• Bulletin of the Korean Mathematical Society
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• v.60 no.5
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• pp.1375-1390
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• 2023

In this note, we shall show that the generalized free products of subgroup separable groups amalgamating a subgroup which itself is a finite extension of a finitely generated normal subgroup of both the factor groups are weakly potent and cyclic subgroup separable. Then we apply our result to generalized free products of finite extensions of finitely generated torsion-free nilpotent groups. Finally, we shall show that their tree products are cyclic subgroup separable.

• Reproductive and Developmental Biology
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• v.31 no.2
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• pp.71-76
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• 2007

Previous studies have shown that BMI-1026 is a potent inhibitor of the cyclin-dependent kinases (cdk). In cell culture, the compound also arrests G2/M strongly and G1/S and S weakly. Two key kinases, cdk1 (p34cdc2 kinase) and mitogen-activated protein (MAP) kinase (erk1 and 2), perform crucial roles during oocyte maturation and, later, metaphase II (MII) arrest. In mammalian oocytes, both kinases are activated gradually around the time of germinal vesicle breakdown (GVBD) and maintain high activity in eggs arrested at metaphase II. In this study, we examined the effects of BMI-1026 on GVBD and MII arrest in mouse oocytes. BMI-1026 inhibited GVBD of immature oocytes and activated MII-arrested oocytes in a concentration-dependent manner, with more than 90% of oocytes exhibiting GVBD inhibition and MII activation at 100 nM This is approximately 500$\sim$1,000 times more potent than the activity reported for the cdk inhibitors roscovitine (${\sim}50{\mu}M$) and butyrolactone (${\sim}100{\mu}M$). Based on the results of previous in vitro kinase assays, we expected BMI-1026 to inhibit only cdk1 activation in oocytes and eggs, not MAP kinase. However, in our cell-based system, it inhibited the activity of both kinases. We also found that the effect of BMI-1026 is reversible. Our results suggest that BMI-1026 inhibits GVBD and activates MII-arrested oocytes efficiently and reversibly and that it also inhibits both cdk1/histone HI kinase and MAP kinase in mouse oocytes.

• Natural Product Sciences
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• v.6 no.4
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• pp.161-164
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• 2000

Herbal medicinal interaction on the purgative action of Chungpesagan-tang, which is one of the traditional Korean medical prescriptions that has been most frequently used for stroke was investigated. Chungpesagan-tang had more potent purgative activity than Rhei Rhizoma alone. When each Chungpesagan-tang composing herbal medicine with Rhei Rhizoma was extracted with water, water extract of Raphani Semen with Rhei Rhizoma had the most potent purgative activity. However, Raphani Semen had not purgative activity. When Rhei Rhizoma with Raphani Semen was extracted, sennoside A content in the water extract was increased. The transformation of sennoside A of Rhei Rhizoma to rheinanthrone by human intestinal microflora was weakly induced by Raphani Semen. These results suggest that the purgative action of Chungpesagan-tang could be controlled by the addition and subtraction of Chungpesagan-tang-composing herbal medicines.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.1-3
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• 2015

This study investigated the inhibitory activities of 2-hydroxyquinoline and its analogs against ${\alpha}$-glucosidase and ${\alpha}$-amylase. Based on the $IC_{50}$ values of 2-hydroxyquinoline analogs tested against ${\alpha}$-glucosidase and ${\alpha}$-amylase, 2-hydroxyquinoline had potent inhibitory activity (64.4 and $130.5{\mu}g/mL$, respectively), while 2-methyl-8-hydroxyquinoline showed weakly inhibitory activity (90.7 and $215.4{\mu}g/mL$, respectively). 2-Methylquinoline demonstrated no activity against ${\alpha}$-glucosidase and ${\alpha}$-amylase. In conclusion, 2-hydroxyquinoline analogs, with the existence of a methyl group and hydroxyl on quinoline, can be useful as a new diabetes treatment.

• BMB Reports
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• v.30 no.6
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• pp.385-389
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• 1997

Many cell types are known to stimulate $CD8^+$ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them. T cells are usually considered very poor in stimulating $CD8^+$ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to $CD8^+$ T cells appeared to stimulate $CD8^+$ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR. In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate $CD8^+$ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

• Natural Product Sciences
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• v.9 no.2
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• pp.64-67
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• 2003

The purgative activities of Whangryunhaedoktang (WT), Chunghyuldan (CD) and Rhei Rhizoma were measured to choose herbal formulae available for stroke patients suffering from constipation. When the laxative activity of Rhei Rhizoma and CD (the same dose as Rhei Rhizoma) compared, Rhei Rhizoma was more potent than CD. WT contained Gardeniae Fructus, which has been used as a laxative, as a ingredient. Nevertheless, WT did not show the purgative activity. WT and CD did not stimulate the transportation of small intestine. However, CD weakly stimulated the transportation of large intestine than Rhei Rhizoma. Accordingly, we believe that CD can be used as a useful purgative for stroke patients with constipation.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.102.2-103
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• 2003

It has been previously reported that luteolin and luteolin-7-glucoside displayed the potent anti-oxidant and anti-inflammatory effects, which have also been successful in reducing vascular smooth muscle cells(VSMCs) proliferation. In this study, a possible anti-proliferative effect and its mechanism on rat aortic VSMCs by luteolin and luteolin-7-glucoside were investigated. Luteolin significantly inhibited the platelet-derived growth factor(PDGF)-BB-induced proliferation of rat aortic VSMCs. While luteolin-7-glucoside weakly inhibited the proliferation. (omitted)

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.179-185
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• 2004

The ethanol extract of Indigofera cordifolia was studied for in vivo gastroprotective activity, cytotoxic activity against oral tumor and normal cells, multidrug resistance (MDR) reversal activity, anti-human immunodeficiency virus (HIV) activity and radical scavenging activity. The extract of I. cordifolia showed potent gastric mucosal protective activity against stomach injury induced by HCl/EtOH solution. However, the gastroprotective activity could not be related to the radical mechanism, because the extract weakly scavenged both OH radical and $O_2*^-$. The extract also showed promising levels of MDR-reversing activity. This study demonstrates the tumor-specific cytotoxic action of the plant extract. However, the extract had no anti-HIV activity. From above results, the study suggests the medicinal importance of I. cordiforia extract.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.217-221
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• 2007

Ginseng has been widely used for the management of anxiety and emotional instability, but there is little experimental evidence supporting these clinical applications. The anxiolytic-like effect of ginseng saponin and polysaccharide fractions of white (WG) and red ginsengs (RG) was investigated using the elevated plus-maze test. The saponin (SF) and polysaccharide (PF) fractions were orally administered to male ICR mice for 3 days and behavioral test for the anxiolytic activity were performed. SF significantly increased the time-spent open arms and number into the in the open arm entries. However, PF weakly increased the time-spent in the open arms, but did not increase number into the open ann entries. The WG showed more potent anxiolytic-like effect than that of RG. The anxiolytic-like activities were antagonized by flumazenil, but not by esmolol. These findings suggest the saponin fractions of WG and RG promote the anxiolytic-like activity by antagonizing GABN/benzodiazepine receptors in mice.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.68-73
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• 2005

Epi-xanthatin analogs containing hydrophilic substituents such as carboxylic acid, alcohol, morpholine, amino acid, and glucose derivatives were synthesized and their in vitro cytotoxicity and in vivo antitumor activity were evaluated. The target compounds were generally cytotoxic against tumor cell lines of human origin with $ED_{50}$ values of $0.1{\sim}30{\mu}g/ml$, except the highly hydrophilic analog 6 containing aspartic acid. Contrary to the potent cytotoxicity weakly hydrophilic analogs 2 and 8 were not active in vivo, or even toxic to the test animals. As a result, hydrophilic analog of epi-xanthatin did not show in vitro cytotoxicity and hydrophobic analogs did not show in vivo antitumor activity, thus it is presumed that amphiphilic analogs or those with medium hydrophilicity would exhibit the antitumor potency in vivo.