Seikwan Oh

Seikwan Oh


Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 July 2015 in Molecules
Verified
Journal Article
Open access
PDF file
JYJi-Yeon Yu
Ji-Yeon Yu
JHJae Yeo Ha
Jae Yeo Ha
KKKyung-Mi Kim
Kyung-Mi Kim
YJYoung-Suk Jung
Young-Suk Jung
JJJae-Chul Jung
Jae-Chul Jung
SOSeikwan Oh
Seikwan Oh
This study provides the scientific basis for the anti-inflammatory effects of licorice extract in a t-BHP (tert-butyl hydrogen peroxide)-induced liver damage model and the effects of its ingredients, glycyrrhizic acid (GA), liquiritin (LQ) and liquiritigenin (LG), in a lipopolysaccharide (LPS)-stimulated microglial cell model. The GA, LQ and LG inhibited the LPS-stimulated elevation of pro-inflammatory mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and interleukin (IL)-6 in BV2 (mouse brain microglia) cells. Furthermore, licorice extract inhibited the expression levels of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in the livers of t-BHP-treated mice models. This result suggested that mechanistic-based evidence substantiating the traditional claims of licorice extract and its three bioactive components can be applied for the treatment of inflammation-related disorders, such as oxidative liver damage and inflammation diseases.

1 November 2017 in Molecules
Verified
Journal Article
Open access
PDF file
JJJae-Chul Jung
Jae-Chul Jung
YLYongnam Lee
Yongnam Lee
MDMin Dongguk
Min Dongguk
MJMankil Jung
Mankil Jung
SOSeikwan Oh
Seikwan Oh
Practical synthesis and biological activities of 4-hydroxy-3-methoxy-2-propene derivatives are described. The novel chalcone derivatives were prepared by acid catalysed one-step condensation of 1,3- or 1,4-diacetylbenzene and 1,3,5-triacetylbenzene with 4-hydroxy-3-methoxybenzaldehyde. They were then evaluated for free radical scavenging activity, suppression of lipopolysaccharides (LPS)-induced NO generation, and anti-excitotoxicity in vitro. It was found that all compounds showed good effects for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, LPS-induced NO generation, and anti-neurotoxicity. Compounds 6 and 7 were potent suppressor of NO generation with the concentration range 10 µM and especially compound 8 showed very potent anti-inflammatory activity with 1 µM. In addition, the di- and tri-acetylbenzyl derivatives 6, 7, and 8 showed enhanced anti-neurotoxicity activity in cultured cortical neurons. Molecular modelling studies to investigate the chemical structural characteristics required for the enhanced biological activities interestingly revealed that compound 8 has the smallest highest occupied molecular orbital-lowest energy unoccupied molecular orbital (HOMO-LUMO) gap, which signifies easy electron and radical transfer between HOMO and LUMO in model studies.

1 January 2013 in Evidence-Based Complementary and Alternative Medicine
Verified
Journal Article
Open access
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YLYeonju Lee
Yeonju Lee
JJJae-Chul Jung
Jae-Chul Jung
SJSoyong Jang
Soyong Jang
JKJieun Kim
Jieun Kim
ZAZulfiqar Ali
Zulfiqar Ali
SOSeikwan Oh
Seikwan Oh
To determine the biological activity ofRhodiola rosea, the protein expression of iNOS and proinflammatory cytokines was measured after the activation of murine microglial BV2 cells by LPS under the exposure of constituents ofRhodiola rosea: crude extract, rosin, rosarin, and salidroside (each 1–50 μg/mL). The LPS-induced expression of iNOS and cytokines in BV2 cells was suppressed by the constituents ofRhodiola roseain a concentration-dependent manner. Also the expression of the proinflammatory factors iNOS, IL-1β, and TNF-αin the kidney and prefrontal cortex of brain in mice was suppressed by the oral administration ofRhodiola roseacrude extract (500 mg/kg). To determine the neuroprotective effect of constituents ofRhodiola rosea, neuronal cells were activated by L-glutamate, and neurotoxicity was analyzed. The L-glutamate-induced neurotoxicity was suppressed by the treatment with rosin but not by rosarin. The level of phosphorylated MAPK, pJNK, and pp38 was increased by L-glutamate treatment but decreased by the treatment with rosin and salidroside. These results indicate thatRhodiola roseamay have therapeutic potential for the treatment of inflammation and neurodegenerative disease.

15 April 2013 in Journal of Ginseng Research
Verified
Journal Article
Open access
SOSergiy Oliynyk
Sergiy Oliynyk
SOSeikwan Oh
Seikwan Oh
Actoprotectors are preparations that increase the mental performance and enhance body stability against physical loads without increasing oxygen consumption. Actoprotectors are regarded as a subclass of adaptogens that hold a significant capacity to increase physical performance. The focus of this article is studying adaptogen herbs of genus Panax (P. ginseng in particular) and their capabilities as actoprotectors. Some animal experiments and human studies about actoprotective properties of genus Panax attest that P. ginseng (administered as an extract) significantly increased the physical and intellectual work capacities, and the data provided suggests that ginseng is a natural source of actoprotectors. Preparations of ginseng can be regarded as potential actoprotectors which give way to further research of its influence on physical and mental work capacity, endurance and restoration after exhaustive physical loads while compared with reference actoprotectors.

17 October 2007 in Neurochemical Research
Verified
Journal Article
Closed access
PDF file
SJSoyong Jang
Soyong Jang
SSSuk Hyo Suh
Suk Hyo Suh
HYHwan-Soo Yoo
Hwan-Soo Yoo
YLYong-Moon Lee
Yong-Moon Lee
SOSeikwan Oh
Seikwan Oh

1 July 2015 in Journal of Ginseng Research
Verified
Journal Article
Open access
YLYeonju Lee
Yeonju Lee
SOSeikwan Oh
Seikwan Oh
It has been known that ginseng can be applied as a potential nutraceutical for memory impairment; however, experiments with animals of old age are few. To determine the memory enhancing effect of red ginseng, C57BL/6 mice (21 mo old) were given experimental diet pellets containing 0.12% red ginseng extract (approximately 200 mg/kg/d) for 3 mo. Young and old mice (4 mo and 21 mo old, respectively) were used as the control group. The effect of red ginseng, which ameliorated memory impairment in aged mice, was quantified using Y-maze test, novel objective test, and Morris water maze. Red ginseng ameliorated age-related declines in learning and memory in older mice. In addition, red ginseng's effect on the induction of inducible nitric oxide synthase and proinflammatory cytokines was investigated in the hippocampus of aged mice. Red ginseng treatment suppressed the production of age-processed inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, and interleukin-1β expressions. Moreover, it was observed that red ginseng had an antioxidative effect on aged mice. The suppressed glutathione level in aged mice was restored with red ginseng treatment. The antioxidative-related enzymes Nrf2 and HO-1 were increased with red ginseng treatment. The results revealed that when red ginseng is administered over long periods, age-related decline of learning and memory is ameliorated through anti-inflammatory activity.