum inhibitory concentrations (MIC) ranging from 0.78 to 6.25 mg/mL and minimum bactericidal concentrations ranging from 3.125 to 12.5 mg/mL. The extract showed strong inhibition of biofilm formation (81.9%) at sub-MIC value and eradication of biofilm at higher concentrations. The motility of Staph. aureus was effectively blocked by the extract. Major compounds emodin, chrysophanol, and physcion were identified in RJH extract using HPLC-linear trap quadrupole (LTQ)/Orbitrap-mass spectrometry. The extract was nontoxic to human epithelial cell lines such as Caco-2 and HT-29 cell lines at concentrations ranging from 0.1 to 0.5 mg/mL, and from 0.1 to 0.75 mg/mL, respectively. These findings suggest that RJH extract could be an alternative to synthetic preservatives in milk and dairy products.