• Pediatric Infection and Vaccine
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• v.5 no.1
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• pp.115-120
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• 1998

Purpose : In the summer 1997, there was an outbreak of aseptic meningitis in Pusan area. We report the clinical features and viral studies of aseptic meningitis in Pusan area in 1997. Methods : 265 children with aseptic meningitis who had been admitted to Department of Pediatrics, St. Benedict Hospital between April to October 1997 were included. Results : 1) Male-to-female ratio was 1.7:1. 2) Mean age was $6.2{\pm}3.29$ years. 3) It occured mostly April to October. 4) Clinical manifestations were fever 99.6%, vomiting 99.2%, headache 99.2%, rash 6.0%. 5) The duration of fever was $3.34{\pm}2.21$ days. 6) The duration of admission was $5.3{\pm}3.21$ days. 7) WBC count in peripheral blood were $11,200{\pm}4,163/mm^3$. 8) WBC count in CSF were $156.1{\pm}394.7/mm^3$. 9) Causative agents were coxsackievirus B5, echovius 6, 30, type nonspecific enterovirus. Conclusion : Aseptic meningitis in 1997 compared with that in 1996 had clinical feature of increase in age, decrease in duration of fever and incidende of rash. It occurred mostly April to October in 1997 and May to October in 1996. Causative agents were coxackievirus B5, echovirus 6, 30, type nonespecific enterovirus in 1997, and echovirus 9, coxsackievirus A24, type nonespecific enterovirus in 1996.

• IMMUNE NETWORK
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• v.22 no.2
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• pp.19.1-19.20
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• 2022

Coxsackievirus B3 (CVB3) infection causes acute pancreatitis and myocarditis. However, its pathophysiological mechanism is unclear. Here, we investigated how lipid metabolism is associated with exacerbation of CVB3 pathology using high-fat diet (HFD)-induced obese mice. Mice were intraperitoneally inoculated with 1×10⁶ pfu/mouse of CVB3 after being fed a control or HFD to induce obesity. Mice were treated with mitoquinone (MitoQ) to reduce the level of mitochondrial ROS (mtROS). In obese mice, lipotoxicity of white adipose tissue-induced inflammation caused increased replication of CVB3 and mortality. The coxsackievirus adenovirus receptor increased under obese conditions, facilitating CVB3 replication in vitro. However, lipid-treated cells with receptor-specific inhibitors did not reduce CVB3 replication. In addition, lipid treatment increased mitochondria-derived vesicle formation and the number of multivesicular bodies. Alternatively, we found that inhibition of lipid-induced mtROS decreased viral replication. Notably, HFD-fed mice were more susceptible to CVB3-induced mortality in association with increased levels of CVB3 replication in adipose tissue, which was ameliorated by administration of the mtROS inhibitor, MitoQ. These results suggest that mtROS inhibitors can be used as potential treatments for CVB3 infection.

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

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.291-297
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• 2018

Coxsackievirus B3 (CVB3) is a very well-known causative agent for viral myocarditis and meningitis in human. However, the effective vaccine and therapeutic drug are not developed yet. CVB3 infection activates host cell AKT signaling. Inhibition of AKT signaling pathway may attenuate CVB3 replication and prevent CVB3-mediate viral myocarditis. In this study, we determined antiviral effect of the selected natural plant extract to develop a therapeutic drug for CVB3 treatment. We screened several chemically extracted natural compounds by using HeLa cell-based cell survival assay. Among them, Linum usitatissimum L. extract was selected for antiviral drug candidate. L. usitatissimum extract significantly decreased CVB3 replication and cell death in CVB3 infected HeLa cells with no cytotoxicity. CVB3 protease 2A induced eIF4G1 cleavage and viral capsid protein VP1 production were dramatically decreased by L. usitatissimum extract treatment. In addition, virus positive and negative strand genome amplification were significantly decreased by 1 mg/ml L. usitatissimum extract treatment. Especially, L. usitatissimum extract was associated with inhibition of AKT signal and maintain mTOR activity. In contrast, Atg12 and LC3 expression were not changed by L. usitatissimum extract treatment. In this study, the potential AKT signal inhibitor, L. usitatissimum extract, was significantly inhibited viral genome replication and protein production by inhibition of AKT signal. These results suggested that L. usitatissimum extract is a novel therapeutic agent for treatment of CVB3-mediated diseases.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1230-1239
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• 2019

Scutellaria baicalensis Georgi has been widely used in China for treatment of various diseases. This study investigated the effect of Scutellaria baicalensis Georgi extracts (SBE) against Coxsackievirus B3 (CVB3)-induced myocarditis in vitro and in vivo. In vitro, Hela cells and primary myocardial cells were infected with CVB3 and treated with SBE ($50-800{\mu}g/ml$) and ribavirin ($200{\mu}M$) for 48 h and then determined by CCK8 assay. Real-time PCR and western blotting assays were performed. In vivo, a myocarditis model was induced in male BALB/c mice by injecting CVB3 suspension intraperitoneally for three times, followed by treatment with SBE (400 and 200 mg/kg) and ribavirin (100 mg/kg) for 28 days. SBE ameliorated the cytotoxicity of CVB3 in Hela cells, especially at $400{\mu}g/ml$ (39.93% vs 65.67%, p < 0.05) without influencing cell growth and also significantly reduced CVB3 replication in primary myocardial cells. The levels of AKT, ERK, and p38 were increased after CVB3 infection. SBE could downregulate the expressions of AKT and p38. In vivo, the mortality rate from CVB3 reached to 66.67%, while 10.00% and 23.33% of this came after 400 and 200 mg/kg SBE treatment, respectively (p < 0.05). The CVB3 replication was obviously reduced after SBE administration from day 5. Similarly, the levels of AKT, ERK, and p38 mRNAs and proteins were increased, and SBE suppressed the expression of AKT and p38. Our study indicates that SBE is a promising potent antiviral agent against CVB3-induced myocarditis by inhibition of virus replication via depressing AKT and p38 expressions.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.109-114
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• 2018

Coxsackievirus Type B3 (CVB3) is an enterovirus that belongs to the Picornaviridae and causes various diseases such as myocarditis and hand-foot-mouth disease. However, an effective antiviral drug is still not developed. In this study, we looked for potential inhibitors of CVB3 replication by examining the survival of CVB3-infected HeLa cells. We detected an antiviral effect by cholic acid and identified it as a candidate inhibitor of CVB3 replication. Cholic acid circulates in the liver and intestines, and it helps the digestion and absorption of lipids in the small intestine. HeLa cells were cultured in 12-well plates and treated with cholic acid (1 and $10{\mu}g/ml$) and $10^6PFU/ml$ of CVB3. After 16 h post-infection, the cells were lysed and subjected to western blot analysis and RT-PCR. The production of the viral capsid protein VP1 was dramatically decreased, and translation initiation factor eIF4G1 cleavage was significantly inhibited by treatment with $10{\mu}g/ml$ cholic acid. Moreover, cholic acid inhibited ERK signaling in CVB3-infected HeLa cells. RT-PCR showed that the amounts of the CVB3 RNA genome and mRNA for the ER stress-related transcription factor ATF4 were significantly reduced. These results showed that cholic acid strongly reduced ER stress and CVB3 proliferation. This compound can be developed as a safe natural therapeutic agent for enterovirus infections.

• 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.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.582-590
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• 2023

Stress granules (SGs) are cytoplasmic aggregates of RNA-protein complexes that form in response to various cellular stresses and are known to restrict viral access to host translational machinery. However, the underlying molecular mechanisms of SGs during viral infections require further exploration. In this study, we evaluated the effect of SG formation on cellular responses to coxsackievirus B3 (CVB3) infection. Sodium arsenite (AS)-mediated SG formation suppressed cell death induced by tumor necrosis factor-alpha (TNF-a)/cycloheximide (CHX) treatment in HeLa cells, during which G3BP1, an essential SG component, contributed to the modulation of apoptosis pathways. SG formation in response to AS treatment blocked CVB3-mediated cell death, possibly via the reduction of mitochondrial reactive oxygen species. Furthermore, we examined whether AS treatment would affect small extracellular vesicle (sEV) formation and secretion during CVB3 infection and modulate human monocytic cell (THP-1) response. CVB3-enriched sEVs isolated from HeLa cells were able to infect and replicate THP-1 cells without causing cytotoxicity. Interestingly, sEVs from AS-treated HeLa cells inhibited CVB3 replication in THP-1 cells. These findings suggest that SG formation during CVB3 infection modulates cellular response by inhibiting the release of CVB3-enriched sEVs.

• 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.

• 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.