• Korean Journal of Pharmacognosy
• /
• v.30 no.1
• /
• pp.25-33
• /
• 1999

In order to find less toxic antiviral agents from basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers.) Karst. EA was examined for antiviral activity against five strains of pathogenic viruses such as encephalomyocarditis virus (EMCV), vesicular stomatitis virus (VSV) Indiana and New Jersey strains, influenza A virus (Flu A), and varicella zoster virus (VZV) in vitro. Antiviral activity was evaluated by plaque reduction assay. Among five strains of viruses tested, EA exhibited the most potent antiviral activity against VSV Indiana strain with 50% effective concentration $(EC_{50})$ of 0.104 mg/ml in Vero cells, and its selectivity index (SI) was 36.5. EA was also examined for the virucidal activity, antiviral activity in preincubation on VSV Indiana strain in order to examine possible mode of antiviral activity. Preincubation of Vero cells with EA did not confer protection against VSV, however, prolonged exposure of cells to EA inhibited the replication of virus dose-dependently. In virucidal activity, the titer of infectious virus did not decrease significantly.

• Korean Journal of Pharmacognosy
• /
• v.50 no.1
• /
• pp.1-10
• /
• 2019

Recently, companion animal culture has grown rapidly and mature, raising interest in preventing and treating animal diseases. In particular, viral infection was a serious threat to companion animal health because there was no proper antiviral drugs. Synthetic antiviral drugs have limitations such as low efficiency, toxicity, and occurrence of resistant viruses. Therefore, attempts to find new anti-viral drugs from natural sources have continued. This review focused on the natural products and active substances that exhibit antiviral activity against three viruses: canine distemper virus (CDV), canine parvovirus (CPV), and feline calicivirus (FCV) that cause fatal diseases in dogs and cats. Natural plant extracts, flavonoids, polysaccharides, alkaloids and saponins showed antiviral activity with various mechanisms and differences in activity depending on the structure. Especially, quercetin and epigallocatechin-3-gallate (EGCG) showed antiviral activity through a multi-mechanism that interferes with the attachment and penetration stages of the virus and inhibits the viral polymerase within the cell. Some natural plant extracts showed a virucidal activity and showed the potential effect as a preventative agent to prevent the viral infection. This review is expected to provide research trend on the development of antiviral natural products for companion animals.

• Microbiology and Biotechnology Letters
• /
• v.21 no.5
• /
• pp.399-405
• /
• 1993

For screening of the antiviral agent from soil, about 520 strains of microorganisms were evaluated for their antiviral activity, About 6.9% of strains showed more than 95% antiviral activity against Herpes Simples Virus (HSV)-1. Two strains among 30 strains active against HSV-1 virus showed a quite strong activity against human immunodeficiency virus.

• Journal of Microbiology
• /
• v.38 no.4
• /
• pp.255-259
• /
• 2000

For rapid and sensitive measurement of antiviral activities, application of a recombinant virus containing firefly luciferase gene was attempted. Recombinant human cytomegalovirus (HCMV) containing luciferase gene driven by HCMV late gene pp28 promoter (HCMV/pp28-luc) was used to test the antiviral activities of three known compounds and the result was compared with results from the conventional plaque assay for measuring the production of infectious viruses. When human fibroblast cells were infected with HCMV/pp28-luc, luciferase activity was observed at 2 days after infection and reached maximum at 6 days after infection, whereas the production of infectious virus was maximal at 4 days after infection. The antiviral activities of ganciclovir, acyclovir, and papaverine were measured in HFF cells infected with HCMV/PP28-luc and the luciferase activity was compared with the infectious virus titers. Luciferase activity decreased as the concentration of ganciclovir or papaverine increased, while there was a slight decrease in luciferase activity with acyclovir. The level of the decrease in Luciferase activity was comparable to the level of decrease in the production of infectious virus. Therefore, the antiviral assay using recombinant virus HCMV/pp28-luc resulted in sensitivity similar to the conventional plaque assay with a significant reduction in assay time.

• ALGAE
• /
• v.30 no.3
• /
• pp.241-246
• /
• 2015

This research was conducted to develop effective and safe marine-derived antiviral compounds against norovirus. The ethyl acetate (EtOAc)-extract from Eisenia bicyclis exhibited strong antiviral activity against murine norovirus (MNV) as a norovirus surrogate. Among the phlorotannins from E. bicyclis, dieckol (DE) and phlorofucofuroeckol-A (PFF) were known to possess the strongest antibacterial activity. In this study, DE and PFF were evaluated for antiviral activity against MNV. DE and PFF exhibited strong anti-MNV activity with 50% effective concentration ($EC_{50}$) of $0.9{\mu}M$. However, PFF exhibited more effective antiviral activity against MNV with higher selective index (668.87) than that of DE (550.60), due to its lower cell toxicity against RAW 264.7. This is the first report on the anti-MNV activity of phlorotannins from seaweed. The results obtained in this study suggest that the phlorotannins could be used as a potential source of natural antiviral agents.

• Fisheries and Aquatic Sciences
• /
• v.17 no.1
• /
• pp.155-158
• /
• 2014

The objective of this study was to evaluate the antiviral activity of Phaeophyta extracts against feline calicivirus (FCV), used as a norovirus surrogate. A bioassay-guided cytotoxicity and virus infectivity assay revealed that methanolic extracts of Phaeophyta possessed significant antiviral activity against FCV. Among them, Eisenia bicyclis extract exhibited the highest antiviral activity against FCV. The 50% effective concentration of the extract ($EC_{50}$) inhibiting FCV viral replication by 50% was $80{\mu}g/mL$. The extract also showed the highest selectivity index, calculated from the ratio of the median cellular cytotoxicity concentration ($CC_{50}$) and $EC_{50}$, indicating antiviral efficacy against FCV. In addition, significant interruption of FCV infection was observed by pretreatment of host Crandall-Reese feline kidney cells with the E. bicyclis extract ($200{\mu}g/mL$) prior to virus infection, in a dosedependent manner.

• International Journal of Advanced Culture Technology
• /
• v.7 no.3
• /
• pp.120-125
• /
• 2019

In this paper, we have isolated six phenolic compounds, such as (+)-catechin (1), taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-xylose (3), quercetin (4), quercetin-3-O-${\alpha}$-L(+)-rhamnose (quercitrin) (5), apigenin-8-C-rhamnosyl-(1'''${\rightarrow}$2'')-glucoside (2''-O-rhamnosylvitexin) (6) from the EtOAc(Ethyl Acetate) and $H_2O$ soluble fractions of Japanese anise(Illicium anisatum L) leaves and twigs. Also, we have evaluated antioxidative and antiviral activity for each isolated compound. The antioxidative test was DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. According to the experimental results, all of the isolated compounds indicated the increased radical scavenging activities as the concentration increases and most of the isolated compounds indicated generally good antioxidative values compare to the controls, ascorbic acid and ${\alpha}$-tocopherol. In the antiviral activities, all of the isolated compounds had no potentials in rhinovirus 1B (HRV 1B). But in enterovirus 71 (EV 71) and Influenza virus A/PR/8 (Influenza PR8), only quercetin (4) indicated the good antiviral activity compare to the control. Based on the above results, we found that the phenolic compounds of Japanese anise may be applied for one of the natural biomass sources that can be used as an antioxidant and an antiviral substance.

• Biomolecules & Therapeutics
• /
• v.23 no.5
• /
• pp.465-470
• /
• 2015

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease ($3C^{pro}$ activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at $10{\mu}M$, but exhibited mild cellular cytotoxicity at $50{\mu}M$, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9-11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with $1{\times}10^6TCID_{50}$ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.

• Archives of Pharmacal Research
• /
• v.26 no.11
• /
• pp.887-891
• /
• 2003

Novel trans-2,2-dimethylcyclopropyl nucleosides were synthesized as potential antiviral agents. The key intermediate, 3, was synthesized via five steps from ethyl chrysanthemate and condensed with purine bases using the Mitsunobu reaction to give six cyclopropyl nucleosides. These synthesized nucleosides did not show any significant antiviral activity against HSV-1, HSV-2, EMCV, Cox B3, or VSV, at concentrations up to 100 $\mu M$.

• Archives of Pharmacal Research
• /
• v.24 no.1
• /
• pp.74-78
• /
• 2001

A preparation of water soluble components (EA) was made from carpophores of Elfvingia applanata (Pers.) Karst and its in vitro antiviral activity on vesicular stomatitis virus [(Indiana serotype, VSV(IND)] was investigated by plaque reduction assay. EA exhibited potent antiviral activity on VSV(IND) growth and negligible cytotoxicity on Vero cells, 50% effective concentration ($EC_{50}C$/) of 104$ug\textrm\/ml$ and 50% cytotoxic concentration ($CC_{50}C$) of 3,793$ug\textrm\/ml$, respectively. Selectivity index (Sl $CC_{50}C$/$EC_{50}C$) of EA on Vero cell and VSV(IND) was about 36.5. EA did not display either a direct virucidal effect on V5V(IND) or induction of antiviral substance by Vero cells upon its treatment. Thus, the mode of antiviral activity of EA was studied at steps of viral adsorption onto cell. When both EA and virus were added to cell monolayers, titer of cell-free virus in culture supernatant increased in ca. 30-40% compared with that of control group and titer of cell-associated virus was 60-100% higher than that of control group. These results suggested that antiviral activity of EA on VSV(IND) might be due to the hindrance of viral entry to cells at eITher endocytosis or loss of envelope.