Hypericin blocks the function of HSV-1 alkaline nuclease and suppresses viral replication.

ETHNOPHARMACOLOGICAL RELEVANCE: Hypericum perforatum L. has a long history in many countries of being used as a herbal medicine. It is also widely used in Chinese herbal medicine for the treatment of infections. Hypericin, a main component extracted from Hypericum perforatum L., has attracted the attention of many researchers for its remarkable antiviral, antitumor and antidepressant effects. AIM OF THE STUDY: To find plant molecules that inhibit the alkaline nuclease (AN) of herpes simplex virus type 1 (HSV-1) and suppress viral replication. MATERIALS AND METHODS: Bioinformatics methods were used to determine which compounds from a variety of natural compounds in our laboratory interact with AN. By this means we predicted that hypericin may interact with AN and suppress HSV-1 replication. Experiments were then carried out to verify whether hypericin inhibits the bioactivity of AN. The Pichia pastoris expression system was used to obtain recombinant AN. The exonuclease and endonuclease activity of AN treated with hypericin were tested by electrophoresis. Immunohistochemical staining of the HSV-1 nucleocapsids was used to find out whether hypericin inhibits the intracellular function of AN. Real-time PCR and western blotting analysis were performed to test viral gene expression and viral protein synthesis. The extent of viral replication inhibited by hypericin was determined by a plaque assay and a time of addition assay. RESULTS: Recombinant AN was obtained by Pichia pastoris expression system. The exonuclease and endonuclease activity of recombinant AN were inhibited by hypericin in the electrophoresis assay. Hypericin showed no inhibitory effect on BeyoZonase™ Super Nuclease or DNase I. T5 Exonuclease activity was inhibited partially by10 µM hypericin, and was completely suppressed by 50 µM hypericin. Hind Ⅲ was inhibited by hypericin at concentrations greater than 100 µM, but EcoR I, BamH I, and Sal I were not inhibited by hypericin. HSV-1 nucleocapsids gathered in the nucleus when the viruses were treated with hypericin. Plaque formation was significantly reduced by hypericin (EC50 against HSV-1 F is 2.59 ± 0.08 µM and EC50 against HSV-1 SM44 is 2.94 ± 0.10 µM). UL12, ICP27, ICP8, gD, and UL53 gene expression (P < 0.01, 4.0 µM hypericin treated group vs control group) and ICP4 (P < 0.05, 6.0 µM hypericin treated group vs control group), ICP8 and gD (P < 0.05, 2.0 µM hypericin treated group vs control group) protein synthesis were inhibited by hypericin. In the time of addition assay, HSV-1 was suppressed by hypericin in the early stages of viral replication. Hypericin exhibits potent virucidal activity against HSV-1 and inhibits the adsorption and penetration of HSV-1. CONCLUSION: Hypericin inhibits the bioactivity of AN and suppresses HSV-1 replication. The data revealed a novel mechanism of the antiherpetic effect of hypericin.

Phenotypic and genotypic acyclovir resistance surveillance of genital herpes simplex virus 2 in South Africa.

Acyclovir (ACV) is currently included in the syndromic management algorithm for genital ulcer disease in South Africa, and is the recommended first-line treatment for herpes simplex virus 2 (HSV-2). In the majority of cases, HSV-2 resistance to ACV is due to amino acid changes within the viral thymidine kinase (TK). Phenotypic and genotypic ACV resistance surveillance of HSV-2 derived from genital ulcer disease swab specimens was conducted at a primary healthcare facility in Johannesburg between 2018 and 2020. The objectives of this surveillance were to identify ACV resistance-associated mutations and polymorphisms in HSV-2 TK, and to determine the phenotypic ACV resistance profiles of the corresponding clinical HSV-2 isolates. Genotypic analysis of TK from 67 HSV-2 positive genital ulcer swabs revealed 48 specimens with TK mutations, conferring 113 nucleotide changes. No resistance-associated mutations were found, however, we identified nine known natural polymorphisms (R26H, A27T, S29A, G39E, N78D, L140F, T159I, R220K and R284S) and five amino acid changes of unknown significance (R18C, G39K, M70R, P75S and L263P). Phenotypic susceptibility testing of 52 cultivable HSV-2 isolates revealed all to be susceptible to ACV with IC50 values of <2 µg/ml. The five amino acid changes of unknown significance identified by genotypic testing were not correlated to phenotypic ACV resistance, and therefore grouped as natural polymorphisms. We did not detect any unknown or resistance-associated mutations in specimens that could not be phenotypically tested for ACV resistance. Our findings will supplement existing databases of HSV antiviral resistance-associated mutations and polymorphisms that could be used for genotypic ACV resistance screening.

Antiviral effect of Artemisia aucheri aqueous extract on UL46 and US6 genes of HSV-1.

HSV-1 is associated with oral lesions. Recently, anti-herpetic activity of different plant species has been investigated. In this study, the effects of Artemisia aucheri aqueous extract on the HSV-1 virus-infected Vero cells were assessed. The highest cell viability occurred in plant aqueous extracts was with a concentration of 75 µg/mL, 1-2 h before viral infection. The IC50 of the aqueous extract of 24.7 µg/ml was calculated. Most percentage of infected cell inhibition (89.6%) was with the chloroform fraction in concentration of 75 µg/ml, and the least percentage of infected cell inhibition (21.7%) was in concentration of 12.5 µg/ml with the ethyl acetate fraction in comparison with untreated control. Moreover, Q-PCR results revealed that the expression of genes UL46 and US6 were significantly reduced in the presence of different treatments utilized in the experiment. In conclusion, the present study proposes that aqueous extracts of medicinal plant Artemisia aucheri have anti-viral property and may be considered as a remedy for HSV-1 treatment.

Positive detection of SARS-CoV-2 combined HSV1 and HHV6B virus nucleic acid in tear and conjunctival secretions of a non-conjunctivitis COVID-19 patient with obstruction of common lacrimal duct.

BACKGROUND: The current outbreak of COVID-19 has spread rapidly all over the world. Respiratory droplets and contaction with infected patients are the two major transmission routes. However, the value of tear virus nucleic acid is still not clear. We dynamic detected the SARS-CoV-2 in eye sample of one COVID-19 patient with obstruction of common lacrimal ducts. METHODS: Besides the routine examination, nasopharyngeal and eye swab were continuously measured by polymerase chain reaction assay and next-generation sequencing (NGS). Gene detection was performed for drug use guidance, and flow cytometry was performed to analyse the lymphocyte subsets. RESULTS: Nasopharyngeal swabs were positive for 22 days, but eye swabs were still continuously positive for 2 weeks after nasopharyngeal swabs turned negative. The low level of lymphocyte and the high level IL-6 lasted for almost 4 weeks, then became near normal. Next-generation sequencing (NGS) confirmed the existing of SARS-CoV-2, HSV1 and HHV6B virus nucleic acid. The gene detection for drug use guidance showed the genetic locus ABCB1 (3435T>C) rs1045642 belonged to type CC and it mean the efficiency of lopinavir-ritonavir would be significantly decreased. The flow cytometry of lymphocyte subsets showed PD-1+  CD95+ cells was accounting for 94.8% in CD3+  CD8+ T subset and for 94.8% in CD3+  TCRγδ+ T subset. CONCLUSIONS: As obstruction of common lacrimal duct, positively detection in one eye for 2 weeks more after nasopharyngeal swab became negative. More eye swabs should be collected from COVID-19 patients, especially from those immunocompromised, those with eye symptoms and those had a history of ocular diseases.

Single-cell RNA-sequencing analysis identifies host long noncoding RNA MAMDC2-AS1 as a co-factor for HSV-1 nuclear transport.

Herpes simplex virus (HSV) type 1 (HSV-1) infection exhibited high heterogeneity at individual cells level, including the different gene expression patterns and varying amounts of progeny virus. However, the underlying mechanism of such variability remains obscure. The importance of host long noncoding RNAs (lncRNAs) in virus infection had been recognized, while the contribution of lncRNAs to the heterogeneous infection remains unknown. Herein, a prior single-cell RNA sequencing data using HSV-1 reporter strain expressing ICP4-YFP was re-analyzed to obtain the differentially expressed lncRNA between the successfully initiated viral gene expression (ICP4-YFP+) cells and the aborted infection cells (ICP4-YFP-). The ICP4-YFP+ population show a higher abundance of MAMDC2 antisense 1 (MAMDC2-AS1) lncRNA than ICP4-YFP- population. MAMDC2-AS1 silencing reduces the expression of HSV-1 immediate early (IE) genes and limit HSV-1 infection in human host cells. Consistently, ectopic expression of MAMDC2-AS1 enhances HSV-1 IE genes transcription and facilitates the formation of HSV-1-induced plaques. Mechanically, both RNA-pull down and RNA immunoprecipitation assays show that MAMDC2-AS1 interacts with the RNA binding protein heat shock protein 90α (Hsp90α), a molecular chaperone involving in the nuclear import of HSV-1. The MAMDC2-AS1-Hsp90α interaction facilitates the nuclear transport of viral tegument protein VP16, the core factor initiating the expression of HSV-1 IE genes. The transcription factor YY1 mediates the induction of MAMDC2-AS1 upon HSV-1 infection. Our study elucidates the contribution of lncRNA to HSV-1 infection susceptibility in human cells and the role of Hsp90α RNA binding activity in HSV-1 infection.

The Antimicrobial and Antiviral Activity of Polyphenols from Almond (Prunus dulcis L.) Skin.

Due to their antimicrobial and antiviral activity potential in vitro, polyphenols are gaining a lot of attention from the pharmaceutical and healthcare industries. A novel antiviral and antimicrobial approach could be based on the use of polyphenols obtained from natural sources. Here, we tested the antibacterial and antiviral effect of a mix of polyphenols present in natural almond skin (NS MIX). The antimicrobial potential was evaluated against the standard American Type Culture Collection (ATCC) and clinical strains of Staphylococcus aureus, including methicillin-resistant (MRSA) strains, by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Herpes simplex virus type I was used for the antiviral assessment of NS MIX by plaque assay. Furthermore, we evaluated the expression of viral cascade antigens. NS MIX exhibited antimicrobial (MIC values of 0.31-1.25 mg/ml) and antiviral activity (decrease in the viral titer ** p < 0.01, and viral DNA accumulation * p < 0.05) against Staphylococcus aureus and HSV-1, respectively. Amongst the isolated compounds, the aglycones epicatechin and catechin showed the greatest activity against S. aureus ATCC 6538P (MIC values of 0.078-0.15 and 0.15 mg/ml, respectively), but were not active against all the other strains. These results could be used to develop novel products for topical use.

Acute retinal necrosis in a patient with remote severe herpes simplex encephalitis.

A 60-year-old man with a history of severe herpes simplex virus type 1 (HSV-1) encephalitis 2 years prior presented with acute onset of visual loss in the left eye. Dilated funduscopic examination showed retinitis and occlusive vasculitis with retinal necrosis. PCR of the vitreous fluid was positive for HSV-1, and he was diagnosed with acute retinal necrosis (ARN) due to HSV-1. The patient was treated with intravenous acyclovir and intravitreous foscarnet for 2 weeks, followed by high dose oral valacyclovir for 2 weeks. He was subsequently placed on planned life-long suppressive valacyclovir. His case demonstrates that acute visual loss concomitant with or subsequent to HSV-1 encephalitis warrants suspicion of ARN. Prompt therapy with effective antiviral medication is necessary to reduce the risk of sight-threatening complications. Chronic suppression with oral antiviral therapy after ARN is recommended to prevent involvement of the contralateral eye, though there is no consensus on the duration and dosage of antivirals.

The anti-HSV-1 effect of quercetin is dependent on the suppression of TLR-3 in Raw 264.7 cells.

Quercetin is a major component of the plant Glycyrrhiza uralensis, which is largely used as a traditional medicine in Asia. Quercetin has been reported to have several biological activities, which include anti-viral and anti-inflammatory effects. We explored the molecular mechanism linking anti-viral and anti-inflammatory activities using an in vitro herpes simplex virus-1 (HSV-1) infection model. Raw 264.7 cells were infected with HSV-1 in the presence or absence of different concentrations of quercetin and infected cell lysates were harvested 24 h later. HSV plaque reduction assays, western blotting (HSV-1gD, HSV-1 ICP0, TLR-2, 3, 9, NF-κB, IRF3), and real time PCR (HSV-1ICP0, HSV-1UL13, HSV-1UL52) were performed to elucidate the mechanism responsible for the anti-HSV-1 effect of quercetin. In addition, TNF-α level was measured. Quercetin significantly lowered HSV infectivity in Raw 264.7 cells and inhibited the expressions of HSV proteins (gD, ICP0) and genes (ICP0, UL13, UL52). Interestingly, quercetin specifically suppressed the expression of TLR-3, and this led to the inhibitions of inflammatory transcriptional factors (NF-κB and IRF3). These findings suggest that the anti-HSV-1 effects of quercetin are related to the suppression of TLR-3 dependent inflammatory responses in Raw 264.7 cells.

First-in-class small molecule potentiators of cancer virotherapy.

The use of engineered viral strains such as gene therapy vectors and oncolytic viruses (OV) to selectively destroy cancer cells is poised to make a major impact in the clinic and revolutionize cancer therapy. In particular, several studies have shown that OV therapy is safe and well tolerated in humans and can infect a broad range of cancers. Yet in clinical studies OV therapy has highly variable response rates. The heterogeneous nature of tumors is widely accepted to be a major obstacle for OV therapeutics and highlights a need for strategies to improve viral replication efficacy. Here, we describe the development of a new class of small molecules for selectively enhancing OV replication in cancer tissue. Medicinal chemistry studies led to the identification of compounds that enhance multiple OVs and gene therapy vectors. Lead compounds increase OV growth up to 2000-fold in vitro and demonstrate remarkable selectivity for cancer cells over normal tissue ex vivo and in vivo. These small molecules also demonstrate enhanced stability with reduced electrophilicity and are highly tolerated in animals. This pharmacoviral approach expands the scope of OVs to include resistant tumors, further potentiating this transformative therapy. It is easily foreseeable that this approach can be applied to therapeutically enhance other attenuated viral vectors.

Nutraceutical activators of AMPK/Sirt1 axis inhibit viral production and protect neurons from neurodegenerative events triggered during HSV-1 infection.

Herpes simplex virus type-1 (HSV-1) is ubiquitous and is able to establish a lifelong persistent latent infection in neurons of infected individuals. It has been estimated that in approximately 70% of the population over 50 years old, the virus enters the brain and infects neurons, and possibly undergoes recurrent reactivation episodes during lifetime, especially in immunodepressed individuals. We previously showed that the sensors AMP-dependent kinase (AMPK) and Sirtuin 1 (Sirt1), involved in survival pathways and neuroprotection, were affected during the course of HSV-1 infection. To evaluate if natural activators of the AMPK/Sirt1 axis, such as Resveratrol and Quercetin could reduce viral propagation and/or counteract the effects of neuronal infection, we analyzed progeny virion production, neuronal viability and neurodegenerative events during HSV-1 infection. We found that the activators of AMPK/Sirt1 axis, increased the viability of infected neurons, significantly reduced the viral titer in the supernatant and the expression of viral genes. More importantly, pretreatment of neurons with Resveratrol or Quercetin significantly reduced the levels of caspase-3 cleaved- and hyperphosphorylated tau associated with HSV-1 infection. These results suggest that activators of the AMPK/Sirt1 axis could be potentially useful in reducing the risk of HSV-1 productive infection in neurons and the cellular damage associated with reactivation episodes.

A spiroketal-enol ether derivative from Tanacetum vulgare selectively inhibits HSV-1 and HSV-2 glycoprotein accumulation in Vero cells.

The inhibitory effects of Tanacetum vulgare rhizome extracts on HSV-1 and HSV-2 in vitro replication were assessed. Unlike extracts obtained from the aerial parts, adsorption inhibition and virucidal activities seemed not to be relevant for the observed antiviral action of tansy rhizome extracts. Instead, the most significant effects were the inhibition of virus penetration and a novel mechanism consisting of the specific arrest of viral gene expression and consequently the decrease of viral protein accumulation within infected cells. Through a bioactivity-guided fractionation protocol we isolated and identified the spiroketal-enol ether derivative (E)-2-(2,4-hexadiynyliden)-1,6-dioxaspiro[4.5]dec-3-ene as the active compound responsible for this inhibitory effect.

Houttuynia cordata targets the beginning stage of herpes simplex virus infection.

Herpes simplex virus (HSV), a common latent virus in humans, causes certain severe diseases. Extensive use of acyclovir (ACV) results in the development of drug-resistant HSV strains, hence, there is an urgent need to develop new drugs to treat HSV infection. Houttuynia cordata (H. cordata), a natural herbal medicine, has been reported to exhibit anti-HSV effects which is partly NF-κB-dependent. However, the molecular mechanisms by which H. cordata inhibits HSV infection are not elucidated thoroughly. Here, we report that H. cordata water extracts (HCWEs) inhibit the infection of HSV-1, HSV-2, and acyclovir-resistant HSV-1 mainly via blocking viral binding and penetration in the beginning of infection. HCWEs also suppress HSV replication. Furthermore, HCWEs attenuate the first-wave of NF-κB activation, which is essential for viral gene expressions. Further analysis of six compounds in HCWEs revealed that quercetin and isoquercitrin inhibit NF-κB activation and additionally, quercetin also has an inhibitory effect on viral entry. These results indicate that HCWEs can inhibit HSV infection through multiple mechanisms and could be a potential lead for development of new drugs for treating HSV.

Long-range connectivity defines behavioral specificity of amygdala neurons.

Memories are acquired and encoded within large-scale neuronal networks spanning different brain areas. The anatomical and functional specificity of such long-range interactions and their role in learning is poorly understood. The amygdala and the medial prefrontal cortex (mPFC) are interconnected brain structures involved in the extinction of conditioned fear. Here, we show that a defined subpopulation of basal amygdala (BA) projection neurons targeting the prelimbic (PL) subdivision of mPFC is active during states of high fear, whereas BA neurons targeting the infralimbic (IL) subdivision are recruited, and exhibit cell-type-specific plasticity, during fear extinction. Pathway-specific optogenetic manipulations demonstrate that the activity balance between pathways is causally involved in fear extinction. Together, our findings demonstrate that, although intermingled locally, long-range connectivity defines distinct subpopulations of amygdala projection neurons and indicate that the formation of long-term extinction memories depends on the balance of activity between two defined amygdala-prefrontal pathways.

Self-organizing maps for the classification of gallic acylate polyphenols as HSV-1 inhibitors.

Herpes simplex virus type 1 (HSV-1), a member of the Herpesviridae family, is a ubiquitous, contagious, hostadapted pathogen that causes a wide variety of disease states, such as herpes labialis ("cold sores") and encephalitis. Recently, due to the appearance of acyclovir-resistant HSV-1 mutants, a rapidly growing area of research has been the identification of novel small molecules (whether found in traditional medicine or not) with antiviral activity. One group of these novel pre-drugs is gallic acylate polyphenols. Here, detailed insight into the influence of the chemical structure on anti- HSV-1 activity of gallic acylate polyphenols has been provided based on an exploration of structure-function relationships through self-organizing maps and counterpropagation neural networks. A number of descriptors were investigated to construct optimized models. The resulting model exhibits a correct prediction rate of 90.67%, with active molecule classification accuracy higher than 95.00%, demonstrating that the electrostatic effect and distance between atoms are related to HSV-1 inhibition for these gallic acylate polyphenols. The results provide insights into the influence of the chemical structure on anti-HSV-1 activity of gallic acylate polyphenols.

Memory recall and modifications by activating neurons with elevated CREB.

Memory is supported by a specific ensemble of neurons distributed in the brain that form a unique memory trace. We previously showed that neurons in the lateral amygdala expressing elevated levels of cAMP response-element binding protein are preferentially recruited into fear memory traces and are necessary for the expression of those memories. However, it is unknown whether artificially activating just these selected neurons in the absence of behavioral cues is sufficient to recall that fear memory. Using an ectopic rat vanilloid receptor TRPV1 and capsaicin system, we found that activating this specific ensemble of neurons was sufficient to recall established fear memory. Furthermore, this neuronal activation induced a reconsolidation-like reorganization process, or strengthening of the fear memory. Thus, our findings establish a direct link between the activation of specific ensemble of neurons in the lateral amygdala and the recall of fear memory and its subsequent modifications.

[Diagnostic and therapeutic strategy for acyclovir-resistant herpes encephalitis].

Acyclovir (ACV), which inhibits the replication of herpes simplex virus, is the standard drug for the treatment of herpes simplex encephalitis. Thanks to the introduction of ACV, the morbidity and mortality of HSE patients have significantly improved. However, the disease is still the severe infection, because it makes some patients with HSE suffer from severe consequences. The sensitivity test of the etiological HSV to ACV is very difficult due to the inability of isolation of the virus from cerebrospinal fluid (CSF). The cases of the ACV treatment-resistant HSE patients have been reported. However, these cases were not virologically confirmed. The first case of encephalitis in newborn baby with HSE caused by an ACV-resistant HSV-1, which was virologically confirmed, was reported by our group. According to the sensitivity profile of the causative viruses to antiviral drugs, the drugs of choice for HSE should be properly considered. Strategy for diagnoses of HSE including antiviral sensitivity assessment and selection of drugs in HSE is reviewed.

Chemical composition and antinociceptive, anti-inflammatory and antiviral activities of Gallesia gorazema (Phytolaccaceae), a potential candidate for novel anti-herpetic phytomedicines.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional medicine, teas made from leaves and bark of Gallesia gorazema are used as antispasmodic, anthelmintic, antihemorrhagic and febrifuge agents. Crude leaves of this plant are also employed as a remedy in the treatment of abscesses, orchitis, gonorrhea and for rheumatic pain relief. this study investigates the presumed antinociceptive and anti-inflammatory activities of leaves and roots Gallesia gorazema (Phytolaccaceae) extracts. The most active extract and its isolated compound, a new natural product, are also evaluated against viruses HSV-1 and HSV-2. MATERIALS AND METHODS: In vivo experiments with mice were used to assess the analgesic and anti-inflammatory activities of Gallesia gorazema extracts. Antiviral activity of extracts and the new natural product was investigated by in vitro experiments. RESULTS: Results show that dichloromethanic root (DRE) and ethanolic leaf (ELE) extracts displayed significant antinociceptive and anti-inflammatory activities in in vivo experiments with mice. Both extracts were also assayed against the herpes simplex viruses HSV-1 and HSV-2, but only DRE was highly active, showing a selective antiviral effect against HSV-1. Phytochemical fractionation of DRE led to the isolation of 28-hydroxyoctacosyl ferulate, a novel natural product, which displayed strong antiviral activity against HSV-1 (EC50=21.6 µg/mL) with a selective index above 9, justifying, at least in part, the high selective antiviral activity observed for DRE. CONCLUSION: These results suggest that the plant Gallesia gorazema is a potential candidate for the development of novel anti-herpetic phytomedicines.

Phenotypic and genotypic characterization of acyclovir-resistant corneal HSV-1 isolates from immunocompetent patients with recurrent herpetic keratitis.

Herpes simplex virus type 1 (HSV-1) is a leading cause of corneal blindness. Acyclovir (ACV) constitutes the standard treatment of HSV infections including herpetic keratitis (HK). HSV resistance to ACV is mainly described in immunocompromised patients. We describe two cases of ACV-resistant corneal HSV-1 in immunocompetent individuals with recurrent HK.

Preclinical therapy of disseminated HER-2⁺ ovarian and breast carcinomas with a HER-2-retargeted oncolytic herpesvirus.

Oncolytic viruses aim to specifically kill tumor cells. A major challenge is the effective targeting of disseminated tumors in vivo. We retargeted herpes simplex virus (HSV) tropism to HER-2 oncoprotein p185, overexpressed in ovary and breast cancers. The HER-2-retargeted R-LM249 exclusively infects and kills tumor cells expressing high levels of human HER-2. Here, we assessed the efficacy of systemically i.p. delivered R-LM249 against disseminated tumors in mouse models that recapitulate tumor spread to the peritoneum in women. The human ovarian carcinoma SK-OV-3 cells implanted intraperitoneally (i.p.) in immunodeficient Rag2⁻/⁻;Il2rg⁻/⁻ mice gave rise to a progressive peritoneal carcinomatosis which mimics the fatal condition in advanced human patients. I.p. administration of R-LM249 strongly inhibited carcinomatosis, resulting in 60% of mice free from peritoneal diffusion, and 95% reduction in the total weight of neoplastic nodules. Intraperitoneal metastases are a common outcome in breast cancer: i.p. administration of R-LM249 strongly inhibited the growth of ovarian metastases of HER-2+ MDA-MB-453 breast cells. Brain metastases were also reduced. Cumulatively, upon i.p. administration the HER-2-redirected oncolytic HSV effectively reduced the growth of ovarian and breast carcinoma disseminated to the peritoneal cavity.

Inhibition of herpes simplex virus type 1 with the modified green tea polyphenol palmitoyl-epigallocatechin gallate.

Green tea polyphenol epigallocatechin gallate (EGCG) is a strong antioxidant that has previously been shown to reduce the number of plaques in HIV-infected cultured cells. Modified EGCG, palmitoyl-EGCG (p-EGCG), is of interest as a topical antiviral agent for herpes simplex virus (HSV-1) infections. This study evaluated the effect of p-EGCG on HSV-infected Vero cells. Results of cell viability and cell proliferation assays indicate that p-EGCG is not toxic to cultured Vero cells and show that modification of the green tea polyphenol epigallocatechin gallate (EGCG) with palmitate increases the effectiveness of EGCG as an antiviral agent. Furthermore, p-EGCG is a more potent inhibitor of herpes simplex virus 1 (HSV-1) than EGCG and can be topically applied to skin, one of the primary tissues infected by HSV. Viral binding assay, plaque forming assay, PCR, real-time PCR, and fluorescence microscopy were used to demonstrate that p-EGCG concentrations of 50 µM and higher block the production of infectious HSV-1 particles. p-EGCG was found to inhibit HSV-1 adsorption to Vero cells. Thus, p-EGCG may provide a novel treatment for HSV-1 infections.