• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.95-95
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• 2018

In this study, we investigated the effect of branch extracts from Vaccinium oldhamii (VOB) on melanin synthesis in B16F10 cells. VOB promoted melanin production in absence or presence of ${\alpha}$-melanocyte-stimulating hormone (${\alpha}-MSH$) in B16F10 cells. However, VOB did not affect the expression of tyrosinase and TRP-1 associated with melanin synthesis at the mRNA and protein level in B16F10. But, VOB decreased TRP-2 protein level and induced tyrosinase activation in B16F10 cells. Inhibition of tyrosinase activity and tyrosinase knockdown attenuated VOB-mediated melanin synthesis. In conclusion, it is thought that VOB may stimulate melanin synthesis through activating tyrosinase activity.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.251-256
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• 2012

A novel series of benzothiazole derivatives were synthesized and assayed in vivo to investigate their hypoglycemic activity by streptozotocin-induced diebetic model in rat. These derivatives showed considerable biological efficacy when compared to glibenclamide, a potent and well known antidiabetic agent as a reference drug. All the compounds were effective, amongst them 3d showed more prominent activity at 100 mg/kg p.o. The experimental results are statistically significant at p<0.01 and p<0.05 level.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.282-288
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• 2006

The effects of extracts from various Oriental medicinal herbs on mast-cell-mediated allergic reactions were investigated in this study. Out of these extracts, the medicinal herb Atractylodis rhizoma alba exhibited the most potent activity in the cells, with $IC_50$ values of $20.5\;{\mu}g/ml$, by DNP-BSA and $33.04\;{\mu}g/ml$, by compound 48/80. Similar to the in vitro activity, Atractylodis rhizoma alba inhibited compound-48/80-induced systemic anaphylaxis by 31.3% at 300 mg/kg in mice. It also suppressed the secretion of $TNF-{\alpha}$, a major pro-inflammatory cytokine in the cells. These results may suggest that Atractylodis rhizoma alba shows anti-allergic activity in compound 48/80-induced anaphylactic mice through the inhibition of mast cells.

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.264-267
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• 2003

Korean medicinal plants were screened for their inhibitory activity against HIV-1 protease. The inhibitory activity of protease was determined by incubating the extracts in reaction mixtures containing protease and substrate $His-Lys-Ala-Arg-Val-Leu-(p-NO_{2}-Phe)-Glu-Ala-Nle-Ser-NH_{2}$ to perform proteolytic cleavage reactions. In this study the twenty six extracts from medicinal plants were investigated. Of the extracts tested, the extracts from the stem of Morus alba. exhibited the strongest activity with inhibition of 81% at a concentration of $100{\mu}g/ml$. The extracts of the flower of Saxjfraga stolonifera, and stems of Euonymus japonica and Castanea crenata showed appreciable inhibitory activity (>50%) against HIV-1 protease at same concentration.

• Korean Journal of Plant Resources
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• v.35 no.6
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• pp.697-703
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• 2022

Under the COVID-19 pandemic, interest in immune enhancement is increasing. Although the immune-enhancing activity of plants of the genus Hibiscus has been reported, there is no study on the immune-enhancing activity of H. syriacus. Thus, in this study, we investigated the immune-enhancing activity of Hibiscus syriacus leaves (HSL) in mouse macrophages, RAW264.7 cells, and immunosuppressed mice. HSL increased the production of immunostimulatory factors such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) and activated the phagocytosis in RAW264.7 cells. The HSL-mediated production of immunostimulatory factors was dependent on toll-like receptor 4 (TLR4), p38, and c-Jun N-terminal kinase (JNK) in RAW264.7 cells. In the immunosuppressed mouse model, HSL increased the spleen index, the levels of the cytokines, and the numbers of lymphocytes, neutrophils, and monocytes. Taken together, HSL may be considered to have immune-enhancing activity and be expected to be used as a potential immune-enhancing agent.

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.264-267
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• 1992

The cytotoxic activity of medicinal plants was screened using A549 human lung cancer cell line. Plant materials were extracted with 80% methanol and fractionated to chloroform and water layers. Each methanol, chloroform, and water extract of thirty-two medicinal plants was tested for cytotoxic activity in A549 cell culture system and the cell viability was measured by SRB assay.

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.5-7
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• 1989

A series of 1-chloro-4-methyl-6-arylazo-9H-thioxanthen-9-ones were synthesized and schistosomicidal activity evaluated. It was found that, 1-chloro-4-methyl-6-(2-hydroxy-1-naphthylazo)-9H-thioxanthen-9-one possessed a promising activity against Schisto-soma mansoni in mice.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.51-55
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• 2005

In vitro ${\beta}$-lactamase inhibitory activity of 6-triazole exomethylenepenam compounds (1, 2, 3, 4, 5 and 6) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of 3, 4 and 5 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type IV enzymes. And, inhibitory activity of 3 and 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin was better than those with sulbactam and with cefoperazone was compared with the sulbactam against ${\beta}$-lactamase producing 27 strains. The synergistic activity of (Z)-form compounds (3 and 5) was better than that of (E)-form compound (4) and sulfone compound (5) was better than sulfide compound (3).

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1455-1464
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• 2003

Several series of compounds (benzoic acids, pyrazolecarboxylic acids, phenoxyacetic acids, and quinolinoxyacetic acids) were prepared and evaluated for their inhibitory activity against PTP-1B. Several compounds showed submicromolar inhibitory activity.

• Journal of the Korean Society of Food Culture
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• v.22 no.3
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• pp.336-341
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• 2007

Antioxidant activity of Astragalus membranaceus, Polygonatum stenophyllum, Angelica gigas, Acanthopanax sessiliflorus and Angelica pubescens extracts cultivated in Jecheon prepared with different solvents were determined by 1,1-diphenyl-2-picrylhydrzyl(DPPH) radical scarvenging ability and thiocyanate method . The highest hydroxy radical scarvenging activity was shown in Acanthopanax sessiliflorus, while the lowest was in Polygonatum stenophyllum. Angelica gigas showed strong antioxidant activity by thiocyanate method. Methanol extracts and water extracts showed higher antioxidant activities than ethanol extracts. Angelica pubescens showed the highest polyphenol contents and Acanthopanax sessiliflorus showed the highest flavonoid contents. Direct correlation between the hydroxy radical scavenging activity and polyphenol contents or flavonoid contents was established by simple regression(r>0.8) in each solvent extracts. Among medicinal plants cultivated in Jecheon, Acanthopanax sessiliflorus and Angelica pubescens showed strong antioxidant activities. These results suggest that methanol or water extracts of several medicinal plant cultivated in Jecheon could be used as natural antioxidants.