The bioactivity-guided isolation of potentially active natural products has been widely utilized in pharmaceutical discovery. In this study, by screening fungal extracts against coxsackievirus B3 (CVB3), three new aspochalasins, templichalasins A‒C (1‒3), along with six known aspochalasins (4‒9) were isolated from an active extract derived from the endophytic fungus Aspergillus templicola LHWf045. Compound 1 features a unique 5/6/5/7/5 pentacyclic ring system, while compounds 2 and 3 possess unusual 5/6/6/7 tetracyclic skeletons. Their structures were characterized through extensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction analysis. Additionally, we demonstrated that compound 4 can be readily converted into compounds 1‒3 under mild acidic conditions and proposed a plausible mechanism for this conversion. Bioactivity evaluation of compounds 1‒9 against CVB3 revealed the inhibitory effects of all compounds against the virus. Notably, compound 9 exhibited superior antiviral activity, surpassing the commercial drug ribavirin in selectivity index (SI) value.
Antiviral Agents/isolation & purification* ; Aspergillus/chemistry* ; Molecular Structure ; Enterovirus B, Human/drug effects* ; Endophytes/chemistry* ; Cytochalasins/isolation & purification* ; Drug Discovery ; Humans

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

<b>OBJECTIVEb>To study the effects of yiqi huoxue recipe and Coxsackie B virus type 3 (CVB3) on the expression of ribosomal protein S20 in rat cardiac myocytes, to explore the pathogenesis of myocarditis induced by CVB3 and the mechanism of yiqi huoxue recipe on gene level, and to further investigate whether yiqi huoxue recipe is an effective prescription for CVB3 myocarditis.

<b>METHODSb>A modified suppression subtractive hybridization (SSH) was used to isolate differentially expressed genes between the CVB3 infection group and the treatment group with yiqi huoxue recipe. The results were further verified by fluorescence RT-PCR.

<b>RESULTSb>The results of SSH showed that the gene expression of ribosomal protein S20 in the treatment group was higher than that in the CVB3 infection group (P<0.05), which agreed with the results of fluorescent RT-PCR.

<b>CONCLUSIONb>Down-regulation of ribosomal protein S20 mRNA expression might be one of the mechanisms in CVB3 myocarditis, and yiqi huoxue recipe could achieve the treatment of viral myocarditis by regulating the expression of ribosomal protein S20.

Animals ; Coxsackievirus Infections ; drug therapy ; virology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enterovirus B, Human ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Myocytes, Cardiac ; drug effects ; metabolism ; virology ; Nucleic Acid Hybridization ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Ribosomal Proteins ; genetics ; metabolism

In order to find antiviral compounds with novel structures, geldanamycin and lamivudine with different antiviral mechanisms were conjunctively synthesized to acquire a new compound TC-GM, and the antiviral activity of TC-GM was measured. The antiviral activity against HIV-1 was examined by p24 antigen ELISA kit. The activity against HBV was examined by dotblot. The activity against HSV and CoxB virus was examined by CPE. TC-GM exhibited broad-spectrum antiviral activities similarly like geldanamycin. TC-GM inhibited the replication of different viruses, including HIV-1, HBV, HSV 1 and 2, CoxB6. TC-GM showed more potent inhibitory activity against HIV-1 and HBV than other detected virus.
Animals ; Anti-HIV Agents ; chemical synthesis ; chemistry ; pharmacology ; Antiviral Agents ; chemical synthesis ; chemistry ; pharmacology ; Benzoquinones ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; Cercopithecus aethiops ; Enterovirus B, Human ; drug effects ; physiology ; HIV-1 ; drug effects ; physiology ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; physiology ; Herpesvirus 1, Human ; drug effects ; physiology ; Herpesvirus 2, Human ; drug effects ; physiology ; Humans ; Lactams, Macrocyclic ; chemical synthesis ; chemistry ; pharmacology ; Lamivudine ; chemical synthesis ; chemistry ; pharmacology ; Madin Darby Canine Kidney Cells ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; pathology ; virology ; Vero Cells ; Virus Replication ; drug effects

<b>OBJECTIVEb>To investigate the effects of Qihong capsule (QH) on HeLa cells infected by coxsackievirus B3 (CVB3) in vitro and its potential antiviral mechanism.

<b>METHODSb>HeLa cells were infected by CVB3 in vitro. XTT assay and plaque inhibition assay were performed to determine the 50 % effective dose, (ED50), 50 % inhibitory concentration (IC50), and 50% cytotoxicity concentration (CC50) of QH and the control drug, ribavirin. The total therapeutic index (TI) was calculated. Anti-viral time-course experiments were performed to compare the anti-viral effects at different time points. The inhibitory effects of QH on the attachment and penetration of CVB3 were also observed.

<b>RESULTSb>XTT assay and plaque inhibition assay showed that the ED50 and IC50 were (7.16+/-0.80) mg/L and (2.63+/-0.50) mg/L in QH group and (4.35+/-0.40) mg/L and (1.92+/-0.30) mg/L in ribavirin group, respectively. CC50 was 16-fold higher in QH group than in ribavirin group QH: (1 648+/-219) mg/L vs. Ribavirin: (103+/-14) mg/L. Time-course studies demonstrated that antiviral effect of QH was mainly found 0-4 hours after infection. QH effectively blocked the attachment and penetration of CVB3 into cells.

<b>CONCLUSIONb>By inhibiting the attachment and penetration of CVB3, QH can effectively inhibit the invasion of virus in vitro with low toxicity.

Antiviral Agents ; pharmacology ; Capsules ; Drugs, Chinese Herbal ; pharmacology ; Enterovirus B, Human ; drug effects ; HeLa Cells ; Humans ; Inhibitory Concentration 50

Animals ; Coxsackievirus Infections ; metabolism ; pathology ; physiopathology ; Enterovirus B, Human ; Female ; Glutathione Peroxidase ; metabolism ; Male ; Mice ; Myocarditis ; virology ; Oxidative Stress ; drug effects ; Selenium ; pharmacology ; Superoxide Dismutase ; metabolism

Cycloheximide (CHX) inhibits protein synthesis in most eukaryotic cells and it is a well-known tool commonly used in biochemical research. In this paper, the antiviral spectrum of CHX against several DNA and RNA viruses have been evaluated. CHX showed strong inhibitory activities against several RNA viruses such as HIV-1, influenza viruses, coxsackie B virus, enterovirus (EV71) and several DNA viruses such as HSV and HCMV. Especially the strong inhibitory activities of CHX against coxsackie B virus and enterovirus caught our attention, since effective drugs available in clinic are limited. The SAR of CHX derivatives also has been discussed in the paper. The hydroxyl group at C-2' and carbonyl group at C-2" of CHX are essential for its antiviral activity. And modification to these groups results its derivatives' antiviral activities reduced or lost.
Antiviral Agents ; chemical synthesis ; chemistry ; pharmacology ; Cell Line ; Cycloheximide ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology ; DNA Viruses ; drug effects ; Enterovirus ; drug effects ; Enterovirus B, Human ; drug effects ; Humans ; RNA Viruses ; drug effects

<b>OBJECTIVEb>To study the protective effects of tetramethylpyrazine (TMPZ) on rat myocardial cells infected by Coxsackie virus B3 (CVB3) and its signal transduction mechanism.

<b>METHODSb>The cultured myocardial cells of neonatal Sprague-Dawley rats were randomly treated with CVB3, CVB3+TMPZ (100 micromol/L), TMPZ (100 micromol/L) (negative control) or DMEM (blank control). After treatment, the beating rate of myocardial cells and the LDH activity in the culture fluid were measured. Cell viability was ascertained with MTT assay. Western blot was used to study the expression of nuclear factor kappa-B (NF-kappaB) protein in myocardial cells.

<b>RESULTSb>The beating rate of myocardial cells in the untreated CVB3 infection group was significantly lower than that in the TMPZ-treated CVB3 infection group (32.0+/-3.6 bpm vs 84.3+/-3.5 bpm, P<0.01). The LDH activity and NF-kappaB expression in the TMPZ-treated CVB3 infection group was significantly reduced when compared with untreated CVB3 infection group (P<0.05, P<0.01, respectively). Cell viability 7 days after CVB3 infection in the TMPZ-treated group was higher than that in the untreated CVB3 infection group (86.7+/-2.7% vs 35.3+/-3.4%; P<0.01).

<b>CONCLUSIONSb>TMPZ can provide protective effects on rat myocardial cells infected by CVB3, possibly by an inhibition of the activity of NF-kappaB in myocardial cells.

Animals ; Cytoprotection ; Enterovirus B, Human ; L-Lactate Dehydrogenase ; metabolism ; Myocardial Contraction ; drug effects ; Myocarditis ; drug therapy ; Myocytes, Cardiac ; drug effects ; virology ; NF-kappa B ; analysis ; physiology ; Pyrazines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; physiology

<b>OBJECTIVEb>INF-lambda has anti-viral and anti-tumor activities. Its application in viral myocarditis (VMC) has not been reported. This study investigated the role of INF-lambda in acute VMC in mice.

<b>METHODSb>Forty mice were randomly divided into three groups: VMC (n=15), IFN-lambda2-treated VMC (n=15) and control (n=10). VMC was induced by an intraperitoneal injection of Coxsackievirus B3 (CVB3).The control group was intraperitoneally injected with 2% PBS. The IFN-lambda2-treated VMC group was administered with 400 ng IFN-lambda2 (0.1 mL) by subcutaneous injections daily, for 5 days. The control and the VMC groups were given equal amount of nomal saline.The surviving mice were sacrificed 9 days after IFN-lambda2 treatment. The pathological changes of heart tissues were examined under a light microscope. Bcl-2 and Bax expression in heart tissues was determined by immunohistochemistry.

<b>RESULTSb>The control group presented normal heart tissues. The INF-lambda2-treated VMC group showed significantly a lower pathological score (1.5+/-0.5) than the untreated VMC group (2.8+/-0.8) (P<0.01). Bcl-2 expression decreased (P<0.01), in contrast, Bax expression increased (P<0.01) in the untreated VMC group compared with that in the control group. INF-lambda2 treatment resulted in an increased Bcl-2 expression (P<0.01) and a decreased Bax expression (P<0.01) compared to the untreated VMC group.

<b>CONCLUSIONSb>INF-lambda2 may alleviate myocardial injuries and inhibit cardiomyocytic apoptosis, thus providing protective effects on myocardial cells in mice with acute VMC.

Animals ; Apoptosis ; drug effects ; Coxsackievirus Infections ; drug therapy ; metabolism ; Cytokines ; therapeutic use ; Enterovirus B, Human ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; drug therapy ; metabolism ; Myocardium ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; analysis ; bcl-2-Associated X Protein ; analysis

Alkaloids ; pharmacology ; Animals ; Apoptosis ; drug effects ; Calcium ; metabolism ; Cells, Cultured ; Enterovirus B, Human ; Myocytes, Cardiac ; drug effects ; virology ; Quinolizines ; pharmacology ; Rats ; Rats, Wistar