• Korean Journal of Pharmacognosy
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• v.48 no.3
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• pp.173-178
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• 2017

We investigated the efficacy of single compound of plant extract in coxsackievirus B3 (CVB3) infection. CVB3 is a main cause of Hand-foot-mouth diseases (HFMD) and viral myocarditis in children and adult. Several single compounds of plant extract were purified by HPLC and tested as antiviral drug candidate. Among them, kaempferol was selected to effective anti-enterovirus compound by HeLa cells survival assay. CVB3 infected HeLa cells were treated with kaempferol ($100{\mu}g/ml-100ng/ml$) and their antiviral effect was confirmed. After 16 hours of treatment, HeLa cells were lysed and proteins were extracted for western blot analysis. CVB3 viral capsid protein VP1 production and transcription factor eIF4G-1 cleavage was significantly decreased in $100{\mu}g/ml$ kaempferol treatment. Virus replication was observed by virus RNA amplification. Kaempferol strongly reduced virus positive and negative strand RNA amplification. Moreover, MAPK signal induced by CVB3 infection, pERK and pmTOR, kaempferol treatment significantly inhibited the activity. Plant extract single compound, kaempferol, is a strong candidate to be developed non-toxic anti-enterovirus treatment agent.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.2012-2018
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• 2016

Coxsackievirus B3 (CVB3) is the main cause of acute myocarditis and dilated cardiomyopathy. Plant extracts are considered as useful materials to develop new antiviral drugs. We had previously selected candidate plant extracts, which showed anti-inflammatory effects. We examined the antiviral effects by using a HeLa cell survival assay. Among these extracts, we chose the Amomi Cardamomi (Amomi) extract, which showed strong antiviral effect and preserved cell survival in CVB3 infection. We investigated the mechanisms underlying the ability of Amomi extract to inhibit CVB3 infection and replication. HeLa cells were infected by CVB3 with or without Amomi extract. Erk and Akt activities, and their correlation with virus replication were observed. Live virus titers in cell supernatants and viral positive- and negative-strand RNA amplification were measured. Amomi extract significantly increased HeLa cell survival in different concentrations ($100-10{\mu}g/ml$). CVB3 capsid protein VP1 expression (76%) and viral protease 2A-induced eIF4G1 cleavage (70%) were significantly decreased in Amomi extract ($100{\mu}g/ml$) treated cells. The levels of positive- (20%) and negative-strand (80%) RNA were dramatically decreased compared with the control, as revealed by reverse transcription-PCR. In addition, Amomi extract improved mice survival (51% vs 26%) and dramatically reduced heart inflammation in a CVB3-induced myocarditis mouse model. These results suggested that Amomi extract significantly inhibited Enterovirus replication and myocarditis damage. Amomi may be developed as a therapeutic drug for Enterovirus.

• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.71-81
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• 2000

We have determined and analyzed the full-length cDNA sequence of a coxsackievirus B3 (CVB3) Korean isolate (CVB3-Korea/97) which has been known as a general human pathogen. The whole genome contains 7,400 nucleotides and has a single large open reading frame with 6,555 nucleotides that encodes a potential polyprotein precursor of 2,185 amino acids. The genome also contains a 5' non-coding region (NCR) of 741 bases and a 3' NCR of 104 bases followed by poly(A) tail. Sequence homologies of nucleotides and deduced amino acids between the CVB3-Korea/97 strain and the prototype (Nancy strain) were 81.7% and 91.5%, respectively. The genes encoding the functional proteins including viral protease and RNA dependent RNA polymerase showed higher homology than those encoding the structural proteins. We have further analyzed the sequences of 5' NCR, VP1 and VP2 of CVB3-Korea/97, which are known as cardiovirulent determining factors at the nucleotide and amino acid levels. Although the CVB 3-Korea/97 strain was isolated from an aseptic meningitis patient without cardiomyopathy, its 234th nucleotide and 165th amino acid were uracil and Asn as same as those of other cardiovirulent strains one. However, the 155th amino acid of VP1, which closely associated with cardiovirulence, was replaced with $Arg^{155}$ by single nucleotide substitution from $A^{2916}$ to $T^{2916}$. Moreover, additional amino acid substitutions were observed in the flanking region of $Asp^{155}$. Taken together, amino acid(s) substitution in VP1 may playa critical role in determining cardiovirulence of the CVB3-Korea/97 strain rather than individual nucleotide replacements in the 5' NCR and/or an amino acid substitution in VP2.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.137-142
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• 2016

Enterovirus is a common cause of several severe diseases such as myocarditis, hand-foot-mouth disease, and meningitis in children and adult. There are many try to develop new antiviral drug for direct treatment in virus infection. However, synthetic chemical antiviral drug is not working. To overcome this limitation, we examined plant extracts. The antiviral effect of plant extracts was screened by HeLa cell survival assay in coxsackievirus B3 (CVB3) infection. We observed a strong antiviral effect of Poria cocos extract in a dose-dependent manner (1 mg/ml~0.01 mg/ml). P. cocos extract (1 mg/ml) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and virus capsid protein VP1 production. CVB3 positive and negative strand RNA amplification were significantly reduced in P. cocos extract treatment. P. cocos extract completely blocked early time activation of ERK and AKT activity in CVB3 infection. Taken together these data indicate that the treatment of P. cocos extract strongly inhibit CVB3 replication. Poria cocos extract may possible to developed as a therapeutic agent for enterovirus.

• Journal of Ginseng Research
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• v.38 no.3
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• pp.173-179
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• 2014

Background: Ginsenosides are the major components responsible for the biochemical and pharmacological actions of ginseng, and have been shown to have various biological activities. In this study, we investigated the antiviral activities of seven ginsenosides [protopanaxatriol (PT) type: Re, Rf, and Rg2; protopanaxadiol (PD) type: Rb1, Rb2, Rc, and Rd)] against coxsackievirus B3 (CVB3), enterovirus 71 (EV71), and human rhinovirus 3 (HRV3). Methods: Assays of antiviral activity and cytotoxicity were evaluated by the sulforhodamine B method using the cytopathic effect (CPE) reduction assay. Results: The antiviral assays demonstrated that, of the seven ginsenosides, the PT-type ginsenosides (Re, Rf, and Rg2) possess significant antiviral activities against CVB3 and HRV3 at a concentration of $100{\mu}g/mL$. Among the PT-type ginsenosides, only ginsenoside Rg2 showed significant anti-EV71 activity with no cytotoxicity to cells at $100{\mu}g/mL$. The PD-type ginsenosides (Rb1, Rb2, Rc, and Rd), by contrast, did not show any significant antiviral activity against CVB3, EV71, and HRV3, and exhibited cytotoxic effects to virus-infected cells. Notably, the antiviral efficacies of PT-type ginsenosides were comparable to those of ribavirin, a commonly used antiviral drug. Conclusion: Collectively, our findings suggest that the ginsenosides Re, Rf, and Rg2 have the potential to be effective in the treatment of CVB3, EV71, and HRV3 infection.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2297-2304
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• 2013

A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 ($IC_{50}=1.08{\mu}g/mL$, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.279-287
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• 2017

The chemical property of cinnamaldehyde is unstable in vivo, although early experiments have shown its obvious therapeutic effects on viral myocarditis (VMC). To overcome this problem, we used cinnamaldehyde as a leading compound to synthesize derivatives. Five derivatives of cinnamaldehyde were synthesized: 4-methylcinnamaldehyde (1), 4-chlorocinnamaldehyde (2), 4-methoxycinnamaldehyde (3), ${\alpha}$-bromo-4-methylcinnamaldehyde (4), and ${\alpha}$-bromo-4-chlorocinnamaldehyde (5). Neonatal rat cardiomyocytes and HeLa cells infected by coxsackievirus B3 (CVB3) were used to evaluate their antiviral and cytotoxic effects. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. Among the derivatives, compound 4 and 5 inhibited the CVB3 in HeLa cells with the half-maximal inhibitory concentrations values of $11.38{\pm}2.22{\mu}M$ and $2.12{\pm}0.37{\mu}M$, respectively. The 50% toxic concentrations of compound 4 and 5-treated cells were 39-fold and 87-fold higher than in the cinnamaldehyde group. Compound 4 and 5 effectively reduced the viral titers and cardiac pathological changes in a dose-dependent manner. In addition, compound 4 and 5 significantly inhibited the secretion, mRNA and protein expressions of inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in CVB3-infected cardiomyocytes, indicating that brominated cinnamaldehyde not only improved the anti-vital activities for VMC, but also had potent anti-inflammatory effects in cardiomyocytes induced by CVB3.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.282-287
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• 2014

The ORI2 (3-[3,4-dihydroxyphenyl]acrylic acid 1-[3,4-dihydroxyphenyl]-2-methoxycarbonylethyl ester) was purified from the extract of Isodon excisus. We confirmed the antiviral effect of ORI2 in a coxsackievirus-induced pancreatitis model. Coxsackievirus B4 (CVB4) is a common cause of pancreatitis and may be reason of the type-1 diabetes. Anti-enteroviral compounds were screened by HeLa cell survival assay. Purified natural compounds were added to HeLa cells cultured 96-well plates after $10^4PFU/ml$ CVB4 pre-incubation for 30 min. ORI2 significantly improved HeLa cell survival in a dose-dependent manner. In addition, ORI2 (1 mM) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and viral VP1 capsid protein production. HeLa cell virus titers and viral RNA replication were significantly decreased in ORI2-treatment in a dose dependent manner (1 mM~0.001 mM). These results demonstrate that ORI2 has a strong antiviral effect. It was significantly decreased virus replication. ORI2 may be developed as a potential therapeutic agent for CVB4.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.33-41
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• 2009

The crushed fruiting body of Alaskan Porodaedalea pini (Brot.) Murrill (syn. Phellinus pini) was extracted in boiling water for 4 h with the yield of 20.5% in dry mass. This hot-water extract showed significant antiviral activity by inhibiting the plaque formation in HeLa cells by coxackievirus B3 (CVB3) and also showed highest inhibitory effect against neuraminidase activity among water extracts of various mushrooms. From the water extract, the ethanol precipitate (EP) and supernatant fraction (ES) were obtained through 75% ethanol precipitation with the yield of 43.3% and 28.3% in dry mass, respectively. Whereas ES did not show any detectable level of antiviral activity, EP showed significant dose-dependent inhibition of plaque formation by CVB3 in HeLa cells with an $EC_{50}$ (50% effective concentration) of 0.45 mg/mL. The cytotoxicity on HeLa cells by EP was relatively low with the $CC_{50}$ (50% cytotoxic concentration) of 2.25 mg/mL. EP also effectively inhibited neuraminidase activity in a dose-dependent manner showing up to 75% inhibition at 1.7 mg/mL. These results suggest that the hot-water extract and its EP of P. pini fruiting body can be a candidate for the development of a potent broad-range antiviral agent against influenza virus(Flu) as well as CVB3. The major active component of EP was shown to be a heteropolysaccharide-protein complex containing glucose as the main sugar residue with mole percentage of 79.8% and other sugars like galactose (19.2%), xylose (17%), mannose (5.8%), and fucose (4.6%) and a small portion (12.7%, in mass) of protein.

• Research in Plant Disease
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• v.28 no.4
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• pp.237-244
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• 2022

Chrysanthemum plants are one of the most economically important plants in South Korea. Both virus and viroid can cause diseases and economic damage to the plants. In this study, we investigated the detection of seven viruses and two viroids in 350 chrysanthemum plants cultivated in Yesan-gun, Chungcheongnam-do. Two viruses, chrysanthemum virus B (CVB) and tomato aspermy virus (TAV), and two viroids, chrysanthemum chlorotic mottle viroid (CChMVd) and chrysanthemum stunt viroid (CSVd), were detected in this study. The two viruses were detected in six samples and one sample, respectively. The two viroids were detected in 97 samples and 21 samples, respectively. The nucleotide sequences of the CVB-CN-Y, TAV-CN-Y, CChMVd-CN-Y, and CSVd-CN-Y obtained in this study showed 83.7-86.9%, 99.2-100.0%, 94.4-99.5%, and 95.7-99.7% identity, respectively, compared to their other strains/isolates. The CVB-CN-Y and TAV-CN-Y showed the greatest nucleotide sequence homology to CVB-GS1 and three TAV isolates (TAV-V, TAV-P, and TAV-ChJ), respectively. The CChMVd-CN-Y and CSVd-CN-Y showed the greatest nucleotide sequence homology to CChMVd-Horst and four CSVd isolates (Au1.1, K4pop, Sagae, and Tochigi), respectively. This study is the report on the infection rate of viruses and viroids in chrysanthemum plants cultivated in Yesan-gun in 2021.