• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.474-485
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• 2013

Pharmacological studies and clinical practices have indicated that Radix Astragali, a dried root of Astragalus membranaceus possesses a lot of biological activities, including antioxidant, hepatoprotective, anti-diabetic, tonic, diuretic, antimicrobial, antiviral, and immunological activities. These biological activities approved by the modern pharmacological studies are mainly due to the constituents of Astragalus membranaceus including polysaccharides, saponins, flavonoids, amino acids, and trace elements. In resent, the main constituents in the root part showing a lot of biological activities has been isolated also from the aboveground parts such as leaves and sprouts in our laboratory. However, the safety evaluation for the aboveground parts of Astragalus membranaceus should be checked before expanding their application as one of food. In the study, a 90-day rat oral gavage study has been conducted with the extracts from Astragalus membranaceus-above-ground parts at doses of 1000, 3000, and 5000mg/kg/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000mg/kg/day of the water-extracts from Astragalus membranaceus-aboveground parts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1629-1636
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• 2015

The edible mushroom Agaricus blazei Murill is known to have many physiological functions, including antitumor, antiviral, and anti-inflammatory effects. Aqueous extracts were obtained by extracting A. blazei in water at $90^{\circ}C$ for 15 h, followed by spray-drying with dextran at a 70:30 ratio. In this study, we examined the immunomodulatory effect of A. blazei Murill water extract (ABM) in BALB/c mice. Mice were administered orally with 4, 20, and 100 mg/kg of ABM for 21 days. ABM-treated mice did not show significant differences in body and organ weights compare to saline-treated control mice. Splenocytes isolated from ABM-administered mice revealed similar levels of cellularity and proliferation compared to control mice, whereas they showed increased natural killer (NK) cell activity and decreased IL-4 and IL-12 production. Different from in vivo results, splenocytes isolated from normal mice showed increased proliferation and $INF-{\gamma}$ production following ABM treatment in vitro. In addition, ABM treatment enhanced macrophage proliferation and nitric oxide (NO) production in a dose-dependent manner. However, ABM had no effect on LPS-induced NO production. These results suggest that A. blazei modulates immune function by increasing NK cell activity and macrophage function.

• Journal of Life Science
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• v.26 no.2
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• pp.265-274
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• 2016

Toxin-antitoxin (TA) systems are ubiquitous genetic modules that are evolutionally conserved in bacteria and archaea. TA systems composed of an intracellular toxin and its antidote (antitoxin) are currently classified into five types. Commonly, activation of toxins under stress conditions inhibits diverse cellular processes and consequently induces cell death or reversible growth inhibition. These effects of toxins play various physiological roles in such as regulation of gene expression, growth control (stress response), programmed cell arrest, persister cells, programmed cell death, phage protection, stabilization of mobile genetic elements or postsegregational killing of plasmid-free cells. Accordingly, bacterial TA systems are commonly considered as stress-responsive genetic modules. However, molecule screening for activation of toxin in TA system is available as development of antimicrobial agents. In addition, cytotoxic effect induced by toxin is used as effective cloning method with antitoxic effect of antitoxin; consequently cells containing cloning vector inserted a target gene can survive and false-positive transformants are removed. Also, TA system is applicable to efficient single protein production in biotechnology industry because toxins that are site-specific ribonuclease inhibit protein synthesis except for target protein. Furthermore, some TA systems that induce apoptosis in eukaryotic cells such as cancer cells or virus-infected cells would have a wide range of applications in eukaryotes, and it will lead to new ways of treating human disease. In this review, we summarize the current knowledge on bacterial TA systems and their applications.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.123-132
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• 2023

Background: Pseudotyped virus systems that incorporate viral proteins have been widely employed for the rapid determination of the effectiveness and neutralizing activity of drug and vaccine candidates in biosafety level 2 facilities. We report an efficient method for producing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus with dual luciferase and fluorescent protein reporters. Moreover, using the established method, we also aimed to investigate whether Korean Red Ginseng (KRG), a valuable Korean herbal medicine, can attenuate infectivity of the pseudotyped virus. Methods: A pseudovirus of SARS-CoV-2 (SARS-2pv) was constructed and efficiently produced using lentivirus vector systems available in the public domain by the introduction of critical mutations in the cytoplasmic tail of the spike protein. KRG extract was dose-dependently treated to Calu-3 cells during SARS2-pv treatment to evaluate the protective activity against SARS-CoV-2. Results: The use of Calu-3 cells or the expression of angiotensin-converting enzyme 2 (ACE2) in HEK293T cells enabled SARS-2pv infection of host cells. Coexpression of transmembrane protease serine subtype 2 (TMPRSS2), which is the activator of spike protein, with ACE2 dramatically elevated luciferase activity, confirming the importance of the TMPRSS2-mediated pathway during SARS-CoV-2 entry. Our pseudovirus assay also revealed that KRG elicited resistance to SARS-CoV-2 infection in lung cells, suggesting its beneficial health effect. Conclusion: The method demonstrated the production of SARS-2pv for the analysis of vaccine or drug candidates. When KRG was assessed by the method, it protected host cells from coronavirus infection. Further studies will be followed for demonstrating this potential benefit.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.79-89
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• 1998

Purpose: Though many antiviral or immunomodulatory agents have been used in patients with chronic HBV hepatitis, interferon is considered to be the only effective therapeutic agent so far. Among immunomodulatory agents, thymodulin, the oral form of thymosin, is currently in clinical trial. We compared the efficacy of alfa-interferon therapy alone with a combined therapy of alfa-interferon and thymodulin in children with chronic active hepatitis B. Method: Twenty three children aged 4.4~13.7 years who were known to be positive for HBsAg and HBeAg in serum for at least 6 months and who had biopsy-proven chronic active hepatitis were given either combined therapy of alfa-interferon and thymodulin or alfa-interferon alone, and all children were HBV DNA positive in their serum at the beginning. Follow-ups have been done for at least 1 year after a 6 month course of therapy and clearance of viral replication markers has been evaluated. Results: 1) During follow up period, 11 (48%) children were seroconverted to anti-HBe and were cleared of HBV DNA from their serum. However, 2 of them relapsed after discontinuance of interferon therapy. 2) Seroconversion occurred more frequently among those who had not been vertically transmitted, had elevated serum ALT levels and low HBV DNA levels before interferon therapy. 3) There was no significant advantage of the combined therapy with thymodulin compared to interferon therapy alone. Conclusion: Combined therapy of alfa-interferon and thymodulin failed to demonstrate synergistic effect. We think that combination therapies of alfa-interferon with other antiviral or immunomodulatory agents need to be studied in order to achieve better therapeutic responses.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.63-68
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• 1996

Background: Interferon-$\gamma$ has various biologic effects, including antiviral effect, antitumor proliferative effect, activation of macrophage and B lymphocyte, and increased expression of major histocompatibility complex. Especially, antitumor proliferative effect of interferon-$\gamma$ has already been proved to be important in vivo as well as in vitro. And, clinical studies of interferon-$\gamma$ have been tried in lung cancer patients. However, the mechanism of antitumor effect of interferon-$\gamma$ has not yet been established despite of many hypotheses. "Necrosis" is a type of cell death which is well known to occur in the circumstances of severe stresses. In contrast, "apoptosis" is another type of cell death which occurs in such biological circumstances as embryonic development, regression of organs, and self-tolerance of lymphocytes. And, apoptosis is an active process of cell death in which cells are dying with fragmentations of their cytoplasms and nuclei. And, in the process of apoptosis the DNAs of cells are cleaved between nucleosomes by unidentified endonuclease and therefore DNAs of apoptotic cells result in a typical electrophoresis pattern known as DNA ladder pattern. Recently it has been suggested that cytotoxic effect of interferon-$\gamma$ occurs via apoptosis. To elucidate the mechanism of antitumor cytotoxic effect of interferon-$\gamma$, we microscopically observed a lung cancer cell line, A549 which was treated with interferon-$\gamma$. We observed A545 treated with interferon-$\gamma$ was dying fragmented. And so, we performed this study to find out that the mechanism of antitumor cytotoxic effect of interferon-$\gamma$ be apoptosis. Method: We treated A549, human lung cancer cell line with various concentration of interferon-$\gamma$ and quantified its cytotoxic effect of various periods, 24 hours, 72 hours and, 120 hours by MTT(dimethylthiazolyl diphenyltetrazolium bromide) bioassay. Also, after we treated A549 with 100 units/mi of interferon-$\gamma$ for 120 hours, we observed the pattern of cell death with inverted microscope and we extracted DNAs from the dead A549 cells and observed the pattern of 1.5% agarose gel electrophoresis with ethidium bromide staining. Result: 1) Cytotoxic effect of interferon-$\gamma$ on A549: For the first 24 hours, threre was little cytotoxic effect and for between 24 hours and 72 hours, there was the beginning of cytotoxic effect and for 120 hours there was increased cytotoxic effect. 2) Pattern of A549 cell death by interferon-$\gamma$: We observed with inverted microscope that A549 cells were dying fragmented. 3) DNA ladder pattern of gel electrophoresis: We observed DNA ladder pattern of gel electrophoresis of extracted DNAs from dead A549 cells. Conclusion: We concluded that the mechanism of interferon-$\gamma$induced cytotoxicity on lung cancer cell line, A549 be via apoptosis.

• Korean Journal of Pharmacognosy
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• v.45 no.1
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• pp.55-61
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• 2014

Microwaves are non-ionizing electromagnetic waves of frequency between 300MHz to 300GHz and positioned between the X-ray and infrared rays in the electromagnetic spectrum. In recent years, the use of microwave for extraction of ingredient from plant material has shown remarkable research interest and potential. Scutellaria radix has been used as a traditional medicine for a variety of diseases. It has been reported to exert beneficial health effects, such as anti-bacterial, antiviral, anti-inflammatory, and free-radical scavenging. Oxidative stress or the accumulation of reactive oxygen species (ROS) leads neuronal cellular death and dysfunction, and it contributes to neuronal degenerative disease such as Alzheimer's disease, Parkinson's disease and stroke. In this study, we aimed to compare the neuroprotective and antioxidant effect of Scutellaria radix extracted by different methods using hot-water extraction (SBE-DW) or microwave extraction (SBE-DW-MW). As a result, we first examined HPLC analysis of hot-water and microwave extracts of Scutellaria radix. The hot-water and microwave extracts of Scutellaria radix showed the discernible difference patterns of HPLC analysis. Microwave-water extracts of Scutellaria radix increased DPPH radical scavenging activity more than hot-water extraction. Microwave-water extracts of Scutellaria radix also showed neuroprotective effects and ROS inhibition against glutamate-induced oxidative stress in mouse hippocampal HT22 cells, but hot-water extraction not showed. In addition, the phosphorylation of MAPKs induced by glutamate insult was prevented by microwave-water extracts of Scutellaria radix. Thus, these results suggested that microwave extraction can be utilized for improving the extraction efficiency and biological activity of Scutellaria radix.

• Journal of Life Science
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• v.28 no.1
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• pp.50-57
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• 2018

Millettia erythrocalyx, a species of plant in the Fabaceae family, is widely distributed in the tropical and subtropical regions of the world, such as the Indies, China, and Thailand. The antiviral activity of flavonoids from M. erythrocalyx has been reported; however, the antioxidative and anticancer activities of M. erythrocalyx remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extract of M. erythrocalyx (EEME) and the molecular mechanism of its anticancer activity in human hepatocellular carcinoma HepG2 cells. EEME exhibited significant antioxidative effects, with a concentration at 50% inhibition ($IC_{50}$) value of $2.74{\mu}g/ml$, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; moreover, it inhibited cell proliferation in a dose-dependent manner in HepG2 cells. Cell cycle analyses showed that EEME induced HepG2 cell accumulation in the subG1 phase in a dose-dependent manner. EEME also induced apoptosis of HepG2 cells, with increases in apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. Treatment with EEME resulted in increased expression of First apoptosis signal (Fas), a death receptor, and Bcl-2-associated X protein (Bax), a proapoptotic protein, and the activation of caspase-3, 8, and 9, resulting in the cleavage of poly (Adenosine diphosphate-ribose) polymerase (PARP). Collectively, these results suggest that EEME may exert an anticancer effect in HepG2 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.262-266
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• 2010

Tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) is a major proinflammatory cytokine involved in the pathophysiology of juvenile rheumatoid arthritis. Etanercept is an effective inhibitor of $TNF-{\alpha}$ and has shown a beneficial effect in patients with JRA. However, the most important cause of concern related to etanercept administration is infection. We report a case of encephalitis in a JRA patient receiving long-term treatment with etanercept. The patient was a 4-year-old boy with refractory JRA, and he received etanercept subcutaneously at a dose of $0.4\;mg\;kg^{-1}\;day^{-1}$ twice a week for 14 months, along with non-steroidal anti-inflammatory drugs, methotrexate, oral steroids, and sulfasalazine. The patient presented with sudden fever, headache, vomiting, a generalized tonic seizure, and changes in mental status. We suspected a central nervous system infection, and simultaneously administered antibiotics, an antiviral agent, and steroids. After 2 days of hospitalization, his mental function returned to normal, and he showed no further seizure-like movements. Brain magnetic resonance imaging scan of the patient showed a multifocal cortical lesion on both sides of the temporoparietooccipital lobe, which indicated encephalitis. Although we were unable to identify the causative organism of encephalitis, we think that the encephalitis may be attributed to infection, and the use of etanercept may have increased the risk of severe infection. Therefore, etanercept was discontinued and the patient recovered shortly after. To the best of our knowledge, this is the first case of encephalitis in a juvenile rheumatoid arthritis patient treated with etanercept.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.140-146
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• 2015

The increase in resistance by pathogenic bacteria to multiple antimicrobial agents has become a significant treat, as the effective antimicrobial agents available for the patients infected by such resistant bacteria are reduced, or even eliminated. Several natural plant extracts have exhibited antibacterial and synergistic activity against various resistant microorganisms. Houttuynia cordata is frequently used by many traditional medicine practicioners for its antimicrobial, antiviral, and anti-inflammatory properties. This study investigated the antibacterial effects of H. cordata extract against clinical multi-resistant bacteria, and compared the two methods used for the antimicrobial susceptibility testing. Thirty isolates of Methicillin-resistant Staphylococcus aureus (MRSA, 10), Vancomycin-resistant Enterococcus faecium (VRE, 10), Carbapenem-resistant Acinetobacter baumannii (CRAB, 10) were included in this study. The antibacterial effect of H. cordata was tested by disk diffusion and microbroth dilution methods as per CLSI guidelines. In disk diffusion, all isolates (30) showed no inhibition to 30,000 ug/mL of H. cordata. But in the microbroth dilution method, $MIC_{90}$ of H. cordata was 4,096 ug/mL, 8,192 ug/mL and 4,096 ug/mL in MRSA, VRE and CRAB, respectively. These results demonstrate that H. cordata exhibits antibacterial activity against MRSA, VRE and CRAB. Moreover, the microbroth dilution method is a more effective method than disk diffusion to evaluate the antibacterial activity of natural products. The Disk diffusion method used to evaluate the antibacterial activity of natural products required new standard guidelines including inoculum concentration of bacteria.