Inhibit Herpes Simplex Research Articles

Berberine Inhibits Herpes Simplex Virus 1 Replication in HEK293T Cells.

Berberine exhibits polytrophic medicinal roles in various diseases and is safe and effective. However, its role and the underlying mechanism in the replication of herpes simplex virus 1 (HSV-1) remain unreported. This research aimed to determine the functional mechanisms of berberine on HSV-1 infection. We determined the CC50 (405.11 ± 15.67 μM) and IC50 (45.6 ± 6.84 μM) of berberine on HEK293T cells infected with HSV-1. Berberine inhibited the transcription and translation of HSV-1 activity-related genes (gD, ICP-4, ICP-5, and ICP-8) in HSV-1-infected HEK293T cells dose-dependently. Berberine also inhibited the phosphorylation of MAPK proteins (JNK and p38) and inflammatory responses induced by HSV-1 infection in HEK293T cells dose-dependently. In conclusion, berberine attenuates HSV-1 replication through its activity, infective ability, and inflammatory response. Our research indicated that berberine may be a candidate drug for HSV-1 infection.

The E3 ubiquitin ligase ARIH1 promotes antiviral immunity and autoimmunity by inducing mono-ISGylation and oligomerization of cGAS

The cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) plays a critical role in antiviral immunity and autoimmunity. The activity and stability of cGAS are fine-tuned by post-translational modifications. Here, we show that ariadne RBR E3 ubiquitin protein ligase 1 (ARIH1) catalyzes the mono-ISGylation and induces the oligomerization of cGAS, thereby promoting antiviral immunity and autoimmunity. Knockdown or knockout of ARIH1 significantly inhibits herpes simplex virus 1 (HSV-1)- or cytoplasmic DNA-induced expression of type I interferons (IFNs) and proinflammatory cytokines. Consistently, tamoxifen-treated ER-Cre;Arih1fl/fl mice and Lyz2-Cre; Arih1fl/fl mice are hypersensitive to HSV-1 infection compared with the controls. In addition, deletion of ARIH1 in myeloid cells alleviates the autoimmune phenotypes and completely rescues the autoimmune lethality caused by TREX1 deficiency. Mechanistically, HSV-1- or cytosolic DNA-induced oligomerization and activation of cGAS are potentiated by ISGylation at its K187 residue, which is catalyzed by ARIH1. Our findings thus reveal an important role of ARIH1 in innate antiviral and autoimmune responses and provide insight into the post-translational regulation of cGAS.

Mouse Mx1 Inhibits Herpes Simplex Virus Type 1 Genomic Replication and Late Gene Expression In Vitro and Prevents Lesion Formation in the Mouse Zosteriform Model.

Myxovirus resistance (Mx) proteins are dynamin-like GTPases that are inducible by interferons (IFNs) following virus infections. Most studies investigating Mx proteins have focused on their activity against influenza A viruses (IAV), although emerging evidence suggests that some Mx proteins may exhibit broader antiviral activity. Herein, we demonstrate that in addition to IAV, overexpression of mouse Mx1 (mMx1), but not mMx2, resulted in potent inhibition of growth of the human alphaherpesviruses herpes simplex virus 1 (HSV-1) and HSV-2, whereas neither inhibited the mouse betaherpesvirus murine cytomegalovirus (MCMV) in vitro. IFN induction of a functional endogenous mMx1 in primary mouse fibroblasts ex vivo was also associated with inhibition of HSV-1 growth. Using an in vitro overexpression approach, we demonstrate that mutations that result in redistribution of mMx1 from the nucleus to the cytoplasm or in loss of its combined GTP binding and GTPase activity also abrogated its ability to inhibit HSV-1 growth. Overexpressed mMx1 did not inhibit early HSV-1 gene expression but was shown to inhibit both replication of the HSV-1 genome as well as subsequent late gene expression. In a mouse model of cutaneous HSV-1 infection, mice expressing a functional endogenous mMx1 showed significant reductions in the severity of skin lesions as well as reduced HSV-1 titers in both the skin and dorsal root ganglia (DRG). Together, these data demonstrate that mMx1 mediates potent antiviral activity against human alphaherpesviruses by blocking replication of the viral genome and subsequent steps in virus replication. Moreover, endogenous mMx1 potently inhibited pathogenesis in the zosteriform mouse model of HSV-1 infection. IMPORTANCE While a number of studies have demonstrated that human Mx proteins can inhibit particular herpesviruses in vitro, we are the first to report the antiviral activity of mouse Mx1 (mMx1) against alphaherpesviruses both in vitro and in vivo. We demonstrate that both overexpressed mMx1 and endogenous mMx1 potently restrict HSV-1 growth in vitro. mMx1-mediated inhibition of HSV-1 was not associated with inhibition of virus entry and/or import of the viral genome into the nucleus, but rather with inhibition of HSV-1 genomic replication as well as subsequent late gene expression. Therefore, inhibition of human alphaherpesviruses by mMx1 occurs by a mechanism that is distinct from that reported for human Mx proteins against herpesviruses. Importantly, we also provide evidence that expression of a functional endogenous mMx1 can limit HSV-1 pathogenesis in a mouse model of infection.

Potent Virustatic Polymer-Lipid Nanomimics Block Viral Entry and Inhibit Malaria Parasites In Vivo.

Infectious diseases continue to pose a substantial burden on global populations, requiring innovative broad-spectrum prophylactic and treatment alternatives. Here, we have designed modular synthetic polymer nanoparticles that mimic functional components of host cell membranes, yielding multivalent nanomimics that act by directly binding to varied pathogens. Nanomimic blood circulation time was prolonged by reformulating polymer–lipid hybrids. Femtomolar concentrations of the polymer nanomimics were sufficient to inhibit herpes simplex virus type 2 (HSV-2) entry into epithelial cells, while higher doses were needed against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given their observed virustatic mode of action, the nanomimics were also tested with malaria parasite blood-stage merozoites, which lose their invasive capacity after a few minutes. Efficient inhibition of merozoite invasion of red blood cells was demonstrated both in vitro and in vivo using a preclinical rodent malaria model. We envision these nanomimics forming an adaptable platform for developing pathogen entry inhibitors and as immunomodulators, wherein nanomimic-inhibited pathogens can be secondarily targeted to sites of immune recognition.

Anthocyanins in Red Jasmine Rice (Oryza sativa L.) Extracts and Efficacy on Inhibition of Herpes Simplex Virus, Free Radicals and Cancer Cell.

Rice is one of the most important food crops in many countries, with nutritional value and health benefits. In this study, the ethanolic and aqueous extracts of red jasmine rice from Chiang Mai, Thailand were examined for their anthocyanins and phenolic contents. The antioxidant and antiviral activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), as well as anticancer activity, were investigated. The total anthocyanins content of 708.03 ± 11.56 mg Cy-3-glc equivalent/g extract, determined from the ethanolic extract, was higher than the aqueous extract. However, the aqueous extract showed the highest total phenolic compound of 81.91 ± 0.51 mg GAE/g extract. In addition, the ethanolic extract demonstrated higher antioxidant activity than aqueous extract using DPPH, ABTS, and FRAP assays by 28.91 ± 3.26 mg GAE/g extract, 189.45 ± 11.58 mg 24 TEAC/g extract, and 3292.46 ± 259.64 g FeSO4/g extract, respectively. In the antiviral assay, it was found that the ethanolic extract of red jasmine rice could inhibit HSV-1 more effectively than HSV-2 when treated before, during, and after the viral attachment on Vero cells, with 50% effective doses of 227.53 ± 2.41, 189.59 ± 7.76, and 192.62 ± 2.40 µg/mL, respectively. The extract also demonstrated the highest reduction of HSV-1 particles at 4 h after treatment and the inhibition of HSV-1 replication. The ethanolic extract exhibited a higher toxicity level than the aqueous extract, as well as the potential to induce DNA fragmentation by intrinsic and extrinsic apoptosis pathways on the Caco-2 cells. These findings suggest that red jasmine rice extract demonstrates nutritional value and biological activity on HSV, free radicals, and cancer cell inhibition.

Prevention of Herpesviridae Infections by Cationic PEGylated Carbosilane Dendrimers.

Infections caused by viruses from the Herpesviridae family produce some of the most prevalent transmitted diseases in the world, constituting a serious global public health issue. Some of the virus properties such as latency and the appearance of resistance to antiviral treatments complicate the development of effective therapies capable of facing the infection. In this context, dendrimers present themselves as promising alternatives to current treatments. In this study, we propose the use of PEGylated cationic carbosilane dendrimers as inhibitors of herpes simplex virus 2 (HSV-2) and human cytomegalovirus (HCMV)infections. Studies of mitochondrial toxicity, membrane integrity, internalization and viral infection inhibition indicated that G2-SN15-PEG, G3-SN31-PEG, G2-SN15-PEG fluorescein isothiocyanate (FITC) labeled and G3-SN31-PEG-FITC dendrimers are valid candidates to target HSV-2 and HCMV infections since they are biocompatible, can be effectively internalized and are able to significantly inhibit both infections. Later studies (including viral inactivation, binding inhibition, heparan sulphate proteoglycans (HSPG)binding and surface plasmon resonance assays) confirmed that inhibition takes place at first infection stages. More precisely, these studies established that their attachment to cell membrane heparan sulphate proteoglycans impede the interaction between viral glycoproteins and these cell receptors, thus preventing infection. Altogether, our research confirmed the high capacity of these PEGylated carbosilane dendrimers to prevent HSV-2 and HCMV infections, making them valid candidates as antiviral agents against Herpesviridae infections.

Native RNA Purification Method for Small RNA Molecules Based on Asymmetrical Flow Field-Flow Fractionation.

RNA molecules provide promising new possibilities for the prevention and treatment of viral infections and diseases. The rapid development of RNA biology and medicine requires advanced methods for the purification of RNA molecules, which allow fast and efficient RNA processing, preferably under non-denaturing conditions. Asymmetrical flow field-flow fractionation (AF4) enables gentle separation and purification of macromolecules based on their diffusion coefficients. The aim of the study was to develop an AF4 method for efficient purification of enzymatically produced antiviral small interfering (si)RNA molecules and to evaluate the overall potential of AF4 in the separation of short single-stranded (ss) and double-stranded (ds) RNA molecules. We show that AF4 separates monomeric ssRNA from dsRNA molecules of the same size and monomeric ssRNA from multimeric forms of the same ssRNA. The developed AF4 method enabled the separation of enzymatically produced 27-nt siRNAs from partially digested substrate dsRNA, which is potentially toxic for mammalian cells. The recovery of AF4-purified enzymatically produced siRNA molecules was about 70%, which is about 20% higher than obtained using anion-exchange chromatography. The AF4-purified siRNAs were not toxic for mammalian cells and fully retained their biological activity as confirmed by efficient inhibition of herpes simplex virus 1 replication in cell culture. Our work is the first to develop AF4 methods for the separation of short RNA molecules.

The Synthesis and Anti-Cytomegalovirus Activity of Piperidine-4-Carboxamides.

Treatment options for human cytomegalovirus (CMV) remain limited and are associated with significant adverse effects and the selection of resistant CMV strains in transplant recipients and congenitally infected infants. Although most approved drugs target and inhibit the CMV DNA polymerase, additional agents with distinct mechanisms of action are needed for the treatment and prevention of CMV. In a large high throughput screen using our CMV-luciferase reporter Towne, we identified several unique inhibitors of CMV replication. Here, we synthesize and test in vitro 13 analogs of the original NCGC2955 hit (1). Analogs with no activity against the CMV-luciferase at 10 µM and 30 µM (2–6, 10–14) were removed from further analysis. Three analogs (7–9) inhibited CMV replication in infected human foreskin fibroblasts. The EC50 of (1) was 1.7 ± 0.6 µM and 1.99 ± 0.15 µM, based on luciferase and plaque assay, respectively. Compounds 7, 8, and 9 showed similar activities: the EC50 values of 7 were 0.21 ± 0.06 µM (luciferase) and 0.55 ± 0.06 (plaque), of 8: 0.28 ± 0.06 µM and 0.42 ± 0.07, and of 9: 0.30 ± 0.05 µM (luciferase) and 0.35 ± 0.07 (plaque). The CC50 for 7, 8, and 9 in non-infected human foreskin fibroblasts was > 500µM, yielding a selectivity index of >1500. Compounds 1, 7, and 8 were also tested in CMV-infected primary human hepatocytes and showed a dose–response against CMV by luciferase activity and viral protein expression. None of the active compounds inhibited herpes simplex virus 1 or 2. Compounds 7 and 8 inhibited mouse CMV replication in vitro. Both inhibited CMV at late stages of replication; 7 reduced virus yield at all late time points, although not to the same degree as letermovir. Finally, the activity of analog 8 was additive with newly identified CMV inhibitors (MLS8969, NFU1827, MSL8554, and MSL8091) and with ganciclovir. Further structural activity development should provide promising anti-CMV agents for use in clinical studies.

Several Mechanisms Contribute to Photodynamic Inhibition of Herpes Simplex Virus 1 Infection by Tricationic Amphiphilic Porphyrin with a Long Alkyl Chain

Several Mechanisms Contribute to Photodynamic Inhibition of Herpes Simplex Virus 1 Infection by Tricationic Amphiphilic Porphyrin with a Long Alkyl Chain

Silencing of proinflammatory NF-κB and inhibition of herpes simplex virus (HSV) replication by ultrasmall gold nanoparticles (2 nm) conjugated with small-interfering RNA.

Azide-terminated ultrasmall gold nanoparticles (2 nm gold core) were covalently functionalized with alkyne-terminated small-interfering siRNA duplexes by copper-catalyzed azide-alkyne cycloaddition (CuAAC; click chemistry). The nanoparticle core was visualized by transmission electron microscopy. The number of attached siRNA molecules per nanoparticle was determined by a combination of atomic absorption spectroscopy (AAS; for gold) and UV-Vis spectroscopy (for siRNA). Each nanoparticle carried between 6 and 10 siRNA duplex molecules which corresponds to a weight ratio of siRNA to gold of about 2.2 : 1. Different kinds of siRNA were conjugated to the nanoparticles, depending on the gene to be silenced. In general, the nanoparticles were readily taken up by cells and highly efficient in gene silencing, in contrast to free siRNA. This was demonstrated in HeLa-eGFP cells (silencing of eGFP) and in LPS-stimulated macrophages (silencing of NF-κB). Furthermore, we demonstrated that nanoparticles carrying antiviral siRNA potently inhibited the replication of Herpes simplex virus 2 (HSV-2) in vitro. This highlights the strong potential of siRNA-functionalized ultrasmall gold nanoparticles in a broad spectrum of applications, including gene silencing and treatment of viral infections, combined with a minimal dose of gold.

ML-SA1 and SN-2 inhibit endocytosed viruses through regulating TRPML channel expression and activity

Transient receptor potential mucolipin 2 and 3 (TRPML2 and TRPML3), as key channels in the endosomal-lysosomal system, are associated with many different cellular processes, including ion release, membrane trafficking and autophagy. In particular, they can also facilitate viral entry into host cells and enhance viral infection. We previously identified that two selective TRPML agonists, ML-SA1 and SN-2, that showed antiviral activities against dengue virus type 2 (DENV2) and Zika virus (ZIKV) in vitro, but their antiviral mechanisms are still elusive. Here, we reported that ML-SA1 could inhibit DENV2 replication by downregulating the expression of both TRPML2 and TRPML3, while the other TRPML activator, SN-2, suppressed DENV2 infection by reducing only TRPML3 expression. Consistently, the channel activities of both TRPML2 and TRPML3 were also found to be associated with the antiviral activity of ML-SA1 on DENV2 and ZIKV, but SN-2 relied only on TRPML3 channel activity. Further mechanistic experiments revealed that ML-SA1 and SN-2 decreased the expression of the late endosomal marker Rab7, dependent on TRPML2 and TRPML3, indicating that these two compounds likely inhibit viral infection by promoting vesicular trafficking from late endosomes to lysosomes and then accelerating lysosomal degradation of the virus. As expected, neither ML-SA1 nor SN-2 inhibited herpes simplex virus type I (HSV-1), whose entry is independent of the endolysosomal network. Together, our work reveals the antiviral mechanisms of ML-SA1 and SN-2 in targeting TRPML channels, possibly leading to the discovery of new drug candidates to inhibit endocytosed viruses.

Ginkgolic Acid Inhibits Coronavirus Strain 229E Infection of Human Epithelial Lung Cells.

Since December 2019, the COVID-19 pandemic has affected more than 200 million individuals around the globe and caused millions of deaths. Although there are now multiple vaccines for SARS-CoV-2, their efficacy may be limited by current and future viral mutations. Therefore, effective antiviral compounds are an essential component to win the battle against the family of coronaviruses. Ginkgolic Acid (GA) is a pan-antiviral molecule with proven effective in vitro and in vivo activity. We previously demonstrated that GA inhibits Herpes Simplex Virus 1 (HSV-1) by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we reported that GA displays broad-spectrum fusion inhibition encompassing all three classes of fusion proteins, including those of HIV, Ebola, influenza A, and Epstein Barr virus. Here, we report that GA exhibited potent antiviral activity against Human Coronavirus strain 229E (HCoV-229E) infection of human epithelial lung cells (MRC-5). GA significantly reduced progeny virus production, expression of viral proteins, and cytopathic effects (CPE). Furthermore, GA significantly inhibited HCoV-229E even when added post-infection. In light of our findings and the similarities of this family of viruses, GA holds promising potential as an effective antiviral treatment for SARS-CoV-2.

Inhibition of herpes simplex virus 1 by cepharanthine via promoting cellular autophagy through up-regulation of STING/TBK1/P62 pathway

Cepharanthine (CEP), a naturally occurring isoquinoline alkaloid extracted from the genus CEP of the Tetrandrine family, was reported to possess many biological activities such as anti-inflammatory, antitumor, antiviral, and immune-enhancing effects. Nevertheless, the underlying mechanisms of CEP against herpes simplex virus type 1 (HSV-1) are still elusive. In this study, we explored the anti-HSV effects and mechanisms of CEP in vitro. The results showed that CEP possessed a strong inhibitory effect against HSV-1 infection with the TC50 of 5.4 μg/mL, the IC50 of 0.835 μg/mL, and the TI of 6.47. Most importantly, CEP could promote the phosphorylation of STING, TBK1, and P62 and the expression of LC3II without induction of interferon by directly targeting the STING/TBK1/P62 signaling pathways. Electron microscopy showed that autophagy induced by CEP could degrade viral particles and cellular components. RT-PCR results revealed that a sharp reduction of large numbers of virus gene transcription in 16 h after CEP treatment. Furthermore, CEP also reduced the HSV-1 gB and gC transcription. In conclusion, one of the effects of CEP was to promote interferon-independent autophagy through STING mediated signaling.

Engineering of Janus-Like Dendrimers with Peptides Derived from Glycoproteins of Herpes Simplex Virus Type 1: Toward a Versatile and Novel Antiviral Platform.

Novel antiviral nanotherapeutics, which may inactivate the virus and block it from entering host cells, represent an important challenge to face viral global health emergencies around the world. Using a combination of bioorthogonal copper-catalyzed 1,3-dipolar alkyne/azide cycloaddition (CuAAC) and photoinitiated thiol–ene coupling, monofunctional and bifunctional peptidodendrimer conjugates were obtained. The conjugates are biocompatible and demonstrate no toxicity to cells at biologically relevant concentrations. Furthermore, the orthogonal addition of multiple copies of two different antiviral peptides on the surface of a single dendrimer allowed the resulting bioconjugates to inhibit Herpes simplex virus type 1 at both the early and the late stages of the infection process. The presented work builds on further improving this attractive design to obtain a new class of therapeutics.

Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains.

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

Poly(dA:dT) Suppresses HSV-2 Infection of Human Cervical Epithelial Cells Through RIG-I Activation.

Epithelial cells of the female reproductive tract (FRT) participate in the initial innate immunity against viral infections. Poly(dA:dT) is a synthetic analog of B form double-stranded (ds) DNA which can activate the interferon (IFN) signaling pathway-mediated antiviral immunity through DNA-dependent RNA Polymerase III. Here we investigated whether poly(dA:dT) could inhibit herpes simplex virus type 2 (HSV-2) infection of human cervical epithelial cells (End1/E6E7). We demonstrated that poly(dA:dT) treatment of End1/E6E7 cells could significantly inhibit HSV-2 infection. Mechanistically, poly(dA:dT) treatment of the cells induced the expression of the intracellular IFNs and the multiple antiviral IFN-stimulated genes (ISGs), including IFN-stimulated gene 15 (ISG15), IFN-stimulated gene 56 (ISG56), 2’-5’-oligoadenylate synthetase 1 (OAS1), 2’-5’-oligoadenylate synthetase 2 (OAS2), myxovirus resistance protein A (MxA), myxovirus resistance protein B (MxB), virus inhibitory protein, endoplasmic reticulum-associated, IFN-inducible (Viperin), and guanylate binding protein 5 (GBP5). Further investigation showed that the activation of RIG-I was largely responsible for poly(dA:dT)-mediated HSV-2 inhibition and IFN/ISGs induction in the cervical epithelial cells, as RIG-I knockout abolished the poly(dA:dT) actions. These observations demonstrate the importance for design and development of AT-rich dsDNA-based intervention strategies to control HSV-2 mucosal transmission in FRT.

Anti-microbial Effects In Vitro and In Vivo of Alstonia scholaris

Alstonia scholaris could be used as a traditional medicinal plant in China for the treatment of acute respiratory, which might be caused by respiratory tract infections. The investigation tested the anti-infective effects of total alkaloids extract (TA) from leaves of A. scholaris, and as a result, TA inhibited herpes simplex virus type 1 (HSV-1), respiratory syncytial virus (RSV) and influenza A virus (H1N1) in vitro respectively. In addition, the survival days of mice were prolonged, and the lung weights and mortality of mice were decreased significantly, after oral administrated TA in H1N1 and beta-hemolytic streptococcus infectious models in vivo respectively. The finding supported partly the traditional usage of A. scholaris in the treatment of respiratory infections.Graphic

Mori ramulus and its Major Component Morusin Inhibit Herpes Simplex Virus Type 1 Replication and the Virus-Induced Reactive Oxygen Species.

Herpes simplex virus type 1 (HSV-1) is ubiquitous in many populations despite the use of acyclovir or related nucleoside analogs for treating infection. Drug resistance impairs the treatment of HSV-infected individuals who have immune deficits, underscoring the need for new safe and effective antiviral agents. Mori ramulus (the young twig of Morus alba L.) has long been used to treat diseases in Korea, Japan, and China. Recent studies have reported multiple pharmacological activities of Mori ramulus and its constituent morusin, but their effects on HSV-1 remain unknown. Here, we found that treatment with Mori ramulus ethanol extract (MRE) significantly reduced the replication of fluorescently labeled HSV-1 in Vero cells and inhibited the expression of HSV-1 envelope glycoprotein D (gD) and tegument protein VP16. MRE, furthermore, blocked HSV-1-induced production of reactive oxygen species (ROS), and this mediated the inhibition of viral replication. We identified morusin as the active antiviral component of MRE and found that morusin post-treatment was sufficient to inhibit viral gD and VP16 in addition to HSV-1-induced ROS production. Therefore, the inhibition of HSV-1-induced ROS may explain the antiviral activity of MRE against HSV-1. MRE or its component morusin may be potentially developed for anti-HSV-1 agents.

The propagation of HSV-1 in high autophagic activity

Autophagy is an intracellular process involving double-membrane vacuoles that ultimately merge with the lysosomes and play a key role in the inhibition of herpessimplex virus 1 (HSV-1) proliferation. This virus is an agent of some lethal neuronal diseases like encephalitis. HSV-1 requires the expression of its latent proteins, such as ICP34.5, to promote cell infection, which disrupts the autophagy process. In this study, we aimed to evaluate the effect of autophagy induction on HSV-1 replication in host cells at the early and late stages of its replication. Furthermore, we explored the consequences of autophagy induction before and after cell infection.Cells were transfected through Beclin-1-expressing plasmids. Autophagy induction was performed with microtubule-associated protein 1 light chain 3 (LC3-II) as an autophagosome formation marker by using flow cytometry. In the first stage, HSV-1 was inoculated into transfected cells 18 hours post-transfection. Next, viral DNA was extracted 18 and 48 hours post-infection, and eventually viral copies per milliliter were calculated through real-time polymerase chain reaction (PCR). For the second stage, the plasmid containing Beclin-1 was transfected to the cells following virus inoculation to examine the influence of autophagy induction after cell infection.Study results have shown that in neuroblastoma cells autophagy activation reduces virus yield from 4×10 5 copies/ml (control sample) to 9×10 4 copies/ml at 24 h postinfection and viral load after 48 h declines up to 1×10 6 copies/ml, which is less than that of the control sample about 5 logs. However, in HeLa cells, we observed a significant reduction in autophagy induction with reducing HSV-1 propagation. Despite these results, HSV-1 proliferation in both cell types increased and these viruses were able to maintain their ability to propagate even in high autophagic activity. Hyperactivation of autophagy can only slow the rate of virus replication. This study may provide new insight into the effect of autophagy on HSV-1 replication.

Novel Antiviral and Antibacterial Activities of Hibiscus schizopetalus.

Hibiscus schizopetalus (Dyer) Hook.f. (Malvaceae) is an ornamental plant. The aim was to investigate its antimicrobial and antioxidant activities. In vitro antiviral, antibacterial, and antioxidant activities of the 70% ethanolic extract (Et-E) of the aerial parts of the plant were determined. The Dichloromethane Fraction (DCM-F) and the n-Butanol Fraction (Bu-F) were assessed using Liquid chromatography–mass spectrometry (LC-MS). The DCM-F showed higher antiviral activities against Coxsackie B4 (CoxB4) viruses (IC50 = 64.13 µg/mL) and adenoviruses (IC50 = 54.88 µg/mL) than acyclovir (IC50 = 72.79 µg/mL for CoxB4 viruses; IC50 = 91.92 µg/mL for adenoviruses). The DCM-F showed higher anti-helicobacter pylori activity (MIC = 3.9 µg/mL) than clarithromycin (MIC = 1.95 µg/mL). The DCM-F inhibited Herpes Simplex Virus (HSV) Type I (IC50 = 29.85 µg/mL) and HSV Type II (IC50 = 74.17 µg/mL). The Bu-F showed higher anti-mycobacterial activity (MIC = 7.81 µg/mL) than isoniazid (MIC = 0.24 µg/mL) and higher antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)(MIC = 7.81 µg/mL) than vancomycin (MIC = 3.9 µg/mL). Antioxidant assays included total antioxidant capacity (TAC), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and iron reducing power. The Bu-F showed the highest antioxidant activity. Chemical profiles were analyzed using HPLC-HR–ESI–MS to identify the metabolites responsible for these biological activities. We identified more than 60 metabolites that belong to anthocyanins, flavonoids, phenolics, terpenes, sterols, and fatty acids. In conclusion, Hibiscus schizopetalus is endowed with metabolites that could be used against viruses and antibiotic-resistant bacteria. They can also be potent antioxidants.