• Biomaterials and Biomechanics in Bioengineering
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• v.1 no.2
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• pp.73-79
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• 2014

Covalent attachment of 1, 4-dimethylnaphthalene (DMN) based endoperoxide forming subunits to a polyvinyl butyral (PVB) backbone has been achieved. The functionalized polymer materials prepared and characterized here can serve as biocompatible carrier systems for studying cellular uptake, intermediate storage and delayed release of singlet oxygen, which opens up new doors for optimizing a variety of medical applications of photogenerated DMN-endoperoxides such as antiviral, antibacterial, antiplasmodial and antitumor activity.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.469-473
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• 1999

EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers). Karst. Anti-influenza A virus (anti-Flu A) activity of EA was examined of Vero cells by plaque reduction assay in vitro. And the combined antiviral effects fo EA with interferon (IFN) alpha and gamma were examined on the multiplication of Flu A with 50% effective concentration ($EC_50$) of 1.50 mg/ml. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. The combination of EA with IFN alpha on Flu A showed more potent synergism with CI values of 0.50~0.52 of 50%, 70%, 90% effective levels than that with IFN gamma with CI values of 0.82~0.99.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.3-3
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• 2021

The ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not only influenced over 1.26 billion people but also caused 2.77 million deaths worldwide (as of March 28, 2021). The vaccination could be the most efficient strategy to prevent SARS-CoV-2 infection. However, the continuous emergence of novel variants such as VUI-202012/01 (United Kingdom) and 501.V2 (South Africa) raises huge concerns about the effectiveness of the vaccine designed to target the original virus strain. Since ancient times regardless of the East and West, the plants which refered in this presentation have been consumed not only as food but also as a natural medicine to treat diverse diseases including infectious diseases. Importantly, these plants contain secondary metabolites that display antiviral activity involved in the inhibition of viral adsorption, penetration, and replication. Also, plant-derived natural medicines are expected to have a wider range of efficacy and fewer side effects than synthetic medicine, discovering novel plant-based viral agents would be a promising strategy to fight against SARS-CoV-2.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.82-84
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• 2023

There were growing reports of herpes zoster reactivation after the coronavirus disease 2019 (COVID-19) vaccination, including a more severe form, herpes zoster ophthalmicus (HZO). A 35-year-old male presented HZO in his left V1 dermatome 10 days after his COVID-19 vaccine booster with Moderna (messenger RNA-1273). He had no history of chronic disease, immunocompromised, autoimmune, malignancy, or long-term immunosuppressive drug use. The rash improved without any further complications after being treated with oral valacyclovir for 7 days. This was a unique case of HZO after the COVID-19 vaccine in a booster setting in healthy younger adults. The association of herpes zoster after a COVID vaccine remained inconclusive and potentially coincidental, especially without the known risk factor. However, we would like to add a report to increase awareness among physicians and the general population, for early recognition and treatment with an antiviral.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.

• 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.30 no.1
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• pp.38-43
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• 2020

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 ㎍/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 ㎍/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 ㎍/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.63-69
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• 1998

To establish in vivo antiviral evaluation system by using murine herpesvirus intracerebral infection model, 5-6 female BALB/c mice per group aged 5 weeks were inoculated i.c. into cerebrum with different inocular HSV-1 F. Signs of clinical disease noted everyday for one month. Observed were body weight decrease, neurological signs and death caused by encephalitis. Mice discontinued body weight decrease were recovered from the disease, and keratitis was often observed during recovery. The groups inoculated with higher than 1,000 PFU showed 100% mortaltiy and $LD_{50}$ was <100 PFU/mouse. To study the effect of virus inoculum sizes on antiviral effect of acyclovir (ACV), mice inoculated with different inocula were administered i.p. with different doses of ACV immediately after infection, and twice a day for 5 days. The higher inculum size, the less protective. $ED_{50}$ of ACV was >25, >25, 18.4 and 8.0 mg/kg b.i.d. in the group infected with 1,000,000, 100,000, 10,000 and 1,000 PFU/mouse, respectively. $LD_{50}$ of ACV was 62.5 mg/kg b.i.d. Therapeutic index of ACV was <2.5, <2.5, 3.0 and 7.0 in the groups with inocula 1,000,000, 100,000, 10,000 and 1,000 PFU/mouse, respectively. Inoculum size 1,000 PFU/mouse showing 100% mortaltiy and 5-6 days mean time to death, 5 days drug administration and 14 days observation will be future experimental conditions.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4291-4295
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• 2015

Background: Chemokines and their receptors influence carcinogenesis and cysteine-cysteine chemokine receptor 5 (CCR5) directs spread of cancer to other tissues. A 32 base pair deletion in the coding region of CCR5 that might alter the expression or function of the protein has been implicated in a variety of immune-mediated diseases. The action of antiviral drugs being proposed as adjuvant therapy in cancer is dependent on CCR5 wild type status. In the present study, distribution of CCR5${\Delta}32$ polymorphism was assessed in North Indian esophageal cancer patients to explore the potential of using chemokine receptors antagonists as adjuvant therapy. Materials and Methods: DNA samples of 175 sporadic esophageal cancer patients (69 males and 106 females) and 175 unrelated healthy control individuals (69 males and 106 females) were screened for the CCR5${\Delta}32$ polymorphism by direct polymerase chain reaction (PCR). Results: The frequencies of wild type homozygous (CCR5/CCR5), heterozygous (CCR5/${\Delta}32$) and homozygous mutant (${\Delta}32/{\Delta}32$) genotypes were 96.0 vs 97.72%, 4.0 vs 1.71% and 0 vs 0.57% in patients and controls respectively. There was no difference in the genotype and allele frequencies of CCR5${\Delta}32$ polymorphism in esophageal cancer patients and control group. Conclusions: The CCR5${\Delta}32$ polymorphism is not associated with esophageal cancer in North Indians. As the majority of patients express the wild type allele, there is potential of using antiviral drug therapy as adjuvant therapy.

• Toxicological Research
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• v.33 no.4
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• pp.343-350
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• 2017

Lamivudine belongs to the set of antiviral agents effective against hepatitis B virus infection. Given case reports on liver injuries after certain antiviral agent treatments, this study examined the effects of lamivudine on alanine aminotransferase (ALT) and total bilirubin (TB) using a medical system database. A total of 1,321 patients taking lamivudine alone or with others were evaluated using laboratory hits in an electronic medical system at Seoul National University Hospital from 2005 through 2011. The patients were grouped according to prior ALT results: G#1, ALT < 40 IU/L; G#2, 40 IU/L ${\leq}$ ALT < 120 IU/L; G#3, 120 IU/L ${\leq}$ ALT < 240 IU/L; and G#4, ALT ${\geq}$ 240 IU/L. In G#1 and G#2 patients, lamivudine or adefovir treatment decreased ALT and TB compared to prior values. In G#3 and G#4 patients with three times the upper limit of normal (ULN) ${\leq}$ ALT < 15 times the ULN, both ALT and TB were decreased after treatment with lamivudine alone, or adefovir following lamivudine therapy, indicating that lamivudine therapy ameliorated liver functions. However, in G#4 patients who experienced severely advanced hepatitis (ALT ${\geq}$ 15 times the ULN, or ${\geq}$ 600 IU/L), lamivudine augmented TBmax ($6.3{\rightarrow}13.3mg/dL$) despite a slight improvement in ALT ($839{\rightarrow}783IU/L$), indicative of exacerbation of bilirubinemia. Patients who used adefovir after lamivudine also showed a high incidence of hyperbilirubinemia when they experienced severely advanced hepatitis. Treatment with adefovir alone did not show the effect. In conclusion, lamivudine may increase the risk of hyperbilirubinemia in patients with severely advanced hepatitis, implying that caution should be exercised when using lamivudine therapy in certain patient populations.