• Natural Product Sciences
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• 제11권3호
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• pp.139-144
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• 2005

Bioflavone quercetin is believed to play an important role preventing bone loss by affecting osteoclastogenesis and regulating many systemic and local factors including hormones and cytokines. This study examined how quercetin acts on tumor necrosis factor-alpha ($TNF-{\alpha}$)-mediated apoptosis in MC3T3-E1 osteoblastic cells. Apoptosis assays revealed the dose-dependent acceleration of quercetin on $TNF-{\alpha}-induced$ apoptosis in MC3T3-E1 cells, which was demonstrated by the increased number of positively stained cells in the trypan blue staining and TUNEL assay, and the migration of many cells to the $sub-G_0/G_1$ phase in flow cytometric analysis. In particular, quercetin treatment alone increased the expression of p53 and p21 proteins in the cells. Consequently, this study showed that quercetin accelerates the $TNF-{\alpha}-induced$ apoptosis in MC3T3-E1 osteoblastic cells.

• Molecules and Cells
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• 제26권2호
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• pp.158-164
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• 2008

Arsenic trioxide (ATO) affects many biological processes such as cell proliferation, apoptosis, differentiation and angiogenesis. L-buthionine sulfoximine (BSO) is an inhibitor of GSH synthesis. We tested whether ATO reduced the viability of lung cancer A549 cells in vitro, and investigated the in vitro effect of the combination of ATO and BSO on cell viability in relation to apoptosis and the cell cycle. ATO caused a dose-dependant decrease of viability of A549 cells with an $IC_{50}$ of more than $50{\mu}m$. Low doses of ATO or BSO ($1{\sim}10{\mu}m$) alone did not induce cell death. However, combined treatment depleted GSH content and induced apoptosis, loss of mitochondrial transmembrane potential (${\Delta}{\Psi}_m$) and cell cycle arrest in G2. Reactive oxygen species (ROS) increased or decreased depending on the concentration of ATO. In addition, BSO generally increased ROS in ATO-treated A549 cells. ROS levels were at least in part related to apoptosis in cells treated with ATO and/or BSO. In conclusion, we have demonstrated that A549 lung cells are very resistant to ATO, and that BSO synergizes with clinically achievable concentration of ATO. Our results suggest that combination treatment with ATO and BSO may be useful for treating lung cancer.

• Toxicological Research
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• 제18권1호
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• pp.47-57
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• 2002

The subacute oral toxicity of 1-(4-methylpiperazinyl)-3-phenylisoquinoline (CWJ- a-5) was investigated in Sprague-Dawley (SD) rats. Five groups of 5 males and 5 females were orally administered at doses of 0, 37.5, 75, 150 and 200 mg/kg with CWJ-a-5 for 2 weeks. In clinical signs, Salivation was observed in the 75, 150 and 500 mg/kg male and female groups. Loss of fur was observed in the 500 mg/kg male and female group. Body weight were significantly decreased in the 150 and 500 mg/kg male groups and in the 500 mg/kg female group. Food consumption was significantly decreased in the 300 mg/kg male group. In serum biochemistry, total cholesterol and phospholipid were significantly increased in 500 mg/kg male and female group. Aspartate aminotransferase was significantly increased in the 500 mg/kg female group. In histopathological examination, vacuolar degeneration of renal tubules in the kidney, vacuolar degeneration of hepatocytes in the liver vacuolar degeneration of myocytes in the heart, vacuolar degeneration of histiocytes in the spleen and thymus, atrophy of seminiferous tubule and degeneration of germinal epithelium in the testis, vacuolar degeneration of corpus luteum, granulosa cell and theca cell in the ovary were observed in the 150 and 500 mg/kg male and female groups. Based on these results, the no observed adverse effect level (NOAEL) with CWJ-a-5 was considered to be 75 mg/kg and the absolute toxic dose was considered to be 150 mg/kg in this study

• Journal of Acupuncture Research
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• 제19권4호
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• pp.190-199
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• 2002

Objective : This study was performed to determine if Scutellaria balicalensis Georgi extract (SbGE) prevents oxidant-induced membrane transport dysfunction in renal tubular cells. Methods : Membrane transport function was estimated by measuring $Na^+$-dependent inorganic phosphate transport in opossum kidney (OK) cells. $H_2O_2$ inhibited phosphate transport in a dose-dependent manner. Results : The inhibitory effect of $H_2O_2$ was significantly prevented SbGE over concentration range of 0.005-0.05%. $H_2O_2$ caused ATP depletion, which was prevented by SbGE. $H_2O_2$ induced the loss of mitochondrial function as evidenced by decreased MTT reduction and its effect was prevented by SbGE. The $H_2O_2$-induced inhibition of phosphate transport was not affected by a potent antioxidant DPPD, but the inhibition was prevented by an iron chelator deferoxamine, suggesting that $H_2O_2$ inhibits $Na^+$-dependent phosphate transport via an iron-dependent nonperoxidative mechanism in renal tubular cells. Conclusion : These data suggest that SbGE may exert the protective effect against oxidant-induced membrane transport dysfunction by a mechanism similar to iron chelators in renal epithelial cells. However, furher studies should be carried out to find the active ingredient(s) of SbGE that exerts the protective effect.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.359-367
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• 2020

Neurodegenerative disorders in the elderly are characterized by gradual loss of memory and cognitive function. Oxidative stress caused by reactive oxygen species is associated with progressive neuronal cell damage and death in Alzheimer's disease, one of the most common neurodegenerative disorders. An edible brown seaweed, Ecklonia cava, contains a variety of biologically active compounds such as phlorotannins. In this study, we comparatively evaluated the total phenolic content, antioxidant capacity, and neuroprotective effects of the phlorotannin-rich extract from E. cava (PEEC). The total phenolic content of PEEC and dieckol was 810.8 mg gallic acid equivalents (GAE)/g and 996.6 mg GAE/g, respectively. Antioxidant capacity of PEEC was 1,233.8 mg vitamin C equivalents (VCE)/g and 392.1 mg VCE/g determined using ABTS and DPPH assays, respectively, while those of dieckol were 2,238.4 mg VCE/g and 817.7 mg VCE/g. High-performance liquid chromatography results revealed 48.08 ± 0.67 mg dieckol/g of PEEC. PEEC had neuroprotective effects in pheochromocytoma (PC-12) and human neuroblastoma (SH-SY5Y) cells against H₂O₂- and AAPH-induced oxidative damage, partly due to reduced intracellular oxidative stress. PEEC treatment inhibited acetylcholinesterase and butyrylcholinesterase in a dose-dependent manner. Taken together, these findings suggest that PEEC is a good source of antioxidants and neuroprotective materials.

• 약학회지
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• 제42권3호
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• pp.275-283
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• 1998

Aclarubicin(ACL)-entrapped freeze dried liposomes were prepared using Microfludizer to attain a sustained release at targeted organs in a prolonged time so that it can reduce th e side effect and maximize the therapeutic effect. The freeze-dried liposomes were evaluated for pharmacokinetics, antitumor activity against Sarcoma 180, cytotoxicity against L1210 and A549 tumor cells, spleen toxicity and myelosuppressive action. The $AUC_{0{\rightarrow}8hr}$ values were $122{\pm}42,\;382{\pm}140,\;419{\pm}171,\;835{\pm}206\;and\;443{\pm}309{\mu}g{\cdot}min/ml$ for free ACL. ACL-liposome formulation I, II, III and IV, respectively. Cytotoidcity of ACL-entrapped liposomes against L1210 and A549 tumor cells was 2-4 times higher than that of free aclarubicin. ACL-liposome formulation I(PC/CHOL/TA) showed the most potent antitumor activity against Sarcoma 180 in mice. The loss of body weight was much smaller with ACL-entrapped liposomes than free ACL after I.p. injection at a dose of 2 mg/kg/day. Compared to free ACL, ACL-entrapped liposomes expressed a lower and delayed spleen toxicity up to 5th day after I.v. administration. Myelosupperssion seemed to be lower with ACL-entrapped liposome of PC/PC-hydrate/CHOL/TA (formulation III) than free aclarubicin.

• 대한두경부종양학회지
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• 제18권2호
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• pp.135-141
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• 2002

Backgrounds and Objectives: Metastasis is a complex multistep process that requires sequential interactions between the invasive cell and the extra-cellular matrix. Transforming growth factor-${\beta}1$ ($TGF-{\beta}1$) is a multifunctional regulator of cellular differentiation, motility and growth. Loss of sensitivity to the growth inhibitory effects by $TGF-{\beta}1$ plays important roles in neoplastic progression. The aim of this study was to investigate the role of $TGF-{\beta}1$ in the neoplastic invasion and metastasis through matrix metalloproteinase (MMP) of laryngeal cancer cell lines. Material and Methods: Two laryngeal cancer cell lines, SNU-899 and SNU-1076 were treated with recombinant $TGF-{\beta}1$, and the expression of MMP-2 and MMP-9 was immunohistochemically evaluated and gelatinase activity was studied by gelatin zymogram. Results: The cell growth inhibition was evident on 4th days after 1ng/ml and 10ng/ml $TGF-{\beta}1$ treatment. The expressions of MMP-2 and MMP-9, and their gelatinase activities were increased in dose-dependent manner. Conclusion: $TGF-{\beta}1$ treatment in laryngeal cancer cell lines induces the expression of MMP-2 and MMP-9, thus playing a role in the digestion of extracellular matrix gelatin.

• IMMUNE NETWORK
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• 제13권5호
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• pp.213-217
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the ${\beta}$-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (${\beta}$-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the ${\beta}$-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.

• Journal of Korean Neurosurgical Society
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• 제29권11호
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• pp.1445-1450
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• 2000

Objectives : The Objective of this study was to analyze the prognostic factors affecting survival in the patients with glioblastomas. Methods : We retrospectively studied 55 consecutive patients with glioblastomas who were admitted to neurosurgery department from January 1988 to March 1998. Fifteen pateients were excluded from the analysis because of follow-up loss and surgical motality. There were 24 male and 16 female patients, with a mean age of 51 years. Surgery consisted of biopsy in 4(10.0%) patients, subtotal resection in 9(22.5%) patients and gross total resection in 27(67.5%) patients. Nine(22.5%) patients received second operation. Twenty-eight(70%) received postoperative radiation therapy. Various levels of radiation dose were used, 6,000 rad over 7 weeks in most cases. The variable factors were examined for their relationship with survival ; age at the time of diagnosis, gender, duration of neurological symptoms, preoperative neurological state(Karnofsky performance score), extent of surgical resection, location of tumor, reoperation, and postoperative radiotherapy and chemotherapy. Result : The mean survival time was 55 weeks, three(7.5%) of the 40 patients survived more than two years. Survival time with biopsy only cases was 24 weeks, for those with subtotal resection 43 weeks, and for those with gross total resection 67 weeks. A mean survival time from the time of reoperation was 42 weeks. Statistically significant survival factors in glioblastoma were extent of surgical resection, postoperative radiotherapy and reoperation. Summary : Results of our series support the views that the extent of surgery, reoperation and postoperative radiation are important prognostic factors. We also recommend radical tumor removal, postoperative radiotherapy and reoperation, if possible.

• BMB Reports
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• 제34권3호
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• pp.268-273
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• 2001

In addition to the recognition site for glutamate, the N-methyl-D-aspartate (NMDA)-preferring glutamate receptor subtype shows a binding site for glycine. In this paper, we present the effects of 3-(4,6-dichloro-2-carboxymethylamino-5,7-dichloroquinoline-2-carboxylic acid (MDL 29951), a potent inhibitor of glycine binding to the NMDA receptor, on glutamate dehydrogenase (GDH) from bovine brains. The incubation of GDH isoproteins from bovine brains with MDL 29951 resulted in a dose-dependent loss of enzyme activity Separately or together, 2-oxoglutarate and NADH did not give an efficient protection against the inhibition, indicating that GDH isoproteins saturated with NADH or 2-oxoglutarate are still open to attack by MDL 29951. MDL 29951 was an uncompetitive inhibitor with respect to both 2-oxoglutarate and NADH for GDH isoproteins. These results suggest that the binding site of MDL 29951 is not directly located at the catalytic site, and the inhibition of GDH isoproteins by MDL 29951 is probably due to a steric hindrance, or a conformational change altered upon the interaction of the enzyme with its inhibitor. The inhibitory effects of MDL 29951 on GDH isoproteins were significantly diminished in the presence of ADP. GDH I reacted more sensitively with ADP than GDH II on the inhibition by MDL 29951. Our results suggest a possibility that the two types of GDHs are differently regulated by MDL 29951, depending on the physiological concentrations of ADP.