• Proceedings of the KSCN Conference
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• 2005.04a
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• pp.180-180
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• 2005

• Proceedings of the KSCN Conference
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• 2005.04a
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• pp.179-179
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• 2005

• Proceedings of the KSCN Conference
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• 2004.12a
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• pp.114-114
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• 2004

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.5
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• pp.299-304
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• 2005

Cardiac hypertrophy contributes an increased risk to major cerebrovascular events. However, the molecular mechanisms underlying cerebrovascular dysfunction during cardiac hypertrophy have not yet been characterized. In the present study, we examined the molecular mechanism of isoproterenol (ISO)-evoked activation of Ras/Raf/MAPK pathways as well as PKA activity in cerebral artery of rabbits, and we also studied whether the activations of these signaling pathways were altered in cerebral artery, during ISO-induced cardiac hypertrophy compared to heart itself. The results show that the mRNA level of c-fos (not c-jun and c-myc) in heart and these genes in cerebral artery were considerably increased during cardiac hypertrophy. These results that the PKA activity and activations of Ras/Raf/ERK cascade as well as c-fos expression in rabbit heart during cardiac hypertrophy were consistent with previous reports. Interestingly, however, we also showed a novel finding that the decreased PKA activity might have differential effects on Ras and Raf expression in cerebral artery during cardiac hypertrophy. In conclusion, there are differences in molecular mechanisms between heart and cerebral artery during cardiac hypertrophy when stimulated with β2 adrenoreceptor (AR), suggesting a possible mechanism underlying cerebrovascular dysfunction during cardiac hypertrophy.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.200-206
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• 2005

Effect of quercetin on NO production and regulation mode of quercetin on oxidative stress, $NF{\kappa}B$ activation, and iNOS expression, possible mechanisms of NO suppression in LPS-stimulated macrophages were investigated. Treatment of RAW 264.7 cells with quercetin significantly reduced lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production dose-dependently ($IC_{50}$, $9.2\;{\mu}M$). Expression of iNOS and specific DNA binding activities of nuclear factor kB ($NF{\kappa}B$) were significantly suppressed by quercetin pretreatment. Quercetin reduced thiobarbituric acid-reactive substances (TBARS) accumulation, enhancing GSH level and antioxidant activities of enzymes, such as superoxide dismutase (SOD) and catalase. These results demonstrate quercetin may ameliorate inflammatory diseases by suppressing NO production through inhibition of iNOS expression, $NF{\kappa}B$ transactivation, and oxidative stress, which may be mediated partially by antioxidative effect of quercetin. Thus, quercetin appears to be used as a potential therapeutic agent for treating LPS-induced inflammatory processes.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.57-64
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• 2007

Ischemic preconditioning (IPC) is known to protect the heart against ischemia/reperfusion (IR)-induced injuries, and regional differences in the mitochondrial antioxidant state during IR or IPC may promote the death or survival of viable and infarcted cardiac tissues under oxidative stress. To date, however, the interplay between the mitochondrial antioxidant enzyme system and the level of reactive oxygen species (ROS) in the body has not yet been resolved. In the present study, we examined the effects of IR- and IPC-induced oxidative stresses on mitochondrial function in viable and infarcted cardiac tissues. Our results showed that the mitochondria from viable areas in the IR-induced group were swollen and fused, whereas those in the infarcted area were heavily damaged. IPC protected the mitochondria, thus reducing cardiac injury. We also found that the activity of the mitochondrial antioxidant enzyme system, which includes manganese superoxide dismutase (Mn-SOD), was enhanced in the viable areas compared to the infarcted areas in proportion with decreasing levels of ROS and mitochondrial DNA (mtDNA) damage. These changes were also present between the IPC and IR groups. Regional differences in Mn-SOD expression were shown to be related to a reduction in mtDNA damage as well as to the release of mitochondrial cytochrome c (Cyt c). To the best of our knowledge, this might be the first study to explore the regional mitochondrial changes during IPC. The present findings are expected to help elucidate the molecular mechanism involved in IPC and helpful in the development of new clinical strategies against ischemic heart disease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.147-150
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• 2005

ent-Kaurane- and ent-pimarane-type diterpenoids were isolated from the methanol extract of Siegesbeckia pubescens by column chromatography. Their structures were elucidated as ent-16$\alpha$H,17-hydroxy-kau­ran-19-oic acid (1), ent-4,17-dihydroxy-16$\alpha$-methyl-kau­ran-19-oic acid (2), ent-16$\beta$,17-dihydroxy-kauran-19-oic acid (3), kirenol (4) and ent-16$\beta$,17,18-trihydroxy-kauran­19-oic acid (5) by spectral analysis. The cytotoxicity of these compounds in Caki cells was assayed by a cell counting kit. Only one group treated with kirenol (4), an entpimarane-type diterpenoid, showed the inhibition of the cell growth in Caki cells.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1376-1378
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• 2008

Tachioside (4-hydroxy-3-methoxy-phenyl-1-O-glucoside), a known phenolic glycoside, was isolated from various bamboo species. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and Trolox equivalent antioxidant capacity determined a significant antioxidant activity of tachioside which was comparable to L-ascorbic acid. Each culm and leaf extracts were tested and the culm of Phyllostachys bambusoides appeared to contain the highest amount of tachioside.

• Proceedings of the KSCN Conference
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• 2005.04a
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• pp.184-184
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• 2005

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.208-210
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• 2005

Four compounds were isolated from Suaeda japonica by repeated column chromatography. Their structures were identified as 2'-hydroxy-6,7-methylenedioxy-isoflavone (1), loliolide (2), dehydrovomifoliol (3), and uridine (4) by spectral analysis and comparison with the published data. All compounds were isolated for the first time from this plant.