• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.117-123
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• 2015

Necrotic enteritis (NE) caused by Clostridium (C.) perfringens commonly occurs in domestic broiler farms since antibiotic supplementation in poultry feed has been banned. We evaluated the antibacterial activities of medicinal plant extracts against C. perfringens isolates to select alternative compounds for preventing NE. We compared antibacterial activities using two methods and evaluated susceptibilities of the isolates based on minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Two (Fraxinus rhynchophylla Hance [FRH] and Geranium koreanum Kom. [GKK]) of the 30 plant extracts had potent antibacterial activities against C. perfringens ATCC 13124 in two assays. The MIC values for FRH and GKK against 20 C. perfringens isolates were $128{\sim}256{\mu}g/mL$ and $32{\sim}128{\mu}g/mL$, respectively. The geometric MIC mean values for the two extracts were $147.2{\mu}g/mL$ and $68.8{\mu}g/mL$, respectively. The MBCs for the two extracts against the same strains were $1,024{\sim}2,048{\mu}g/mL$ and $256{\sim}1,024{\mu}g/mL$, respectively. The geometric mean MIC and MBC for GKK were about two-fold lower than those of FRH. The modified spot-on-lawn assay may be useful for measuring primary antibacterial potential. FRH and GKK are expected to be used as feed additives to prevent or treat NE in veterinary practice.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.700-704
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• 2007

In the recent, increased concern has been focused on the pharmacology and clinical utility of herbal extracts and derivatives as a drug or adjunct to chemotherapy and immunotherapy. Here we investigated the role of the extract of Anethi Fructus in the expression of inflammatory mediators, surface molecule, and related receptors in vitro. In murine macrophage RAW 264.7 cells and peritoneal macrophages of C57BL/6N mice, water extract of Anethi Fructus increased the production of secretary tumor necrosis factor (TNF)-a and Nitric oxide (NO), and the expression level of CD14, LPS co-receptor and CD86, co-stimulatory molecule compared to negative natural extract ex vivo. The water extract of Anethi Fructus increased the production of interferon (IFN)-g from splenocytes. Also, water extract of Anethi Fructus increased ConA-induced cell proliferation. These results suggest that water extract of Anethi Fructus may enhance the immune response through immune modulation of macrophage and lymphocytes.

• 건강소식
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• v.18 no.9 s.190
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• pp.54-57
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• 1994

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.171-175
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• 2008

In the recently, increased concern has been focused on the pharmacology and clinical utility of herbal extracts and derivatives as a drug or adjunct to chemotherapy and immunotherapy. Here we investigated the effect of the water extract of Loranthi Ramulus (LR) in production of inflammatory mediators and expression of toll-like receptor (TLR)-4, CD14 from peritoneal macrophage. We assayed the effect of LR water extract in cell proliferation in vitro and Th1/Th2 cytokine level in vivo. In peritoneal macrophages, water extract of LR water extract increased the production of Nitric oxide (NO) and $TNF-{\alpha}$. Also, LR water extract increased Con A-induced cell proliferation and IgG1, IgG2a level in serum. However, i.p. injection of water extract of LR water extract did not affect the level of $TNF-{\alpha}$, $IFN-{\gamma}$, IL-2, IL-4 and IL-5 in serum of mice. These studies indicate that LR water extract induces macrophage activation and suggest the possible use of LR water extract in macrophage-based immunotherapies.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.173-179
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• 2020

Leishmaniasis is a prevalent cause of death and animal morbidity in underdeveloped countries of endemic area. However, there is few vaccine and effective drugs. Antimicrobial peptides are involved in the innate immune response in many organisms and are being developed as novel drugs against parasitic infections. In the present study, we synthesized a 5-amino acid peptide REDLK, which mutated the C-terminus of Pseudomonas exotoxin, to identify its effect on the Leishmania tarentolae. Promastigotes were incubated with different concentration of REDLK peptide, and the viability of parasite was assessed using MTT and Trypan blue dye. Morphologic damage of Leishmania was analyzed by light and electron microscopy. Cellular apoptosis was observed using the annexin V-FITC/PI apoptosis detection kit, mitochondrial membrane potential assay kit and flow cytometry. Our results showed that Leishmania tarentolae was susceptible to REDLK in a dose-dependent manner, disrupt the surface membrane integrity and caused parasite apoptosis. In our study, we demonstrated the leishmanicidal activity of an antimicrobial peptide REDLK from Pseudomonas aeruginosa against Leishmania tarentolae in vitro and present a foundation for further research of anti-leishmanial drugs.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1587-1594
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• 2023

Since its first report in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a grave threat to public health. Virus-specific countermeasures, such as vaccines and therapeutics, have been developed and have contributed to the control of the viral pandemic, which has become endemic. Nonetheless, new variants continue to emerge and could cause a new pandemic. Consequently, it is important to comprehensively understand viral evolution and the roles of mutations in viral infectivity and transmission. SARS-CoV-2 beta variant encode mutations (D614G, N501Y, E484K, and K417N) in the spike which are frequently found in other variants as well. While their individual role in viral infectivity has been elucidated against various therapeutic antibodies, it still remains unclear whether those mutations may act additively or synergistically when combined. Here, we report that N501Y mutation shows differential effect on two therapeutic antibodies tested. Interestingly, the relative importance of E484K and K417N mutations in antibody evasion varies depending on the antibody type. Collectively, these findings suggest that continuous efforts to develop effective antibody therapeutics and combinatorial treatment with multiple antibodies are more rational and effective forms of treatment.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1852-1859
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• 2019

Chikungunya virus (CHIKV) is a single-stranded positive-sense RNA virus, belonging to the genus Alphavirus of the Togaviridae family. It causes multiple symptoms, including headache, fever, severe joint and muscle pain, and arthralgia. Since CHIKV was first isolated in Tanzania in 1952, there have been multiple outbreaks of chikungunya fever. However, its pathogenesis and mechanisms of viral immune evasion have been poorly understood. In addition, the exact roles of individual CHIKV genes on the host innate immune response remain largely unknown. To investigate if CHIKV-encoded genes modulate the type I interferon (IFN) response, each and every CHIKV gene was screened for its effects on the induction of the IFN-β promoter. Here we report that CHIKV nsP2, E2 and E1 strongly suppressed activation of the IFN-β promoter induced by the MDA5/RIG-I receptor signaling pathway, suggesting that nsP2, E2, and E1 are the major antagonists against induction of IFN-β. Delineation of underlying mechanisms of CHIKV-mediated inhibition of the IFN-β pathway may help develop virus-specific therapeutics and vaccines.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.665-673
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• 2015

After invasion of red blood cells, malaria matures within the cell by degrading hemoglobin avidly. For enormous protein breakdown in trophozoite stage, many efficient and ordered proteolysis networks have been postulated and exploited. In this study, a potential interaction of a 60-kDa Plasmodium falciparum (Pf)-heat shock protein (Hsp60) and Pf-calpain, a cysteine protease, was explored. Pf-infected RBC was isolated and the endogenous Pf-Hsp60 and Pf-calpain were determined by western blot analysis and similar antigenicity of GroEL and Pf-Hsp60 was determined with anti-Pf-Hsp60. Potential interaction of Pf-calpain and Pf-Hsp60 was determined by immunoprecipitation and immunofluorescence assay. Mizoribine, a well-known inhibitor of Hsp60, attenuated both Pf-calpain enzyme activity as well as P. falciparum growth. The presented data suggest that the Pf-Hsp60 may function on Pf-calpain in a part of networks during malaria growth.

• Natural Product Sciences
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• v.13 no.4
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• pp.283-288
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• 2007

Acanthopanacis Cortex (AC) has been popularly used as an herbal medicine for medical treatment of rheumatoid arthritis, insomnia, impotence and diabetes. Here, we investigated immunostimulating effects of the aqueous extract of AC on macrophage. We studied nitric oxide (NO) and tumor necrosis factor (TNF)-${\alpha}$ release in response to AC treatment, as they are important secretory products of macrophage. AC alone induce the NO and TNF-${\alpha}$ production. AC increase c-Jun NH2-terminal kinase 1/2 (JNK) and extracellular signal-regulated kinase (ERK) phosphorylation but does not p38 activation in RAW 264.7 cells. Also AC resulted in the enhanced cell-surface expression of CD80 and CD14. In addition, AC resulted in enhanced T cell-stimulatory capacity and increased T cell secretion of interferon (IFN)-gamma. After feeding with AC to mouse for 10 days, the change of $CD28^+$ and $CD40^+$ population was analyzed. AC increased $CD28^+$ population in splenocytes in vivo. These studies indicate that AC induces macrophage activation and suggest the possible use of AC in macrophage-based immunotherapies.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.999-1007
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• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in Saudi Arabia in 2012 and related infection cases have been reported in over 20 countries. Roughly 10,000 human cases have so far been reported in total with fatality rates at up to 40%. The majority of cases have occurred in Saudi Arabia with mostly sporadic outbreaks outside the country except for the one in South Korea in 2015. The Korean MERS-CoV strain was isolated from the second Korean patient and its genome was fully sequenced and deposited. To develop virus-specific protective and therapeutic agents against the Korean isolate and to investigate molecular determinants of virus-host interactions, it is of paramount importance to generate its full-length cDNA. Here we report that two full-length cDNAs from a Korean patient-isolated MERS-CoV strain were generated by a combination of conventional cloning techniques and efficient Gibson assembly reactions. The full-length cDNAs were validated by restriction analysis and their sequence was verified by Sanger method. The resulting cDNA was efficiently transcribed in vitro and the T7 promoter-driven expression was robust. The resulting reverse genetic system will add to the published list of MERS-CoV cDNAs and facilitate the development of Korean isolate-specific antiviral measures.